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Libby AE, Solt CM, Jackman MR, Sherk VD, Foright RM, Johnson GC, Nguyen TT, Breit MJ, Hulett N, Rudolph MC, Roberson PA, Wellberg EA, Jambal P, Scalzo RL, Higgins J, Kumar TR, Wierman ME, Pan Z, Shankar K, Klemm DJ, Moreau KL, Kohrt WM, MacLean PS. Effects of follicle-stimulating hormone on energy balance and tissue metabolic health after loss of ovarian function. Am J Physiol Endocrinol Metab 2024; 326:E626-E639. [PMID: 38536037 DOI: 10.1152/ajpendo.00400.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/29/2024] [Accepted: 03/20/2024] [Indexed: 05/01/2024]
Abstract
Loss of ovarian function imparts increased susceptibility to obesity and metabolic disease. These effects are largely attributed to decreased estradiol (E2), but the role of increased follicle-stimulating hormone (FSH) in modulating energy balance has not been fully investigated. Previous work that blocked FSH binding to its receptor in mice suggested this hormone may play a part in modulating body weight and energy expenditure after ovariectomy (OVX). We used an alternate approach to isolate the individual and combined contributions of FSH and E2 in mediating energy imbalance and changes in tissue-level metabolic health. Female Wistar rats were ovariectomized and given the gonadotropin releasing hormone (GnRH) antagonist degarelix to suppress FSH production. E2 and FSH were then added back individually and in combination for a period of 3 wk. Energy balance, body mass composition, and transcriptomic profiles of individual tissues were obtained. In contrast to previous studies, suppression and replacement of FSH in our paradigm had no effect on body weight, body composition, food intake, or energy expenditure. We did, however, observe organ-specific effects of FSH that produced unique transcriptomic signatures of FSH in retroperitoneal white adipose tissue. These included reductions in biological processes related to lipogenesis and carbohydrate transport. In addition, rats administered FSH had reduced liver triglyceride concentration (P < 0.001), which correlated with FSH-induced changes at the transcriptomic level. Although not appearing to modulate energy balance after loss of ovarian function in rats, FSH may still impart tissue-specific effects in the liver and white adipose tissue that might affect the metabolic health of those organs.NEW & NOTEWORTHY We find no effect of follicle-stimulating hormone (FSH) on energy balance using a novel model in which rats are ovariectomized, subjected to gonadotropin-releasing hormone antagonism, and systematically given back FSH by osmotic pump. However, tissue-specific effects of FSH on adipose tissue and liver were observed in this study. These include unique transcriptomic signatures induced by the hormone and a stark reduction in hepatic triglyceride accumulation.
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Affiliation(s)
- Andrew E Libby
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Claudia M Solt
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Matthew R Jackman
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Vanessa D Sherk
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
- Center for Scientific Review, National Institutes of Health, Bethesda, Maryland, United States
| | - Rebecca M Foright
- Department of Anatomy and Cell Biology, University of Kansas Medical Campus, Kansas City, Kansas, United States
| | - Ginger C Johnson
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Thi-Tina Nguyen
- Section of Nutrition, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Matthew J Breit
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Nicholas Hulett
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Michael C Rudolph
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Campus, Oklahoma City, Oklahoma, United States
| | - Paul A Roberson
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Elizabeth A Wellberg
- Stephenson Cancer Center, University of Oklahoma Health Sciences Campus, Oklahoma City, Oklahoma, United States
| | - Purevsuren Jambal
- Section of Nutrition, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Rebecca L Scalzo
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Janine Higgins
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - T Rajendra Kumar
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Margaret E Wierman
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Zhaoxing Pan
- Section of Endocrinology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Kartik Shankar
- Section of Nutrition, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Dwight J Klemm
- Cardiovascular Pulmonary Research Laboratory, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Kerrie L Moreau
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Wendy M Kohrt
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Paul S MacLean
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
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Huebschmann AG, Scalzo RL, Yang X, Schmiege SJ, Reusch JEB, Dunn AL, Chapman K, Regensteiner JG. Type 2 diabetes is linked to higher physiologic markers of effort during exercise. Front Clin Diabetes Healthc 2024; 5:1346716. [PMID: 38741611 PMCID: PMC11089245 DOI: 10.3389/fcdhc.2024.1346716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/26/2024] [Indexed: 05/16/2024]
Abstract
Background People with type 2 diabetes (T2D) have lower rates of physical activity (PA) than the general population. This is significant because insufficient PA is linked to cardiovascular morbidity and mortality, particularly in individuals with T2D. Previously, we identified a novel barrier to physical activity: greater perceived effort during exercise in women. Specifically, women with T2D experienced exercise at low-intensity as greater effort than women without T2D at the same low-intensity - based on self-report and objective lactate measurements. A gap in the literature is whether T2D confers greater exercise effort in both sexes and across a range of work rates. Objectives Our overarching objective was to address these gaps regarding the influence of T2D and relative work intensity on exercise effort. We hypothesized that T2D status would confer greater effort during exercise across a range of work rates below the aerobic threshold. Methods This cross-sectional study enrolled males and post-menopausal females aged 50-75 years. Measures of exercise effort included: 1) heart rate, 2) lactate and 3) self-report of Rating of Perceived Exertion (RPE); each assessment was during the final minute of a 5-minute bout of treadmill exercise. Treadmill exercise was performed at 3 work rates: 1.5 mph, 2.0 mph, and 2.5 mph, respectively. To determine factors influencing effort, separate linear mixed effect models assessed the influence of T2D on each outcome of exercise effort, controlling for work rate intensity relative to peak oxygen consumption (%VO2peak). Models were adjusted for any significant demographic associations between effort and age (years), sex (male/female), baseline physical activity, or average blood glucose levels. Results We enrolled n=19 people with T2D (47.4% female) and n=18 people (55.6% female) with no T2D. In the models adjusted for %VO2peak, T2D status was significantly associated with higher heart rate (p = 0.02) and lactate (p = 0.01), without a significant association with RPE (p = 0.58). Discussions Across a range of low-to-moderate intensity work rates in older, sedentary males and females, a diagnosis of T2D conferred higher objective markers of effort but did not affect RPE. Greater objective effort cannot be fully attributed to impaired fitness, as it persisted despite adjustment for %VO2peak. In order to promote regular exercise and reduce cardiovascular risk for people with T2D, 1) further efforts to understand the mechanistic targets that influence physiologic exercise effort should be sought, and 2) comparison of the effort and tolerability of alternative exercise training prescriptions is warranted.
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Affiliation(s)
- Amy G. Huebschmann
- Division of General Internal Medicine, University of Colorado, Aurora, CO, United States
- Ludeman Family Center for Women’s Health Research, University of Colorado, Aurora, CO, United States
- Adult and Child Center for Outcomes Research and Delivery Science, University of Colorado, Aurora, CO, United States
| | - Rebecca L. Scalzo
- Ludeman Family Center for Women’s Health Research, University of Colorado, Aurora, CO, United States
- Division of Endocrinology, University of Colorado, Aurora, CO, United States
- Eastern Colorado Veterans Administration Medical Center, Aurora, CO, United States
| | - Xinyi Yang
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado, Aurora, CO, United States
| | - Sarah J. Schmiege
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado, Aurora, CO, United States
| | - Jane E. B. Reusch
- Ludeman Family Center for Women’s Health Research, University of Colorado, Aurora, CO, United States
- Division of Endocrinology, University of Colorado, Aurora, CO, United States
- Eastern Colorado Veterans Administration Medical Center, Aurora, CO, United States
| | - Andrea L. Dunn
- Senior Scientist Emeritus, Klein-Buendel, Inc., Golden, CO, United States
| | - Kristina Chapman
- Division of General Internal Medicine, University of Colorado, Aurora, CO, United States
| | - Judith G. Regensteiner
- Division of General Internal Medicine, University of Colorado, Aurora, CO, United States
- Ludeman Family Center for Women’s Health Research, University of Colorado, Aurora, CO, United States
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Thomas NS, Scalzo RL, Wellberg EA. Diabetes mellitus in breast cancer survivors: metabolic effects of endocrine therapy. Nat Rev Endocrinol 2024; 20:16-26. [PMID: 37783846 DOI: 10.1038/s41574-023-00899-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/01/2023] [Indexed: 10/04/2023]
Abstract
Breast cancer is the most common invasive malignancy in the world, with millions of survivors living today. Type 2 diabetes mellitus (T2DM) is also a globally prevalent disease that is a widely studied risk factor for breast cancer. Most breast tumours express the oestrogen receptor and are treated with systemic therapies designed to disrupt oestrogen-dependent signalling. Since the advent of targeted endocrine therapy six decades ago, the mortality from breast cancer has steadily declined; however, during the past decade, an elevated risk of T2DM after breast cancer treatment has been reported, particularly for those who received endocrine therapy. In this Review, we highlight key events in the history of endocrine therapies, beginning with the development of tamoxifen. We also summarize the sequence of reported adverse metabolic effects, which include dyslipidaemia, hepatic steatosis and impaired glucose tolerance. We discuss the limitations of determining a causal role for breast cancer treatments in T2DM development from epidemiological data and describe informative preclinical studies that suggest complex mechanisms through which endocrine therapy might drive T2DM risk and progression. We also reinforce the life-saving benefits of endocrine therapy and highlight the need for better predictive biomarkers of T2DM risk and preventive strategies for the growing population of breast cancer survivors.
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Affiliation(s)
- Nisha S Thomas
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Stephenson Cancer Center, Oklahoma City, OK, USA
- Harold Hamm Diabetes Center, Oklahoma City, OK, USA
| | - Rebecca L Scalzo
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
| | - Elizabeth A Wellberg
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Stephenson Cancer Center, Oklahoma City, OK, USA.
- Harold Hamm Diabetes Center, Oklahoma City, OK, USA.
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Abushamat LA, Enge D, Fujiwara T, Schäfer M, Clark EW, Englund EK, Scalzo RL, Johnston A, Rafferty D, Schauer IE, Whipple MO, Hunter K, Huebschmann AG, Nadeau KJ, Jarvis K, Barker AJ, Regensteiner JG, Reusch JEB. Obesity dominates early effects on cardiac structure and arterial stiffness in people with type 2 diabetes. J Hypertens 2023; 41:1775-1784. [PMID: 37589719 PMCID: PMC10592255 DOI: 10.1097/hjh.0000000000003534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
OBJECTIVE Type 2 diabetes (T2D) and obesity are global epidemics leading to excess cardiovascular disease (CVD). This study investigates standard and novel cardiac MRI parameters to detect subclinical cardiac and central vascular dysfunction in inactive people with and without T2D. METHODS Physically inactive age and BMI-similar premenopausal women and men with ( n = 22) and without [ n = 34, controls with overweight/obesity (CWO)] uncomplicated T2D were compared to an age-similar and sex-similar reference control cohort ( n = 20). Left ventricular (LV) structure, function, and aortic stiffness were assessed by MRI. Global arterial pulse wave velocity (PWV) was assessed using carotid-to-femoral applanation tonometry. Regional PWV was measured via 2D phase-contrast MRI and 4D flow MRI. RESULTS Global arterial PWV did not differ between CWO and T2D. 2D PC-MRI PWV in the ascending aorta was higher in people with T2D compared with CWOs ( P < 0.01). 4D flow PWV in the thoracic aorta was higher in CWO ( P < 0.01), and T2D ( P < 0.001) compared with RC. End-diastolic volume, end-systolic volume, stroke volume, and cardiac output were lower in CWO and T2D groups compared with reference control. CONCLUSION Subclinical changes in arterial stiffening and cardiac remodeling in inactive CWO and T2D compared with reference control support obesity and/or physical inactivity as determinants of incipient CVD complications in uncomplicated T2D. Future studies should determine the mechanistic causes of the CVD complications in greater detail in order to create therapeutic targets. CLINICAL TRIAL REGISTRATION Cardiovascular Mechanisms of Exercise Intolerance in Diabetes and the Role of Sex (NCT03419195).
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Affiliation(s)
- Layla A Abushamat
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Daniel Enge
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Ludeman Family Center for Women's Health Research
- Department of Bioengineering
| | - Takashi Fujiwara
- Department of Radiology, Section of Pediatric Radiology, Children's Hospital Colorado
| | - Michal Schäfer
- Division of General Internal Medicine
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus
- University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus
| | - Ethan W Clark
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Erin K Englund
- Department of Radiology, Section of Pediatric Radiology, Children's Hospital Colorado
| | - Rebecca L Scalzo
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Ludeman Family Center for Women's Health Research
- Rocky Mountain Regional Veterans Administration Medical Center (VAMC), Aurora, Colorado
| | - Aspen Johnston
- University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional Veterans Administration Medical Center (VAMC), Aurora, Colorado
| | | | - Irene E Schauer
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Ludeman Family Center for Women's Health Research
- Rocky Mountain Regional Veterans Administration Medical Center (VAMC), Aurora, Colorado
| | - Mary O Whipple
- Division of General Internal Medicine
- School of Nursing, University of Minnesota, Minneapolis, Minnesota
| | | | - Amy G Huebschmann
- Ludeman Family Center for Women's Health Research
- Division of General Internal Medicine
| | - Kristen J Nadeau
- Ludeman Family Center for Women's Health Research
- Pediatric Endocrinology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Kelly Jarvis
- Department of Radiology, Northwestern University, Chicago, Illinois, USA
| | - Alex J Barker
- Department of Bioengineering
- Department of Radiology, Section of Pediatric Radiology, Children's Hospital Colorado
| | - Judith G Regensteiner
- Ludeman Family Center for Women's Health Research
- Division of General Internal Medicine
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus
| | - Jane E B Reusch
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Ludeman Family Center for Women's Health Research
- Rocky Mountain Regional Veterans Administration Medical Center (VAMC), Aurora, Colorado
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5
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Hulett NA, Knaub LA, Hull SE, Pott GB, Peelor R, Miller BF, Shankar K, Rudolph MC, Reusch JEB, Scalzo RL. Sex Differences in the Skeletal Muscle Response to a High Fat, High Sucrose Diet in Rats. Nutrients 2023; 15:4438. [PMID: 37892512 PMCID: PMC10610114 DOI: 10.3390/nu15204438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/28/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
Men are diagnosed with type 2 diabetes at lower body mass indexes than women; the role of skeletal muscle in this sex difference is poorly understood. Type 2 diabetes impacts skeletal muscle, particularly in females who demonstrate a lower oxidative capacity compared to males. To address mechanistic differences underlying this sex disparity, we investigated skeletal muscle mitochondrial respiration in female and male rats in response to chronic high-fat, high-sugar (HFHS) diet consumption. Four-week-old Wistar Rats were fed a standard chow or HFHS diet for 14 weeks to identify sex-specific adaptations in mitochondrial respirometry and characteristics, transcriptional patterns, and protein profiles. Fat mass was greater with the HFHS diet in both sexes when controlled for body mass (p < 0.0001). Blood glucose and insulin resistance were greater in males (p = 0.01) and HFHS-fed rats (p < 0.001). HFHS-fed males had higher mitochondrial respiration compared with females (p < 0.01 sex/diet interaction). No evidence of a difference by sex or diet was found for mitochondrial synthesis, dynamics, or quality to support the mitochondrial respiration sex/diet interaction. However, transcriptomic analyses indicate sex differences in nutrient handling. Sex-specific differences occurred in PI3K/AKT signaling, PPARα/RXRα, and triacylglycerol degradation. These findings may provide insight into the clinical sex differences in body mass index threshold for diabetes development and tissue-specific progression of insulin resistance.
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Affiliation(s)
- Nicholas A. Hulett
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA; (N.A.H.); (J.E.B.R.)
| | - Leslie A. Knaub
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA; (N.A.H.); (J.E.B.R.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
| | - Sara E. Hull
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA; (N.A.H.); (J.E.B.R.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
| | - Gregory B. Pott
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
| | - Rick Peelor
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA (B.F.M.)
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Benjamin F. Miller
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA (B.F.M.)
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Kartik Shankar
- Department of Pediatrics, Section of Nutrition, University of Colorado School of Medicine (UCSOM), Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Michael C. Rudolph
- Department of Physiology, Harold Hamm Diabetes Center, Oklahoma University Health Sciences Center, Oklahoma City, OK 73104, USA;
| | - Jane E. B. Reusch
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA; (N.A.H.); (J.E.B.R.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
- Ludeman Family Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA
| | - Rebecca L. Scalzo
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA; (N.A.H.); (J.E.B.R.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
- Ludeman Family Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO 80045, USA
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6
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Whipple MO, Pinto AJ, Abushamat LA, Bergouignan A, Chapman K, Huebschmann AG, Masters KS, Nadeau KJ, Scalzo RL, Schauer IE, Rafferty D, Reusch JE, Regensteiner JG. Sex Differences in Physical Activity Among Individuals With Type 2 Diabetes Across the Life Span: A Systematic Review and Meta-analysis. Diabetes Care 2022; 45:2163-2177. [PMID: 36044665 PMCID: PMC9472508 DOI: 10.2337/dc22-0576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/06/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND Physical activity (PA) is a cornerstone of type 2 diabetes mellitus (T2DM) treatment. Sex differences in PA behavior or barriers/facilitators to PA among individuals with T2DM are unclear. PURPOSE To summarize the evidence related to sex differences in participation in PA and barriers/facilitators to PA among individuals with T2DM across the life span. DATA SOURCES Systematic searches (CRD42021254246) were conducted with Ovid MEDLINE, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Allied and Complementary Medicine Database (AMED), APA PsychInfo, and SPORTDiscus. STUDY SELECTION We included studies with assessment of PA, sedentary behaviors (SB), or barriers/facilitators to PA among individuals with T2DM by sex or gender. DATA EXTRACTION Participant characteristics, meeting PA guidelines, participation in PA and SB, and barriers/facilitators to PA were extracted by two independent reviewers. DATA SYNTHESIS A total of 53 articles (65,344 participants) were included in the systematic review and 21 articles in the meta-analysis. Sex differences were not observed in meeting of PA guidelines among adolescents (odds ratio 0.70 [95% CI 0.31, 1.59]), but males were more likely than females to meet PA guidelines among adults (1.65 [1.36, 2.01]) and older adults (1.63 [1.27, 2.09]). Males performed more moderate-to-vigorous PA (MVPA) than females across all age-groups. Common barriers to PA were lack of time (men) and lack of social support and motivation (women). LIMITATIONS Limitations include heterogeneity of measures used to assess PA and lack of stratification of data by sex. CONCLUSIONS Sex differences in meeting PA guidelines were not observed among adolescents but were apparent among adults and older adults with T2DM. Females consistently engaged in less MVPA than males across the life span.
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Affiliation(s)
- Mary O. Whipple
- School of Nursing, University of Minnesota, Minneapolis, MN
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Ana J. Pinto
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Layla A. Abushamat
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Section of Cardiovascular Research, Baylor College of Medicine, Houston, TX
| | - Audrey Bergouignan
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, CO
- Hubert Curien Pluridisciplinary Institute UMR7178, CNRS and Université de Strasbourg, Strasbourg, France
| | - Kristina Chapman
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Amy G. Huebschmann
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Kevin S. Masters
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, CO
- Clinical Health Psychology, Department of Psychology, University of Colorado Denver, Denver, CO
| | - Kristen J. Nadeau
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Pediatric Endocrinology, University of Colorado Anschutz Medical Campus, Aurora, CO
- Children’s Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Rebecca L. Scalzo
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Rocky Mountain Regional VA Medical Center, Aurora, CO
| | - Irene E. Schauer
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Rocky Mountain Regional VA Medical Center, Aurora, CO
| | - Deirdre Rafferty
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Jane E.B. Reusch
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Rocky Mountain Regional VA Medical Center, Aurora, CO
| | - Judith G. Regensteiner
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Ludeman Family Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
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7
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Hulett NA, Scalzo RL, Reusch JEB. Glucose Uptake by Skeletal Muscle within the Contexts of Type 2 Diabetes and Exercise: An Integrated Approach. Nutrients 2022; 14:nu14030647. [PMID: 35277006 PMCID: PMC8839578 DOI: 10.3390/nu14030647] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 02/01/2023] Open
Abstract
Type 2 diabetes continues to negatively impact the health of millions. The inability to respond to insulin to clear blood glucose (insulin resistance) is a key pathogenic driver of the disease. Skeletal muscle is the primary tissue for maintaining glucose homeostasis through glucose uptake via insulin-dependent and -independent mechanisms. Skeletal muscle is also responsive to exercise-meditated glucose transport, and as such, exercise is a cornerstone for glucose management in people with type 2 diabetes. Skeletal muscle glucose uptake requires a concert of events. First, the glucose-rich blood must be transported to the skeletal muscle. Next, the glucose must traverse the endothelium, extracellular matrix, and skeletal muscle membrane. Lastly, intracellular metabolic processes must be activated to maintain the diffusion gradient to facilitate glucose transport into the cell. This review aims to examine the physiology at each of these steps in healthy individuals, analyze the dysregulation affecting these pathways associated with type 2 diabetes, and describe the mechanisms by which exercise acts to increase glucose uptake.
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Affiliation(s)
- Nicholas A. Hulett
- Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA; (N.A.H.); (R.L.S.)
| | - Rebecca L. Scalzo
- Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA; (N.A.H.); (R.L.S.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
- Center for Women’s Health Research, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA
| | - Jane E. B. Reusch
- Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA; (N.A.H.); (R.L.S.)
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO 80045, USA
- Center for Women’s Health Research, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA
- Correspondence:
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8
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Scalzo RL, Foright RM, Hull SE, Knaub LA, Johnson-Murguia S, Kinanee F, Kaplan J, Houck JA, Johnson G, Sharp RR, Gillen AE, Jones KL, Zhang AMY, Johnson JD, MacLean PS, Reusch JEB, Wright-Hobart S, Wellberg EA. Breast Cancer Endocrine Therapy Promotes Weight Gain With Distinct Adipose Tissue Effects in Lean and Obese Female Mice. Endocrinology 2021; 162:bqab174. [PMID: 34410380 PMCID: PMC8455348 DOI: 10.1210/endocr/bqab174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Indexed: 12/19/2022]
Abstract
Breast cancer survivors treated with tamoxifen and aromatase inhibitors report weight gain and have an elevated risk of type 2 diabetes, especially if they have obesity. These patient experiences are inconsistent with, preclinical studies using high doses of tamoxifen which reported acute weight loss. We investigated the impact of breast cancer endocrine therapies in a preclinical model of obesity and in a small group of breast adipose tissue samples from women taking tamoxifen to understand the clinical findings. Mature female mice were housed at thermoneutrality and fed either a low-fat/low-sucrose (LFLS) or a high-fat/high-sucrose (HFHS) diet. Consistent with the high expression of Esr1 observed in mesenchymal stem cells from adipose tissue, endocrine therapy was associated with adipose accumulation and more preadipocytes compared with estrogen-treated control mice but resulted in fewer adipocyte progenitors only in the context of HFHS. Analysis of subcutaneous adipose stromal cells revealed diet- and treatment-dependent effects of endocrine therapies on various cell types and genes, illustrating the complexity of adipose tissue estrogen receptor signaling. Breast cancer therapies supported adipocyte hypertrophy and associated with hepatic steatosis, hyperinsulinemia, and glucose intolerance, particularly in obese females. Current tamoxifen use associated with larger breast adipocyte diameter only in women with obesity. Our translational studies suggest that endocrine therapies may disrupt adipocyte progenitors and support adipocyte hypertrophy, potentially leading to ectopic lipid deposition that may be linked to a greater type 2 diabetes risk. Monitoring glucose tolerance and potential interventions that target insulin action should be considered for some women receiving life-saving endocrine therapies for breast cancer.
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Affiliation(s)
- Rebecca L Scalzo
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Center for Women’s Health Research; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Regional VA Medical Center, Aurora, CO 80045, USA
| | - Rebecca M Foright
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Sara E Hull
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Leslie A Knaub
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Stevi Johnson-Murguia
- Department of Pathology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Research Center, Oklahoma City, OK 73104, USA
| | - Fotobari Kinanee
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jeffrey Kaplan
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Julie A Houck
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ginger Johnson
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rachel R Sharp
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Research Center, Oklahoma City, OK 73104, USA
| | - Austin E Gillen
- Division of Hematology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Kenneth L Jones
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Research Center, Oklahoma City, OK 73104, USA
| | - Anni M Y Zhang
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - James D Johnson
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Paul S MacLean
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Center for Women’s Health Research; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jane E B Reusch
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Center for Women’s Health Research; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Regional VA Medical Center, Aurora, CO 80045, USA
| | - Sabrina Wright-Hobart
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Elizabeth A Wellberg
- Center for Women’s Health Research; University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Pathology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Research Center, Oklahoma City, OK 73104, USA
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Stout MB, Scalzo RL, Wellberg EA. Persistent Metabolic Effects of Tamoxifen: Considerations for an Experimental Tool and Clinical Breast Cancer Treatment. Endocrinology 2021; 162:6308425. [PMID: 34161568 PMCID: PMC8282119 DOI: 10.1210/endocr/bqab126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Indexed: 02/06/2023]
Abstract
The selective estrogen receptor (ER) modulator tamoxifen is frequently used in preclinical studies to induce Cre recombinase and generate conditional transgenic mice. In addition, it is often prescribed to treat ER-positive breast cancer, which is diagnosed in approximately 150 000 people each year. In mice, protocols to activate Cre-ER transgenes require tamoxifen administration by several methods, including oral gavage, IP injection, or intragastric injection, spanning a wide range of doses to achieve transgene induction. As a result, the reported metabolic effects of tamoxifen treatment are not always consistent with anecdotal reports from breast cancer patients, or with expected outcomes based on the overall metabolically protective role of estrogen. A greater awareness of tamoxifen's adverse metabolic effects is critical to designing studies with appropriate controls, especially those investigations focused on metabolic outcomes.
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Affiliation(s)
- Michael B Stout
- Department of Nutritional Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Harold Hamm Diabetes Center, Oklahoma City, OK, USA
| | - Rebecca L Scalzo
- Division of Endocrinology, Metabolism & Diabetes, Department of Medicine; University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Center for Women’s Health Research; University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
| | - Elizabeth A Wellberg
- Harold Hamm Diabetes Center, Oklahoma City, OK, USA
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Stephenson Cancer Center, Oklahoma City, OK, USA
- Correspondence: Elizabeth Wellberg, PhD, University of Oklahoma Health Sciences Center, 975 NE 10th St, BRC 309, Oklahoma City, OK 73104, United States. E-mail:
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Whipple MO, Masters KS, Huebschmann AG, Scalzo RL, Reusch JE, Bergouignan A, Regensteiner JG. Acute effects of sedentary breaks on vascular health in adults at risk for type 2 diabetes: A systematic review. Vasc Med 2021; 26:448-458. [PMID: 33977799 PMCID: PMC9074004 DOI: 10.1177/1358863x211009307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of this systematic review was to evaluate the available evidence regarding the acute effects of interrupting/breaking up prolonged sedentary behavior (SB) on vascular health among individuals at elevated risk for type 2 diabetes (T2D). Searches of MEDLINE, Embase, Web of Science, and Cochrane Library databases were conducted on April 7, 2020. Included studies: (1) examined the effect of breaking up prolonged SB in adults with or at elevated risk for T2D and (2) assessed a vascular health outcome, such as blood pressure (BP), flow-mediated dilation (FMD), pulse-wave velocity, or endothelin-1. A total of 20 articles (17 unique studies) were included. Only three studies reported adequate statistical power for the specified vascular outcome. The available evidence suggests that light and moderate intensity activity breaks are effective in acutely lowering BP when compared to prolonged sitting. The small number of studies that included FMD or other vascular outcomes prohibits conclusions regarding the impact of SB breaks on these outcomes. Few studies evaluating the impact of breaking up SB among adults at risk for T2D have included and been adequately powered to examine vascular outcomes, but our preliminary finding, that certain SB breaks improve BP, provides proof-of-concept for this line of inquiry. Future studies should examine both the acute and chronic vascular effects of breaking up SB among individuals most vulnerable to the effects of SB (e.g. older adults, those with T2D), as these individuals are both highly sedentary and at greatest risk of poor health outcomes. PROSPERO ID: CRD42020183423.
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Affiliation(s)
- Mary O. Whipple
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Geriatric Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Kevin S. Masters
- Department of Psychology, Clinical Health Psychology, University of Colorado Denver, Denver, CO
- Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Amy G. Huebschmann
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Rebecca L. Scalzo
- Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Rocky Mountain Regional VA, Aurora, CO
| | - Jane E.B. Reusch
- Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Rocky Mountain Regional VA, Aurora, CO
| | - Audrey Bergouignan
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Institut Pluridisciplinaire Hubert Curien, French National Center for Scientific Research, Université de Strasbourg, UMR 7178, Strasbourg, France
| | - Judith G. Regensteiner
- Division of General Internal Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Center for Women’s Health Research, University of Colorado Anschutz Medical Campus, Aurora, CO
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11
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Wellberg EA, Johnson-Murguia S, MacLean PS, Johnson JD, Reusch JEB, Scalzo RL. Breast Cancer Endocrine Therapy Exhausts Adipocyte Progenitors Promoting Weight Gain and Glucose Intolerance. J Endocr Soc 2021. [PMCID: PMC8265747 DOI: 10.1210/jendso/bvab048.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Breast cancer survivors treated with anti-estrogen therapies report weight gain and have an elevated risk of type 2 diabetes. Here, we show that current tamoxifen use did not influence body mass index but associated with larger breast adipocyte diameter only in women with obesity, suggesting adipose tissue may be targeted by breast cancer therapies. To understand the mechanisms behind these clinical findings, we investigated the impact of estrogen deprivation and tamoxifen in a relevant pre-clinical murine model of obesity. Specifically, mature female mice were housed at thermoneutrality and fed either a low-fat/low-sucrose (LFLS) or a high-fat/high-sucrose (HFHS) diet. Consistent with the high expression of Esr1 observed in single-cell RNA sequencing of mesenchymal stem cells from mouse adipose tissue, endocrine therapies associated with adipose accumulation and preadipocyte expansion, but resulted in adipocyte progenitor depletion only in the context of HFHS. Consequently, 7-week endocrine therapy supported adipocyte hypertrophy and was associated with hepatic steatosis, hyperinsulinemia, insulin resistance, and glucose intolerance, particularly in HFHS fed females. We administered HFHS fed females either metformin or pioglitazone, glucose lowering drugs used to treat diabetes, or treadmill interval exercise during endocrine therapy with the goal of improving whole body metabolism. All interventions prevented the effects of tamoxifen but not estrogen deprivation on adipocyte size and insulin resistance in HFHS-fed mice. This translational study suggests that endocrine therapies may act via ER-alpha to directly disrupt adipocyte progenitors and support adipocyte hypertrophy, leading to ectopic lipid deposition that may promote hyperinsulinemia, insulin resistance and type 2 diabetes. Interventions that target insulin action should be considered for some women receiving life-saving endocrine therapies for breast cancer.
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Affiliation(s)
| | | | - Paul S MacLean
- University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | | | - Jane E B Reusch
- University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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12
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Scalzo RL, Schauer IE, Rafferty D, Knaub LA, Kvaratskhelia N, Johnson TK, Pott GB, Abushamat LA, Whipple MO, Huebschmann AG, Cree-Green M, Reusch JEB, Regensteiner JG. Single-leg exercise training augments in vivo skeletal muscle oxidative flux and vascular content and function in adults with type 2 diabetes. J Physiol 2021; 600:963-978. [PMID: 33569797 DOI: 10.1113/jp280603] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/28/2021] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS People with type 2 diabetes (T2D) have impaired skeletal muscle oxidative flux due to limited oxygen delivery. In the current study, this impairment in oxidative flux in people with T2D was abrogated with a single-leg exercise training protocol. Additionally, single-leg exercise training increased skeletal muscle CD31 content, calf blood flow and state 4 mitochondrial respiration in all participants. ABSTRACT Cardiorespiratory fitness is impaired in type 2 diabetes (T2D), conferring significant cardiovascular risk in this population; interventions are needed. Previously, we reported that a T2D-associated decrement in skeletal muscle oxidative flux is ameliorated with acute use of supplemental oxygen, suggesting that skeletal muscle oxygenation is rate-limiting to in vivo mitochondrial oxidative flux during exercise in T2D. We hypothesized that single-leg exercise training (SLET) would improve the T2D-specific impairment in in vivo mitochondrial oxidative flux during exercise. Adults with (n = 19) and without T2D (n = 22) with similar body mass indexes and levels of physical activity participated in two weeks of SLET. Following SLET, in vivo oxidative flux measured by 31 P-MRS increased in participants with T2D, but not people without T2D, measured by the increase in initial phosphocreatine synthesis (P = 0.0455 for the group × exercise interaction) and maximum rate of oxidative ATP synthesis (P = 0.0286 for the interaction). Additionally, oxidative phosphorylation increased in all participants with SLET (P = 0.0209). After SLET, there was no effect of supplemental oxygen on any of the in vivo oxidative flux measurements in either group (P > 0.02), consistent with resolution of the T2D-associated oxygen limitation previously observed at baseline in subjects with T2D. State 4 mitochondrial respiration also improved in muscle fibres ex vivo. Skeletal muscle vasculature content and calf blood flow increased in all participants with SLET (P < 0.0040); oxygen extraction in the calf increased only in T2D (P = 0.0461). SLET resolves the T2D-associated impairment of skeletal muscle in vivo mitochondrial oxidative flux potentially through improved effective blood flow/oxygen delivery.
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Affiliation(s)
- Rebecca L Scalzo
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.,Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.,Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA
| | - Irene E Schauer
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.,Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA
| | - Deirdre Rafferty
- Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Leslie A Knaub
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.,Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA
| | - Nina Kvaratskhelia
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Taro Kaelix Johnson
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Gregory B Pott
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.,Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA
| | - Layla A Abushamat
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.,Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA
| | - Mary O Whipple
- Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Amy G Huebschmann
- Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.,Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Melanie Cree-Green
- Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.,Division of Pediatric Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jane E B Reusch
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.,Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.,Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.,Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA
| | - Judith G Regensteiner
- Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.,Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
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13
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Abushamat LA, McClatchey PM, Scalzo RL, Schauer I, Huebschmann AG, Nadeau KJ, Liu Z, Regensteiner JG, Reusch JEB. Mechanistic Causes of Reduced Cardiorespiratory Fitness in Type 2 Diabetes. J Endocr Soc 2020; 4:bvaa063. [PMID: 32666009 PMCID: PMC7334033 DOI: 10.1210/jendso/bvaa063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes (T2D) has been rising in prevalence in the United States and worldwide over the past few decades and contributes to significant morbidity and premature mortality, primarily due to cardiovascular disease (CVD). Cardiorespiratory fitness (CRF) is a modifiable cardiovascular (CV) risk factor in the general population and in people with T2D. Young people and adults with T2D have reduced CRF when compared with their peers without T2D who are similarly active and of similar body mass index. Furthermore, the impairment in CRF conferred by T2D is greater in women than in men. Various factors may contribute to this abnormality in people with T2D, including insulin resistance and mitochondrial, vascular, and cardiac dysfunction. As proof of concept that understanding the mediators of impaired CRF in T2D can inform intervention, we previously demonstrated that an insulin sensitizer improved CRF in adults with T2D. This review focuses on how contributing factors influence CRF and why they may be compromised in T2D. Functional exercise capacity is a measure of interrelated systems biology; as such, the contribution of derangement in each of these factors to T2D-mediated impairment in CRF is complex and varied. Therefore, successful approaches to improve CRF in T2D should be multifaceted and individually designed. The current status of this research and future directions are outlined.
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Affiliation(s)
- Layla A Abushamat
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | | | - Rebecca L Scalzo
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Rocky Mountain Regional VA, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Irene Schauer
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Rocky Mountain Regional VA, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Amy G Huebschmann
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Kristen J Nadeau
- Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Zhenqi Liu
- Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Judith G Regensteiner
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Jane E B Reusch
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Rocky Mountain Regional VA, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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14
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Scalzo RL, Rafferty D, Schauer I, Huebschmann AG, Cree-Green M, Reusch JEB, Regensteiner JG. Sitagliptin improves diastolic cardiac function but not cardiorespiratory fitness in adults with type 2 diabetes. J Diabetes Complications 2019; 33:561-566. [PMID: 31182338 PMCID: PMC7278036 DOI: 10.1016/j.jdiacomp.2019.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/17/2019] [Accepted: 05/05/2019] [Indexed: 01/04/2023]
Abstract
BACKGROUND People with type 2 diabetes mellitus (T2D) have preclinical cardiac and vascular dysfunction associated with low cardiorespiratory fitness (CRF). This is especially concerning because CRF is a powerful predictor of cardiovascular mortality, a primary issue in T2D management. Glucagon-like pepetide-1 (GLP-1) augments cardiovascular function and our previous data in rodents demonstrate that potentiating the GLP-1 signal with a dipeptidyl peptidase-4 (DPP4) inhibitor augments CRF. Lacking are pharmacological treatments which can target T2D-specific physiological barriers to exercise to potentially permit adaptations necessary to improve CRF and thereby health outcomes in people with T2D. We therefore hypothesized that administration of a DPP4-inhibitor (sitagliptin) would improve CRF in adults with T2D. METHODS AND RESULTS Thirty-eight participants (64 ± 1 years; mean ± SE) with T2D were randomized in a double-blinded study to receive 100 mg/day sitagliptin, 2 mg/day glimepiride, or placebo for 3 months after baseline measurements. Fasting glucose decreased with both glimepiride and sitagliptin compared with placebo (P = 0.002). CRF did not change in any group (Placebo: Pre: 15.4 ± 0.9 vs. Post: 16.1 ± 1.1 ml/kg/min vs. Glimepiride: 18.5 ± 1.0 vs. 17.7 ± 1.2 ml/kg/min vs. Sitagliptin: 19.1 ± 1.2 vs. 18.3 ± 1.1 ml/kg/min; P = 0.3). Sitagliptin improved measures of cardiac diastolic function, however, measures of vascular function did not change with any treatment. CONCLUSIONS Three months of sitagliptin improved diastolic cardiac function, however, CRF did not change. These data suggest that targeting the physiological contributors to CRF with sitagliptin alone is not an adequate strategy to improve CRF in people with T2D. CLINICAL TRIALS REGISTRATION www.clinicaltrials.gov NCT01951339.
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Affiliation(s)
- Rebecca L Scalzo
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine, United States of America; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, United States of America; Rocky Mountain Regional Veterans Administration Medical Center, United States of America.
| | - Deirdre Rafferty
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine, United States of America
| | - Irene Schauer
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine, United States of America; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, United States of America; Rocky Mountain Regional Veterans Administration Medical Center, United States of America
| | - Amy G Huebschmann
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine, United States of America; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, United States of America
| | - Melanie Cree-Green
- Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, United States of America; Division of Pediatric Endocrinology, University of Colorado School of Medicine, United States of America
| | - Jane E B Reusch
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine, United States of America; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, United States of America; Rocky Mountain Regional Veterans Administration Medical Center, United States of America
| | - Judith G Regensteiner
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine, United States of America; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, United States of America
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15
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Cree-Green M, Scalzo RL, Harrall K, Newcomer BR, Schauer IE, Huebschmann AG, McMillin S, Brown MS, Orlicky D, Knaub L, Nadeau KJ, McClatchey PM, Bauer TA, Regensteiner JG, Reusch JEB. Supplemental Oxygen Improves In Vivo Mitochondrial Oxidative Phosphorylation Flux in Sedentary Obese Adults With Type 2 Diabetes. Diabetes 2018; 67:1369-1379. [PMID: 29643061 PMCID: PMC6463751 DOI: 10.2337/db17-1124] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/29/2018] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes is associated with impaired exercise capacity. Alterations in both muscle perfusion and mitochondrial function can contribute to exercise impairment. We hypothesized that impaired muscle mitochondrial function in type 2 diabetes is mediated, in part, by decreased tissue oxygen delivery and would improve with oxygen supplementation. Ex vivo muscle mitochondrial content and respiration assessed from biopsy samples demonstrated expected differences in obese individuals with (n = 18) and without (n = 17) diabetes. Similarly, in vivo mitochondrial oxidative phosphorylation capacity measured in the gastrocnemius muscle via 31P-MRS indicated an impairment in the rate of ADP depletion with rest (27 ± 6 s [diabetes], 21 ± 7 s [control subjects]; P = 0.008) and oxidative phosphorylation (P = 0.046) in type 2 diabetes after isometric calf exercise compared with control subjects. Importantly, the in vivo impairment in oxidative capacity resolved with oxygen supplementation in adults with diabetes (ADP depletion rate 5.0 s faster, P = 0.012; oxidative phosphorylation 0.046 ± 0.079 mmol/L/s faster, P = 0.027). Multiple in vivo mitochondrial measures related to HbA1c These data suggest that oxygen availability is rate limiting for in vivo mitochondrial oxidative exercise recovery measured with 31P-MRS in individuals with uncomplicated diabetes. Targeting muscle oxygenation could improve exercise function in type 2 diabetes.
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Affiliation(s)
- Melanie Cree-Green
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Rebecca L Scalzo
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology and Metabolism, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Kylie Harrall
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- School of Pharmacy, University of Colorado Anschutz Medical Campus, Aurora, CO
| | | | - Irene E Schauer
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Division of Endocrinology and Metabolism, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Veterans Affairs Medical Center, Denver, CO
| | - Amy G Huebschmann
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Division of General Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Shawna McMillin
- Division of General Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Mark S Brown
- Department of Radiology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - David Orlicky
- Division of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Leslie Knaub
- Division of Endocrinology and Metabolism, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Kristen J Nadeau
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - P Mason McClatchey
- Division of Endocrinology and Metabolism, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Timothy A Bauer
- Division of General Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Judith G Regensteiner
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Division of General Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Jane E B Reusch
- Center for Women's Health Research, Anschutz Medical Campus, Aurora, CO
- Veterans Affairs Medical Center, Denver, CO
- Division of General Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
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16
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Scalzo RL, Knaub LA, Hull SE, Keller AC, Hunter K, Walker LA, Reusch JEB. Glucagon-like peptide-1 receptor antagonism impairs basal exercise capacity and vascular adaptation to aerobic exercise training in rats. Physiol Rep 2018; 6:e13754. [PMID: 29984491 PMCID: PMC6036104 DOI: 10.14814/phy2.13754] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 12/18/2022] Open
Abstract
Cardiorespiratory fitness (CRF) inversely predicts cardiovascular (CV) mortality and CRF is impaired in people with type 2 diabetes (T2D). Aerobic exercise training (ET) improves CRF and is associated with decreased risk of premature death in healthy and diseased populations. Understanding the mechanisms contributing to ET adaptation may identify targets for reducing CV mortality of relevance to people with T2D. The antihyperglycemic hormone glucagon-like peptide-1 (GLP-1) influences many of the same pathways as exercise and may contribute to CV adaptation to ET. We hypothesized that GLP-1 is necessary for adaptation to ET. Twelve-week-old male Wistar rats were randomized (n = 8-12/group) to receive PBS or GLP-1 receptor antagonist (exendin 9-39 (Ex(9-39)) via osmotic pump for 4 weeks ± ET. CRF was greater with ET (P < 0.01). Ex(9-39) treatment blunted CRF in both sedentary and ET rats (P < 0.001). Ex(9-39) attenuated acetylcholine-mediated vasodilation, while this response was maintained with Ex(9-39)+ET (P = 0.04). Aortic stiffness was greater with Ex(9-39) (P = 0.057) and was made worse when Ex(9-39) was combined with ET (P = 0.004). Ex vivo aortic vasoconstriction with potassium and phenylephrine was lower with Ex(9-39) (P < 0.0001). Carotid strain improved with PBS + ET but did not change in the Ex(9-39) rats with ET (P < 0.0001). Left ventricular mitochondrial respiration was elevated with Ex(9-39) (P < 0.02). GLP-1 receptor antagonism impairs CRF with and without ET, attenuates the vascular adaptation to ET, and elevates cardiac mitochondrial respiration. These data suggest that GLP-1 is integral to the adaptive vascular response to ET.
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Affiliation(s)
- Rebecca L. Scalzo
- Division of EndocrinologyUniversity of Colorado School of MedicineAuroraColorado
| | - Leslie A. Knaub
- Division of EndocrinologyUniversity of Colorado School of MedicineAuroraColorado
| | - Sara E. Hull
- Division of EndocrinologyUniversity of Colorado School of MedicineAuroraColorado
| | - Amy C. Keller
- Division of EndocrinologyUniversity of Colorado School of MedicineAuroraColorado
- Department of MedicineDenver VA Medical CenterUniversity of Colorado School of MedicineAuroraColorado
| | - Kendall Hunter
- Division of BioengineeringUniversity of Colorado School of MedicineAuroraColorado
| | - Lori A. Walker
- Division of CardiologyUniversity of Colorado School of MedicineAuroraColorado
| | - Jane E. B. Reusch
- Division of EndocrinologyUniversity of Colorado School of MedicineAuroraColorado
- Department of MedicineDenver VA Medical CenterUniversity of Colorado School of MedicineAuroraColorado
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17
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Wahl MP, Scalzo RL, Regensteiner JG, Reusch JEB. Mechanisms of Aerobic Exercise Impairment in Diabetes: A Narrative Review. Front Endocrinol (Lausanne) 2018; 9:181. [PMID: 29720965 PMCID: PMC5915473 DOI: 10.3389/fendo.2018.00181] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/04/2018] [Indexed: 12/21/2022] Open
Abstract
The prevalence of diabetes in the United States and globally has been rapidly increasing over the last several decades. There are now estimated to be 30.3 million people in the United States and 422 million people worldwide with diabetes. Diabetes is associated with a greatly increased risk of cardiovascular mortality, which is the leading cause of death in adults with diabetes. While exercise training is a cornerstone of diabetes treatment, people with diabetes have well-described aerobic exercise impairments that may create an additional diabetes-specific barrier to adding regular exercise to their lifestyle. Physiologic mechanisms linked to exercise impairment in diabetes include insulin resistance, cardiac abnormalities, mitochondrial function, and the ability of the body to supply oxygen. In this paper, we highlight the abnormalities of exercise in type 2 diabetes as well as potential therapeutic approaches.
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Affiliation(s)
- Matthew P. Wahl
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, CO, United States
- Veterans Administration Eastern Colorado Health Care System, Denver, CO, United States
| | - Rebecca L. Scalzo
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, CO, United States
- Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
| | - Judith G. Regensteiner
- Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
- Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, CO, United States
| | - Jane E. B. Reusch
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, CO, United States
- Veterans Administration Eastern Colorado Health Care System, Denver, CO, United States
- Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
- *Correspondence: Jane E. B. Reusch,
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18
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Scalzo RL, Bauer TA, Harrall K, Moreau K, Ozemek C, Herlache L, McMillin S, Huebschmann AG, Dorosz J, Reusch JEB, Regensteiner JG. Acute vitamin C improves cardiac function, not exercise capacity, in adults with type 2 diabetes. Diabetol Metab Syndr 2018; 10:7. [PMID: 29456629 PMCID: PMC5813393 DOI: 10.1186/s13098-018-0306-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 01/04/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND People with type 2 diabetes (T2D) have impaired exercise capacity, even in the absence of complications, which is predictive of their increased cardiovascular mortality. Cardiovascular dysfunction is one potential cause of this exercise defect. Acute infusion of vitamin C has been separately shown to improve diastolic and endothelial function in prior studies. We hypothesized that acute vitamin C infusion would improve exercise capacity and that these improvements would be associated with improved cardiovascular function. METHODS Adults with T2D (n = 31, 7 female, 24 male, body mass index (BMI): 31.5 ± 0.8 kg/m2) and BMI-similar healthy adults (n = 21, 11 female, 10 male, BMI: 30.4 ± 0.7 kg/m2) completed two randomly ordered visits: IV infusion of vitamin C (7.5 g) and a volume-matched saline infusion. During each visit peak oxygen uptake (VO2peak), brachial artery flow mediated dilation (FMD), reactive hyperemia (RH; plethysmography), and cardiac echocardiography were measured. General linear mixed models were utilized to assess the differences in all study variables. RESULTS Acute vitamin C infusion improved diastolic function, assessed by lateral and septal E:E' (P < 0.01), but did not change RH (P = 0.92), or VO2peak (P = 0.33) in any participants. CONCLUSION Acute vitamin C infusion improved diastolic function but did not change FMD, forearm reactive hyperemia, or peak exercise capacity. Future studies should further clarify the role of endothelial function as well as other possible physiological causes of exercise impairment in order to provide potential therapeutic targets.Trial registration NCT00786019. Prospectively registered May 2008.
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Affiliation(s)
- Rebecca L. Scalzo
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), 12801 E17th Ave, Aurora, CO 80045 USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Timothy A. Bauer
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Kylie Harrall
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Kerrie Moreau
- Division of Geriatrics, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- VAMC-Geriatric Research Education and Clinical Center (GRECC), Denver, CO 80215 USA
| | - Cemal Ozemek
- Division of Geriatrics, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Leah Herlache
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Shawna McMillin
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Amy G. Huebschmann
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Jennifer Dorosz
- Division of Cardiology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
| | - Jane E. B. Reusch
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), 12801 E17th Ave, Aurora, CO 80045 USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Veterans Administration Medical Center (VAMC), Denver, CO 80215 USA
| | - Judith G. Regensteiner
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
- Department of Medicine, Center for Women’s Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA
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Lu L, Ye S, Scalzo RL, Reusch JEB, Greyson CR, Schwartz GG. Metformin prevents ischaemic ventricular fibrillation in metabolically normal pigs. Diabetologia 2017; 60:1550-1558. [PMID: 28497164 PMCID: PMC5798228 DOI: 10.1007/s00125-017-4287-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 03/29/2017] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS Metformin is the drug most often used to treat type 2 diabetes. Evidence suggests that metformin may reduce mortality of individuals with type 2 diabetes, but the mechanism of such an effect is unknown and outcomes of metformin treatment in people without diabetes have not been determined. If metformin favourably affected mortality of non-diabetic individuals, it might have even broader therapeutic utility. We evaluated the effect of metformin on myocardial energetics and ischaemic ventricular fibrillation (VF) in metabolically normal pigs. METHODS Domestic farm pigs were treated with metformin (30 mg kg-1 day-1 orally for 2-3 weeks; n = 36) or received no treatment (n = 37). Under anaesthesia, pigs underwent up to 90 min low-flow regional myocardial ischaemia followed by 45 min of reperfusion. Pigs were monitored for arrhythmia, monophasic action potential morphology, haemodynamics and myocardial substrate utilisation, AMP-activated protein kinase (AMPK) phosphorylation activity and ATP concentration. RESULTS Death due to VF occurred in 12% of pigs treated with metformin compared with 50% of untreated controls (p = 0.03). The anti-fibrillatory effect of metformin was associated with attenuation of action potential shortening in ischaemic myocardium (p = 0.02) and attenuation of the difference in action potential duration between ischaemic and non-ischaemic regions (p < 0.001) compared with untreated controls. Metformin had no effect on myocardial contractile function, oxygen consumption, or glucose or lactate utilisation. During ischaemia, however, metformin treatment amplified the activation of AMPK and preserved ATP concentration in myocardium compared with untreated controls (each p < 0.05). CONCLUSIONS/INTERPRETATION Chronic treatment of metabolically normal pigs with metformin at a clinically relevant dose reduces mortality from ischaemic VF. This protection is associated with preservation of myocardial energetics during ischaemia. Maintenance of myocardial ATP concentration during ischaemia is likely to prevent action potential shortening, heterogeneity of repolarisation, and propensity for lethal arrhythmia. The findings suggest that metformin might be protective in non-diabetic individuals with coronary heart disease.
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Affiliation(s)
- Li Lu
- Cardiology Section, Denver VA Medical Center, 1055 Clermont St, Mail Code 111B, Denver, CO, 80220, USA
- University of Colorado School of Medicine, Aurora, CO, USA
| | - Shuyu Ye
- Cardiology Section, Denver VA Medical Center, 1055 Clermont St, Mail Code 111B, Denver, CO, 80220, USA
- University of Colorado School of Medicine, Aurora, CO, USA
| | - Rebecca L Scalzo
- University of Colorado School of Medicine, Aurora, CO, USA
- Endocrinology/Metabolism Section, Denver VA Medical Center, Denver, CO, USA
| | - Jane E B Reusch
- University of Colorado School of Medicine, Aurora, CO, USA
- Endocrinology/Metabolism Section, Denver VA Medical Center, Denver, CO, USA
| | - Clifford R Greyson
- Cardiology Section, Denver VA Medical Center, 1055 Clermont St, Mail Code 111B, Denver, CO, 80220, USA
- University of Colorado School of Medicine, Aurora, CO, USA
| | - Gregory G Schwartz
- Cardiology Section, Denver VA Medical Center, 1055 Clermont St, Mail Code 111B, Denver, CO, 80220, USA.
- University of Colorado School of Medicine, Aurora, CO, USA.
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Scalzo RL, Paris HL, Binns SE, Davis JL, Beals JW, Melby CL, Luckasen GJ, Hickey MS, Miller BF, Hamilton KL, Bell C. Ergogenic properties of metformin in simulated high altitude. Clin Exp Pharmacol Physiol 2017; 44:729-738. [DOI: 10.1111/1440-1681.12761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/22/2017] [Accepted: 03/28/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Rebecca L. Scalzo
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Hunter L. Paris
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Scott E. Binns
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Janelle L. Davis
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Joseph W. Beals
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Christopher L. Melby
- Department of Food Science and Human Nutrition Colorado State University Fort Collins CO USA
| | - Gary J. Luckasen
- Heart Center of the Rockies University of Colorado Health Fort Collins CO USA
| | - Matthew S. Hickey
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Benjamin F. Miller
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Karyn L. Hamilton
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Christopher Bell
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
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21
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Rafferty DM, Scalzo RL, Carter S, Regensteiner JG, Huebschmann AG. Subjective and Objective Measures of Physical Exertion in Adults With and Without Type 2 Diabetes. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000519791.28056.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Scalzo RL, Moreau KL, Ozemek C, Herlache L, McMillin S, Gilligan S, Huebschmann AG, Bauer TA, Dorosz J, Reusch JEB, Regensteiner JG. Exenatide improves diastolic function and attenuates arterial stiffness but does not alter exercise capacity in individuals with type 2 diabetes. J Diabetes Complications 2017; 31:449-455. [PMID: 27884660 PMCID: PMC5787373 DOI: 10.1016/j.jdiacomp.2016.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/19/2016] [Accepted: 10/03/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Exercise is recommended as a cornerstone of treatment for type 2 diabetes mellitus (T2DM), however, it is often poorly adopted by patients. Even in the absence of apparent cardiovascular disease, persons with T2DM have an impaired ability to carry out maximal and submaximal exercise and these impairments are correlated with cardiac and endothelial dysfunction. Glucagon-like pepetide-1 (GLP-1) augments endothelial and cardiac function in T2DM. We hypothesized that administration of a GLP-1 agonist (exenatide) would improve exercise capacity in T2DM. METHODS AND RESULTS Twenty-three participants (64±4years; mean±SE) with uncomplicated T2DM were randomized in a double-blinded manner to receive either 10μg BID of exenatide or matching placebo after baseline measurements. Treatment with exenatide did not improve VO2peak (P=0.1464) or VO2 kinetics (P=0.2775). Diastolic function, assessed via resting lateral E:E', was improved with administration of exenatide compared with placebo (Placebo Pre: 7.6±1.0 vs. Post: 8.4±1.2 vs. Exenatide Pre: 8.1±0.7 vs. Post: 6.7±0.6; P=0.0127). Additionally, arterial stiffness measured by pulse wave velocity, was reduced with exenatide treatment compared with placebo (Placebo Pre: 10.5±0.8 vs. Post: 11.5±1.1s vs. Exenatide Pre: 11.4±1.8 vs. Post: 10.2±1.4s; P=0.0373). Exenatide treatment did not improve endothelial function (P=0.1793). CONCLUSIONS Administration of exenatide improved cardiac function and reduced arterial stiffness, however, these changes were not accompanied by improved functional exercise capacity. In order to realize the benefits of this drug on exercise capacity, combining exenatide with aerobic exercise training in participants with T2DM may be warranted.
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Affiliation(s)
- Rebecca L Scalzo
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Kerrie L Moreau
- Division of Geriatrics, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215; VAMC-Geriatric Research Education and Clinical Center (GRECC), Denver, Colorado 80215
| | - Cemal Ozemek
- Division of Geriatrics, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Leah Herlache
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Shawna McMillin
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Sarah Gilligan
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Amy G Huebschmann
- Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215; Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Tim A Bauer
- Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Jennifer Dorosz
- Division of Cardiology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215
| | - Jane E B Reusch
- Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215; Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215; Veterans Administration Medical Center (VAMC), Denver, Colorado 80215
| | - Judith G Regensteiner
- Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215; Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine (UCSOM), Denver, Colorado 80215.
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23
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Davis JL, Paris HL, Beals JW, Binns SE, Giordano GR, Scalzo RL, Schweder MM, Blair E, Bell C. Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia-Reperfusion Injury. Nutr Metab Insights 2016; 9:25-30. [PMID: 27375360 PMCID: PMC4915787 DOI: 10.4137/nmi.s39764] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 04/27/2016] [Accepted: 04/29/2016] [Indexed: 12/12/2022] Open
Abstract
Intravenous administration of vitamin C has been shown to decrease oxidative stress and, in some instances, improve physiological function in adult humans. Oral vitamin C administration is typically less effective than intravenous, due in part to inferior vitamin C bioavailability. The purpose of this study was to determine the efficacy of oral delivery of vitamin C encapsulated in liposomes. On 4 separate randomly ordered occasions, 11 men and women were administered an oral placebo, or 4 g of vitamin C via oral, oral liposomal, or intravenous delivery. The data indicate that oral delivery of 4 g of vitamin C encapsulated in liposomes (1) produces circulating concentrations of vitamin C that are greater than unencapsulated oral but less than intravenous administration and (2) provides protection from ischemia–reperfusion-mediated oxidative stress that is similar to the protection provided by unencapsulated oral and intravenous administrations.
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Affiliation(s)
- Janelle L Davis
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Hunter L Paris
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Joseph W Beals
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Scott E Binns
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Gregory R Giordano
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Rebecca L Scalzo
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Melani M Schweder
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Emek Blair
- Empirical Labs, Fort Collins, Colorado, USA.; Nutritional Biomimetics LLC, Fort Collins, Colorado, USA.; Present address: Valimenta Labs, Fort Collins, Colorado, USA
| | - Christopher Bell
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
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Scalzo RL, Binns SE, Klochak AL, Giordano GR, Paris HL, Sevits KJ, Beals JW, Biela LM, Larson DG, Luckasen GJ, Irwin D, Schroeder T, Hamilton KL, Bell C. Methazolamide Plus Aminophylline Abrogates Hypoxia-Mediated Endurance Exercise Impairment. High Alt Med Biol 2015; 16:331-42. [DOI: 10.1089/ham.2015.0066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Rebecca L. Scalzo
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Scott E. Binns
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Anna L. Klochak
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Gregory R. Giordano
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Hunter L.R. Paris
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Kyle J. Sevits
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Joseph W. Beals
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Laurie M. Biela
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Dennis G. Larson
- Heart Center of the Rockies, University of Colorado Health, Fort Collins, Colorado
| | - Gary J. Luckasen
- Heart Center of the Rockies, University of Colorado Health, Fort Collins, Colorado
| | - David Irwin
- University of Colorado–Denver, Denver, Colorado
| | - Thies Schroeder
- Department of Physical Chemistry, University of Mainz, Mainz, Germany
| | - Karyn L. Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Christopher Bell
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
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25
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Scalzo RL, Peltonen GL, Binns SE, Klochak AL, Szallar SE, Wood LM, Larson DG, Luckasen GJ, Irwin D, Schroeder T, Hamilton KL, Bell C. The Effects of Sympathetic Inhibition on Metabolic and Cardiopulmonary Responses to Exercise in Hypoxic Conditions. Wilderness Environ Med 2015; 26:520-4. [PMID: 26183071 DOI: 10.1016/j.wem.2015.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 04/15/2015] [Accepted: 04/17/2015] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Pre-exertion skeletal muscle glycogen content is an important physiological determinant of endurance exercise performance: low glycogen stores contribute to premature fatigue. In low-oxygen environments (hypoxia), the important contribution of carbohydrates to endurance performance is further enhanced as glucose and glycogen dependence is increased; however, the insulin sensitivity of healthy adult humans is decreased. In light of this insulin resistance, maintaining skeletal muscle glycogen in hypoxia becomes difficult, and subsequent endurance performance is impaired. Sympathetic inhibition promotes insulin sensitivity in hypoxia but may impair hypoxic exercise performance, in part due to suppression of cardiac output. Accordingly, we tested the hypothesis that hypoxic exercise performance after intravenous glucose feeding in a low-oxygen environment will be attenuated when feeding occurs during sympathetic inhibition. METHODS On 2 separate occasions, while breathing a hypoxic gas mixture, 10 healthy men received 1 hour of parenteral carbohydrate infusion (20% glucose solution in saline; 75 g), after which they performed stationary cycle ergometer exercise (~65% maximal oxygen uptake) until exhaustion. Forty-eight hours before 1 visit, chosen randomly, sympathetic inhibition via transdermal clonidine (0.2 mg/d) was initiated. RESULTS The mean time to exhaustion after glucose feeding both with and without sympathetic inhibition was not different (22.7 ± 5.4 minutes vs 23.5 ± 5.1 minutes; P = .73). CONCLUSIONS Sympathetic inhibition protects against hypoxia-mediated insulin resistance without influencing subsequent hypoxic endurance performance.
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Affiliation(s)
- Rebecca L Scalzo
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Garrett L Peltonen
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Scott E Binns
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Anna L Klochak
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Steve E Szallar
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Lacey M Wood
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Dennis G Larson
- Heart Center of the Rockies, University of Colorado Health, Fort Collins, CO (Drs Larson and Luckasen)
| | - Gary J Luckasen
- Heart Center of the Rockies, University of Colorado Health, Fort Collins, CO (Drs Larson and Luckasen)
| | - David Irwin
- University of Colorado Denver, Denver, CO (Dr Irwin)
| | - Thies Schroeder
- Department of Physical Chemistry, University of Mainz, Mainz, Germany (Dr Schroeder)
| | - Karyn L Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood)
| | - Christopher Bell
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO (Drs Scalzo, Hamilton, and Bell, Mr Peltonen, Binns, and Szallar, and Ms Klochak and Wood).
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26
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Scalzo RL, Peltonen GL, Binns SE, Shankaran M, Giordano GR, Hartley DA, Klochak AL, Lonac MC, Paris HLR, Szallar SE, Wood LM, Peelor FF, Holmes WE, Hellerstein MK, Bell C, Hamilton KL, Miller BF. Greater muscle protein synthesis and mitochondrial biogenesis in males compared with females during sprint interval training. FASEB J 2014; 28:2705-14. [DOI: 10.1096/fj.13-246595] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Rebecca L. Scalzo
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Garrett L. Peltonen
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Scott E. Binns
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | | | - Gregory R. Giordano
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Dylan A. Hartley
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Anna L. Klochak
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Mark C. Lonac
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Hunter L. R. Paris
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Steve E. Szallar
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Lacey M. Wood
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Frederick F. Peelor
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | | | - Marc K. Hellerstein
- KineMed, Inc.EmeryvilleCaliforniaUSA
- Department of Nutritional Sciences and ToxicologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Christopher Bell
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Karyn L. Hamilton
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
| | - Benjamin F. Miller
- Department of Health and Exercise ScienceColorado State UniversityFort CollinsColoradoUSA
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27
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Chicco AJ, Le CH, Schlater AE, Nguyen AD, Kaye SD, Beals JW, Scalzo RL, Bell C, Gnaiger E, Costa DP, Crocker DE, Kanatous SB. High fatty acid oxidation capacity and phosphorylation control despite elevated leak and reduced respiratory capacity in northern elephant seal muscle mitochondria. J Exp Biol 2014; 217:2947-55. [DOI: 10.1242/jeb.105916] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Abstract
Northern elephant seals (Mirounga angustirostris) are extreme, hypoxia-adapted endotherms that rely largely on aerobic metabolism during extended breath-hold dives in near freezing water temperatures. While many aspects of their physiology have been characterized to account for these remarkable feats, the contribution of adaptations in the aerobic powerhouses of muscle cells, the mitochondria, are unknown. In the present study, the ontogeny and comparative physiology of elephant seal muscle mitochondrial respiratory function was investigated under a variety of substrate conditions and respiratory states. Intact mitochondrial networks were studied by high-resolution respirometry in saponin-permeabilized fiber bundles obtained from primary swimming muscles of pup, juvenile, and adult seals, and compared to fibers from adult human vastus laterais. Results indicate that seal muscle maintains a high capacity for fatty acid oxidation despite a progressive decrease in total respiratory capacity as animals mature from pups to adults. This is explained by a progressive increase in phosphorylation control and fatty acid utilization over pyruvate in adult seals compared to humans and seal pups. Interestingly, despite higher indices of oxidative phosphorylation efficiency, juvenile and adult seals also exhibit a ~50% greater capacity for respiratory leak compared to humans and pups. The ontogeny of this phenotype suggests it is an adaptation of muscle to the prolonged breath-hold exercise and highly variable ambient temperatures experienced by mature elephant seals. These studies highlight the remarkable plasticity of mammalian mitochondria to meet the demands for both efficient ATP production and endothermy in a cold, oxygen-limited environment.
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28
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Scarpati ML, Scalzo RL, Vita G, Gambacorta A. Chemiotropic behavior of female olive fly (Bactrocera oleae GMEL.) onOlea europaea L. J Chem Ecol 2013; 22:1027-36. [PMID: 24227622 DOI: 10.1007/bf02029952] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/1995] [Accepted: 01/07/1996] [Indexed: 11/27/2022]
Abstract
An interpretation is given of a number of observations on the chemiotropic behavior ofBactrocera oleae in connection with olive maceration water and the fly's return to the olive groves after the first summer rains. To this end, the headspace of both maceration water and leaf leaching water, simulating rainfall, were examined. In both cases, the presence of ammonia, which is generally known to attract fruit flies (Diptera, Tephritidae), was detected and, for the first time, in addition to other compounds that are inert for the fly, the presence of styrene was also detected. This aromatic hydrocarbon was found to be a strong attractant. It is shown that both ammonia and styrene are products of the metabolism of microbial flora present on the olive and leaf surface.
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Affiliation(s)
- M L Scarpati
- Dipartimento di Chimica, University "La Sapienza", Rome, Italy
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29
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Sevits KJ, Melanson EL, Swibas T, Binns SE, Klochak AL, Lonac MC, Peltonen GL, Scalzo RL, Schweder MM, Smith AM, Wood LM, Melby CL, Bell C. Total daily energy expenditure is increased following a single bout of sprint interval training. Physiol Rep 2013; 1:e00131. [PMID: 24303194 PMCID: PMC3841058 DOI: 10.1002/phy2.131] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 09/23/2013] [Accepted: 09/27/2013] [Indexed: 12/29/2022] Open
Abstract
REGULAR ENDURANCE EXERCISE IS AN EFFECTIVE STRATEGY FOR HEALTHY WEIGHT MAINTENANCE, MEDIATED VIA INCREASED TOTAL DAILY ENERGY EXPENDITURE (TDEE), AND POSSIBLY AN INCREASE IN RESTING METABOLIC RATE (RMR: the single largest component of TDEE). Sprint interval training (SIT) is a low-volume alternative to endurance exercise; however, the utility of SIT for healthy weight maintenance is less clear. In this regard, it is feasible that SIT may evoke a thermogenic response above and beyond the estimates required for prevention of weight gain (i.e., >200-600 kJ). The purpose of these studies was to investigate the hypotheses that a single bout of SIT would increase RMR and/or TDEE. Study 1: RMR (ventilated hood) was determined on four separate occasions in 15 healthy men. Measurements were performed over two pairs of consecutive mornings; each pair was separated by 7 days. Immediately following either the first or third RMR measurement (randomly assigned) subjects completed a single bout of SIT (cycle ergometer exercise). RMR was unaffected by a single bout of SIT (7195 ± 285 kJ/day vs. 7147 ± 222, 7149 ± 246 and 6987 ± 245 kJ/day (mean ± SE); P = 0.12). Study 2: TDEE (whole-room calorimeter) was measured in 12 healthy men, on two consecutive days, one of which began with a single bout of SIT (random order). Sprint exercise increased TDEE in every research participant (9169 ± 243 vs. 10,111 ± 260 kJ/day; P < 0.0001); the magnitude of increase was 946 ± 62 kJ/day (∼10%). These data provide support for SIT as a strategy for increasing TDEE, and may have implications for healthy body weight maintenance.
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Affiliation(s)
- Kyle J Sevits
- Department of Food Science and Human Nutrition, Colorado State University Fort Collins, Colorado
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30
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Beals JW, Le CH, Scalzo RL, Binns SE, Giordano GR, Klochak AL, Paris HL, Sevits KE, Bell C, Chicco AJ. Influence of sprint interval training on skeletal muscle mitochondria as determined by high‐resolution respirometry. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1132.33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Joseph W Beals
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Catherine H Le
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Rebecca L Scalzo
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Scott E Binns
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | | | - Anna L Klochak
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Hunter L Paris
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Kyle E Sevits
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Christopher Bell
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Adam J Chicco
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
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31
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Peltonen GL, Scalzo RL, Schweder MM, Larson DG, Luckasen GJ, Irwin D, Hamilton KL, Schroeder T, Bell C. Sympathetic inhibition attenuates hypoxia induced insulin resistance in healthy adult humans. J Physiol 2012; 590:2801-9. [PMID: 22495590 DOI: 10.1113/jphysiol.2011.227090] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Acute exposure to hypoxia decreases insulin sensitivity in healthy adult humans; the mechanism is unclear, but increased activation of the sympathetic nervous system may be involved. We have investigated the hypothesis that short-term sympathetic inhibition attenuates hypoxia induced insulin resistance. Insulin sensitivity (via the hyperinsulinaemic euglycaemic clamp) was determined in 10 healthy men (age 23 ± 1 years, body mass index 24.2 ± 0.8 kg m⁻² (means ± SEM)), in a random order, during normoxia (FIO₂ =0.21), hypoxia (FIO₂ =0.11), normoxia and sympathetic inhibition (via 48 h transdermal administration of the centrally acting α2-adrenergic receptor agonist, clonidine), and hypoxia and sympathetic inhibition.Oxyhaemoglobin saturation (pulse oximetry) was decreased (P<0.001) with hypoxia (63 ± 2%) compared with normoxia (96 ± 0%), and was unaffected by sympathetic inhibition (P>0.25). The area under the noradrenaline curve (relative to the normoxia response) was increased with hypoxia (137 ± 13%; P =0.02); clonidine prevented the hypoxia induced increase (94 ± 14%; P =0.43). The glucose infusion rate (adjusted for fat free mass and circulating insulin concentration) required to maintain blood glucose concentration at 5 mmol l⁻¹ during administration of insulin was decreased in hypoxia compared with normoxia (225 ± 23 vs. 128 ± 30 nmol (kg fat free mass)⁻¹ pmol l⁻¹ min⁻¹; P =0.03), and unchanged during normoxia and sympathetic inhibition (219 ± 19; P =0.86) and hypoxia and sympathetic inhibition (169 ± 23; P =0.23). We conclude that short-term sympathetic inhibition attenuates hypoxia induced insulin resistance.
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Affiliation(s)
- Garrett L Peltonen
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523-1582, USA
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32
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Peltonen GL, Scalzo RL, Schweder MM, Szallar SE, Binns SE, Wood LM, Klochak AL, Schroeder T, Irwin DC, Hamilton KL, Bell C. Sympathetic inhibition attenuates hypoxia induced insulin resistance. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1150.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Rebecca L Scalzo
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | | | - Steve E Szallar
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Scott E Binns
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Lacey M Wood
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Anna L Klochak
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Thies Schroeder
- Department of Radiation OncologyDuke University School of MedicineDurhamNC
| | - David C Irwin
- Anschutz Medical CampusUniversity of Colorado DenverAuroraCO
| | - Karyn L Hamilton
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
| | - Christopher Bell
- Health and Exercise ScienceColorado State UniversityFort CollinsCO
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