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Zhu T, Chen Q, Chen H, You L, Liu D, Zhang X, Li F, Wu H, Tang J, Lin D, Sun K, Yan L, Ren M. Independent and interactive associations of heart rate and obesity with type 2 diabetes mellites: A population-based study. J Diabetes 2024; 16:e13529. [PMID: 38599825 PMCID: PMC11006609 DOI: 10.1111/1753-0407.13529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/13/2023] [Accepted: 12/25/2023] [Indexed: 04/12/2024] Open
Abstract
BACKGROUND Although obesity and heart rate (HR) were closely related to the prevalence and development of type 2 diabetes mllitus (T2DM), few studies have shown a co-association effect of them on T2DM. We aimed at assessing the interactive effects of HR and obesity with prevalence of T2DM in Chinese population, providing the exact cutpoint of the risk threshold for blood glucose with high HR. MATERIALS AND METHODS In the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal study (REACTION) cohorts (N = 8398), the relationship between HR and T2DM was explored by linear regression, logistic regression, and restricted cubic spline, and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Interaction terms between HR and body mass index (BMI) and HR and waist circumference (WC) were introduced into the logistic regression model. RESULTS In those with HR > 88.0 beats/min, fasting plasma glucose and oral glucose tolerance tests were significantly correlated with HR, and the prevalence of T2DM was highly correlated with HR (all p < .05). There were interactive associations of HR and obesity in patients with T2DM with HR < 74 beats/min. CONCLUSION High HR was in interaction with obesity, associating with prevalence of T2DM. The newly subdivided risk threshold for HR with T2DM might be HR > 88 beats/minute.
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Affiliation(s)
- Tianxin Zhu
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Qingyu Chen
- Health Examination Center, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Hongxing Chen
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Lili You
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Dan Liu
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Xiaoyun Zhang
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Feng Li
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Hongshi Wu
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Juying Tang
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Diaozhu Lin
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Kan Sun
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Li Yan
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Meng Ren
- Department of Endocrinology, Sun Yat‐sen Memorial HospitalSun Yat‐sen UniversityGuangzhouChina
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2
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Kohlenberg JD, Laurenti MC, Egan AM, Wismayer DS, Bailey KR, Cobelli C, Man CD, Vella A. Differential contribution of alpha and beta cell dysfunction to impaired fasting glucose and impaired glucose tolerance. Diabetologia 2023; 66:201-212. [PMID: 36112169 PMCID: PMC9742343 DOI: 10.1007/s00125-022-05794-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/02/2022] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS People with isolated impaired fasting glucose (IFG) have normal beta cell function. We hypothesised that an increased glucose threshold for beta cell secretion explains IFG. METHODS We used graded glucose infusion to examine the relationship of insulin secretion rate (ISR) and glucagon secretion rate (GSR) with rising glucose. We studied 39 non-diabetic individuals (53 ± 2 years, BMI 30 ± 1 kg/m2), categorised by fasting glucose and glucose tolerance status. After an overnight fast, a variable insulin infusion was used to maintain glucose at ~4.44 mmol/l (07:00 to 08:30 hours). At 09:00 hours, graded glucose infusion commenced at 1 mg kg-1 min-1 and doubled every 60 min until 13:00 hours. GSR and ISR were calculated by nonparametric deconvolution from concentrations of glucagon and C-peptide, respectively. RESULTS The relationship of ISR with glucose was linear and the threshold for insulin secretion in isolated IFG did not differ from that in people with normal fasting glucose and normal glucose tolerance. GSR exhibited a single-exponential relationship with glucose that could be characterised by G50, the change in glucose necessary to suppress GSR by 50%. G50 was increased in IFG compared with normal fasting glucose regardless of the presence of impaired or normal glucose tolerance. CONCLUSIONS/INTERPRETATION These data show that, in non-diabetic humans, alpha cell dysfunction contributes to the pathogenesis of IFG independently of defects in insulin secretion. We also describe a new index that quantifies the suppression of glucagon secretion by glucose.
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Affiliation(s)
- Jacob D Kohlenberg
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Marcello C Laurenti
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Aoife M Egan
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Daniel Schembri Wismayer
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kent R Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Claudio Cobelli
- Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Adrian Vella
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA.
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3
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McKenzie BA, Chen FL, Gruen ME, Olby NJ. Canine Geriatric Syndrome: A Framework for Advancing Research in Veterinary Geroscience. Front Vet Sci 2022; 9:853743. [PMID: 35529834 PMCID: PMC9069128 DOI: 10.3389/fvets.2022.853743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/23/2022] [Indexed: 12/26/2022] Open
Abstract
Biological aging is the single most important risk factor for disease, disability, and ultimately death in geriatric dogs. The effects of aging in companion dogs also impose significant financial and psychological burdens on their human caregivers. The underlying physiologic processes of canine aging may be occult, or early signs of aging may be ignored because of the misconception that biological aging is natural and therefore inevitable. The ability to detect, quantify, and mitigate the deleterious processes of canine aging would greatly enhance veterinary preventative medicine and animal welfare. In this paper we propose a new conceptual framework for aging in dogs, the Canine Geriatric Syndrome (CGS). CGS consists of the multiple, interrelated physical, functional, behavioral, and metabolic changes that characterize canine aging as well as the resulting clinical manifestations, including frailty, diminished quality of life, and age-associated disease. We also identify potential key components of a CGS assessment tool, a clinical instrument that would enable veterinarians to diagnose CGS and would facilitate the development and testing of interventions to prolong healthspan and lifespan in dogs by directly targeting the biological mechanisms of aging. There are many gaps in our knowledge of the mechanisms and phenotype of aging in dogs that must be bridged before a CGS assessment tool can be deployed. The conceptual framework of CGS should facilitate identifying these gaps and should stimulate research to better characterize the processes and effects of aging in dogs and to identify the most promising preventative strategies to target these.
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Affiliation(s)
| | - Frances L. Chen
- Cellular Longevity Inc., dba Loyal, San Francisco, CA, United States
| | - Margaret E. Gruen
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Natasha J. Olby
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
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4
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Ader M, Bergman RN. Hyperinsulinemic Compensation for Insulin Resistance Occurs Independent of Elevated Glycemia in Male Dogs. Endocrinology 2021; 162:6300300. [PMID: 34132779 PMCID: PMC8282122 DOI: 10.1210/endocr/bqab119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Indexed: 11/19/2022]
Abstract
Insulin resistance engenders a compensatory increase in plasma insulin. Inadequate compensation is a primary element in the pathogenesis of type 2 diabetes. The signal that heralds developing insulin resistance and initiates hyperinsulinemic compensation is not known. It has often been assumed to be increased glucose. We tested this assumption by determining whether development of fasting and/or glucose-stimulated hyperinsulinemia with diet-induced insulin resistance occurs because of concomitant elevation of glycemia. Male dogs (n = 58) were fed a hypercaloric, fat-supplemented diet for 6 weeks. Dogs underwent magnetic resonance imaging to quantify total and regional (visceral, subcutaneous) adiposity as well as euglycemic hyperinsulinemic clamps. A subset of animals also underwent an insulin-modified intravenous glucose tolerance test to assess insulin sensitivity, acute insulin response (AIRg), and glucose effectiveness. Fat feeding caused modest weight gain, increased visceral and subcutaneous fat, and insulin resistance at both peripheral and hepatic levels. Hyperinsulinemic compensation was observed in fasting levels as well as increased AIRg. However, we observed absolutely no increase in carefully measured fasting, evening (6 to 8 pm) or nocturnal glycemia (2 to 4 am). Insulin resistance and hyperinsulinemia occurred despite no elevation in 24-hour glucose. Compensatory development of hyperinsulinemia during diet-induced insulin resistance occurs without elevated fasting or 24-hour glycemia. These data refute the idea that glucose itself is a requisite signal for β-cell upregulation. Alternative feedback mechanisms need to be identified.
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Affiliation(s)
- Marilyn Ader
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Correspondence: Marilyn Ader, Ph.D., Associate Director, Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, 116 N. Robertson Blvd, PACT 700.8V, Los Angeles, CA 90048, United States. E-mail:
| | - Richard N Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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5
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Koh HCE, Mittendorfer B. Adipose tissue lipolysis, plasma fatty acids, and glucose homeostasis in people with obesity: New pieces that help solve the puzzle. EBioMedicine 2021; 66:103311. [PMID: 33813133 PMCID: PMC8047496 DOI: 10.1016/j.ebiom.2021.103311] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 12/30/2022] Open
Affiliation(s)
- Han-Chow E Koh
- Center for Human Nutrition, Department of Medicine at Washington University School of Medicine, 660 S Euclid Avenue; Campus Box 8031, St. Louis, MO 63110, United States
| | - Bettina Mittendorfer
- Center for Human Nutrition, Department of Medicine at Washington University School of Medicine, 660 S Euclid Avenue; Campus Box 8031, St. Louis, MO 63110, United States.
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6
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Brouwer A, Asare Bediako I, Paszkiewicz RL, Kolka CM, Bergman RN, Broussard JL. Impact of sleep deprivation and high-fat feeding on insulin sensitivity and beta cell function in dogs. Diabetologia 2020; 63:875-884. [PMID: 32016566 PMCID: PMC7304935 DOI: 10.1007/s00125-019-05084-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/06/2019] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Insufficient sleep is increasingly recognised as a major risk factor for the development of obesity and diabetes, and short-term sleep loss in clinical studies leads to a reduction in insulin sensitivity. Sleep loss-induced metabolic impairments are clinically relevant, since reductions in insulin sensitivity after sleep loss are comparable to insulin sensitivity differences between healthy individuals and those with impaired glucose tolerance. However, the relative effects of sleep loss vs high-fat feeding in the same individual have not been assessed. In addition, to our knowledge no diurnal (active during the daytime) non-human mammalian model of sleep loss-induced metabolic impairment exists, which limits our ability to study links between sleep and metabolism. METHODS This study examined the effects of one night of total sleep deprivation on insulin sensitivity and beta cell function, as assessed by an IVGTT, before and after 9 months of high-fat feeding in a canine model. RESULTS One night of total sleep deprivation in lean dogs impaired insulin sensitivity to a similar degree as a chronic high-fat diet (HFD)(normal sleep: 4.95 ± 0.45 mU-1 l-1 min-1; sleep deprivation: 3.14 ± 0.21 mU-1 l-1 min-1; HFD: 3.74 ± 0.48 mU-1 l-1 min-1; mean ± SEM). Hyperinsulinaemic compensation was induced by the chronic HFD, suggesting adequate beta cell response to high-fat feeding. In contrast, there was no beta cell compensation after one night of sleep deprivation, suggesting that there was metabolic dysregulation with acute sleep loss that, if sustained during chronic sleep loss, could contribute to the risk of type 2 diabetes. After chronic high-fat feeding, acute total sleep deprivation did not cause further impairments in insulin sensitivity (sleep deprivation + chronic HFD: 3.28 mU-1 l-1 min-1). CONCLUSIONS/INTERPRETATION Our findings provide further evidence that sleep is important for metabolic health and establish a diurnal animal model of metabolic disruption during insufficient sleep.
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Affiliation(s)
- Annelies Brouwer
- Sleep and Metabolism Laboratory, Department of Health and Exercise Science, Colorado State University, 1582 Campus Delivery, Fort Collins, CO, 80523-1582, USA
- Amsterdam UMC, Vrije Universiteit, Department of Psychiatry, Amsterdam Public Health Research Institute, Amsterdam, the Netherlands
- GGZ inGeest Specialized Mental Health Care, Amsterdam, the Netherlands
| | - Isaac Asare Bediako
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Rebecca L Paszkiewicz
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Cathryn M Kolka
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Richard N Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Josiane L Broussard
- Sleep and Metabolism Laboratory, Department of Health and Exercise Science, Colorado State University, 1582 Campus Delivery, Fort Collins, CO, 80523-1582, USA.
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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7
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Bergman RN. Origins and History of the Minimal Model of Glucose Regulation. Front Endocrinol (Lausanne) 2020; 11:583016. [PMID: 33658981 PMCID: PMC7917251 DOI: 10.3389/fendo.2020.583016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 12/22/2020] [Indexed: 01/17/2023] Open
Abstract
It has long been hoped that our understanding of the pathogenesis of diabetes would be helped by the use of mathematical modeling. In 1979 Richard Bergman and Claudio Cobelli worked together to find a "minimal model" based upon experimental data from Bergman's laboratory. Model was chosen as the simplest representation based upon physiology known at the time. The model itself is two quasi-linear differential equations; one representing insulin kinetics in plasma, and a second representing the effects of insulin and glucose itself on restoration of the glucose after perturbation by intravenous injection. Model would only be sufficient if it included a delay in insulin action; that is, insulin had to enter a remote compartment, which was interstitial fluid (ISF). Insulin suppressed endogenous glucose output (by liver) slowly. Delay proved to be due to initial suppression of lipolysis; resultant lowering of free fatty acids reduced liver glucose output. Modeling also demanded that normalization of glucose after injection included an effect of glucose itself on glucose disposal and endogenous glucose production - these effects were termed "glucose effectiveness." Insulin sensitivity was calculated from fitting the model to intravenous glucose tolerance test data; the resulting insulin sensitivity index, SI, was validated with the glucose clamp method in human subjects. Model allowed us to examine the relationship between insulin sensitivity and insulin secretion. Relationship was described by a rectangular hyperbola, such that Insulin Secretion x Insulin Sensitivity = Disposition Index (DI). Latter term represents ability of the pancreatic beta-cells to compensate for insulin resistance due to factors such as obesity, pregnancy, or puberty. DI has a genetic basis, and predicts the onset of Type 2 diabetes. An additional factor was clearance of insulin by the liver. Clearance varies significantly among animal or human populations; using the model, clearance was shown to be lower in African Americans than Whites (adults and children), and may be a factor accounting for greater diabetes prevalence in African Americans. The research outlined in the manuscript emphasizes the powerful approach by which hypothesis testing, experimental studies, and mathematical modeling can work together to explain the pathogenesis of metabolic disease.
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8
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Bergman RN, Piccinini F, Kabir M, Kolka CM, Ader M. Hypothesis: Role of Reduced Hepatic Insulin Clearance in the Pathogenesis of Type 2 Diabetes. Diabetes 2019; 68:1709-1716. [PMID: 31431441 PMCID: PMC6702636 DOI: 10.2337/db19-0098] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/02/2019] [Indexed: 12/19/2022]
Abstract
There is wide variance among individuals in the fraction of insulin cleared by the liver (20% to 80%). Hepatic insulin clearance is 67% lower in African Americans than European Americans. Clearance is also lower in African American children 7-13 years of age. Lower hepatic insulin clearance will result in peripheral hyperinsulinemia: this exacerbates insulin resistance, which stresses the β-cells, possibly resulting in their ultimate failure and onset of type 2 diabetes. We hypothesize that lower insulin clearance can be a primary cause of type 2 diabetes in at-risk individuals.
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Affiliation(s)
- Richard N Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Francesca Piccinini
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Morvarid Kabir
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Cathryn M Kolka
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Marilyn Ader
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
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9
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Ness KM, Strayer SM, Nahmod NG, Chang AM, Buxton OM, Shearer GC. Two nights of recovery sleep restores the dynamic lipemic response, but not the reduction of insulin sensitivity, induced by five nights of sleep restriction. Am J Physiol Regul Integr Comp Physiol 2019; 316:R697-R703. [PMID: 30892916 DOI: 10.1152/ajpregu.00336.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chronic inadequate sleep is associated with increased risk of cardiometabolic diseases. The mechanisms involved are poorly understood but involve changes in insulin sensitivity, including within adipose tissue. The aim of this study was to assess the effects of sleep restriction on nonesterified fatty acid (NEFA) suppression profiles in response to an intravenous glucose tolerance test (IVGTT) and to assess whether 2 nights of recovery sleep (a "weekend") is sufficient to restore metabolic health. We hypothesized that sleep restriction impairs both glucose and lipid metabolism, specifically adipocyte insulin sensitivity, and the dynamic lipemic response of adipocyte NEFA release during an IVGTT. Fifteen healthy men completed an inpatient study of 3 baseline nights (10 h of time in bed/night), followed by 5 nights of 5 h of time in bed/night and 2 recovery nights (10 h of time in bed/night). IVGTTs were performed on the final day of each condition. Reductions in insulin sensitivity without a compensatory change in acute insulin response to glucose were consistent with prior studies (insulin sensitivity P = 0.002; acute insulin response to glucose P = 0.23). The disposition index was suppressed by sleep restriction and did not recover after recovery sleep (P < 0.0001 and P = 0.01, respectively). Fasting NEFAs were not different from baseline in either the restriction or recovery conditions. NEFA rebound was significantly suppressed by sleep restriction (P = 0.01) but returned to baseline values after recovery sleep. Our study indicates that sleep restriction impacts NEFA metabolism and demonstrates that 2 nights of recovery sleep may not be adequate to restore glycemic health.
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Affiliation(s)
- Kelly M Ness
- The Huck Institutes of the Life Sciences, Pennsylvania State University , University Park, Pennsylvania.,Department of Biobehavioral Health, Pennsylvania State University , University Park, Pennsylvania.,Department of Nutritional Sciences, Pennsylvania State University , University Park, Pennsylvania
| | - Stephen M Strayer
- The Huck Institutes of the Life Sciences, Pennsylvania State University , University Park, Pennsylvania.,Department of Biobehavioral Health, Pennsylvania State University , University Park, Pennsylvania
| | - Nicole G Nahmod
- Department of Biobehavioral Health, Pennsylvania State University , University Park, Pennsylvania
| | - Anne-Marie Chang
- Department of Biobehavioral Health, Pennsylvania State University , University Park, Pennsylvania
| | - Orfeu M Buxton
- The Huck Institutes of the Life Sciences, Pennsylvania State University , University Park, Pennsylvania.,Department of Biobehavioral Health, Pennsylvania State University , University Park, Pennsylvania.,Division of Sleep and Circadian Disorders, Harvard Medical School , University Park, Pennsylvania.,Department of Social and Behavioral Sciences, Harvard Chan School of Public Health , Boston, Massachusetts.,Sleep Health Institute, Departments of Medicine and Neurology, Brigham and Women's Hospital , Boston, Massachusetts
| | - Gregory C Shearer
- The Huck Institutes of the Life Sciences, Pennsylvania State University , University Park, Pennsylvania.,Department of Nutritional Sciences, Pennsylvania State University , University Park, Pennsylvania
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10
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Rynders CA, Pereira RI, Bergouignan A, Kealey EH, Bessesen DH. Associations Among Dietary Fat Oxidation Responses to Overfeeding and Weight Gain in Obesity-Prone and Resistant Adults. Obesity (Silver Spring) 2018; 26:1758-1766. [PMID: 30358145 PMCID: PMC6214358 DOI: 10.1002/oby.22321] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/30/2018] [Accepted: 08/30/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVE This study tested the hypothesis that 3 days of overfeeding (OF) decreases dietary fat oxidation and predicts longitudinal weight change in adults classified as obesity prone (OP) and obesity resistant (OR) based on self-identification and personal and family weight history. Changes in diurnal profiles of plasma metabolites and hormones were measured to probe mechanisms. METHODS Adults identified as OP (n = 22; BMI: 23.9 ± 2.4 kg/m2 ) and OR (n = 30; BMI: 20.5 ± 2.2 kg/m2 ) completed 3 days of eucaloric (EU) feeding and 3 days of OF. On day 3, the 24-hour total and dietary fat oxidation was measured using room calorimetry and an oral 14 C tracer. Plasma glucose, insulin, triglycerides, and nonesterified fatty acid (NEFA) concentrations were frequently sampled over 24 hours. Body composition was measured annually for 4.0 ± 1.4 years in a subsample (n = 19 OP and 23 OR). RESULTS Dietary fat oxidation over 24 hours was not altered by OF versus EU (P = 0.54). Weight gain in OP correlated with lower nocturnal NEFA concentrations during OF (r = -0.60; P = 0.006) and impaired fuel selection over 24 hours (metabolic inflexibility, wake respiratory quotient-sleep respiratory quotient) (r = -0.48; P = 0.04). CONCLUSIONS Short-term OF did not alter dietary fat oxidation. Lower nocturnal NEFA availability and metabolic inflexibility to overfeeding may be factors contributing to weight gain.
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Affiliation(s)
- Corey A. Rynders
- Division of Geriatric Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Rocio I. Pereira
- Denver Health Medical Center, Division of Endocrinology, Denver, Colorado, USA
| | - Audrey Bergouignan
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
- Anschutz Health & Wellness Center at the University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
- IPHC-DEPE, Université de Strasbourg, Strasbourg, France
- UMR 7178 Centre National de la Recherche scientifique (CNRS), Strasbourg, France
| | - Elizabeth H. Kealey
- Anschutz Health & Wellness Center at the University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Daniel H. Bessesen
- Denver Health Medical Center, Division of Endocrinology, Denver, Colorado, USA
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
- Anschutz Health & Wellness Center at the University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
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11
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Kim JS, Lee H, Jung CH, Lee SJ, Ha TY, Ahn J. Chicoric acid mitigates impaired insulin sensitivity by improving mitochondrial function. Biosci Biotechnol Biochem 2018; 82:1197-1206. [DOI: 10.1080/09168451.2018.1451742] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract
Mitochondrial dysfunction is associated with insulin resistance. Although chicoric acid (CA) is known to have beneficial effects on insulin sensitivity, the involvement of mitochondrial function has not been elucidated yet. Here, we investigated the effect of CA on insulin resistance and mitochondrial dysfunction. In palmitate-induced insulin-resistant C2C12 myotubes, CA improved impaired glucose uptake and insulin signaling pathways, along with enhanced mitochondrial membrane potential and oxygen consumption. CA treatment in diet-induced obese mice ameliorated glucose tolerance and increased insulin sensitivity. CA treatment also recovered the dysregulated expression of glucose metabolism-related genes in the high-fat-fed mice. CA significantly increased the mitochondrial DNA content, citrate synthase, and ATP content, as well as the expression of genes related to mitochondrial biogenesis and oxidative phosphorylation in the liver and skeletal muscle in high-fat- fed obese mice. These findings suggested that CA attenuates insulin resistance and promotes insulin sensitivity by enhancing mitochondrial function.
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Affiliation(s)
- Ji-Sun Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University , Seoul, Republic of Korea
- Division of Nutrition and Metabolism Research, Korea Food Research Institute , Wanju, Republic of Korea
| | - Hyunjung Lee
- Division of Nutrition and Metabolism Research, Korea Food Research Institute , Wanju, Republic of Korea
| | - Chang Hwa Jung
- Division of Nutrition and Metabolism Research, Korea Food Research Institute , Wanju, Republic of Korea
| | - Sung-Joon Lee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University , Seoul, Republic of Korea
| | - Tae-Youl Ha
- Division of Nutrition and Metabolism Research, Korea Food Research Institute , Wanju, Republic of Korea
| | - Jiyun Ahn
- Division of Nutrition and Metabolism Research, Korea Food Research Institute , Wanju, Republic of Korea
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12
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Russo L, Muturi HT, Ghadieh HE, Ghanem SS, Bowman TA, Noh HL, Dagdeviren S, Dogbey GY, Kim JK, Heinrich G, Najjar SM. Liver-specific reconstitution of CEACAM1 reverses the metabolic abnormalities caused by its global deletion in male mice. Diabetologia 2017; 60:2463-2474. [PMID: 28913658 PMCID: PMC5788286 DOI: 10.1007/s00125-017-4432-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 07/17/2017] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS The carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) promotes insulin clearance. Mice with global null mutation (Cc1 -/-) or with liver-specific inactivation (L-SACC1) of Cc1 (also known as Ceacam1) gene display hyperinsulinaemia resulting from impaired insulin clearance, insulin resistance, steatohepatitis and obesity. Because increased lipolysis contributes to the metabolic phenotype caused by transgenic inactivation of CEACAM1 in the liver, we aimed to further investigate the primary role of hepatic CEACAM1-dependent insulin clearance in insulin and lipid homeostasis. To this end, we examined whether transgenic reconstitution of CEACAM1 in the liver of global Cc1 -/- mutant mice reverses their abnormal metabolic phenotype. METHODS Insulin response was assessed by hyperinsulinaemic-euglycaemic clamp analysis and energy balance was analysed by indirect calorimetry. Mice were overnight-fasted and refed for 7 h to assess fatty acid synthase activity in the liver and the hypothalamus in response to insulin release during refeeding. RESULTS Liver-based rescuing of CEACAM1 restored insulin clearance, plasma insulin level, insulin sensitivity and steatohepatitis caused by global deletion of Cc1. It also reversed the gain in body weight and total fat mass observed with Cc1 deletion, in parallel to normalising energy balance. Mechanistically, reversal of hyperphagia appeared to result from reducing fatty acid synthase activity and restoring insulin signalling in the hypothalamus. CONCLUSIONS/INTERPRETATION Despite the potential confounding effects of deleting Cc1 from extrahepatic tissues, liver-based rescuing of CEACAM1 resulted in full normalisation of the metabolic phenotype, underscoring the key role that CEACAM1-dependent hepatic insulin clearance pathways play in regulating systemic insulin sensitivity, lipid homeostasis and energy balance.
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Affiliation(s)
- Lucia Russo
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Harrison T Muturi
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA
| | - Hilda E Ghadieh
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Simona S Ghanem
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Thomas A Bowman
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Hye Lim Noh
- Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA, USA
| | - Sezin Dagdeviren
- Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA, USA
| | - Godwin Y Dogbey
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA
| | - Jason K Kim
- Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA, USA
| | - Garrett Heinrich
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Sonia M Najjar
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA.
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA.
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13
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Rynders CA, Bergouignan A, Kealey E, Bessesen DH. Ability to adjust nocturnal fat oxidation in response to overfeeding predicts 5-year weight gain in adults. Obesity (Silver Spring) 2017; 25:873-880. [PMID: 28440048 PMCID: PMC5407418 DOI: 10.1002/oby.21807] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/29/2017] [Accepted: 01/30/2017] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To determine whether metabolic responses to short-term overfeeding predict longitudinal changes in body weight. METHODS Twenty-four-hour energy expenditure (EE) and substrate utilization were measured at baseline in a room calorimeter following 3 days of eucaloric and hypercaloric feeding (40% excess) in a sample of lean adults (n: 34; age: 28 ± 2 y; BMI: 22 ± 3 kg/m2 ). Body mass and fat mass (dual-energy x-ray absorptiometry) were measured annually for 5 years. Regression analyses examined whether changes in EE and fuel use with overfeeding predicted body weight and composition changes over 5 years. RESULTS Overfeeding increased EE and reduced fat oxidation when examined over the 24-hour, waking, and nocturnal periods. Absolute change in body mass over 5 years was 3.0 ± 0.6 kg (average rate of change = 0.7 ± 0.1 kg/y, P < 0.001). Lower nocturnal (but not 24-hour or waking) fat oxidation (r = -0.42, P = 0.01) and EE (r = -0.33, P = 0.05) with overfeeding were the strongest predictors of 5-year weight gain. When adjusted for covariates, changes in nocturnal fat oxidation and EE with overfeeding predicted 41% of the variance in weight change (P = 0.02). CONCLUSIONS Failure to maintain fat oxidation at night following a period of overfeeding appears to be associated with a metabolic phenotype favoring weight gain.
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Affiliation(s)
- Corey A Rynders
- Division of Geriatric Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Audrey Bergouignan
- Anschutz Health & Wellness Center at the University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Elizabeth Kealey
- Anschutz Health & Wellness Center at the University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Daniel H Bessesen
- Anschutz Health & Wellness Center at the University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
- Division of Endocrinology, Denver Health Medical Center, Denver, Colorado, USA
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14
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Morton GJ, Muta K, Kaiyala KJ, Rojas JM, Scarlett JM, Matsen ME, Nelson JT, Acharya NK, Piccinini F, Stefanovski D, Bergman RN, Taborsky GJ, Kahn SE, Schwartz MW. Evidence That the Sympathetic Nervous System Elicits Rapid, Coordinated, and Reciprocal Adjustments of Insulin Secretion and Insulin Sensitivity During Cold Exposure. Diabetes 2017; 66:823-834. [PMID: 28115396 PMCID: PMC5360298 DOI: 10.2337/db16-1351] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 01/03/2017] [Indexed: 12/21/2022]
Abstract
Dynamic adjustment of insulin secretion to compensate for changes of insulin sensitivity that result from alteration of nutritional or metabolic status is a fundamental aspect of glucose homeostasis. To investigate the role of the brain in this coupling process, we used cold exposure as an experimental paradigm because the sympathetic nervous system (SNS) helps to coordinate the major shifts of tissue glucose utilization needed to ensure that increased thermogenic needs are met. We found that glucose-induced insulin secretion declined by 50% in rats housed at 5°C for 28 h, and yet, glucose tolerance did not change, owing to a doubling of insulin sensitivity. These potent effects on insulin secretion and sensitivity were fully reversed by returning animals to room temperature (22°C) for 4 h or by intravenous infusion of the α-adrenergic receptor antagonist phentolamine for only 30 min. By comparison, insulin clearance was not affected by cold exposure or phentolamine infusion. These findings offer direct evidence of a key role for the brain, acting via the SNS, in the rapid, highly coordinated, and reciprocal changes of insulin secretion and insulin sensitivity that preserve glucose homeostasis in the setting of cold exposure.
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Affiliation(s)
- Gregory J Morton
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Kenjiro Muta
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Karl J Kaiyala
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA
| | - Jennifer M Rojas
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Jarrad M Scarlett
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
- Department of Pediatric Gastroenterology and Hepatology, Seattle Children's Hospital, Seattle, WA
| | - Miles E Matsen
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Jarrell T Nelson
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Nikhil K Acharya
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
| | - Francesca Piccinini
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Darko Stefanovski
- New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Richard N Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Gerald J Taborsky
- Veterans Affairs Puget Sound Health Care System, Department of Veterans Affairs Medical Center, Seattle, WA
| | - Steven E Kahn
- Veterans Affairs Puget Sound Health Care System, Department of Veterans Affairs Medical Center, Seattle, WA
| | - Michael W Schwartz
- University of Washington Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA
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15
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Zhou Q, Gu Y, Lang H, Wang X, Chen K, Gong X, Zhou M, Ran L, Zhu J, Mi M. Dihydromyricetin prevents obesity-induced slow-twitch-fiber reduction partially via FLCN/FNIP1/AMPK pathway. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1282-1291. [PMID: 28363698 DOI: 10.1016/j.bbadis.2017.03.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/10/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022]
Abstract
Obesity is often accompanied by decreases in the proportion of skeletal muscle slow-twitch fibers and insulin sensitivity. Increased plasma non-esterified fatty acids (NEFA) levels are responsible for obesity-associated insulin resistance. Palmitate, one of the most elevated plasma NEFA in obesity, has been recognized as the principle inducer of insulin resistance. The present study showed that increased plasma NEFA levels were negatively linked to slow-twitch fiber proportion and insulin sensitivity, while slow-twitch fiber proportion was positively correlated to insulin sensitivity in high fat diet (HFD)-fed and ob/ob mice. Dihydromyricetin (DHM) intervention increased slow-twitch fiber proportion and improved insulin resistance. In cultured C2C12 myotubes, palmitate treatment resulted in decrease of slow-twitch fiber specific Myh7 expression and insulin resistance, concomitant with folliculin (FLCN) and folliculin-interacting protein 1 (FNIP1) expression increase, AMP-activated protein kinase (AMPK) inactivation and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression decrease. Those palmitate-induced effects could be blocked by knock-down of FLCN expression or DHM intervention. Meanwhile, the protective effects of DHM were alleviated by over-expression of FLCN. In addition, the changes in AMPK activity and expression of FLCN and FNIP1 in vivo were consistent with those occurring in vitro. These findings suggest that DHM treatment prevents palmitate-induced slow-twitch fibers decrease partially via FLCN-FNIP1-AMPK pathway thereby improving insulin resistance in obesity.
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Affiliation(s)
- Qicheng Zhou
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Yeyun Gu
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Hedong Lang
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Xiaolan Wang
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Ka Chen
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Xinhua Gong
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Min Zhou
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Li Ran
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China
| | - Jundong Zhu
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China.
| | - Mantian Mi
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, PR China.
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16
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Initial hyperinsulinemia and subsequent β-cell dysfunction is associated with elevated palmitate levels. Pediatr Res 2016; 80:267-74. [PMID: 27064244 DOI: 10.1038/pr.2016.80] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/03/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND The prevalence of obesity-related diabetes in childhood is increasing and circulating levels of nonesterified fatty acids may constitute a link. Here, the association between palmitate and insulin secretion was investigated in vivo and in vitro. METHODS Obese and lean children and adolescents (n = 80) were included. Palmitate was measured at fasting; insulin and glucose during an oral glucose tolerance test (OGTT). Human islets were cultured for 0 to 7 d in presence of 0.5 mmol/l palmitate. Glucose-stimulated insulin secretion (GSIS), insulin content and apoptosis were measured. RESULTS Obese subjects had fasting palmitate levels between 0.10 and 0.33 mmol/l, with higher average levels compared to lean subjects. While obese children with elevated palmitate (>0.20 mmol/l) had accentuated insulin levels during OGTT, obese adolescents with high palmitate had delayed first-phase insulin response. In human islets exposed to palmitate for 2 d GSIS was twofold enhanced, but after 7 d attenuated. Intracellular insulin content decreased time-dependently in islets cultured in the presence of palmitate and cleaved caspase 3 increased. CONCLUSION The rapid accentuated and delayed insulin secretory responses observed in obese children and adolescents, respectively, with high palmitate levels may reflect changes in islet secretory activity and integrity induced by extended exposure to the fatty acid.
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