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Hallman IAM, Raekallio MR, Karikoski NP. The effect of an alpha2-adrenoceptor antagonist on equine carbohydrate metabolism after intravenous glucose load. Domest Anim Endocrinol 2025; 92:106946. [PMID: 40305955 DOI: 10.1016/j.domaniend.2025.106946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2025] [Revised: 04/25/2025] [Accepted: 04/25/2025] [Indexed: 05/02/2025]
Abstract
Vatinoxan is a peripherally acting alpha2-adrenoceptor antagonist used in veterinary medicine to attenuate the side effects of alpha2-adrenoceptor agonists. Vatinoxan also increases insulin response and reduces blood glucose (BG) after intravenous glucose in other species. The aim of this study was to investigate the effects of vatinoxan on BG and insulin concentration in horses after intravenous glucose. The design was an assessor-blind cross-over study. Nine horses were assigned to intravenous vatinoxan (0.2 mg/kg; VAT) or saline (SAL). Horses were administered an intravenous glucose bolus (150 mg/kg) immediately before each treatment. Blood samples were collected until 300 min. Differences between treatments were evaluated with repeated measures analysis of covariance. Change from baseline was used as a response. p < 0.05 was considered significant. After intravenous glucose, BG and insulin increased in all horses. VAT significantly reduced the increase in BG compared with SAL (p = 0.005). Although insulin increased initially significantly more after VAT at 15 min (median 45.7, min-max 20.7-61.6 µIU/mL) compared with SAL (p = 0.04; 28.3, 17.2-44.5 µIU/mL), there was no significant difference in the overall treatment effect. Peak insulin concentration occurred significantly earlier (p = 0.04) after VAT (median Tmax 30, min-max 15-60 min) than SAL (median Tmax 60, 15-60 min). In conclusion, vatinoxan induced an earlier insulin peak than saline and reduced BG increase after intravenous glucose load. Vatinoxan could potentially modify insulin secretion from the pancreas during hyperglycaemia, but more research is warranted.
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Affiliation(s)
- I A M Hallman
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, PL 57, Helsinki, 00014, Finland.
| | - M R Raekallio
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, PL 57, Helsinki, 00014, Finland
| | - N P Karikoski
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, PL 57, Helsinki, 00014, Finland
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Ezeh U, Chen YI, Pall M, Buyalos RP, Chan JL, Pisarska MD, Azziz R. Alterations in nonesterified free fatty acid trafficking rather than hyperandrogenism contribute to metabolic health in obese women with polycystic ovary syndrome. Fertil Steril 2024; 121:1040-1052. [PMID: 38307453 DOI: 10.1016/j.fertnstert.2024.01.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/04/2024]
Abstract
OBJECTIVE To determine whether alterations in nonesterified fatty acid (NEFA) dynamics or degree of hyperandrogenism (HA) contribute to the difference in insulin sensitivity between women with metabolically healthy obese polycystic ovary syndrome (PCOS) (MHO-PCOS) and women with metabolically unhealthy obese PCOS (MUO-PCOS). DESIGN Prospective cross-sectional study. SETTING Tertiary-care academic center. PATIENTS One hundred twenty-five obese women with PCOS. INTERVENTION Consecutive obese (body mass index [BMI] ≥ 30 kg/m2) oligo-ovulatory women (n = 125) with PCOS underwent an oral glucose tolerance test and a subgroup of 16 participants underwent a modified frequently sampled intravenous glucose tolerance test to determine insulin-glucose and -NEFA dynamics. MAIN OUTCOME MEASURES Degree of insulin resistance (IR) in adipose tissue (AT) basally (Adipo-IR) and dynamically (the nadir in NEFA levels observed [NEFAnadir], the time it took for NEFA levels to reach nadir [TIMEnadir], and the percent suppression in plasma NEFA levels from baseline to nadir [%NEFAsupp]); peak lipolysis rate (SNEFA) and peak rate of NEFA disposal from plasma pool (KNEFA); whole-body insulin-glucose interaction (acute response of insulin to glucose [AIRg], insulin sensitivity index [Si], glucose effectiveness [Sg], and disposition index [Di]); and HA (hirsutism score, total and free testosterone levels, and dehydroepiandrosterone sulfate levels). RESULTS A total of 85 (68%) women were MUO-PCOS and 40 (32%) were MHO-PCOS using the homeostasis model of assessment of IR. Subjects with MUO-PCOS and MHO-PCOS did not differ in mean age, BMI, waist-to-hip ratio, HA, and lipoprotein levels. By a modified frequently sampled intravenous glucose tolerance test, eight women with MUO-PCOS had lesser Si, KNEFA, and the percent suppression in plasma NEFA levels from baseline to nadir (%NEFAsupp) and greater TIMEnadir, NEFAnadir, and baseline adipose tissue IR index (Adipo-IR) than eight subjects with MHO-PCOS, but similar fasting NEFA levels and SNEFA. Women with MUO-PCOS had a higher homeostasis model of assessment-β% and fasting insulin levels than women with MHO-PCOS. In bivalent analysis, Si correlated strongly and negatively with Adipo-IR and NEFAnadir, weakly and negatively with TIMEnadir, and positively with KNEFA and %NEFAsupp, in women with MUO-PCOS only. CONCLUSION Independent of age and BMI, women with MUO-PCOS have reduced NEFA uptake and altered insulin-mediated NEFA suppression, but no difference in HA, compared with women with MHO-PCOS. Altered insulin-mediated NEFA suppression, rather than HA or lipolysis rate, contributes to variations in insulin sensitivity among obese women with PCOS.
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Affiliation(s)
- Uche Ezeh
- California IVF Fertility Center, Sacramento, California; Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California; Department of Obstetrics and Gynecology, Heersink School of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama; Department of Obstetrics and Gynecology, Alta Bates Summit Medical Center (Sutter), Berkeley, California
| | - Yd Ida Chen
- Department of Pediatrics and Medicine, Harbor- University of California (UCLA) Medical Center, Torrance, California; Department of Medicine, The David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Marita Pall
- Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California
| | - Richard P Buyalos
- Fertility and Surgical Associates of California, Thousand Oaks, California
| | - Jessica L Chan
- Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California
| | - Margareta D Pisarska
- Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California; Department of Obstetrics and Gynecology, UCLA, Los Angeles, California
| | - Ricardo Azziz
- Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California; Department of Obstetrics and Gynecology, Heersink School of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama; Department of Medicine, Heersink School of Medicine, UAB, Birmingham, Alabama; Department of Healthcare Organization and Policy, School of Public Health, UAB, Birmingham, Alabama; Department of Health Policy, Management and Behavior, School of Public Health, State University of New York at Albany, Albany, New York.
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3
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Morettini M, Palumbo MC, Göbl C, Burattini L, Karusheva Y, Roden M, Pacini G, Tura A. Mathematical model of insulin kinetics accounting for the amino acids effect during a mixed meal tolerance test. Front Endocrinol (Lausanne) 2022; 13:966305. [PMID: 36187117 PMCID: PMC9519856 DOI: 10.3389/fendo.2022.966305] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/25/2022] [Indexed: 11/30/2022] Open
Abstract
Amino acids (AAs) are well known to be involved in the regulation of glucose metabolism and, in particular, of insulin secretion. However, the effects of different AAs on insulin release and kinetics have not been completely elucidated. The aim of this study was to propose a mathematical model that includes the effect of AAs on insulin kinetics during a mixed meal tolerance test. To this aim, five different models were proposed and compared. Validation was performed using average data, derived from the scientific literature, regarding subjects with normal glucose tolerance (CNT) and with type 2 diabetes (T2D). From the average data of the CNT and T2D people, data for two virtual populations (100 for each group) were generated for further model validation. Among the five proposed models, a simple model including one first-order differential equation showed the best results in terms of model performance (best compromise between model structure parsimony, estimated parameters plausibility, and data fit accuracy). With regard to the contribution of AAs to insulin appearance/disappearance (kAA model parameter), model analysis of the average data from the literature yielded 0.0247 (confidence interval, CI: 0.0168 - 0.0325) and -0.0048 (CI: -0.0281 - 0.0185) μU·ml-1/(μmol·l-1·min), for CNT and T2D, respectively. This suggests a positive effect of AAs on insulin secretion in CNT, and negligible effect in T2D. In conclusion, a simple model, including single first-order differential equation, may help to describe the possible AAs effects on insulin kinetics during a physiological metabolic test, and provide parameters that can be assessed in the single individuals.
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Affiliation(s)
- Micaela Morettini
- Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy
| | | | - Christian Göbl
- Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria
| | - Laura Burattini
- Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy
| | - Yanislava Karusheva
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany
- German Center for Diabetes Research, Partner Düsseldorf, Neuherberg, Germany
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany
- German Center for Diabetes Research, Partner Düsseldorf, Neuherberg, Germany
- Department of Endocrinology and Diabetology, Medical Faculty and University Hospital, Heinrich-Heine University, Düsseldorf, Germany
| | | | - Andrea Tura
- CNR Institute of Neuroscience, Padova, Italy
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Stefanovski D, Punjabi NM, Boston RC, Watanabe RM. Insulin Action, Glucose Homeostasis and Free Fatty Acid Metabolism: Insights From a Novel Model. Front Endocrinol (Lausanne) 2021; 12:625701. [PMID: 33815283 PMCID: PMC8010655 DOI: 10.3389/fendo.2021.625701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/01/2021] [Indexed: 12/05/2022] Open
Abstract
Glucose and free fatty acids (FFA) are essential nutrients that are both partly regulated by insulin. Impaired insulin secretion and insulin resistance are hallmarks of aberrant glucose disposal, and type 2 diabetes (T2DM). In the current study, a novel model of FFA kinetics is proposed to estimate the role insulin action on FFA lipolysis and oxidation allowing estimation of adipose tissue insulin sensitivity (SIFFA ). Twenty-five normal volunteers were recruited for the current study. To participate, volunteers had to be less than 40 years of age and have a body mass index (BMI) < 30 kg/m2, and be free of medical comorbidity. The proposed model of FFA kinetics was used to analyze the data derived from the insulin-modified FSIGT. Mean fractional standard deviations of the parameter estimates were all less than 20%. Standardized residuals of the fit of the model to the FFA temporal data were randomly distributed, with only one estimated point lying outside the 2-standard deviation range, suggesting an acceptable fit of the model to the FFA data. The current study describes a novel one-compartment non-linear model of FFA kinetics during an FSIGT that provides an FFA metabolism insulin sensitivity parameter (SIFFA ). Furthermore, the models suggest a new role of glucose as the modulator of FFA disposal. Estimates of SIFFA confirmed previous findings that FFA metabolism is more sensitive to changes in insulin than glucose metabolism. Novel derived indices of insulin sensitivity of FFA (SIFFA ) were correlated with minimal model indices. These associations suggest a cooperative rather than competitive interplay between the two primary nutrients (glucose and FFA) and allude to the FFA acting as the buffer, such that glucose homeostasis is maintained.
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Affiliation(s)
- Darko Stefanovski
- School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, PA, United States
- *Correspondence: Darko Stefanovski,
| | - Naresh M. Punjabi
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Raymond C. Boston
- School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, PA, United States
| | - Richard M. Watanabe
- Department of Preventive Medicine, Keck School of Medicine of USC, Los Angeles, CA, United States
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Ezeh U, Chen IYD, Chen YH, Azziz R. Adipocyte Insulin Resistance in PCOS: Relationship With GLUT-4 Expression and Whole-Body Glucose Disposal and β-Cell Function. J Clin Endocrinol Metab 2020; 105:5834379. [PMID: 32382742 PMCID: PMC7274487 DOI: 10.1210/clinem/dgaa235] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/29/2020] [Indexed: 01/16/2023]
Abstract
CONTEXT Impaired sensitivity to the antilipolytic action of insulin in adipose tissue (AT) may play a role in determining metabolic dysfunction in polycystic ovary syndrome (PCOS). OBJECTIVES To test the hypothesis that insulin resistance (IR) in AT is associated with whole-body insulin sensitivity and β-cell function in PCOS. RESEARCH DESIGN AND SETTING Prospective cross-sectional study. METHODS Eighteen participants with PCOS and 18-matched control participants underwent a modified frequently sampled intravenous glucose tolerance test (mFSIVGTT); subgroups underwent single-slice computed tomography scans determining AT distribution and adipocyte glucose transporter type 4 (GLUT-4) expression. MAIN OUTCOME MEASURES IR in AT in basal (by the adipose insulin resistance index [Adipo-IR]) and dynamic (mFSIVGTT-derived indices of insulin-mediated nonesterified fatty acids [NEFA] suppression [NEFAnadir, TIMEnadir, and %NEFAsupp]) states; whole-body insulin-mediated glucose uptake and insulin secretion in basal (by homeostatic model assessment [HOMA]-IR and HOMA-β%) and dynamic (mFSIVGTT-derived insulin sensitivity index [Si], acute insulin response to glucose [AIRg], and disposition index [Di]) states. RESULTS Participants with PCOS had higher HOMA-IR and HOMA-β%, lower Si and Di, higher longer TIMEnadir, higher Adipo-IR and NEFAnadir, and a trend toward lower GLUT-4, than the control group participants. Adipo-IR was associated with dynamic state IR in AT (NEFAnadir TIMEnadir, and %NEFAsupp), but only in PCOS, and with HOMA-IR and HOMA-β% in both groups. NEFAnadir and TIMEnadir were negatively and %NEFAsupp positively associated with Si only in PCOS, but not with AIRg and Di, or GLUT-4 expression. CONCLUSION Women with PCOS demonstrated increased IR in AT, which is closely associated with whole-body IR but not with dynamic state β-cell function or adipocyte GLUT-4 gene expression.
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Affiliation(s)
- Uche Ezeh
- Department of Obstetrics and Gynecology, Stanford Healthcare-ValleyCare Hospital, Pleasanton, California
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ida Y-D Chen
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
| | - Yen-Hao Chen
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ricardo Azziz
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Obstetrics & Gynecology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
- Department of Health Policy, Management and Behavior, School of Public Health, University at Albany, SUNY, Albany, New York
- Department of Obstetrics & Gynecology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Correspondence and Reprint Requests: Ricardo Azziz, American Society for Reproductive Medicine, 1209 Montgomery Hwy, Birmingham, AL. E-mail:
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6
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Ezeh U, Arzumanyan Z, Lizneva D, Mathur R, Chen YH, Boston RC, Chen YDI, Azziz R. Alterations in plasma non-esterified fatty acid (NEFA) kinetics and relationship with insulin resistance in polycystic ovary syndrome. Hum Reprod 2020; 34:335-344. [PMID: 30576500 DOI: 10.1093/humrep/dey356] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 12/10/2018] [Indexed: 12/19/2022] Open
Abstract
STUDY QUESTION Are non-esterified fatty acid (NEFA) kinetics altered in women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER Women with PCOS, particularly obese subjects, have dysregulated plasma NEFA kinetics in response to changes in plasma insulin and glucose levels, which are associated with insulin resistance (IR) independently of the fasting plasma NEFA levels. WHAT IS KNOWN ALREADY Elevated plasma NEFA levels are associated with IR in many disorders, although the homeostasis of NEFA kinetics and its relationship to IR in women with PCOS is unknown. STUDY DESIGN, SIZE, DURATION We prospectively compared insulin sensitivity and NEFA kinetics in 29 PCOS and 29 healthy controls women matched for BMI. PARTICIPANTS/MATERIALS, SETTING, METHODS This study was conducted in a tertiary institution. Plasma NEFA, glucose and insulin levels were assessed during a modified frequently sampled intravenous glucose tolerance test (mFSIVGTT). Minimal models were used to assess insulin sensitivity (Si) and NEFA kinetics (i.e. model-derived initial plasma NEFA level [NEFA0], phi constant [Φ], reflecting glucose-mediated inhibition of lipolysis and measures of maximum rate of lipolysis [SFFA] and NEFA uptake from plasma [KFFA]). MAIN RESULTS AND THE ROLE OF CHANCE The study provides new evidence that women with PCOS have defective NEFA kinetics characterized by: (i) lower basal plasma NEFA levels, measured directly and modeled (NEFA0), and (ii) a greater glucose-mediated inhibition of lipolysis in the remote or interstitial space (reflected by a lower affinity constant [Φ]). There were no differences, however, in the maximal rates of adipose tissue lipolysis (SFFA) and the rate at which NEFA leaves the plasma pool (KFFA). The differences observed in NEFA kinetics were exacerbated, and almost exclusively observed, in the obese PCOS subjects. LIMITATIONS, REASONS FOR CAUTION Our study did not study NEFA subtypes. It was also cross-sectional and based on women affected by PCOS as defined by the 1990 National Institutes of Health (NIH) criteria (i.e. Phenotypes A and B) and identified in the clinical setting. Consequently, extrapolation of the present data to other phenotypes of PCOS should be made with caution. Furthermore, our data is exploratory and therefore requires validation with a larger sample size. WIDER IMPLICATIONS OF THE FINDINGS Dysfunction in NEFA kinetics may be a marker of metabolic dysfunction in nondiabetic obese women with PCOS and may be more important than simply assessing circulating NEFA levels at a single point in time for understanding the mechanism(s) underlying the IR of PCOS. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by NIH grants R01-DK073632 and R01-HD29364 to R.A.; a Career Development Award from MD Medical Group, Moscow, RF, to D.L. and Augusta University funds to Y.-H.C. RA serves as consultant to Ansh Labs, Medtronics, Spruce Biosciences and Latitude Capital. U.E., Z.A., D.L., R.M., Y.-H.C., R.C.B. and Y.D.I.C. have no competing interests to declare. TRIAL REGISTRATION NUMBER Not applicable.
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Affiliation(s)
- Uche Ezeh
- Department of Obstetrics and Gynecology, Stanford Health Care-ValleyCare Hospital, 5555 W. Las Positas Blvd, Pleasanton, CA, USA.,Department of Obstetrics and Gynecology, Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Zorayr Arzumanyan
- Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Daria Lizneva
- Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Ruchi Mathur
- Department of Obstetrics and Gynecology, Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yen-Hao Chen
- Department of Obstetrics and Gynecology, Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Raymond C Boston
- New Bolton Center, University of Pennsylvania, Kennett Square, PA, USA
| | - Y-D Ida Chen
- Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Ricardo Azziz
- Department of Obstetrics and Gynecology, Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.,Department of Obstetrics & Gynecology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.,Department of Obstetrics & Gynecology, Albany Medical College, Albany, NY, USA.,Department of Health Policy, Management & Behavior, School of Public Health, University at Albany, SUNY, Albany, NY, USA
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7
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Stefanovski D, Boston RC, Punjabi NM. Sleep-Disordered Breathing and Free Fatty Acid Metabolism. Chest 2020; 158:2155-2164. [PMID: 32565268 DOI: 10.1016/j.chest.2020.05.600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 05/15/2020] [Accepted: 05/24/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Sleep-disordered breathing (SDB) is independently associated with insulin resistance, glucose intolerance, and type 2 diabetes mellitus. However, data on whether SDB alters the metabolism of free fatty acids (FFAs) are lacking. RESEARCH QUESTION The primary objective of the current study was to characterize alterations in FFA metabolism across the spectrum of SDB severity. STUDY DESIGN AND METHODS The study sample included 118 participants with and without SDB who underwent full-montage polysomnography, the frequently sampled IV glucose tolerance test (FSIGTT), and body composition measurements including determination of percent body fat. Parameters of lipolysis suppression, time to FFA nadir, and FFA rebound after an IV glucose challenge were derived using a mathematical model. Multivariable regression analyses were used to characterize the independent associations between SDB severity and parameters of FFA metabolism. RESULTS SDB severity, as assessed by the apnea-hypopnea index, was associated with adipocyte insulin resistance, a decrease in the glucose- and insulin-mediated suppression of lipolysis, a longer duration to reach a nadir in FFA levels during the FSIGTT, and a sluggish rebound in FFA levels after suppression. Severity of SDB-related hypoxemia was independently associated with adipocyte insulin resistance and the time to reach the FFA nadir during the FSIGTT. Finally, a higher percentage of stage N3 sleep was positively associated with greater suppression of lipolysis and a faster rebound in the FFA levels during the FSIGTT. INTERPRETATION Independent of adiposity, SDB is associated with impairments in FFA metabolism, which may contribute to the development of glucose intolerance and type 2 diabetes in SDB.
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Affiliation(s)
- Darko Stefanovski
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, New Bolton, Philadelphia, PA
| | - Ray C Boston
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, New Bolton, Philadelphia, PA
| | - Naresh M Punjabi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.
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Walker RE, Ford JL, Boston RC, Savinova OV, Harris WS, Green MH, Shearer GC. Trafficking of nonesterified fatty acids in insulin resistance and relationship to dysglycemia. Am J Physiol Endocrinol Metab 2020; 318:E392-E404. [PMID: 31910030 PMCID: PMC7099405 DOI: 10.1152/ajpendo.00331.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In adipose, insulin functions to suppress intracellular lipolysis and secretion of nonesterified fatty acid (NEFA) into plasma. We applied glucose and NEFA minimal models (MM) following a frequently sampled intravenous glucose tolerance test (FSIVGTT) to assess glucose-specific and NEFA-specific insulin resistance. We used total NEFA and individual fatty acids in the NEFA MM, comparing the model parameters in metabolic syndrome (MetSyn) subjects (n = 52) with optimally healthy controls (OptHC; n = 14). Results are reported as mean difference (95% confidence interval). Using the glucose MM, MetSyn subjects had lower [-73% (-82, -57)] sensitivity to insulin (Si) and higher [138% (44, 293)] acute insulin response to glucose (AIRg). Using the NEFA MM, MetSyn subjects had lower [-24% (-35, -13)] percent suppression, higher [32% (15, 52)] threshold glucose (gs), and a higher [81% (12, 192)] affinity constant altering NEFA secretion (ϕ). Comparing fatty acids, percent suppression was lower in myristic acid (MA) than in all other fatty acids, and the stearic acid (SA) response was so unique that it did not fit the NEFA MM. MA and SA percent of total were increased at 50 min after glucose injection, whereas oleic acid (OA) and palmitic acid (PA) were decreased (P < 0.05). We conclude that the NEFA MM, as well as the response of individual NEFA fatty acids after a FSIVGTT, differ between OptHC and MetSyn subjects and that the NEFA MM parameters differ between individual fatty acids.
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Affiliation(s)
- Rachel E Walker
- Department of Nutritional Sciences; The Pennsylvania State University, University Park, Pennsylvania
| | - Jennifer L Ford
- Department of Nutritional Sciences; The Pennsylvania State University, University Park, Pennsylvania
| | - Raymond C Boston
- Department of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Olga V Savinova
- Sanford Research/University of South Dakota, Sioux Falls, South Dakota
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York
| | - William S Harris
- Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota
| | - Michael H Green
- Department of Nutritional Sciences; The Pennsylvania State University, University Park, Pennsylvania
| | - Gregory C Shearer
- Department of Nutritional Sciences; The Pennsylvania State University, University Park, Pennsylvania
- Sanford Research/University of South Dakota, Sioux Falls, South Dakota
- Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota
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9
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Anholm C, Kumarathurai P, Samkani A, Pedersen LR, Boston RC, Nielsen OW, Kristiansen OP, Fenger M, Madsbad S, Sajadieh A, Haugaard SB. Effect of liraglutide on estimates of lipolysis and lipid oxidation in obese patients with stable coronary artery disease and newly diagnosed type 2 diabetes: A randomized trial. Diabetes Obes Metab 2019; 21:2012-2016. [PMID: 31050161 DOI: 10.1111/dom.13761] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 01/16/2023]
Abstract
Elevated levels of non-esterified fatty acids (NEFA) play a role in insulin resistance, impaired beta-cell function and they are a denominator of the abnormal atherogenic lipid profile that characterizes obese patients with type 2 diabetes (T2DM). We hypothesized that the GLP-1 receptor agonist liraglutide, in combination with metformin, would reduce lipolysis. In a randomized, double-blind, placebo-controlled, cross-over trial, 41 T2DM patients with coronary artery disease were randomized and treated with liraglutide-metformin vs placebo-metformin during 12- + 12-week periods with a wash-out period of at least 2 weeks before and between the intervention periods. NEFA kinetics were estimated using the Boston Minimal Model of NEFA metabolism, with plasma NEFA and glucose levels measured during a standard 180-minute frequently sampled intravenous glucose tolerance test. Liraglutide-metformin reduced estimates of lipolysis. Furthermore, placebo-metformin increased estimates of lipid oxidation, while treatment with liraglutide eliminated this effect. We conclude that liraglutide exerts a clinically relevant reduction in estimates of lipolysis and lipid oxidation which is explained, in part, by improved insulin secretion, as revealed by an intravenous glucose tolerance test.
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Affiliation(s)
- Christian Anholm
- Department of Internal Medicine, Copenhagen University Hospital, Glostrup, Denmark
- Department of Internal Medicine, Copenhagen University Hospital, Amager, Denmark
| | - Preman Kumarathurai
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Amirsalar Samkani
- Department of Endocrinology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Lene R Pedersen
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Raymond C Boston
- Departments of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Olav W Nielsen
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Ole P Kristiansen
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Mogens Fenger
- Department of Clinical Biochemistry, Copenhagen University Hospital, Hvidovre, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
| | - Ahmad Sajadieh
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Steen B Haugaard
- Department of Internal Medicine, Copenhagen University Hospital, Amager, Denmark
- Department of Endocrinology, Copenhagen University Hospital, Bispebjerg, Denmark
- Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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10
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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: 3.8] [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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11
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Salin S, Vanhatalo A, Jaakkola S, Elo K, Taponen J, Boston R, Kokkonen T. Effects of dry period energy intake on insulin resistance, metabolic adaptation, and production responses in transition dairy cows on grass silage–based diets. J Dairy Sci 2018; 101:11364-11383. [DOI: 10.3168/jds.2018-14728] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022]
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12
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Fiamoncini J, Rundle M, Gibbons H, Thomas EL, Geillinger-Kästle K, Bunzel D, Trezzi JP, Kiselova-Kaneva Y, Wopereis S, Wahrheit J, Kulling SE, Hiller K, Sonntag D, Ivanova D, van Ommen B, Frost G, Brennan L, Bell J, Daniel H. Plasma metabolome analysis identifies distinct human metabotypes in the postprandial state with different susceptibility to weight loss-mediated metabolic improvements. FASEB J 2018; 32:5447-5458. [PMID: 29718708 DOI: 10.1096/fj.201800330r] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Health has been defined as the capability of the organism to adapt to challenges. In this study, we tested to what extent comprehensively phenotyped individuals reveal differences in metabolic responses to a standardized mixed meal tolerance test (MMTT) and how these responses change when individuals experience moderate weight loss. Metabolome analysis was used in 70 healthy individuals. with profiling of ∼300 plasma metabolites during an MMTT over 8 h. Multivariate analysis of plasma markers of fatty acid catabolism identified 2 distinct metabotype clusters (A and B). Individuals from metabotype B showed slower glucose clearance, had increased intra-abdominal adipose tissue mass and higher hepatic lipid levels when compared with individuals from metabotype A. An NMR-based urine analysis revealed that these individuals also to have a less healthy dietary pattern. After a weight loss of ∼5.6 kg over 12 wk, only the subjects from metabotype B showed positive changes in the glycemic response during the MMTT and in markers of metabolic diseases. Our study in healthy individuals demonstrates that more comprehensive phenotyping can reveal discrete metabotypes with different outcomes in a dietary intervention and that markers of lipid catabolism in plasma could allow early detection of the metabolic syndrome.-Fiamoncini, J., Rundle, M., Gibbons, H., Thomas, E. L., Geillinger-Kästle, K., Bunzel, D., Trezzi, J.-P., Kiselova-Kaneva, Y., Wopereis, S., Wahrheit, J., Kulling, S. E., Hiller, K., Sonntag, D., Ivanova, D., van Ommen, B., Frost, G., Brennan, L., Bell, J. Daniel, H. Plasma metabolome analysis identifies distinct human metabotypes in the postprandial state with different susceptibility to weight loss-mediated metabolic improvements.
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Affiliation(s)
- Jarlei Fiamoncini
- Department of Food and Nutrition, Technische Universität München, Freising-Weihenstephan, Germany
| | - Milena Rundle
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Helena Gibbons
- University College Dublin (UCD) School of Agriculture and Food Science, Institute of Food and Health, Dublin, Ireland
| | - E Louise Thomas
- Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London, United Kingdom
| | | | - Diana Bunzel
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner Institut, Karlsruhe, Germany
| | - Jean-Pierre Trezzi
- Integrated Biobank of Luxembourg, Dudelange, Luxembourg.,Centre for Systems Biomedicine, Esch-sur-Alzette, Luxembourg
| | - Yoana Kiselova-Kaneva
- Department of Biochemistry, Molecular Medicine, and Nutrigenomics, Medical University-Varna, Varna, Bulgaria
| | - Suzan Wopereis
- Department of Microbiology and Systems Biology, Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands
| | | | - Sabine E Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner Institut, Karlsruhe, Germany
| | - Karsten Hiller
- Braunschweig Integrated Centre of Systems Biology, University of Braunschweig, Braunschweig, Germany.,Department of Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Denise Sonntag
- Department of Microbiology and Systems Biology, Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands
| | - Diana Ivanova
- Department of Biochemistry, Molecular Medicine, and Nutrigenomics, Medical University-Varna, Varna, Bulgaria
| | - Ben van Ommen
- Department of Microbiology and Systems Biology, Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands
| | - Gary Frost
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Lorraine Brennan
- University College Dublin (UCD) School of Agriculture and Food Science, Institute of Food and Health, Dublin, Ireland
| | - Jimmy Bell
- Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Hannelore Daniel
- Department of Food and Nutrition, Technische Universität München, Freising-Weihenstephan, Germany
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13
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Salin S, Vanhatalo A, Elo K, Taponen J, Boston R, Kokkonen T. Effects of dietary energy allowance and decline in dry matter intake during the dry period on responses to glucose and insulin in transition dairy cows. J Dairy Sci 2017; 100:5266-5280. [DOI: 10.3168/jds.2016-11871] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 03/11/2017] [Indexed: 12/13/2022]
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14
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Perazzolo S, Hirschmugl B, Wadsack C, Desoye G, Lewis RM, Sengers BG. The influence of placental metabolism on fatty acid transfer to the fetus. J Lipid Res 2017; 58:443-454. [PMID: 27913585 PMCID: PMC5282960 DOI: 10.1194/jlr.p072355] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/17/2016] [Indexed: 12/15/2022] Open
Abstract
The factors determining fatty acid transfer across the placenta are not fully understood. This study used a combined experimental and computational modeling approach to explore placental transfer of nonesterified fatty acids and identify the rate-determining processes. Isolated perfused human placenta was used to study the uptake and transfer of 13C-fatty acids and the release of endogenous fatty acids. Only 6.2 ± 0.8% of the maternal 13C-fatty acids taken up by the placenta was delivered to the fetal circulation. Of the unlabeled fatty acids released from endogenous lipid pools, 78 ± 5% was recovered in the maternal circulation and 22 ± 5% in the fetal circulation. Computational modeling indicated that fatty acid metabolism was necessary to explain the discrepancy between uptake and delivery of 13C-fatty acids. Without metabolism, the model overpredicts the fetal delivery of 13C-fatty acids 15-fold. Metabolic rate was predicted to be the main determinant of uptake from the maternal circulation. The microvillous membrane had a greater fatty acid transport capacity than the basal membrane. This study suggests that incorporation of fatty acids into placental lipid pools may modulate their transfer to the fetus. Future work needs to focus on the factors regulating fatty acid incorporation into lipid pools.
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Affiliation(s)
- Simone Perazzolo
- Faculty of Engineering and Environment, University of Southampton, SO17 1BJ, UK
- Institute for Life Sciences Southampton, University of Southampton, SO17 1BJ, UK
| | - Birgit Hirschmugl
- Department of Obstetrics and Gynecology, Medical University of Graz, 8036 Graz, Austria
| | - Christian Wadsack
- Department of Obstetrics and Gynecology, Medical University of Graz, 8036 Graz, Austria
| | - Gernot Desoye
- Department of Obstetrics and Gynecology, Medical University of Graz, 8036 Graz, Austria
| | - Rohan M Lewis
- Institute for Life Sciences Southampton, University of Southampton, SO17 1BJ, UK
- Bioengineering Research Group, Faculty of Medicine, University of Southampton, SO17 1BJ, UK
| | - Bram G Sengers
- Faculty of Engineering and Environment, University of Southampton, SO17 1BJ, UK
- Institute for Life Sciences Southampton, University of Southampton, SO17 1BJ, UK
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15
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Individualized Hydrocodone Therapy Based on Phenotype, Pharmacogenetics, and Pharmacokinetic Dosing. Clin J Pain 2016; 31:1026-35. [PMID: 25621429 DOI: 10.1097/ajp.0000000000000214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES (1) To quantify hydrocodone (HC) and hydromorphone (HM) metabolite pharmacokinetics with pharmacogenetics in CYP2D6 ultra-rapid metabolizer (UM), extensive metabolizer (EM), and poor metabolizer (PM) metabolizer phenotypes. (2) To develop an HC phenotype-specific dosing strategy for HC that accounts for HM production using clinical pharmacokinetics integrated with pharmacogenetics for patient safety. SETTING In silico clinical trial simulation. PARTICIPANTS Healthy white men and women without comorbidities or history of opioid, or any other drug or nutraceutical use, age 26.3±5.7 years (mean±SD; range, 19 to 36 y) and weight 71.9±16.8 kg (range, 50 to 108 kg). MAIN OUTCOME MEASURES CYP2D6 phenotype-specific HC clinical pharmacokinetic parameter estimates and phenotype-specific percentages of HM formed from HC. RESULTS PMs had lower indices of HC disposition compared with UMs and EMs. Clearance was reduced by nearly 60% and the t1/2 was increased by about 68% compared with EMs. The canonical order for HC clearance was UM>EM>PM. HC elimination mainly by the liver, represented by ke, was reduced about 70% in PM. However, HC's apparent Vd was not significantly different among UMs, EMs, and PM. The canonical order of predicted plasma HM concentrations was UM>EM>PM. For each of the CYP2D6 phenotypes, the mean predicted HM levels were within HM's therapeutic range, which indicates HC has significant phenotype-dependent pro-drug effects. CONCLUSIONS Our results demonstrate that pharmacogenetics afford clinicians an opportunity to individualize HC dosing, while adding enhanced opportunity to account for its conversion to HM in the body.
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16
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Li Y, Chow CC, Courville AB, Sumner AE, Periwal V. Modeling glucose and free fatty acid kinetics in glucose and meal tolerance test. Theor Biol Med Model 2016; 13:8. [PMID: 26934990 PMCID: PMC4776401 DOI: 10.1186/s12976-016-0036-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 02/26/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Quantitative evaluation of insulin regulation on plasma glucose and free fatty acid (FFA) in response to external glucose challenge is clinically important to assess the development of insulin resistance (World J Diabetes 1:36-47, 2010). Mathematical minimal models (MMs) based on insulin modified frequently-sampled intravenous glucose tolerance tests (IM-FSIGT) are widely applied to ascertain an insulin sensitivity index (IEEE Rev Biomed Eng 2:54-96, 2009). Furthermore, it is important to investigate insulin regulation on glucose and FFA in postprandial state as a normal physiological condition. A simple way to calculate the appearance rate (Ra) of glucose and FFA would be especially helpful to evaluate glucose and FFA kinetics for clinical applications. METHODS A new MM is developed to simulate the insulin modulation of plasma glucose and FFA, combining IM-FSIGT with a mixed meal tolerance test (MT). A novel simple functional form for the appearance rate (Ra) of glucose or FFA in the MT is developed. Model results are compared with two other models for data obtained from 28 non-diabetic women (13 African American, 15 white). RESULTS The new functional form for Ra of glucose is an acceptable empirical approximation to the experimental Ra for a subset of individuals. When both glucose and FFA are included in FSIGT and MT, the new model is preferred using the Bayes Information Criterion (BIC). CONCLUSIONS Model simulations show that the new MM allows consistent application to both IM-FSIGT and MT data, balancing model complexity and data fitting. While the appearance of glucose in the circulation has an important effect on FFA kinetics in MT, the rate of appearance of FFA can be neglected for the time-period modeled.
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Affiliation(s)
- Yanjun Li
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), MSC 5621, LBM, NIDDK, NIH, Bethesda, MD, 20892-5621, USA.
| | - Carson C Chow
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), MSC 5621, LBM, NIDDK, NIH, Bethesda, MD, 20892-5621, USA.
| | - Amber B Courville
- Nutrition Department, Clinical Center, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, 20892, USA.
| | - Anne E Sumner
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, 20892, USA.
| | - Vipul Periwal
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), MSC 5621, LBM, NIDDK, NIH, Bethesda, MD, 20892-5621, USA.
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17
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Sips FLP, Nyman E, Adiels M, Hilbers PAJ, Strålfors P, van Riel NAW, Cedersund G. Model-Based Quantification of the Systemic Interplay between Glucose and Fatty Acids in the Postprandial State. PLoS One 2015; 10:e0135665. [PMID: 26356502 PMCID: PMC4565650 DOI: 10.1371/journal.pone.0135665] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/29/2015] [Indexed: 11/18/2022] Open
Abstract
In metabolic diseases such as Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease, the systemic regulation of postprandial metabolite concentrations is disturbed. To understand this dysregulation, a quantitative and temporal understanding of systemic postprandial metabolite handling is needed. Of particular interest is the intertwined regulation of glucose and non-esterified fatty acids (NEFA), due to the association between disturbed NEFA metabolism and insulin resistance. However, postprandial glucose metabolism is characterized by a dynamic interplay of simultaneously responding regulatory mechanisms, which have proven difficult to measure directly. Therefore, we propose a mathematical modelling approach to untangle the systemic interplay between glucose and NEFA in the postprandial period. The developed model integrates data of both the perturbation of glucose metabolism by NEFA as measured under clamp conditions, and postprandial time-series of glucose, insulin, and NEFA. The model can describe independent data not used for fitting, and perturbations of NEFA metabolism result in an increased insulin, but not glucose, response, demonstrating that glucose homeostasis is maintained. Finally, the model is used to show that NEFA may mediate up to 30–45% of the postprandial increase in insulin-dependent glucose uptake at two hours after a glucose meal. In conclusion, the presented model can quantify the systemic interactions of glucose and NEFA in the postprandial state, and may therefore provide a new method to evaluate the disturbance of this interplay in metabolic disease.
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Affiliation(s)
- Fianne L. P. Sips
- Department of Biomedical Engineering, Eindhoven University of Technology, Postbus 513, 5600 MB, Eindhoven, The Netherlands
- * E-mail:
| | - Elin Nyman
- Department of Biomedical Engineering, Linköping University, SE-58185, Linköping, Sweden
- CVMD iMED DMPK AstraZeneca R&D, 431 83, Mölndal, Sweden
| | - Martin Adiels
- Health Metrics at Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Peter A. J. Hilbers
- Department of Biomedical Engineering, Eindhoven University of Technology, Postbus 513, 5600 MB, Eindhoven, The Netherlands
| | - Peter Strålfors
- Department of Clinical and Experimental Medicine, Linköping University, SE-58185, Linköping, Sweden
| | - Natal A. W. van Riel
- Department of Biomedical Engineering, Eindhoven University of Technology, Postbus 513, 5600 MB, Eindhoven, The Netherlands
| | - Gunnar Cedersund
- Department of Biomedical Engineering, Linköping University, SE-58185, Linköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, SE-58185, Linköping, Sweden
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18
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Linares OA, Schiesser WE, Fudin J, Pham TC, Bettinger JJ, Mathew RO, Daly AL. In silico ordinary differential equation/partial differential equation hemodialysis model estimates methadone removal during dialysis. J Pain Res 2015; 8:417-29. [PMID: 26229501 PMCID: PMC4516209 DOI: 10.2147/jpr.s84615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background There is a need to have a model to study methadone’s losses during hemodialysis to provide informed methadone dose recommendations for the practitioner. Aim To build a one-dimensional (1-D), hollow-fiber geometry, ordinary differential equation (ODE) and partial differential equation (PDE) countercurrent hemodialyzer model (ODE/PDE model). Methodology We conducted a cross-sectional study in silico that evaluated eleven hemodialysis patients. Patients received a ceiling dose of methadone hydrochloride 30 mg/day. Outcome measures included: the total amount of methadone removed during dialysis; methadone’s overall intradialytic mass transfer rate coefficient, km; and, methadone’s removal rate, jME. Each metric was measured at dialysate flow rates of 250 mL/min and 800 mL/min. Results The ODE/PDE model revealed a significant increase in the change of methadone’s mass transfer with increased dialysate flow rate, %Δkm=18.56, P=0.02, N=11. The total amount of methadone mass transferred across the dialyzer membrane with high dialysate flow rate significantly increased (0.042±0.016 versus 0.052±0.019 mg/kg, P=0.02, N=11). This was accompanied by a small significant increase in methadone’s mass transfer rate (0.113±0.002 versus 0.014±0.002 mg/kg/h, P=0.02, N=11). The ODE/PDE model accurately predicted methadone’s removal during dialysis. The absolute value of the prediction errors for methadone’s extraction and throughput were less than 2%. Conclusion ODE/PDE modeling of methadone’s hemodialysis is a new approach to study methadone’s removal, in particular, and opioid removal, in general, in patients with end-stage renal disease on hemodialysis. ODE/PDE modeling accurately quantified the fundamental phenomena of methadone’s mass transfer during hemodialysis. This methodology may lead to development of optimally designed intradialytic opioid treatment protocols, and allow dynamic monitoring of outflow plasma opioid concentrations for model predictive control during dialysis in humans.
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Affiliation(s)
- Oscar A Linares
- Translational Genomic Medicine Lab, Plymouth Pharmacokinetic Modeling Study Group, Plymouth, MI, USA
| | - William E Schiesser
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Jeffrey Fudin
- University of Connecticut School of Pharmacy, Storrs, CT, USA ; Western New England College of Pharmacy, Springfield, MA, USA ; Albany College of Pharmacy and Health Sciences, Albany, NY, USA ; Stratton VA Medical Center, Albany, NY, USA
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Ishikawa T, Graham JL, Stanhope KL, Havel PJ, La Merrill MA. Effect of DDT exposure on lipids and energy balance in obese Sprague-Dawley rats before and after weight loss. Toxicol Rep 2015; 2:990-995. [PMID: 28962439 PMCID: PMC5598246 DOI: 10.1016/j.toxrep.2015.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/03/2015] [Accepted: 07/05/2015] [Indexed: 11/30/2022] Open
Abstract
Dichlorodiphenyltrichloroethane (DDT) and its metabolites accumulate in adipose tissue through dietary exposure, and have been proposed to contribute to the development of abdominal obesity, insulin resistance and dyslipidemia. Toxicity may also result when DDT and its metabolites are released from adipose tissue into the bloodstream as a result of rapid weight loss. We hypothesized that DDT-exposed rats fed a high fat diet (HFD) followed by 60% calorie restriction would have an adverse metabolic response to rapid weight loss. To test this, we exposed obese Sprague-Dawley (SD) rats to DDT and a HFD over one month followed by 60% calorie restricted diet for two weeks, and examined metabolic parameters throughout the study. During the HFD feeding period, DDT-exposed rats had significantly elevated postprandial non-esterified fatty acids (NEFAs) and decreased body temperature compared with control rats. During calorie restriction, DDT-exposed rats had lowered food efficiency (weight gained/calories consumed), body temperature, and circulating TSH. Our findings suggest that exposure to DDT may impairs metabolic substrate utilization in rats during dynamic periods of weight gain and weight loss.
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Key Words
- CR, caloric restriction
- CVD, cardiovascular disease
- DDE
- DDE, dichlorodiphenyldichloroethylene
- DDT
- DDT, dichlorodiphenyltrichloroethane
- Dyslipidemia
- Food efficiency
- HFD, high fat diet
- NEFA, non esterified fatty acid
- OLTT, oral lipid tolerance test
- SD, Sprague Dawley
- T2DM, type 2 diabetes mellitus
- T3, triiodothyronine
- T4, thyroxine
- TG, triglyceride
- TSH, thyroid-stimulating hormone
- Thermoregulation
- Thyroid hormone
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Affiliation(s)
- Tomoko Ishikawa
- Department of Environmental Toxicology, University of California Davis, Davis, CA 95616, USA
| | - James L. Graham
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
- Department of Nutrition, University of California Davis, Davis, CA 95616, USA
| | - Kimber L. Stanhope
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
- Department of Nutrition, University of California Davis, Davis, CA 95616, USA
| | - Peter J. Havel
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
- Department of Nutrition, University of California Davis, Davis, CA 95616, USA
| | - Michele A. La Merrill
- Department of Environmental Toxicology, University of California Davis, Davis, CA 95616, USA
- Correspondence to: Department of Toxicology, One Shields Avenue, Davis, CA 95616, USA.
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Linares OA, Fudin J, Schiesser WE, Daly Linares AL, Boston RC. CYP2D6 Phenotype-Specific Codeine Population Pharmacokinetics. J Pain Palliat Care Pharmacother 2015; 29:4-15. [DOI: 10.3109/15360288.2014.997854] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Thomaseth K, Brehm A, Pavan A, Pacini G, Roden M. Modeling glucose and free fatty acid kinetics during insulin-modified intravenous glucose tolerance test in healthy humans: role of counterregulatory response. Am J Physiol Regul Integr Comp Physiol 2014; 307:R321-31. [DOI: 10.1152/ajpregu.00314.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Insulin administration during insulin-modified intravenous glucose tolerance test (IM-IVGTT) can induce transient hypoglycemia in healthy insulin-sensitive subjects. This triggers counterregulatory reflex (CRR) responses, which influence the kinetics of glucose and nonesterified fatty acids (NEFA), and undermines the accuracy of mathematical modeling methods that do not explicitly account for CRR. The aim of this study is to evaluate mathematical models of glucose and NEFA kinetics against experimental data in the presence or absence of CRR. Thirteen healthy nondiabetic subjects underwent a standard IM-IVGTT and a modified test (GC-IM-IVGTT) with a variable glucose infusion preventing hypoglycemia. While model predictions fit very well with glucose and NEFA data from GC-IM-IVGTT, they lagged behind observations from IM-IVGTT during recovery from hypoglycemia, independently of insulinemia, which did not differ significantly between protocols. A modification to the glucose minimal model, using the glucose concentration below a threshold as a signal for CRR, improves model predictions for both glucose and NEFA. The associated increase in endogenous glucose production correlates, among various CRR hormones, mainly with the dynamics of glucagon concentration. The modified minimal models introduce new parameters that quantify strength and duration of CRR following hypoglycemia. Although CRR represents an unwanted side-effect in IM-IVGTT occurring only in insulin-sensitive subjects, this study provides new insights leading to improved procedures for estimating insulin sensitivity from IM-IVGTT, which may also allow for assessing the individual capacity of recovery from hypoglycemic events in patients treated with insulin or insulin-releasing drugs.
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Affiliation(s)
- Karl Thomaseth
- Institute of Biomedical Engineering, National Research Council, Padua, Italy
| | - Attila Brehm
- Karl-Landsteiner Institute for Endocrinology and Metabolism at 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Alessandra Pavan
- Institute of Biomedical Engineering, National Research Council, Padua, Italy
| | - Giovanni Pacini
- Institute of Biomedical Engineering, National Research Council, Padua, Italy
| | - Michael Roden
- Department of Endocrinology and Diabetology, University Hospital, Düsseldorf, Germany; and
- German Center for Diabetes Research, Düsseldorf, Germany
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22
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Anholm C, Kumarathurai P, Klit MS, Kristiansen OP, Nielsen OW, Ladelund S, Madsbad S, Sajadieh A, Haugaard SB. Adding liraglutide to the backbone therapy of biguanide in patients with coronary artery disease and newly diagnosed type-2 diabetes (the AddHope2 study): a randomised controlled study protocol. BMJ Open 2014; 4:e005942. [PMID: 25031198 PMCID: PMC4401817 DOI: 10.1136/bmjopen-2014-005942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Newly diagnosed type 2 diabetes mellitus (T2DM) in patients with coronary artery disease (CAD) more than doubles the risk of death compared with otherwise matched glucose tolerant patients. The biguanide metformin is the drug of choice in treatment of T2DM and has shown to ameliorate cardiovascular morbidity in patients with T2DM and myocardial infarction (MI). The incretin hormone, glucagon-like peptide-1 (GLP-1) improves β-cell function, insulin sensitivity and causes weight loss and has been suggested to have beneficial effects on cardiac function. The GLP-1 receptor agonist (GLP-1RA), liraglutide, is currently used for treatment of T2DM but its potential effect on cardiac function has not been investigated in detail. We hypothesised that liraglutide added to metformin backbone therapy in patients with CAD and newly diagnosed T2DM will improve β-cell function and left ventricular systolic function during dobutamine stress. METHODS AND ANALYSES 40 patients with CAD and newly diagnosed T2DM will receive the intervention liraglutide+metformin and placebo+metformin in this investigator-initiated, double blind, randomised, placebo-controlled, cross-over 12 plus 12 weeks intervention study with a 2-week washout period. The primary cardiovascular end point is changes in left ventricular ejection fraction during stress echocardiography. The primary endocrine end point is β-cell function evaluated during a frequently sampled intravenous glucose tolerance test. Secondary end points include heart rate variability, diurnal blood pressure, glucagon suppression and inflammatory response (urine, blood and adipose tissue). ETHICS AND DISSEMINATION This study is approved by the Danish Medicines Agency, the Danish Dataprotection Agency and the Regional Committee on Biomedical Research Ethics of the Capital Region of Denmark. The trial will be carried out under the guidance from the GCP unit at Copenhagen University Hospital of Bispebjerg and in accordance with the ICH-GCP guidelines and the Helsinki Declaration. TRIAL REGISTRATIONS NUMBER Clinicaltrials.gov ID: NCT01595789, EudraCT: 2011-005405-78.
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Affiliation(s)
- Christian Anholm
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
- Department of Internal Medicine, Copenhagen University Hospital, Amager, Denmark
| | - Preman Kumarathurai
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Malene S Klit
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Ole P Kristiansen
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Olav W Nielsen
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Steen Ladelund
- Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
| | - Ahmad Sajadieh
- Department of Cardiology, Copenhagen University Hospital, Bispebjerg, Denmark
| | - Steen B Haugaard
- Department of Internal Medicine, Copenhagen University Hospital, Amager, Denmark
- Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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Linares OA, Daly D, Linares AD, Stefanovski D, Boston RC. Personalized Oxycodone Dosing: Using Pharmacogenetic Testing and Clinical Pharmacokinetics to Reduce Toxicity Risk and Increase Effectiveness. PAIN MEDICINE 2014; 15:791-806. [DOI: 10.1111/pme.12380] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Salin S, Taponen J, Elo K, Simpura I, Vanhatalo A, Boston R, Kokkonen T. Effects of abomasal infusion of tallow or camelina oil on responses to glucose and insulin in dairy cows during late pregnancy. J Dairy Sci 2012; 95:3812-25. [DOI: 10.3168/jds.2011-5206] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 03/06/2012] [Indexed: 01/01/2023]
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25
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Ramos-Roman MA, Lapidot SA, Phair RD, Parks EJ. Insulin activation of plasma nonesterified fatty acid uptake in metabolic syndrome. Arterioscler Thromb Vasc Biol 2012; 32:1799-808. [PMID: 22723441 DOI: 10.1161/atvbaha.112.250019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Insulin control of fatty acid metabolism has long been deemed dominated by suppression of adipose lipolysis. The goal of the present study was to test the hypothesis that this single role of insulin is insufficient to explain observed fatty acid dynamics. METHODS AND RESULTS Fatty acid kinetics were measured during a meal tolerance test and insulin sensitivity assessed by intravenous glucose tolerance test in overweight human subjects (n=15; body mass index, 35.8 ± 7.1 kg/m(2)). Non-steady state tracer kinetic models were formulated and tested using ProcessDB software. Suppression of adipose fatty acid release, by itself, could not account for postprandial nonesterified fatty acid concentration changes, but adipose suppression combined with insulin activation of fatty acid uptake was consistent with the measured data. The observed insulin K(m) for nonesterified fatty acid uptake was inversely correlated with both insulin sensitivity of glucose uptake (intravenous glucose tolerance test insulin sensitivity; r=-0.626; P=0.01) and whole body fat oxidation after the meal (r=-0.538; P=0.05). CONCLUSIONS These results support insulin regulation of fatty acid turnover by both release and uptake mechanisms. Activation of fatty acid uptake is consistent with the human data, has mechanistic precedent in cell culture, and highlights a new potential target for therapies aimed at improving the control of fatty acid metabolism in insulin-resistant disease states.
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Affiliation(s)
- Maria A Ramos-Roman
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390-9052, USA
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26
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Morbiducci U, Di Benedetto G, Kautzky-Willer A, Deriu MA, Pacini G, Tura A. Identification of a model of non-esterified fatty acids dynamics through genetic algorithms: the case of women with a history of gestational diabetes. Comput Biol Med 2011; 41:146-53. [PMID: 21333978 DOI: 10.1016/j.compbiomed.2011.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 12/24/2010] [Accepted: 01/10/2011] [Indexed: 01/10/2023]
Abstract
Elevation in non-esterified fatty acids (NEFA) has been shown to modulate insulin secretion and it is considered as a risk factor for the development of type 2 diabetes. Here we present a method that complements a mathematical model of NEFA kinetics with genetic algorithms for model identification. The complemented strategy allowed to assess parameters of NEFA kinetics and to get insight into their relationship with insulin during oral glucose tolerance tests in women with former gestational diabetes: (i) providing a reliable estimation of the model parameters, (ii) assuring the usability of the model, and (iii) promoting and facilitating its application in a clinical context.
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Hirsch D, Odorico J, Radke N, Hanson M, Danobeitia JS, Hullett D, Alejandro R, Ricordi C, Fernandez LA. Correction of insulin sensitivity and glucose disposal after pancreatic islet transplantation: preliminary results. Diabetes Obes Metab 2010; 12:994-1003. [PMID: 20880346 PMCID: PMC6419521 DOI: 10.1111/j.1463-1326.2010.01290.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Pancreatic islet transplantation (PIT) represents a potential curative treatment for patients with type 1 diabetes, but only 10-15% of patients remain insulin independent 5 years post-transplant. It is not known whether intrinsic insulin resistance exacerbated by immunosuppression plays a pivotal role in low graft survival. The study objective was to understand the changes in insulin resistance, glucose effectiveness (S(g)) and free fatty acid dynamics (FFAd) before and after PIT. METHODS Insulin sensitivity index (S(i)), S(g) and FFAd were measured before and after PIT in 10 lean patients, 8 of whom reached insulin independence. Modified Bergman minimal model of frequently sampled intravenous glucose tolerance tests were performed pretransplant and at 12 months post-transplant. Nine non-diabetic control (NDC) subjects matched by age, gender and BMI were used. RESULTS Pretransplant S(i) and S(g) were 3.5 ± 0.8 × 10(-5)/min/(pmol/l) and 0.74 ± 0.24 × 10(-2)/min, respectively. S(i) was significantly lower than matched NDCs [10.8 ± 0.6 × 10(-5)/min/(pmol/l), p < 0.004]; S(g) did not reach statistical significance (1.27 ± 0.22 × 10(-2)/min, p = 0.25). Compared to pretransplant values, mean post-transplant S(i) and S(g) were 9.6 ± 1.3 × 10(-5)/min/(pmol/l)and 1.28 ± 0.22 ×10(-2)/min, respectively, indicating significant improvement for S(i) but not S(g) (p = 0.008 and p = 0.06). Twelve-month post-PIT compared to NDC values were not significantly different (p = 0.58 and 0.97, respectively). In addition, fractional disposal rate for FFA which directly depends on the endogenous insulin release (10-20 min) nearly normalized after PIT (p = 0.06). CONCLUSION These preliminary findings demonstrate that PIT can restore glucose disposal and insulin sensitivity and partially correct glucose effectiveness and FFAd.
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Affiliation(s)
- D Hirsch
- Department of Surgery, Division of Transplantation, University of Wisconsin, Madison, WI 53792-7375, USA
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Karakas SE, Almario RU, Kim K. Serum fatty acid binding protein 4, free fatty acids, and metabolic risk markers. Metabolism 2009; 58:1002-7. [PMID: 19394980 PMCID: PMC2720822 DOI: 10.1016/j.metabol.2009.02.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 02/13/2009] [Indexed: 01/22/2023]
Abstract
Fatty acid binding protein (FABP) 4 chaperones free fatty acids (FFAs) in the adipocytes during lipolysis. Serum FFA relates to metabolic syndrome, and serum FABP4 is emerging as a novel risk marker. In 36 overweight/obese women, serum FABP4 and FFA were measured hourly during 5-hour oral glucose tolerance test. Insulin resistance was determined using frequently sampled intravenous glucose tolerance test. Serum lipids and inflammation markers were measured at fasting. During oral glucose tolerance test, serum FABP4 decreased by 40%, reaching its nadir at 3 hours (from 45.3 +/- 3.1 to 31.9 +/- 1.6 ng/mL), and stayed below the baseline at 5 hours (35.9 +/- 2.2 ng/mL) (P < .0001 for both, compared with the baseline). Serum FFA decreased by 10-fold, reaching a nadir at 2 hours (from 0.611 +/- 0.033 to 0.067 +/- 0.004 mmol/L), then rebounded to 0.816 +/- 0.035 mmol/L at 5 hours (P < .001 for both, compared with baseline). Both fasting FABP4 and nadir FABP4 correlated with obesity. Nadir FABP4 correlated also with insulin resistance parameters from frequently sampled intravenous glucose tolerance test and with inflammation. Nadir FFA, but not fasting FFA, correlated with the metabolic syndrome parameters. In conclusion, fasting FABP4 related to metabolic risk markers more strongly than fasting FFA. Nadir FABP4 and nadir FFA measured after glucose loading may provide better risk assessment than the fasting values.
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Affiliation(s)
- Sidika E Karakas
- Department of Internal Medicine, Division of Endocrinology, Clinical Nutrition and Vascular Medicine, The University of California at Davis, Davis, CA 95817, USA.
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Boston RC, Moate PJ. NEFA minimal model parameters estimated from the oral glucose tolerance test and the meal tolerance test. Am J Physiol Regul Integr Comp Physiol 2008; 295:R395-403. [PMID: 18565832 DOI: 10.1152/ajpregu.90317.2008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The kinetics of nonesterified fatty acid (NEFA) metabolism in humans requires quantification to facilitate understanding of diseases like type 1 and 2 diabetes, metabolic syndrome, and obesity, and the mechanisms underpinning various interventions. Oral glucose tolerance tests (OGTT) and glucose meal tolerance tests (MTT) are potentially useful procedures for enabling quantification of NEFA kinetics because they both cause transitory, but substantial, declines and then rebounds in plasma NEFA concentrations in response to physiologically relevant increases in plasma glucose. The Boston MINIMAL model of NEFA kinetics was developed to analyze data from the intravenous glucose tolerance test (IVGTT), but in this work, we present for the first time its application to modeling NEFA data from both OGTT and MTT studies. This model enables estimation of SFFA (micromol.l(-1).min(-1)) (a parameter describing the maximum rate of lipolysis), and KFFA (%/min) (a parameter related to NEFA oxidation rate). The model could well describe the trajectories of NEFA concentrations following an OGTT (R2 in excess of 0.97) but was not as successful with the MTT (R2>0.65). Model parameters derived from analysis of OGTT and MTT data were well identified with coefficients of variation generally less than 15%. Type 2 diabetes, body mass index, and dietary treatment (high-fat vs. high-glycemic-index diets) were all shown to have significant effects on model parameters. Modeling plasma NEFA concentrations over 24 h has helped to identify and quantify the extent that periprandial NEFA peaks and nocturnal elevation in plasma NEFA can be accounted for by our model.
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Affiliation(s)
- Ray C Boston
- School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, 382 W. St. Road, Kennett Square, PA 19348, USA.
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