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Voigt JH, Lauritsen KM, Pedersen SB, Hansen TK, Møller N, Jessen N, Laurenti MC, Dalla Man C, Vella A, Gormsen LC, Søndergaard E. Four weeks SGLT2 inhibition improves beta cell function and glucose tolerance without affecting muscle free fatty acid or glucose uptake in subjects with type 2 diabetes. Basic Clin Pharmacol Toxicol 2024; 134:643-656. [PMID: 38409617 DOI: 10.1111/bcpt.13991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 01/25/2024] [Accepted: 02/06/2024] [Indexed: 02/28/2024]
Abstract
AIMS Sodium glucose co-transporter-2 (SGLT2) inhibition lowers glucose levels independently of insulin, leading to reduced insulin secretion and increased lipolysis, resulting in elevated circulating free fatty acids (FFAs). While SGLT2 inhibition improves tissue insulin sensitivity, the increase in circulating FFAs could reduce insulin sensitivity in skeletal muscle and the liver. We aimed to investigate the effects of SGLT2 inhibition on substrate utilization in skeletal muscle and the liver and to measure beta-cell function and glucose tolerance. METHODS Thirteen metformin-treated individuals with type 2 diabetes were randomized to once-daily empagliflozin 25 mg or placebo for 4 weeks in a crossover design. Skeletal muscle glucose and FFA uptake together with hepatic tissue FFA uptake were measured using [18F]FDG positron emission tomography/computed tomography (PET/CT) and [11C]palmitate PET/CT. Insulin secretion and action were estimated using the oral minimal model. RESULTS Empagliflozin did not affect glucose (0.73 ± 0.30 vs. 1.16 ± 0.64, μmol/g/min p = 0.11) or FFA (0.60 ± 0.30 vs. 0.56 ± 0.3, μmol/g/min p = 0.54) uptake in skeletal muscle. FFA uptake in the liver (21.2 ± 10.1 vs. 19 ± 8.8, μmol/100 ml/min p = 0.32) was unaffected. Empagliflozin increased total beta-cell responsivity (20 ± 8 vs. 14 ± 9, 10-9 min-1, p < 0.01) and glucose effectiveness (2.6 × 10-2 ± 0.3 × 10-2 vs. 2.4 × 10-2 ± 0.3 × 10-2, dL/kg/min, p = 0.02). CONCLUSIONS Despite improved beta-cell function and glucose tolerance, empagliflozin does not appear to affect skeletal muscle FFA or glucose uptake.
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Affiliation(s)
| | - Katrine M Lauritsen
- Steno Diabetes Center Aarhus, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Danish Diabetes Academy, Odense University Hospital, Odense, Denmark
| | - Steen Bønløkke Pedersen
- Steno Diabetes Center Aarhus, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Niels Møller
- Steno Diabetes Center Aarhus, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Jessen
- Steno Diabetes Center Aarhus, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Marcello C Laurenti
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, Minnesota, USA
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Adrian Vella
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, Minnesota, USA
| | - Lars C Gormsen
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Søndergaard
- Steno Diabetes Center Aarhus, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Danish Diabetes Academy, Odense University Hospital, Odense, Denmark
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, Minnesota, USA
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Karakaplan ND, Song Y, Laurenti MC, Vella A, Jensen MD. Suppression of Endogenous Insulin Secretion by Euglycemic Hyperinsulinemia. J Clin Endocrinol Metab 2024; 109:e596-e601. [PMID: 37758511 PMCID: PMC10795933 DOI: 10.1210/clinem/dgad563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/07/2023] [Accepted: 09/21/2023] [Indexed: 10/03/2023]
Abstract
CONTEXT The impact of insulin, particularly exogenous hyperinsulinemia, on insulin secretion in humans is debated. OBJECTIVE We assessed the effects of exogenous hyperinsulinemia on insulin secretion and whether the response is altered in insulin resistance associated with obesity. METHODS Insulin secretion rates (ISRs) during euglycemic hyperinsulinemic clamp studies (52 volunteers) were calculated using a model that employs plasma C-peptide concentrations. One study involved a 2-step insulin clamp and the other study was a single step insulin clamp. For both studies the goal was to achieve plasma glucose concentrations of 95 mg/dL during the clamp irrespective of fasting glucose concentrations. The percent change in ISR from fasting to the end of the insulin clamp interval was the main outcome. Linear regression and analysis of covariance were used to test for the effects of insulin on ISR and to test for group differences. RESULTS ISR was greater in obese volunteers (P < .001) under fasting and hyperinsulinemic clamp conditions. The change in plasma glucose from baseline to the end of the insulin clamp interval was highly correlated with the change in ISR (r = 0.61, P < .001). From baseline to the end of the clamp we observed a 27% (SD 20) suppression of ISR. The participants who underwent a 2-step insulin clamp had greater suppression of ISR during the second step than the first step (P < .001). The proportional suppression of ISR during euglycemic hyperinsulinemia was not different between nonobese and obese groups (P = .19). CONCLUSION Hyperinsulinemia suppresses endogenous insulin secretion and the relative change in insulin secretion produced by exogenous insulin did not differ between nonobese and obese people.
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Affiliation(s)
- Nesrin Damla Karakaplan
- Endocrine Research Unit, Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN 55905, USA
| | - Yilin Song
- Endocrine Research Unit, Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN 55905, USA
| | - Marcello C Laurenti
- Endocrine Research Unit, Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN 55905, USA
| | - Adrian Vella
- Endocrine Research Unit, Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN 55905, USA
| | - Michael D Jensen
- Endocrine Research Unit, Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN 55905, USA
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Welch AA, Farahani RA, Egan AM, Laurenti MC, Zeini M, Vella M, Bailey KR, Cobelli C, Dalla Man C, Matveyenko A, Vella A. Glucagon-like peptide-1 receptor blockade impairs islet secretion and glucose metabolism in humans. J Clin Invest 2023; 133:e173495. [PMID: 37751301 PMCID: PMC10645389 DOI: 10.1172/jci173495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUNDProglucagon can be processed to glucagon-like peptide1 (GLP-1) within the islet, but its contribution to islet function in humans remains unknown. We sought to understand whether pancreatic GLP-1 alters islet function in humans and whether this is affected by type 2 diabetes.METHODSWe therefore studied individuals with and without type 2 diabetes on two occasions in random order. On one occasion, exendin 9-39, a competitive antagonist of the GLP-1 Receptor (GLP1R), was infused, while on the other, saline was infused. The tracer dilution technique ([3-3H] glucose) was used to measure glucose turnover during fasting and during a hyperglycemic clamp.RESULTSExendin 9-39 increased fasting glucose concentrations; fasting islet hormone concentrations were unchanged, but inappropriate for the higher fasting glucose observed. In people with type 2 diabetes, fasting glucagon concentrations were markedly elevated and persisted despite hyperglycemia. This impaired suppression of endogenous glucose production by hyperglycemia.CONCLUSIONThese data show that GLP1R blockade impairs islet function, implying that intra-islet GLP1R activation alters islet responses to glucose and does so to a greater degree in people with type 2 diabetes.TRIAL REGISTRATIONThis study was registered at ClinicalTrials.gov NCT04466618.FUNDINGThe study was primarily funded by NIH NIDDK DK126206. AV is supported by DK78646, DK116231 and DK126206. CDM was supported by MIUR (Italian Minister for Education) under the initiative "Departments of Excellence" (Law 232/2016).
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Affiliation(s)
- Andrew A. Welch
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Rahele A. Farahani
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Aoife M. Egan
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Marcello C. Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Maya Zeini
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Max Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Kent R. Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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Faggionato E, Laurenti MC, Vella A, Man CD. Nonlinear Mixed Effects Modeling of Glucagon Kinetics in Healthy Subjects. IEEE Trans Biomed Eng 2023; 70:2733-2740. [PMID: 37030857 PMCID: PMC10509356 DOI: 10.1109/tbme.2023.3262974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
OBJECTIVE To date, the lack of a model of glucagon kinetics precluded the possibility of estimating and studying glucagon secretion in vivo, e.g., using deconvolution, as done for other hormones like insulin and C-peptide. Here, we used a nonlinear mixed effects technique to develop a robust population model of glucagon kinetics, able to describe both the typical population kinetics (TPK) and the between-subject variability (BSV), and relate this last to easily measurable subject characteristics. METHODS Thirty-four models of increasing complexity (variably including covariates and correlations among random effects) were identified on glucagon profiles obtained from 53 healthy subjects, who received a constant infusion of somatostatin to suppress endogenous glucagon production, followed by a continuous infusion of glucagon (65 ng/kg/min). Model selection was performed based on its ability to fit the data, provide precise parameter estimates, and parsimony criteria. RESULTS A two-compartment model was the most parsimonious. The model was able to accurately describe both the TPK and the BSV of model parameters as function of body mass and body surface area. Parameters were precisely estimated, with central volume of distribution V1 = 5.46 L and peripheral volume of distribution V2 = 5.51 L. The introduction of covariates resulted in a significant shrinkage of the unexplained BSV and considerably improved the model fit. CONCLUSION We developed a robust population model of glucagon kinetics. SIGNIFICANCE This model provides a deeper understanding of glucagon kinetics and is usable to estimate glucagon secretion in vivo by deconvolution of plasma glucagon concentration data.
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Schembri Wismayer D, Laurenti MC, Song Y, Egan AM, Welch AA, Bailey KR, Cobelli C, Dalla Man C, Jensen MD, Vella A. Effects of overnight fasting milieu on indices of β-cell function and glucose metabolism in subjects without diabetes. Am J Physiol Endocrinol Metab 2023. [PMID: 37285600 PMCID: PMC10393375 DOI: 10.1152/ajpendo.00043.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 06/06/2023] [Indexed: 06/09/2023]
Abstract
OBJECTIVE Elevated fasting free fatty acids (FFA) are associated with Impaired Glucose Tolerance (IGT) and decreased β-cell function (quantified as Disposition Index (DI)). We sought to examine how changes in fasting FFA and glucose alter islet function. METHODS We studied 10 subjects with Normal Fasting Glucose (NFG) and Normal Glucose Tolerance (NGT) on 2 occasions. On one occasion, Intralipid® and glucose were infused overnight to mimic conditions present in IFG/IGT. In addition, we studied 7 subjects with IFG/IGT on 2 occasions. On one occasion insulin was infused to lower overnight FFA and glucose concentrations to those observed in people with NFG/NGT. The following morning, a labeled mixed meal was used to measure postprandial glucose metabolism and β-cell function. RESULTS Elevation of overnight fasting FFA and glucose in NFG/NGT did not alter peak or integrated glucose concentrations (2.0 ± 0.1 vs 2.0 ± 0.1 Mol per 5 h, Saline vs. Intralipid® / glucose, p = 0.55). While overall β-cell function quantified by the Disposition Index was unchanged, the dynamic component of β-cell responsivity (fd) was decreased by Intralipid® and glucose infusion (9 ± 1 vs. 16 ± 3 10-9, p = 0.02). In people with IFG/IGT, insulin did not alter postprandial glucose concentrations or indices of β-cell function. Endogenous glucose production and glucose disappearance was also unchanged in both groups. CONCLUSIONS We conclude that acute, overnight changes in FFA and glucose concentrations do not alter islet function or glucose metabolism in prediabetes.
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Grants
- DK TR000135 HHS | NIH | NIDDK | Division of Diabetes, Endocrinology, and Metabolic Diseases (DEM)
- DK78646 HHS | NIH | NIDDK | Division of Diabetes, Endocrinology, and Metabolic Diseases (DEM)
- DK116231 HHS | NIH | NIDDK | Division of Diabetes, Endocrinology, and Metabolic Diseases (DEM)
- DK126206 HHS | NIH | NIDDK | Division of Diabetes, Endocrinology, and Metabolic Diseases (DEM)
- DK40484 HHS | NIH | NIDDK | Division of Diabetes, Endocrinology, and Metabolic Diseases (DEM)
- DK45343 HHS | NIH | NIDDK | Division of Diabetes, Endocrinology, and Metabolic Diseases (DEM)
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Affiliation(s)
- Daniel Schembri Wismayer
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Marcello C Laurenti
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States
| | - Yilin Song
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Aoife M Egan
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Andrew A Welch
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Kent R Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, United States
| | - Claudio Cobelli
- Department of Woman and Child's Health, University of Padova, Padova, Italy
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Michael D Jensen
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Adrian Vella
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, United States
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Farahani RA, Egan AM, Welch AA, Laurenti MC, Cobelli C, Dalla Man C, Vella A. The Effect of Glucagon-Like Peptide 1 Receptor Blockade on Glucagon-Induced Stimulation of Insulin Secretion. Diabetes 2023; 72:449-454. [PMID: 36562995 PMCID: PMC10260388 DOI: 10.2337/db22-0709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
Data from transgenic rodent models suggest that glucagon acts as an insulin secretagogue by signaling through the glucagon-like peptide 1 receptor (GLP-1R) present on β-cells. However, its net contribution to physiologic insulin secretion in humans is unknown. To address this question, we studied individuals without diabetes in two separate experiments. Each subject was studied on two occasions in random order. In the first experiment, during a hyperglycemic clamp, glucagon was infused at 0.4 ng/kg/min, increasing by 0.2 ng/kg/min every hour for 5 h. On one day, exendin-9,39 (300 pmol/kg/min) was infused to block GLP-1R, while on the other, saline was infused. The insulin secretion rate (ISR) was calculated by nonparametric deconvolution from plasma concentrations of C-peptide. Endogenous glucose production and glucose disappearance were measured using the tracer-dilution technique. Glucagon concentrations, by design, did not differ between study days. Integrated ISR was lower during exendin-9,39 infusion (213 ± 26 vs. 191 ± 22 nmol/5 h, saline vs. exendin-9,39, respectively; P = 0.02). In the separate experiment, exendin-9,39 infusion, compared with saline infusion, also decreased the β-cell secretory response to a 1-mg glucagon bolus. These data show that, in humans without diabetes, glucagon partially stimulates the β-cell through GLP-1R.
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Affiliation(s)
- Rahele A. Farahani
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN
| | - Aoife M. Egan
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN
| | - Andrew A. Welch
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN
| | - Marcello C. Laurenti
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN
| | - 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 & Metabolism, Mayo Clinic College of Medicine, Rochester, MN
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2022] [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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Laurenti MC, Arora P, Dalla Man C, Andrews JC, Rizza RA, Matveyenko A, Bailey KR, Cobelli C, Vella A. The relationship between insulin and glucagon concentrations in non-diabetic humans. Physiol Rep 2022; 10:e15380. [PMID: 35822422 PMCID: PMC9277417 DOI: 10.14814/phy2.15380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 06/02/2023] Open
Abstract
Abnormal postprandial suppression of glucagon in Type 2 diabetes (T2DM) has been attributed to impaired insulin secretion. Prior work suggests that insulin and glucagon show an inverse coordinated relationship. However, dysregulation of α-cell function in prediabetes occurs early and independently of changes in β-cells, which suggests insulin having a less significant role on glucagon control. We therefore, sought to examine whether hepatic vein hormone concentrations provide evidence to further support the modulation of glucagon secretion by insulin. As part of a series of experiments to measure the effect of diabetes-associated genetic variation in TCF7L2 on islet cell function, hepatic vein insulin and glucagon concentrations were measured at 2-minute intervals during fasting and a hyperglycemic clamp. The experiment was performed on 29 nondiabetic subjects (age = 46 ± 2 years, BMI 28 ± 1 Kg/m2 ) and enabled post-hoc analysis, using Cross-Correlation and Cross-Approximate Entropy (Cross-ApEn) to evaluate the interaction of insulin and glucose. Mean insulin concentrations rose from fasting (33 ± 4 vs. 146 ± 12 pmol/L, p < 0.01) while glucagon was suppressed (96 ± 8 vs. 62 ± 5 ng/L, p < 0.01) during the clamp. Cross-ApEn was used to measure pattern reproducibility in the two hormones using glucagon as control mechanism (0.78 ± 0.03 vs. 0.76 ± 0.03, fasting vs. hyperglycemia) and using insulin as a control mechanism (0.78 ± 0.02 vs. 0.76 ± 0.03, fasting vs. hyperglycemia). Values did not differ between the two scenarios. Cross-correlation analysis demonstrated a small in-phase coordination between insulin and glucagon concentrations during fasting, which inverted during hyperglycemia. This data suggests that the interaction between the two hormones is not driven by either. On a minute-to-minute basis, direct control and secretion of glucagon is not mediated (or restrained) by insulin.
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Affiliation(s)
- Marcello C. Laurenti
- Division of Endocrinology, Diabetes & MetabolismEndocrine Research Unit, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical SciencesRochesterMinnesotaUSA
| | - Praveer Arora
- Division of Endocrinology, Diabetes & MetabolismEndocrine Research Unit, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
| | - Chiara Dalla Man
- Department of Information EngineeringUniversity of PadovaPadovaItaly
| | - James C. Andrews
- Vascular and Interventional Radiology, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
| | - Robert A. Rizza
- Division of Endocrinology, Diabetes & MetabolismEndocrine Research Unit, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
| | - Aleksey Matveyenko
- Division of Endocrinology, Diabetes & MetabolismEndocrine Research Unit, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
| | - Kent R. Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
| | - Claudio Cobelli
- Department of Woman and Child's HealthUniversity of PadovaPadovaItaly
| | - Adrian Vella
- Division of Endocrinology, Diabetes & MetabolismEndocrine Research Unit, Mayo Clinic, College of Medicine and ScienceRochesterMinnesotaUSA
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Adams JD, Egan AM, Laurenti MC, Schembri Wismayer D, Bailey KR, Cobelli C, Dalla Man C, Vella A. The Effect of Diabetes-Associated Variation in TCF7L2 on Postprandial Glucose Metabolism When Glucagon and Insulin Concentrations Are Matched. Metab Syndr Relat Disord 2022; 20:329-335. [PMID: 35442800 PMCID: PMC9419949 DOI: 10.1089/met.2021.0136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background: The rs7903146 variant in the TCF7L2 gene is associated with defects in postprandial insulin and glucagon secretion and increased risk of type 2 diabetes. However, it is unclear if this variant has effects on glucose metabolism that are independent of islet function. Methods: We studied 54 nondiabetic subjects on two occasions where endogenous hormone secretion was inhibited by somatostatin. Twenty-nine subjects were homozygous for the diabetes-associated allele (TT) and 25 for the diabetes-protective allele (CC) at rs7903146, but otherwise matched for anthropometric characteristics. On 1 day, glucagon infused at a rate of 0.65 ng/kg/min, and at 0 min prevented a fall in glucagon (nonsuppressed day). On the contrary, infusion commenced at 120 min to create a transient fall in glucagon (suppressed day). Subjects received glucose (labeled with [3-3H]-glucose) infused to mimic the systemic appearance of oral glucose. Insulin was infused to mimic a prandial insulin response. Endogenous glucose production (EGP) was measured using the tracer dilution technique. Results: Lack of glucagon suppression increased postchallenge glucose concentrations and impaired EGP suppression. However, in the presence of matched insulin and glucagon concentrations, genetic variation in TCF7L2 did not alter glucose metabolism. Conclusion: These data suggest that genetic variation in TCF7L2 alters glucose metabolism through changes in islet hormone secretion.
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Affiliation(s)
- Jon D Adams
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Aoife M Egan
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Marcello C Laurenti
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Daniel Schembri Wismayer
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Kent R Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Claudio Cobelli
- Department of Woman and Child's Health and 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, Minnesota, USA
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Simha V, Lanza IR, Dasari S, Klaus KA, Le Brasseur N, Vuckovic I, Laurenti MC, Cobelli C, Port JD, Nair KS. Impaired Muscle Mitochondrial Function in Familial Partial Lipodystrophy. J Clin Endocrinol Metab 2022; 107:346-362. [PMID: 34614176 PMCID: PMC8764358 DOI: 10.1210/clinem/dgab725] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Indexed: 01/04/2023]
Abstract
CONTEXT Familial partial lipodystrophy (FPL), Dunnigan variety is characterized by skeletal muscle hypertrophy and insulin resistance besides fat loss from the extremities. The cause for the muscle hypertrophy and its functional consequences is not known. OBJECTIVE To compare muscle strength and endurance, besides muscle protein synthesis rate between subjects with FPL and matched controls (n = 6 in each group). In addition, we studied skeletal muscle mitochondrial function and gene expression pattern to help understand the mechanisms for the observed differences. METHODS Body composition by dual-energy X-ray absorptiometry, insulin sensitivity by minimal modelling, assessment of peak muscle strength and fatigue, skeletal muscle biopsy and calculation of muscle protein synthesis rate, mitochondrial respirometry, skeletal muscle transcriptome, proteome, and gene set enrichment analysis. RESULTS Despite increased muscularity, FPL subjects did not demonstrate increased muscle strength but had earlier fatigue on chest press exercise. Decreased mitochondrial state 3 respiration in the presence of fatty acid substrate was noted, concurrent to elevated muscle lactate and decreased long-chain acylcarnitine. Based on gene transcriptome, there was significant downregulation of many critical metabolic pathways involved in mitochondrial biogenesis and function. Moreover, the overall pattern of gene expression was indicative of accelerated aging in FPL subjects. A lower muscle protein synthesis and downregulation of gene transcripts involved in muscle protein catabolism was observed. CONCLUSION Increased muscularity in FPL is not due to increased muscle protein synthesis and is likely due to reduced muscle protein degradation. Impaired mitochondrial function and altered gene expression likely explain the metabolic abnormalities and skeletal muscle dysfunction in FPL subjects.
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MESH Headings
- Absorptiometry, Photon
- Adult
- Aged
- Female
- Gene Expression Profiling
- Humans
- Lipodystrophy, Familial Partial/genetics
- Lipodystrophy, Familial Partial/metabolism
- Lipodystrophy, Familial Partial/pathology
- Lipodystrophy, Familial Partial/physiopathology
- Male
- Middle Aged
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/pathology
- Muscle Strength/physiology
- Muscle, Skeletal/cytology
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Physical Endurance/physiology
- Proteolysis
- Young Adult
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Affiliation(s)
- Vinaya Simha
- Divisions of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ian R Lanza
- Divisions of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Surendra Dasari
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Nathan Le Brasseur
- Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Ivan Vuckovic
- Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | | | | | - John D Port
- Radiology, Mayo Clinic, Rochester, MN 55905, USA
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11
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Adams JD, Egan AM, Laurenti MC, Schembri Wismayer D, Bailey KR, Cobelli C, Dalla Man C, Vella A. Insulin secretion and action and the response of endogenous glucose production to a lack of glucagon suppression in nondiabetic subjects. Am J Physiol Endocrinol Metab 2021; 321:E728-E736. [PMID: 34658253 PMCID: PMC8782666 DOI: 10.1152/ajpendo.00284.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Type 2 diabetes is a disease characterized by impaired insulin secretion and defective glucagon suppression in the postprandial period. We examined the effect of impaired glucagon suppression on glucose concentrations and endogenous glucose production (EGP) at different degrees of insulin secretory impairment. The contribution of anthropometric characteristics, peripheral, and hepatic insulin action to this variability was also examined. To do so, we studied 54 nondiabetic subjects on two occasions in which endogenous hormone secretion was inhibited by somatostatin, with glucagon infused at a rate of 0.65 ng/kg/min, at 0 min to prevent a fall in glucagon (nonsuppressed day) or at 120 min to create a transient fall in glucagon (suppressed day). Subjects received glucose (labeled with [3-3H]-glucose) infused to mimic the systemic appearance of 50-g oral glucose. Insulin was infused to mimic a prandial insulin response in 18 subjects, another 18 received 80% of the dose, and the remaining 18 received 60%. EGP was measured using the tracer-dilution technique. Decreased prandial insulin resulted in greater % increase in peak glucose but not in integrated glucose concentrations attributable to nonsuppressed glucagon. The % change in integrated EGP was unaffected by insulin dose. Multivariate regression analysis, adjusted for age, sex, weight, and insulin dose, did not show a relationship between the EGP response to impaired suppression of glucagon and insulin action as measured at the time of screening by oral glucose tolerance. A similar analysis for hepatic insulin action also did not show a relationship with the EGP response. These data indicate that the effect of impaired glucagon suppression on EGP is independent of anthropometric characteristics and insulin action.NEW & NOTEWORTHY In prediabetes, anthropometric characteristics as well as insulin action do not alter the hepatic response to glucagon. The postprandial suppression or lack of suppression of glucagon secretion is an important factor governing postprandial glucose tolerance independent of insulin secretion.
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Affiliation(s)
- Jon D Adams
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
- Department of Health and Human Performance, College of Charleston, Charleston, South Carolina
| | - Aoife M Egan
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Marcello C Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Daniel Schembri Wismayer
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Kent R Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Claudio Cobelli
- Department of Woman and Child'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 & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
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12
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Laurenti MC, Matveyenko A, Vella A. Measurement of Pulsatile Insulin Secretion: Rationale and Methodology. Metabolites 2021; 11:metabo11070409. [PMID: 34206296 PMCID: PMC8305896 DOI: 10.3390/metabo11070409] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 12/29/2022] Open
Abstract
Pancreatic β-cells are responsible for the synthesis and exocytosis of insulin in response to an increase in circulating glucose. Insulin secretion occurs in a pulsatile manner, with oscillatory pulses superimposed on a basal secretion rate. Insulin pulses are a marker of β-cell health, and secretory parameters, such as pulse amplitude, time interval and frequency distribution, are impaired in obesity, aging and type 2 diabetes. In this review, we detail the mechanisms of insulin production and β-cell synchronization that regulate pulsatile insulin secretion, and we discuss the challenges to consider when measuring fast oscillatory secretion in vivo. These include the anatomical difficulties of measuring portal vein insulin noninvasively in humans before the hormone is extracted by the liver and quickly removed from the circulation. Peripheral concentrations of insulin or C-peptide, a peptide cosecreted with insulin, can be used to estimate their secretion profile, but mathematical deconvolution is required. Parametric and nonparametric approaches to the deconvolution problem are evaluated, alongside the assumptions and trade-offs required for their application in the quantification of unknown insulin secretory rates from known peripheral concentrations. Finally, we discuss the therapeutical implication of targeting impaired pulsatile secretion and its diagnostic value as an early indicator of β-cell stress.
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Affiliation(s)
- Marcello C. Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN 55905, USA; (M.C.L.); (A.M.)
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, USA
| | - Aleksey Matveyenko
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN 55905, USA; (M.C.L.); (A.M.)
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN 55905, USA; (M.C.L.); (A.M.)
- Correspondence: ; Tel.: +1-507-255-6515; Fax: +1-507-255-4828
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13
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Egan AM, Laurenti MC, Hurtado Andrade MD, Dalla Man C, Cobelli C, Bailey KR, Vella A. Limitations of the fasting proinsulin to insulin ratio as a measure of β-cell health in people with and without impaired glucose tolerance. Eur J Clin Invest 2021; 51:e13469. [PMID: 33289929 PMCID: PMC8169515 DOI: 10.1111/eci.13469] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND The fasting proinsulin to insulin ratio is elevated in people with type 2 diabetes and has been suggested as a marker of β-cell health. However, its utility in discriminating between individuals with varying degrees of β-cell dysfunction is unclear. Proinsulin has a very different half-life to insulin and unlike insulin does not undergo hepatic extraction prior to reaching the systemic circulation. Given these limitations, we sought to examine the relationship between fasting and postprandial concentrations of β-cell polypeptides (proinsulin, insulin and C-peptide) in people with normal and impaired glucose tolerance in differing metabolic environments. DESIGN Subjects were studied on two occasions in random order while undergoing an oral challenge. During one study day, free fatty acids were elevated (to induce insulin resistance) by infusion of Intralipid with heparin. Proinsulin to insulin and proinsulin to C-peptide ratios were calculated for the 0-, 30-, 60- and 240-minute time points. Insulin action (Si) and β-cell responsivity (Φ) indices were calculated using the oral minimal model. RESULTS The fasting proinsulin to c-peptide or fasting proinsulin to insulin ratios did not differ between groups and did not predict subsequent β-cell responsivity to glucose during the glycerol or Intralipid study days in either group. CONCLUSIONS Among nondiabetic individuals, the fasting proinsulin to insulin ratio is not a useful marker of β-cell function.
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Affiliation(s)
- Aoife M Egan
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic, Rochester, MN, USA
| | - Marcello C Laurenti
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic, Rochester, MN, USA
| | | | - Chiara Dalla Man
- Department of Information Engineering, Università degli Studi di Padova, Padova, Italy
| | - Claudio Cobelli
- Department of Information Engineering, Università degli Studi di Padova, Padova, Italy
| | - Kent R Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Adrian Vella
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic, Rochester, MN, USA
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14
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Laurenti MC, Dalla Man C, Varghese RT, Andrews JC, Jones JG, Barosa C, Rizza RA, Matveyenko A, De Nicolao G, Bailey KR, Cobelli C, Vella A. Insulin Pulse Characteristics and Insulin Action in Non-diabetic Humans. J Clin Endocrinol Metab 2021; 106:1702-1709. [PMID: 33606017 PMCID: PMC8344841 DOI: 10.1210/clinem/dgab100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Pulsatile insulin secretion is impaired in diseases such as type 2 diabetes that are characterized by insulin resistance. This has led to the suggestion that changes in insulin pulsatility directly impair insulin signaling. We sought to examine the effects of pulse characteristics on insulin action in humans, hypothesizing that a decrease in pulse amplitude or frequency is associated with impaired hepatic insulin action. METHODS We studied 29 nondiabetic subjects on two occasions. On 1 occasion, hepatic and peripheral insulin action was measured using a euglycemic clamp. The deuterated water method was used to estimate the contribution of gluconeogenesis to endogenous glucose production. On a separate study day, we utilized nonparametric stochastic deconvolution of frequently sampled peripheral C-peptide concentrations during fasting to reconstruct portal insulin secretion. In addition to measuring basal and pulsatile insulin secretion, we used approximate entropy to measure orderliness and Fourier transform to measure the average, and the dispersion of, insulin pulse frequencies. RESULTS In univariate analysis, basal insulin secretion (R2 = 0.16) and insulin pulse amplitude (R2 = 0.09) correlated weakly with insulin-induced suppression of gluconeogenesis. However, after adjustment for age, sex, and weight, these associations were no longer significant. The other pulse characteristics also did not correlate with the ability of insulin to suppress endogenous glucose production (and gluconeogenesis) or to stimulate glucose disappearance. CONCLUSIONS Overall, our data demonstrate that insulin pulse characteristics, considered independently of other factors, do not correlate with measures of hepatic and peripheral insulin sensitivity in nondiabetic humans.
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Affiliation(s)
- Marcello C Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN, USA
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Ron T Varghese
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN, USA
| | - James C Andrews
- Vascular and Interventional Radiology, Mayo Clinic, Rochester, MN, USA
| | - John G Jones
- Center for Neurosciences, University of Coimbra, Coimbra, Portugal
| | - Cristina Barosa
- Center for Neurosciences, University of Coimbra, Coimbra, Portugal
| | - Robert A Rizza
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN, USA
| | - Aleksey Matveyenko
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN, USA
- Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Giuseppe De Nicolao
- Department of Computer Engineering and Systems Science, University of Pavia, Pavia, Italy
| | - Kent R Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Claudio Cobelli
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, MN, USA
- Correspondence: Adrian Vella MD, Endocrine Research Unit, Mayo Clinic College of Medicine, 200 First ST SW, 5–194 Joseph, Rochester, MN 55905, USA.
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15
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Abstract
Impaired glucose tolerance arises out of impaired postprandial insulin secretion and delayed suppression of glucagon. These defects occur early and independently in the pathogenesis of prediabetes. Quantification of the contribution of α-cell dysfunction to glucose tolerance has been lacking because knowledge of glucagon kinetics in humans is limited. Therefore, in a series of experiments examining the interaction of glucagon suppression with insulin secretion we studied 51 nondiabetic subjects (age = 54 ± 13 yr, BMI = 28 ± 4 kg/m2). Glucose was infused to mimic the systemic appearance of an oral challenge. Somatostatin was used to inhibit endogenous hormone secretion. 120 min after the start of the experiment, glucagon was infused at 0.65 ng/kg/min. The rise in glucagon concentrations was used to estimate its kinetic parameters [volume of distribution (Vd), half-life (t1/2), and clearance rate (CL)]. A single-exponential model provided the best fit for the data, and individualized kinetic parameters were estimated: Vd = 8.2 ± 2.7 L, t1/2 = 4 ± 1.1 min, CL = 1.4 ± 0.33 L/min. Stepwise linear regression was used to correlate Vd with BMI and sex (R2adj = 0.44), whereas CL similarly correlated with lean body mass or BSA (both R2 = 0.28). This enabled the development of a population-based model using anthropometric characteristics to predict Vd and CL. These data demonstrate that it is feasible to derive glucagon kinetic parameters from anthropometric characteristics, thereby enabling quantitation of the rate of glucagon appearance in the systemic circulation in large populations.NEW & NOTEWORTHY State-of-the-art measurement of insulin secretion in humans is accomplished by deconvolution of peripheral C-peptide concentrations using population-derived parameters of C-peptide kinetics. In contrast, knowledge of the kinetic parameters of glucagon in humans is lacking so that measurement of glucagon secretion to date is largely qualitative. This series of experiments enabled measurement of glucagon kinetics in 51 subjects, and subsequently, stepwise linear regression was used to correlate these parameters with anthropometric characteristics. This enabled the development of a population-based model using anthropometric characteristics to predict the volume of distribution and the rate of clearance. This is a necessary first step in the development of a model to quantitate of glucagon secretion and action (and its contribution to glucose tolerance) in large populations.
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Affiliation(s)
- Marcello C Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Jon D Adams
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | | | - Aoife M Egan
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
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16
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Laurenti MC, Dalla Man C, Varghese RT, Andrews JC, Rizza RA, Matveyenko A, De Nicolao G, Cobelli C, Vella A. Diabetes-associated genetic variation in TCF7L2 alters pulsatile insulin secretion in humans. JCI Insight 2020; 5:136136. [PMID: 32182220 DOI: 10.1172/jci.insight.136136] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/05/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUNDMetabolic disorders such as type 2 diabetes have been associated with a decrease in insulin pulse frequency and amplitude. We hypothesized that the T allele at rs7903146 in TCF7L2, previously associated with β cell dysfunction, would be associated with changes in these insulin pulse characteristics.METHODSTwenty-nine nondiabetic subjects (age 46 ± 2, BMI 28 ± 1 kg/m2) participated in this study. Of these, 16 were homozygous for the C allele at rs7903146 and 13 were homozygous for the T allele. Deconvolution of peripheral C-peptide concentrations allowed the reconstruction of portal insulin secretion over time. These data were used for subsequent analyses. Pulse orderliness was assessed by approximate entropy (ApEn), and the dispersion of insulin pulses was measured by a frequency dispersion index (FDI) after a Fast Fourier Transform (FFT) of individual insulin secretion rates.RESULTSDuring fasting conditions, the CC genotype group exhibited decreased pulse disorderliness compared with the TT genotype group (1.10 ± 0.03 vs. 1.19 ± 0.04, P = 0.03). FDI decreased in response to hyperglycemia in the CC genotype group, perhaps reflecting less entrainment of insulin secretion during fasting.CONCLUSIONDiabetes-associated variation in TCF7L2 is associated with decreased orderliness and pulse dispersion, unchanged by hyperglycemia. Quantification of ApEn and FDI could represent novel markers of β cell health.FUNDINGThis work was funded by US NIH (DK78646, DK116231), University of Padova research grant CPDA145405, and Mayo Clinic General Clinical Research Center (UL1 TR000135).
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Affiliation(s)
- Marcello C Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, Minnesota, USA
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Ron T Varghese
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Robert A Rizza
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, Minnesota, USA
| | - Aleksey Matveyenko
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Giuseppe De Nicolao
- Department of Computer Engineering and Systems Science, University of Pavia, Pavia, Italy
| | - Claudio Cobelli
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, Rochester, Minnesota, USA
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17
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Adams JD, Dalla Man C, Laurenti MC, Andrade MDH, Cobelli C, Rizza RA, Bailey KR, Vella A. Fasting glucagon concentrations are associated with longitudinal decline of β-cell function in non-diabetic humans. Metabolism 2020; 105:154175. [PMID: 32045582 PMCID: PMC7093233 DOI: 10.1016/j.metabol.2020.154175] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 01/31/2023]
Abstract
PURPOSE Abnormal glucagon concentrations are a feature of prediabetes but it is uncertain if α-cell dysfunction contributes to a longitudinal decline in β-cell function. We therefore sought to determine if a decline in β-cell function is associated with a higher nadir glucagon in the postprandial period or with higher fasting glucagon. METHODS This was a longitudinal study in which 73 non-diabetic subjects were studied on 2 occasions 6.6 ± 0.3 years apart using a 2-hour, 7-sample oral glucose tolerance test. Disposition Index (DI) was calculated using the oral minimal model applied to the measurements of glucose, insulin, C-peptide concentrations during the studies. We subsequently examined the relationship of glucagon concentrations at baseline with change in DI (used as a measure of β-cell function) after adjusting for changes in weight and the baseline value of DI. RESULTS After adjusting for covariates, nadir postprandial glucagon concentrations were not associated with changes in β-cell function as quantified by DI. On the other hand, fasting glucagon concentrations during the baseline study were inversely correlated with longitudinal changes in DI. CONCLUSIONS Defects in α-cell function, manifest as elevated fasting glucagon, are associated with a subsequent decline in β-cell function. It remains to be ascertained if abnormal α-cell function contributes directly to loss of β-cell secretory capacity in the pathogenesis of type 2 diabetes.
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Affiliation(s)
- Jon D Adams
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Marcello C Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - M Daniela Hurtado Andrade
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Claudio Cobelli
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Robert A Rizza
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kent R Bailey
- Biomedical Statistics and Informatics, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA.
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18
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Laurenti MC, Vella A, Varghese RT, Andrews JC, Sharma A, Kittah NE, Rizza RA, Matveyenko A, De Nicolao G, Cobelli C, Dalla Man C. Assessment of pulsatile insulin secretion derived from peripheral plasma C-peptide concentrations by nonparametric stochastic deconvolution. Am J Physiol Endocrinol Metab 2019; 316:E687-E694. [PMID: 30807214 PMCID: PMC6580177 DOI: 10.1152/ajpendo.00519.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The characteristics of pulsatile insulin secretion are important determinants of type 2 diabetes pathophysiology, but they are understudied due to the difficulties in measuring pulsatile insulin secretion noninvasively. Deconvolution of either peripheral C-peptide or insulin concentrations offers an appealing alternative to hepatic vein catheterization. However, to do so, there are a series of methodological challenges to overcome. C-peptide has a relatively long half-life and accumulates in the circulation. On the other hand, peripheral insulin concentrations reflect relatively fast clearance and hepatic extraction as it leaves the portal circulation to enter the systemic circulation. We propose a method based on nonparametric stochastic deconvolution of C-peptide concentrations, using individually determined C-peptide kinetics, to overcome these limitations. The use of C-peptide (instead of insulin) concentrations allows estimation of portal (and not post-hepatic) insulin pulses, whereas nonparametric stochastic deconvolution allows evaluation of pulsatile signals without any a priori assumptions of pulse shape and occurrence. The only assumption required is the degree of smoothness of the (unknown) secretion rate. We tested this method first on simulated data and then on 29 nondiabetic subjects studied during euglycemia and hyperglycemia and compared our estimates with the profiles obtained from hepatic vein insulin concentrations. This method produced satisfactory results both in the ability to fit the data and in providing reliable estimates of pulsatile secretion, in agreement with hepatic vein measurements. In conclusion, the proposed method enables reliable and noninvasive measurement of pulsatile insulin secretion. Future studies will be needed to validate this method in people with type 2 diabetes.
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Affiliation(s)
- Marcello C Laurenti
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
- Department of Information Engineering, University of Padua , Padua , Italy
| | - Adrian Vella
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
| | - Ron T Varghese
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
| | - James C Andrews
- Vascular and Interventional Radiology, Mayo Clinic , Rochester, Minnesota
| | - Anu Sharma
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
| | - Nana Esi Kittah
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
| | - Robert A Rizza
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
| | - Aleksey Matveyenko
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic , Rochester, Minnesota
- Physiology and Biomedical Engineering, Mayo Clinic , Rochester, Minnesota
| | - Giuseppe De Nicolao
- Department of Computer Engineering and Systems Science, University of Pavia , Pavia , Italy
| | - Claudio Cobelli
- Department of Information Engineering, University of Padua , Padua , Italy
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padua , Padua , Italy
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19
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Shah M, Laurenti MC, Dalla Man C, Ma J, Cobelli C, Rizza RA, Vella A. Contribution of endogenous glucagon-like peptide-1 to changes in glucose metabolism and islet function in people with type 2 diabetes four weeks after Roux-en-Y gastric bypass (RYGB). Metabolism 2019; 93:10-17. [PMID: 30586575 PMCID: PMC6401231 DOI: 10.1016/j.metabol.2018.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/07/2018] [Accepted: 12/20/2018] [Indexed: 01/03/2023]
Abstract
UNLABELLED Glucagon-Like Peptide-1 (GLP-1) is an insulin secretagogue which is elevated after Roux-en-Y Gastric Bypass (RYGB). However, its contribution to glucose metabolism after RYGB remains uncertain. AIMS We tested the hypothesis that GLP-1 lowers postprandial glucose concentrations and improves β-cell function after RYGB. MATERIALS AND METHODS To address these questions we used a labeled mixed meal to assess glucose metabolism and islet function in 12 obese subjects with type 2 diabetes studied before and four weeks after RYGB. During the post-RYGB study subjects were randomly assigned to receive an infusion of either saline or Exendin-9,39 a competitive antagonist of GLP-1 at its receptor. Exendin-9,39 was infused at 300 pmol/kg/min for 6 h. All subjects underwent RYGB for medically-complicated obesity. RESULTS Exendin-9,39 resulted in increased integrated incremental postprandial glucose concentrations (181 ± 154 vs. 582 ± 129 mmol per 6 h, p = 0.02). In contrast, this was unchanged in the presence of saline (275 ± 88 vs. 315 ± 66 mmol per 6 h, p = 0.56) after RYGB. Exendin-9,39 also impaired β-cell responsivity to glucose but did not alter Disposition Index (DI). CONCLUSIONS These data indicate that the elevated GLP-1 concentrations that occur early after RYGB improve postprandial glucose tolerance by enhancing postprandial insulin secretion.
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Affiliation(s)
- Meera Shah
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
| | - Marcello C Laurenti
- Department of Information Engineering, University of Padua, Via Gradenigo 6A, Padua 35131, Italy.
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padua, Via Gradenigo 6A, Padua 35131, Italy.
| | - Jing Ma
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
| | - Claudio Cobelli
- Department of Information Engineering, University of Padua, Via Gradenigo 6A, Padua 35131, Italy.
| | - Robert A Rizza
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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20
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Adams JD, Treiber G, Hurtado MD, Laurenti MC, Dalla Man C, Cobelli C, Rizza RA, Vella A. Increased Rates of Meal Absorption Do Not Explain Elevated 1-Hour Glucose in Subjects With Normal Glucose Tolerance. J Endocr Soc 2018; 3:135-145. [PMID: 30591957 PMCID: PMC6302905 DOI: 10.1210/js.2018-00222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/16/2018] [Indexed: 01/12/2023] Open
Abstract
Context In subjects with normal fasting glucose (NFG) and normal glucose tolerance (NGT), glucose concentrations >155 mg/dL 1 hour after 75 g of oral glucose predict increased risk of progression to diabetes. Recently, it has been suggested that the mechanism underlying this abnormality is increased gut absorption of glucose. Objective We sought to determine the rate of systemic appearance of meal-derived glucose in subjects classified by their 1-hour glucose after a 75-g oral glucose challenge. Design This was a cross-sectional study. Participating subjects underwent a 75-g oral glucose challenge and a labeled mixed meal test. Setting An inpatient clinical research unit at an academic medical center. Participants Thirty-six subjects with NFG/NGT participated in this study. Interventions Subjects underwent an oral glucose tolerance test. Subsequently, they underwent a labeled mixed meal to measure fasting and postprandial glucose metabolism. Main Outcome Measures We examined β-cell function and the rate of meal appearance (Meal Ra) in NFG/NGT subjects. Subsequently, we examined the relationship of peak postchallenge glucose with Meal Ra and indices of β-cell function. Results Peak glucose concentrations correlated inversely with β-cell function. No relationship of Meal Ra with peak postchallenge glucose concentrations was observed. Conclusion In subjects with NFG/NGT, elevated 1-hour peak postchallenge glucose concentrations reflect impaired β-cell function rather than increased systemic meal appearance.
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Affiliation(s)
- J D Adams
- Division of Endocrinology, Diabetes, and Metabolism, Mayo Clinic, Rochester, Minnesota
| | - Gerlies Treiber
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Maria Daniela Hurtado
- Division of Endocrinology, Diabetes, and Metabolism, Mayo Clinic, Rochester, Minnesota
| | - Marcello C Laurenti
- Department of Information Engineering, Università di Padova, 36131 Padova, Italy
| | - Chiara Dalla Man
- Department of Information Engineering, Università di Padova, 36131 Padova, Italy
| | - Claudio Cobelli
- Department of Information Engineering, Università di Padova, 36131 Padova, Italy
| | - Robert A Rizza
- Division of Endocrinology, Diabetes, and Metabolism, Mayo Clinic, Rochester, Minnesota
| | - Adrian Vella
- Division of Endocrinology, Diabetes, and Metabolism, Mayo Clinic, Rochester, Minnesota
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21
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Varghese RT, Man CD, Laurenti MC, Piccinini F, Sharma A, Shah M, Bailey KR, Rizza RA, Cobelli C, Vella A. Performance of individually measured vs population-based C-peptide kinetics to assess β-cell function in the presence and absence of acute insulin resistance. Diabetes Obes Metab 2018; 20:549-555. [PMID: 28862812 PMCID: PMC5946313 DOI: 10.1111/dom.13106] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/22/2017] [Accepted: 08/29/2017] [Indexed: 01/07/2023]
Abstract
AIMS To compare the performance of population-based kinetics with that of directly measured C-peptide kinetics when used to calculate β-cell responsivity indices, and to study people with and without acute insulin resistance to ensure that population-based kinetics apply to all conditions where β-cell function is measured. METHODS Somatostatin was used to inhibit endogenous insulin secretion in 56 people without diabetes. Subsequently, a C-peptide bolus was administered and the changing concentrations were used to calculate individual kinetic measures of C-peptide clearance. In addition, the participants were studied on 2 occasions in random order using an oral glucose tolerance test (OGTT). On one occasion, free fatty acid elevation, to cause insulin resistance, was achieved by infusion of Intralipid + heparin. The Disposition Index (DI) was then estimated by the oral minimal model using either population-based or individual C-peptide kinetics. RESULTS There were marked differences in the exchange variables (k 12 and k 21 ) of the model describing C-peptide kinetics, but smaller differences in the fractional clearance; that is, the irreversible loss from the accessible compartment (k 01 ), obtained from population-based estimates compared with experimental measurement. Because it is predominantly influenced by k 01 , DI estimated using individual kinetics correlated well with DI estimated using population-based kinetics. CONCLUSIONS These data support the use of population-based measures of C-peptide kinetics to estimate β-cell function during an OGTT.
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Affiliation(s)
- Ron T. Varghese
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, 200 1 St SW, 5-194 Joseph, Rochester, Minnesota USA
| | - Chiara Dalla Man
- Department of Information Engineering, Universita’ di Padova, Via Gradenigo 6B, Padova, Italy
| | - Marcello C. Laurenti
- Department of Information Engineering, Universita’ di Padova, Via Gradenigo 6B, Padova, Italy
| | - Francesca Piccinini
- Department of Information Engineering, Universita’ di Padova, Via Gradenigo 6B, Padova, Italy
| | - Anu Sharma
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, 200 1 St SW, 5-194 Joseph, Rochester, Minnesota USA
| | - Meera Shah
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, 200 1 St SW, 5-194 Joseph, Rochester, Minnesota USA
| | - Kent R. Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, 200 1 St SW, Rochester, Minnesota USA
| | - Robert A. Rizza
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, 200 1 St SW, 5-194 Joseph, Rochester, Minnesota USA
| | - Claudio Cobelli
- Department of Information Engineering, Universita’ di Padova, Via Gradenigo 6B, Padova, Italy
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic, 200 1 St SW, 5-194 Joseph, Rochester, Minnesota USA
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22
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Sharma A, Laurenti MC, Dalla Man C, Varghese RT, Cobelli C, Rizza RA, Matveyenko A, Vella A. Glucose metabolism during rotational shift-work in healthcare workers. Diabetologia 2017; 60:1483-1490. [PMID: 28551698 PMCID: PMC5860643 DOI: 10.1007/s00125-017-4317-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/26/2017] [Indexed: 01/05/2023]
Abstract
AIMS/HYPOTHESIS Shift-work is associated with circadian rhythm disruption and an increased risk of obesity and type 2 diabetes. We sought to determine the effect of rotational shift-work on glucose metabolism in humans. METHODS We studied 12 otherwise healthy nurses performing rotational shift-work using a randomised crossover study design. On each occasion, participants underwent an isotope-labelled mixed meal test during a simulated day shift and a simulated night shift, enabling simultaneous measurement of glucose flux and beta cell function using the oral minimal model. We sought to determine differences in fasting and postprandial glucose metabolism during the day shift vs the night shift. RESULTS Postprandial glycaemic excursion was higher during the night shift (381±33 vs 580±48 mmol/l per 5 h, p<0.01). The time to peak insulin and C-peptide and nadir glucagon suppression in response to meal ingestion was also delayed during the night shift. While insulin action did not differ between study days, the beta cell responsivity to glucose (59±5 vs 44±4 × 10-9 min-1; p<0.001) and disposition index were decreased during the night shift. CONCLUSIONS/INTERPRETATION Impaired beta cell function during the night shift may result from normal circadian variation, the effect of rotational shift-work or a combination of both. As a consequence, higher postprandial glucose concentrations are observed during the night shift.
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Affiliation(s)
- Anu Sharma
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic College of Medicine, 200 First St SW, 5-194 Joseph, Rochester, MN, 55905, USA
| | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Ron T Varghese
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic College of Medicine, 200 First St SW, 5-194 Joseph, Rochester, MN, 55905, USA
| | - Claudio Cobelli
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Robert A Rizza
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic College of Medicine, 200 First St SW, 5-194 Joseph, Rochester, MN, 55905, USA
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Adrian Vella
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic College of Medicine, 200 First St SW, 5-194 Joseph, Rochester, MN, 55905, USA.
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23
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Newhouse LP, Joyner MJ, Curry TB, Laurenti MC, Man CD, Cobelli C, Vella A, Limberg JK. Three hours of intermittent hypoxia increases circulating glucose levels in healthy adults. Physiol Rep 2017; 5:5/1/e13106. [PMID: 28087818 PMCID: PMC5256164 DOI: 10.14814/phy2.13106] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 12/08/2016] [Accepted: 12/08/2016] [Indexed: 01/10/2023] Open
Abstract
An independent association exists between sleep apnea and diabetes. Animal models suggest exposure to intermittent hypoxia, a consequence of sleep apnea, results in altered glucose metabolism and fasting hyperglycemia. However, it is unknown if acute exposure to intermittent hypoxia increases glucose concentrations in nondiabetic humans. We hypothesized plasma glucose would be increased from baseline following 3 h of intermittent hypoxia in healthy humans independent of any effect on insulin sensitivity. Eight (7M/1F, 21–34 years) healthy subjects completed two study visits randomized to 3 h of intermittent hypoxia or continuous normoxia, followed by an oral glucose tolerance test. Intermittent hypoxia consisted of 25 hypoxic events per hour where oxygen saturation (SpO2) was significantly reduced (Normoxia: 97 ± 1%, Hypoxia: 90 ± 2%, P < 0.01). Venous plasma glucose concentrations were measured on both visits before and after the 3 h protocol. No changes in plasma glucose were observed from baseline after 3 h of continuous normoxia (5.1 ± 0.2 vs. 5.1 ± 0.1 mmol/L, P > 0.05). In contrast, circulating glucose concentrations were increased after 3 h of intermittent hypoxia when compared to baseline (5.0 ± 0.2 vs. 5.3 ± 0.2 mmol/L, P = 0.01). There were no detectable changes in insulin sensitivity following intermittent hypoxia when compared to continuous normoxia, as assessed by the oral glucose tolerance test (P > 0.05). Circulating glucose is increased after 3 h of intermittent hypoxia in healthy humans, independent of any lasting changes in insulin sensitivity. These novel findings could explain, in part, the high prevalence of diabetes in patients with sleep apnea and warrant future studies to identify underlying mechanisms.
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Affiliation(s)
| | | | - Timothy B Curry
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Claudio Cobelli
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Adrian Vella
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
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