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Rayas M, Gastaldelli A, Honka H, Pezzica S, Carli F, Peterson R, DeFronzo R, Salehi MS. GLP-1 enhances beta-cell response to protein ingestion and bariatric surgery amplifies it. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2023.10.22.23297377. [PMID: 37961500 PMCID: PMC10635165 DOI: 10.1101/2023.10.22.23297377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
OBJECTIVE Protein ingestion stimulates β-cell secretion and alters glucose flux. Enhanced action of glucagon-like peptide 1 (GLP-1) and increased plasma glucose excursion contribute to prandial hyperinsulinemia after gastric bypass surgery (GB) and sleeve gastrectomy (SG). We examined the contribution of endogenous GLP-1 to glucose kinetics and β-cell response to protein ingestion under basal glucose concentrations in humans, and whether these responses are affected by rerouted gut after GB or SG. DESIGN Glucose fluxes, insulin secretion rate (ISR), and incretin responses to a 50-gram oral protein load were compared between 10 non-diabetic individuals with GB, 9 matched subjects with SG and 7 non-operated controls (CN) with and without intravenous infusion of exendin-(9- 39) [Ex-9), a specific GLP-1 receptor (GLP-1R) antagonist. RESULTS Blocking GLP-1R increased the plasma glucose concentration before and after protein ingestion in all 3 groups (p<0.05) and decreased β-cell sensitivity to glucose in the first 30 minutes of protein ingestion (p<0.05). Reduction in the prandial ISR3h by Ex-9 infusion, however, only was observed in GB and SG (p<0.05 for interaction) and not in controls. Also, GLP-1R blockade increased post-protein insulin action in GB and SG, but not CN (p=0.09 for interaction). Endogenous glucose production (EGP) during the first 60 minutes after protein ingestion was increased in all 3 groups but EGP3h only was accentuated in GB by Ex-9 infusion (p<0.05 for interaction). CONCLUSION These findings are consistent with both a pancreatic and extrapancreatic role for GLP-1 during protein ingestion in humans, and GLP-1 actions are exaggerated by bariatric surgery.
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Salehi M, Peterson R, Tripathy D, Pezzica S, DeFronzo R, Gastaldelli A. Differential effect of gastric bypass versus sleeve gastrectomy on insulinotropic action of endogenous incretins. Obesity (Silver Spring) 2023; 31:2774-2785. [PMID: 37853989 PMCID: PMC10593483 DOI: 10.1002/oby.23872] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/09/2023] [Accepted: 06/26/2023] [Indexed: 10/20/2023]
Abstract
OBJECTIVE Prandial hyperinsulinemia after Roux-en-Y gastric bypass surgery (GB), and to lesser degree after sleeve gastrectomy (SG), has been attributed to rapid glucose flux from the gut and increased insulinotropic gut hormones. However, β-cell sensitivity to exogenous incretin is reduced after GB. This study examines the effect of GB versus SG on prandial glycemia and β-cell response to increasing concentrations of endogenous incretins. METHODS Glucose kinetics, insulin secretion rate (ISR), and incretin responses to 50-g oral glucose ingestion were compared between ten nondiabetic participants with GB versus nine matched individuals with SG and seven nonoperated normal glucose tolerant control individuals (CN) with and without administration of 200 mg of sitagliptin. RESULTS Fasting glucose and hormonal levels were similar among three groups. Increasing plasma concentrations of endogenous incretins by two- to three-fold diminished prandial glycemia and increased β-cell secretion in all three groups (p < 0.05), but insulin secretion per insulin sensitivity (i.e., disposition index) was increased only in GB (p < 0.05 for interaction). However, plot of the slope of ISR (from premeal to peak values) versus plasma glucagon-like peptide-1 concentration was smaller after GB compared with SG and CN. CONCLUSIONS After GB, increasing incretin activity augments prandial β-cell response whereas the β-cell sensitivity to increasing plasma concentrations of endogenous incretin is diminished.
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Affiliation(s)
- Marzieh Salehi
- Division of Diabetes, University of Texas at San Antonio, San Antonio, TX, United States
- STVHCS, Audie Murphy Hospital, San Antonio, TX, United States
| | - Richard Peterson
- Department of Surgery, University of Texas at San Antonio, San Antonio, TX, United States
| | - Devjit Tripathy
- Division of Diabetes, University of Texas at San Antonio, San Antonio, TX, United States
| | - Samantha Pezzica
- Cardiometabolic Risk Unit, CNR Institute of Clinical Physiology, Pisa, Italy
| | - Ralph DeFronzo
- Division of Diabetes, University of Texas at San Antonio, San Antonio, TX, United States
| | - Amalia Gastaldelli
- Division of Diabetes, University of Texas at San Antonio, San Antonio, TX, United States
- Cardiometabolic Risk Unit, CNR Institute of Clinical Physiology, Pisa, Italy
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Mittendorfer B, Patterson BW, Magkos F, Yoshino M, Bradley DP, Eagon JC, Klein S. β Cell function after Roux-en-Y gastric bypass surgery or reduced energy intake alone in people with obesity. JCI Insight 2023; 8:e170307. [PMID: 37166995 PMCID: PMC10371232 DOI: 10.1172/jci.insight.170307] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/08/2023] [Indexed: 05/12/2023] Open
Abstract
BackgroundThe effects of diet-induced weight loss (WL) and WL after Roux-en-Y gastric bypass (RYGB) surgery on β cell function (BCF) are unclear because of conflicting results from different studies, presumably because of differences in the methods used to measure BCF, the amount of WL between treatment groups, and baseline BCF. We evaluated the effect of WL after RYGB surgery or reduced energy intake alone on BCF in people with obesity with and without type 2 diabetes.MethodsBCF (insulin secretion in relationship to plasma glucose) was assessed before and after glucose or mixed-meal ingestion before and after (a) progressive amounts (6%, 11%, 16%) of WL induced by a low-calorie diet (LCD) in people with obesity without diabetes, (b) ~20% WL after RYGB surgery or laparoscopic adjustable gastric banding (LAGB) in people with obesity without diabetes, and (c) ~20% WL after RYGB surgery or LCD alone in people with obesity and diabetes.ResultsDiet-induced progressive WL in people without diabetes progressively decreased BCF. Marked WL after LAGB or RYGB in people without diabetes did not alter BCF. Marked WL after LCD or RYGB in people with diabetes markedly increased BCF, without a difference between groups.ConclusionMarked WL increases BCF in people with obesity and diabetes but not in people with obesity without diabetes. The effect of RYGB-induced WL on BCF is not different from the effect of matched WL after LAGB or LCD alone.trial registrationNCT00981500, NCT02207777, NCT01299519.FundingNIH grants R01 DK037948, P30 DK056341, P30 DK020579, UL1 TR002345.
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Salehi M, Peterson R, Tripathy D, Pezzica S, DeFronzo R, Gastaldelli A. Insulinotropic effect of endogenous incretins is greater after gastric bypass than sleeve gastrectomy despite diminished beta-cell sensitivity to plasma incretins. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.28.23287755. [PMID: 37034666 PMCID: PMC10081422 DOI: 10.1101/2023.03.28.23287755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
BACKGROUND/AIMS Prandial hyperinsulinemia after Roux-en Y gastric bypass surgery (GB), and to lesser degree after sleeve gastrectomy (SG), has been attributed to rapid glucose flux from the gut and increased insulinotropic gut hormones. However, β-cell sensitivity to exogenous incretin is markedly reduced after GB. This study examines the effect of GB versus SG on prandial glycemia and β-cell response to increasing concentrations of endogenous incretins. METHODS Glucose kinetics, insulin secretion rate (ISR), and incretin responses to 50-gram oral glucose ingestion were compared between 10 non-diabetic subjects with GB versus 9 matched individuals with SG and 7 non-operated normal glucose tolerant controls (CN) on two days with and without administration of 200 mg sitagliptin. RESULTS Fasting glucose and hormonal levels were similar among 3 groups. Increasing plasma concentrations of endogenous incretins by 2-3-fold diminished post-OGTT glycemia and increased β-cell secretion in all 3 groups (p<0.05), but insulin secretion per insulin sensitivity (i.e., disposition index) was increased only in GB (p<0.05 for interaction). As a result, sitagliptin administration led to hypoglycemia in 3 of 10 GB. Yet, plot of the slope of ISR versus the increase in endogenous incretin concentration was smaller after GB compared to both SG and CN. CONCLUSION Augmented glycemic-induced β-cell response caused by enhanced incretin activity is unique to GB and not shared with SG. However, the β-cell sensitivity to increasing concentrations of endogenous incretin is smaller after bariatric surgery, particularly after GB, compared to non-operated controls, indicating a long-term adaptation of gut-pancreas axis after these procedures. HIGHLIGHTS What is known?: Glycemic effects of gastric bypass (GB) and sleeve gastrectomy (SG) is attributed to rapid nutrient flux and enhanced insulinotropic effects of gut hormones but β-cell sensitivity to exogenous GLP-1 or GIP is diminished after GB. What the present findings add?: Post-OGTT β-cell sensitivity to enhanced endogenous incretins by DPP4i is markedly reduced in bariatric subjects versus non-operated controls, and yet insulin secretory response (disposition index) is increased leading to hypoglycemia in GB and not SG. Significance?: Blunted sensitivity to GLP-1 may represent β-cell adaptation to massive elevation in GLP-1 secretion following bariatric surgery to protect against hypoglycemia.The differential effect of enhanced concentrations of incretins on post-OGTT insulin response (disposition index) among GB versus SG highlights a distinct adaptive process among the two procedures.Augmented insulinotropic effects of gut hormones on postprandial insulin secretory response after GB despite a reduced beta-cell sensitivity to plasma concentrations of GLP-1 makes a case for non-hormonal mechanisms of GLP-1 action after GB.Better understanding of long-term effects of bariatric surgery on gut-pancreas axis activity is critical in development of GLP-1-based strategies to address glucose abnormalities (both hyperglycemia and hypoglycemia) in these settings.
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Nakamura Y, Horie I, Kanetaka K, Eguchi S, Nakamichi S, Hongo R, Takashima M, Kawakami A, Abiru N. Exenatide challenge in oral glucose tolerance test is insufficient for predictions of glucose metabolism and insulin secretion after sleeve gastrectomy (SG) in obese patients with type 2 diabetes: a pilot study to establish a preoperative model to estimate β-cell function following augmented glucagon-like peptide-1 secretion after SG. Endocr J 2022; 69:1457-1465. [PMID: 35896344 DOI: 10.1507/endocrj.ej22-0224] [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] [Indexed: 12/30/2022] Open
Abstract
The postoperative increase in glucagon-like peptide-1 (GLP-1) is the main factor to improve glucose metabolism following sleeve gastrectomy (SG) in obese patients with type 2 diabetes. We investigated whether the β-cell responsiveness to an injection of exogenous GLP-1 in the preoperative period could determine the postoperative glucose tolerance in 18 patients underwent SG. In the preoperative period, a regular oral glucose tolerance test (OGTT) and an exenatide-challenge during OGTT (Ex-OGTT) were performed to evaluate the β-cell function and its responsiveness to GLP-1. The postoperative glucose tolerance was evaluated by another regular OGTT performed at 3 months after SG. The significant decrease in glucose levels with enhanced secretions of insulin and GLP-1 was observed in OGTT at 3 months after SG. The area under the curve of glucose from 0 to 120 minutes (AUC glucose0-120 min) and the insulinogenic index (I.I.) in OGTT at 3 months post-SG were significantly improved compared to those in preoperative period, but comparable with those in Ex-OGTT. AUC glucose0-120 min and I.I. in OGTT at 3 months post-SG were significantly correlated with not only those in Ex-OGTT, but also those in the preoperative regular OGTT. Conversely, the correlations calculated by the Spearman's ρ were stronger in the latter than the former. This exenatide-challenge protocol might be useful to estimate glucose tolerance and insulin secretion after SG, however, it may be insufficient to improve predictability of a patient who is likely to achieve a significant benefit on glucose metabolism from receiving SG.
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Affiliation(s)
- Yuta Nakamura
- Department of Endocrinology and Metabolism, Division of Advanced Preventive Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Ichiro Horie
- Department of Endocrinology and Metabolism, Division of Advanced Preventive Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Kengo Kanetaka
- Department of Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Susumu Eguchi
- Department of Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Seiko Nakamichi
- Department of General Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Ryoko Hongo
- Department of Nutrition Science, Faculty of Nursing and Nutrition, University of Nagasaki, Nagasaki 851-2195, Japan
| | - Miwa Takashima
- Nutritional Management Division, Nagasaki University Hospital, Nagasaki 852-8501, Japan
| | - Atsushi Kawakami
- Department of Endocrinology and Metabolism, Division of Advanced Preventive Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Norio Abiru
- Department of Endocrinology and Metabolism, Division of Advanced Preventive Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
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Buser A, Joray C, Schiavon M, Kosinski C, Minder B, Nakas CT, Man CD, Muka T, Herzig D, Bally L. Effects of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy on β-Cell Function at 1 Year After Surgery: A Systematic Review. J Clin Endocrinol Metab 2022; 107:3182-3197. [PMID: 35895383 PMCID: PMC9681618 DOI: 10.1210/clinem/dgac446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Indexed: 11/19/2022]
Abstract
Bariatric surgery is a highly effective obesity treatment resulting in substantial weight loss and improved glucose metabolism. We hereby aimed to summarize available evidence of the effect of the 2 most common bariatric surgery procedures, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), on dynamic measures of β-cell function (BCF). A systematic search of the literature was conducted in 3 bibliographic databases for studies reporting effects of RYGB and/or SG on BCF assessed using dynamic metabolic perturbation (oral or intravenous bolus stimulation), performed before and 1 year (±3 months) after surgery. Twenty-seven unique studies (6 randomized controlled trials and 21 observational studies), involving a total of 1856 obese adults, were included for final analysis. Twenty-five and 9 studies report effects of RYGB and SG on BCF, respectively (7 studies compared the 2 procedures). Seven studies report results according to presurgical diabetes status. Owing to variable testing procedures and BCF indices reported, no meta-analysis was feasible, and data were summarized qualitatively. For both surgical procedures, most studies suggest an increase in BCF and disposition index, particularly when using oral stimulation, with a more pronounced increase in diabetic than nondiabetic individuals. Additionally, limited indications for greater effects after RYGB versus SG were found. The quality of the included studies was, in general, satisfactory. The considerable heterogeneity of test protocols and outcome measures underscore the need for a harmonization of BCF testing in future research.
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Affiliation(s)
| | | | - Michele Schiavon
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Christophe Kosinski
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Service of Endocrinology, Diabetes and Metabolism, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Beatrice Minder
- Public Health & Primary Care Library, University Library of Bern, University of Bern, Switzerland
| | - Christos T Nakas
- Laboratory of Biometry, School of Agriculture, University of Thessaly, Nea Ionia-Volos, Magnesia, Greece
- University Institute of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Taulant Muka
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | | | - Lia Bally
- Correspondence: Lia Bally, MD, PhD, Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Bern University Hospital, Freiburgstrasse 15, 3010 Bern, Switzerland.
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Herzig D, Schiavon M, Tripyla A, Lehmann V, Meier J, Jainandunsing S, Kuenzli C, Stauffer TP, Dalla Man C, Bally L. Unraveling, contributing factors to the severity of postprandial hypoglycemia after gastric bypass surgery. Surg Obes Relat Dis 2022; 19:467-472. [PMID: 36509672 DOI: 10.1016/j.soard.2022.10.037] [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: 03/24/2022] [Revised: 09/22/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Despite the increasing prevalence of postbariatric hypoglycemia (PBH), a late metabolic complication of bariatric surgery, our understanding of its diverse manifestations remains incomplete. OBJECTIVES To contrast parameters of glucose-insulin homeostasis in 2 distinct phenotypes of PBH (mild versus moderate hypoglycemia) based on nadir plasma glucose. SETTING University Hospital (Bern, Switzerland). METHODS Twenty-five subjects with PBH following gastric bypass surgery (age, 41 ± 12 years; body mass index, 28.1 ± 6.1kg/m2) received 75g of glucose with frequent blood sampling for glucose, insulin, C-peptide, and glucagon-like peptide 1 (GLP)-1. Based on nadir plasma glucose (</≥50mg/dL), subjects were grouped into level 1 (L1) and level 2 (L2) PBH groups. Beta-cell function (BCF), GLP-1 exposure (λ), beta-cell sensitivity to GLP-1 (π), potentiation of insulin secretion by GLP-1 (PI), first-pass hepatic insulin extraction (HE), insulin sensitivity (SI), and rate of glucose appearance (Ra) were calculated using an oral model of GLP-1 action coupled with the oral minimal model. RESULTS Nadir glucose was 43.3 ± 6.0mg/dL (mean ± standard deviation) and 60.1 ± 9.1mg/dL in L2- and L1-PBH, respectively. Insulin exposure was significantly higher in L2 versus L1 (P = .004). Mathematical modeling revealed higher BCF in L2 versus L1 (34.3 versus 18.8 10-9∗min-1; P = .003). Despite an increased GLP-1 exposure in L2 compared to L1 PBH (50.7 versus 31.9pmol∗L-1∗min∗102; P = .021), no significant difference in PI was observed (P = .204). No significant differences were observed for HE, Ra, and SI. CONCLUSIONS Our results suggest that higher insulin exposure in PBH patients with lower postprandial nadir glucose values mainly relate to a higher responsiveness to glucose, rather than GLP-1.
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Affiliation(s)
- David Herzig
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Michele Schiavon
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Afroditi Tripyla
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Vera Lehmann
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jasmin Meier
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Sjaam Jainandunsing
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of Internal Medicine, Maasstad Hospital, Rotterdam, the Netherlands
| | | | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Lia Bally
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
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Shah A, Prasad M, Mark V, Holst JJ, Laferrère B. Glucagon-like peptide-1 effect on β-cell function varies according to diabetes remission status after Roux-en-Y gastric bypass. Diabetes Obes Metab 2022; 24:2081-2089. [PMID: 35676799 PMCID: PMC9595602 DOI: 10.1111/dom.14793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/20/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022]
Abstract
AIMS The contribution of endogenous glucagon-like peptide (GLP)-1 to β-cell function after Roux-en-Y gastric bypass surgery (RYGB) is well established in normoglycaemic individuals, but not in those with postoperative hyperglycaemia. We, therefore, studied the effect of GLP-1 on β-cell function in individuals with varying degrees of type 2 diabetes mellitus (T2D) control after RYGB. MATERIALS AND METHODS Glucose, insulin secretion rates, β-cell glucose sensitivity and glucagon were measured during an oral glucose tolerance test before (saline only) and at 3, 12 and 24 months after RYGB with and without infusion of the GLP-1 receptor blocker exendin9-39 (EX9). The cohort was retrospectively classified based on T2D remission (REM) status at the latest study time point: REM (n = 5), persistent T2D (n = 8), or impaired glucose tolerance (n = 16). RESULTS EX9 blunted the increase in β-cell glucose sensitivity at 3 months (-44.1%, p < .001) and 12 months (-43.3%, p < .001), but not at 24 months (-12.4%, p = .243). EX9 enhanced postprandial glucagon concentrations by 62.0% at 3 months (p = .008), 46.5% at 12 months (p = .055), and 30.4% at 24 months (p = .017). EX9 counterintuitively decreased glucose concentrations at 3 months in the entire cohort (p < .001) but had no effect on glycaemia at 12 and 24 months in persistent T2D and impaired glucose tolerance; it minimally worsened glycaemia in REM at 12 months. CONCLUSIONS GLP-1 blockade reversed the improvement in β-cell function observed after RYGB, but this effect varied temporally and by REM status. GLP-1 blockade transiently and minimally worsened glycaemia only in REM, and lowered postprandial glucose values at 3 months, regardless of REM status.
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Affiliation(s)
- Ankit Shah
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, New Jersey, USA
| | - Malini Prasad
- New York Obesity Nutrition Research Center, Division of Endocrinology. Department of Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Victoria Mark
- New York Obesity Nutrition Research Center, Division of Endocrinology. Department of Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Jens Juul Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
- Novo Nordisk Foundation Centre for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Blandine Laferrère
- Division of Endocrinology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
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9
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Prasad M, Mark V, Ligon C, Dutia R, Nair N, Shah A, Laferrère B. Role of the Gut in the Temporal Changes of β-Cell Function After Gastric Bypass in Individuals With and Without Diabetes Remission. Diabetes Care 2022; 45:469-476. [PMID: 34857533 PMCID: PMC8914419 DOI: 10.2337/dc21-1270] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/10/2021] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The role of the gut in diabetes remission after Roux-en-Y gastric bypass (RYGB) is incompletely understood. We assessed the temporal change in insulin secretory capacity after RYGB, using oral and intravenous (IV) glucose, in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS Longitudinal, prospective measures of β-cell function were assessed after oral glucose intake and graded glucose infusion in individuals with severe obesity and diabetes studied at 0, 3 (n = 29), 12 (n = 24), and 24 (n = 20) months after RYGB. Data were collected between 2015 and 2019 in an academic clinical research center. RESULTS The decreases in body weight, fat mass, waist circumference, and insulin resistance after surgery (all P < 0.001 at 12 and 24 months) did not differ according to diabetes remission status. In contrast, both the magnitude and temporal changes in β-cell glucose sensitivity after oral glucose intake differed by remission status (P = 0.04): greater (6.5-fold; P < 0.01) and sustained in those in full remission, moderate and not sustained past 12 months in those with partial remission (3.3-fold; P < 0.001), and minimal in those not experiencing remission (2.7-fold; P = not significant). The improvement in β-cell function after IV glucose administration was not apparent until 12 months, significant only in those in full remission, and only ∼33% of that observed after oral glucose intake. Preintervention β-cell function and its change after surgery predicted remission; weight loss and insulin sensitivity did not. CONCLUSIONS Our data show the time course of changes in β-cell function after RYGB. The improvement in β-cell function after RYGB, but not changes in weight loss or insulin sensitivity, drives diabetes remission.
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Affiliation(s)
- Malini Prasad
- New York Nutrition Obesity Research Center, Columbia University Irving Medical Center, New York, NY
| | - Victoria Mark
- New York Nutrition Obesity Research Center, Columbia University Irving Medical Center, New York, NY
| | - Chanel Ligon
- Department of Medicine, Columbia University Irving Medical Center, New York, NY
| | - Roxanne Dutia
- New York Nutrition Obesity Research Center, Columbia University Irving Medical Center, New York, NY
| | - Nandini Nair
- Division of Endocrinology, Columbia University Irving Medical Center, New York, NY
| | - Ankit Shah
- Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ
| | - Blandine Laferrère
- New York Nutrition Obesity Research Center, Columbia University Irving Medical Center, New York, NY.,Department of Medicine, Columbia University Irving Medical Center, New York, NY.,Division of Endocrinology, Columbia University Irving Medical Center, New York, NY
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10
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Fatima F, Hjelmesæth J, Birkeland KI, Gulseth HL, Hertel JK, Svanevik M, Sandbu R, Småstuen MC, Hartmann B, Holst JJ, Hofsø D. Gastrointestinal Hormones and β-Cell Function After Gastric Bypass and Sleeve Gastrectomy: A Randomized Controlled Trial (Oseberg). J Clin Endocrinol Metab 2022; 107:e756-e766. [PMID: 34463768 DOI: 10.1210/clinem/dgab643] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Indexed: 02/04/2023]
Abstract
CONTEXT Whether Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) differentially affect postprandial gastrointestinal hormones and β-cell function in type 2 diabetes remains unclear. OBJECTIVE We aimed to compare gastrointestinal hormones and β-cell function, assessed by an oral glucose tolerance test (OGTT) 5 weeks and 1 year after surgery, hypothesizing higher glucagon-like peptide-1 (GLP-1) levels and greater β-cell response to glucose after RYGB than after SG. METHODS This study was a randomized, triple-blind, single-center trial at a tertiary care center in Norway. The primary outcomes were diabetes remission and IVGTT-derived β-cell function. Participants with obesity and type 2 diabetes were allocated (1:1) to RYGB or SG. We measured gastrointestinal hormone profiles and insulin secretion as β-cell glucose sensitivity (β-GS) derived from 180-minute OGTTs. RESULTS Participants were 106 patients (67% women), mean (SD) age 48 (10) years. Diabetes remission rates at 1 year were higher after RYGB than after SG (77% vs 48%; P = 0.002). Incremental area under the curve (iAUC0-180) GLP-1 and β-GS increased more after RYGB than after SG, with 1-year between-group difference 1173 pmol/L*min (95% CI, 569-1776; P = 0.0010) and 0.45 pmol/kg/min/mmol (95% CI, 0.15-0.75; P = 0.0032), respectively. After surgery, fasting and postprandial ghrelin levels were higher and decremental AUC0-180 ghrelin, iAUC0-180 glucose-dependent insulinotropic polypeptide, and iAUC0-60 glucagon were greater after RYGB than after SG. Diabetes remission at 1 year was associated with higher β-GS and higher GLP-1 secretion. CONCLUSION RYGB was associated with greater improvement in β-cell function and higher postprandial GLP-1 levels than SG.
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Affiliation(s)
- Farhat Fatima
- Morbid Obesity Centre, Vestfold Hospital Trust, 3103 Tønsberg, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
| | - Jøran Hjelmesæth
- Morbid Obesity Centre, Vestfold Hospital Trust, 3103 Tønsberg, Norway
- Department of Endocrinology, Morbid Obesity and Preventive Medicine, Institute of Clinical Medicine, University of Oslo, 0424 Oslo, Norway
| | - Kåre Inge Birkeland
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
- Department of Transplantation, Oslo University Hospital, 0424 Oslo, Norway
| | - Hanne Løvdal Gulseth
- Department of Chronic Diseases and Ageing, Norwegian Institute of Public Health, 0213 Oslo, Norway
| | | | - Marius Svanevik
- Morbid Obesity Centre, Vestfold Hospital Trust, 3103 Tønsberg, Norway
- Department of Surgery, Vestfold Hospital Trust, 3103 Tønsberg, Norway
| | - Rune Sandbu
- Morbid Obesity Centre, Vestfold Hospital Trust, 3103 Tønsberg, Norway
- Department of Surgery, Vestfold Hospital Trust, 3103 Tønsberg, Norway
| | - Milada Cvancarova Småstuen
- Morbid Obesity Centre, Vestfold Hospital Trust, 3103 Tønsberg, Norway
- Department of Nutrition and Management, Oslo Metropolitan University, 0130 Oslo, Norway
| | - Bolette Hartmann
- NNF Center for Basic Metabolic Research and Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jens Juul Holst
- NNF Center for Basic Metabolic Research and Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Dag Hofsø
- Morbid Obesity Centre, Vestfold Hospital Trust, 3103 Tønsberg, Norway
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11
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Walker JT, Saunders DC, Brissova M, Powers AC. The Human Islet: Mini-Organ With Mega-Impact. Endocr Rev 2021; 42:605-657. [PMID: 33844836 PMCID: PMC8476939 DOI: 10.1210/endrev/bnab010] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Indexed: 02/08/2023]
Abstract
This review focuses on the human pancreatic islet-including its structure, cell composition, development, function, and dysfunction. After providing a historical timeline of key discoveries about human islets over the past century, we describe new research approaches and technologies that are being used to study human islets and how these are providing insight into human islet physiology and pathophysiology. We also describe changes or adaptations in human islets in response to physiologic challenges such as pregnancy, aging, and insulin resistance and discuss islet changes in human diabetes of many forms. We outline current and future interventions being developed to protect, restore, or replace human islets. The review also highlights unresolved questions about human islets and proposes areas where additional research on human islets is needed.
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Affiliation(s)
- John T Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Diane C Saunders
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Marcela Brissova
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Alvin C Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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12
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Hindsø M, Svane MS, Hedbäck N, Holst JJ, Madsbad S, Bojsen-Møller KN. The role of GLP-1 in postprandial glucose metabolism after bariatric surgery: a narrative review of human GLP-1 receptor antagonist studies. Surg Obes Relat Dis 2021; 17:1383-1391. [PMID: 33771461 DOI: 10.1016/j.soard.2021.01.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/22/2020] [Accepted: 01/28/2021] [Indexed: 12/14/2022]
Abstract
The Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) bariatric procedures lead to remission or improvement of type 2 diabetes. A weight loss-independent augmentation of postprandial insulin secretion contributes to the improvement in glycemic control after RYGB and is associated with a ∼10-fold increase in plasma concentrations of the incretin hormone glucagon-like peptide-1 (GLP-1). However, the physiologic importance of the markedly increased postprandial GLP-1 secretion after RYGB has been much debated. The effect of GLP-1 receptor blockade after RYGB has been investigated in 12 studies. The studies indicate a shift toward a more prominent role for GLP-1 in postprandial β-cell function after RYGB. The effect of GLP-1 receptor antagonism on glucose tolerance after RYGB is more complex and is associated with important methodological challenges. The postprandial GLP-1 response is less enhanced after SG compared with RYGB. However, the effect of GLP-1 receptor blockade after SG has been examined in 1 study only and needs further investigation.
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Affiliation(s)
- Morten Hindsø
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
| | - Maria S Svane
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Nora Hedbäck
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, University of Copenhagen and Novo Nordisk Foundation Center for Basic Metabolic Research, Copenhagen, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
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13
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Amouyal C, Castel J, Guay C, Lacombe A, Denom J, Migrenne-Li S, Rouault C, Marquet F, Georgiadou E, Stylianides T, Luquet S, Le Stunff H, Scharfmann R, Clément K, Rutter GA, Taboureau O, Magnan C, Regazzi R, Andreelli F. A surrogate of Roux-en-Y gastric bypass (the enterogastro anastomosis surgery) regulates multiple beta-cell pathways during resolution of diabetes in ob/ob mice. EBioMedicine 2020; 58:102895. [PMID: 32739864 PMCID: PMC7393530 DOI: 10.1016/j.ebiom.2020.102895] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bariatric surgery is an effective treatment for type 2 diabetes. Early post-surgical enhancement of insulin secretion is key for diabetes remission. The full complement of mechanisms responsible for improved pancreatic beta cell functionality after bariatric surgery is still unclear. Our aim was to identify pathways, evident in the islet transcriptome, that characterize the adaptive response to bariatric surgery independently of body weight changes. METHODS We performed entero-gastro-anastomosis (EGA) with pyloric ligature in leptin-deficient ob/ob mice as a surrogate of Roux-en-Y gastric bypass (RYGB) in humans. Multiple approaches such as determination of glucose tolerance, GLP-1 and insulin secretion, whole body insulin sensitivity, ex vivo glucose-stimulated insulin secretion (GSIS) and functional multicellular Ca2+-imaging, profiling of mRNA and of miRNA expression were utilized to identify significant biological processes involved in pancreatic islet recovery. FINDINGS EGA resolved diabetes, increased pancreatic insulin content and GSIS despite a persistent increase in fat mass, systemic and intra-islet inflammation, and lipotoxicity. Surgery differentially regulated 193 genes in the islet, most of which were involved in the regulation of glucose metabolism, insulin secretion, calcium signaling or beta cell viability, and these were normalized alongside changes in glucose metabolism, intracellular Ca2+ dynamics and the threshold for GSIS. Furthermore, 27 islet miRNAs were differentially regulated, four of them hubs in a miRNA-gene interaction network and four others part of a blood signature of diabetes resolution in ob/ob mice and in humans. INTERPRETATION Taken together, our data highlight novel miRNA-gene interactions in the pancreatic islet during the resolution of diabetes after bariatric surgery that form part of a blood signature of diabetes reversal. FUNDING European Union's Horizon 2020 research and innovation programme via the Innovative Medicines Initiative 2 Joint Undertaking (RHAPSODY), INSERM, Société Francophone du Diabète, Institut Benjamin Delessert, Wellcome Trust Investigator Award (212625/Z/18/Z), MRC Programme grants (MR/R022259/1, MR/J0003042/1, MR/L020149/1), Diabetes UK (BDA/11/0004210, BDA/15/0005275, BDA 16/0005485) project grants, National Science Foundation (310030-188447), Fondation de l'Avenir.
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Affiliation(s)
- Chloé Amouyal
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Diabetology department, F-75013 Paris, France
| | - Julien Castel
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Claudiane Guay
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Amélie Lacombe
- PreclinICAN, Institute of Cardiometabolism and Nutrition, Paris, France
| | - Jessica Denom
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | | | - Christine Rouault
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France
| | - Florian Marquet
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France
| | - Eleni Georgiadou
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | | | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Hervé Le Stunff
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Raphael Scharfmann
- Université de Paris, Cochin Institute, Inserm U1016, Paris 75014, France
| | - Karine Clément
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France; APHP, Pitié-Salpêtrière Hospital, Nutrition department, F-75013 Paris, France
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK; Lee Kong Chian School of Medicine, Nan Yang Technological University, Singapore
| | - Olivier Taboureau
- Université de Paris, BFA, Team CMPLI, Inserm U1133, CNRS UMR 8251, Paris, France
| | | | - Romano Regazzi
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Rue du Bugnon 7, CH-1005 Lausanne, Switzerland
| | - Fabrizio Andreelli
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Diabetology department, F-75013 Paris, France.
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14
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Gimeno RE, Briere DA, Seeley RJ. Leveraging the Gut to Treat Metabolic Disease. Cell Metab 2020; 31:679-698. [PMID: 32187525 PMCID: PMC7184629 DOI: 10.1016/j.cmet.2020.02.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 11/23/2019] [Accepted: 02/20/2020] [Indexed: 02/07/2023]
Abstract
25 years ago, the future of treating obesity and diabetes focused on end organs known to be involved in energy balance and glucose regulation, including the brain, muscle, adipose tissue, and pancreas. Today, the most effective therapies are focused around the gut. This includes surgical options, such as vertical sleeve gastrectomy and Roux-en-Y gastric bypass, that can produce sustained weight loss and diabetes remission but also extends to pharmacological treatments that simulate or amplify various signals that come from the gut. The purpose of this Review is to discuss the wealth of approaches currently under development that seek to further leverage the gut as a source of novel therapeutic opportunities with the hope that we can achieve the effects of surgical interventions with less invasive and more scalable solutions.
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Affiliation(s)
- Ruth E Gimeno
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46225, USA
| | - Daniel A Briere
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46225, USA
| | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, MI 48109, USA.
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15
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Douros JD, Tong J, D’Alessio DA. The Effects of Bariatric Surgery on Islet Function, Insulin Secretion, and Glucose Control. Endocr Rev 2019; 40:1394-1423. [PMID: 31241742 PMCID: PMC6749890 DOI: 10.1210/er.2018-00183] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 04/23/2019] [Indexed: 01/19/2023]
Abstract
Although bariatric surgery was developed primarily to treat morbid obesity, evidence from the earliest clinical observations to the most recent clinical trials consistently demonstrates that these procedures have substantial effects on glucose metabolism. A large base of research indicates that bariatric surgeries such as Roux-en-Y gastric bypass (RYGB), vertical sleeve gastrectomy (VSG), and biliopancreatic diversion (BPD) improve diabetes in most patients, with effects frequently evident prior to substantial weight reduction. There is now unequivocal evidence from randomized controlled trials that the efficacy of surgery is superior to intensive life-style/medical management. Despite advances in the clinical understanding and application of bariatric surgery, there remains only limited knowledge of the mechanisms by which these procedures confer such large changes to metabolic physiology. The improvement of insulin sensitivity that occurs with weight loss (e.g., the result of diet, illness, physical training) also accompanies bariatric surgery. However, there is evidence to support specific effects of surgery on insulin clearance, hepatic glucose production, and islet function. Understanding the mechanisms by which surgery affects these parameters of glucose regulation has the potential to identify new targets for therapeutic discovery. Studies to distinguish among bariatric surgeries on key parameters of glucose metabolism are limited but would be of considerable value to assist clinicians in selecting specific procedures and investigators in delineating the resulting physiology. This review is based on literature related to factors governing glucose metabolism and insulin secretion after the commonly used RYGB and VSG, and the less frequently used BPD and adjustable gastric banding.
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Affiliation(s)
- Jonathan D Douros
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - Jenny Tong
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - David A D’Alessio
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
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16
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Temporal plasticity of insulin and incretin secretion and insulin sensitivity following sleeve gastrectomy contribute to sustained improvements in glucose control. Mol Metab 2019; 28:144-150. [PMID: 31326351 PMCID: PMC6822258 DOI: 10.1016/j.molmet.2019.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/19/2019] [Accepted: 07/02/2019] [Indexed: 12/25/2022] Open
Abstract
Objective Bariatric surgery acutely improves glucose control, an effect that is generally sustained for years in most patients. The acute postoperative glycemic reduction is at least partially mediated by enhanced incretin secretion and islet function, and occurs independent of caloric restriction, whereas the sustained improvement in glucose control is associated with increased insulin sensitivity. However, studies in humans with bariatric surgery suggest that these elevations are not static but undergo coordinated regulation throughout the postoperative time course. The studies described here test the hypothesis that incretin secretion, islet function, and peripheral insulin sensitivity undergo temporal regulation following bariatric surgery as a means to regulate glucose homeostasis. Methods Incretin secretion, islet function, and insulin sensitivity in mice with vertical sleeve gastrectomy (VSG) were compared to sham-operated controls that were pair-fed for 90d, matching food consumption and body-weight between groups. Results Glucose clearance and insulin secretion were enhanced in VSG mice compared to controls during mixed-meal tolerance tests (MMTT) at 12 and 80 days postoperatively, as were prandial GLP-1, GIP, and glucagon levels. Insulin sensitivity was comparable between groups 14d after surgery, but significantly greater in the VSG group at day 75, despite similar body-weight gain between groups. Glucose stimulated insulin secretion was greater in VSG mice compared to controls in vivo (I.P. glucose injection) and ex vivo (islet perifusion) indicating a rapid and sustained enhancement of β-cell function after surgery. Notably, glycemia following a MMTT was progressively higher over time in the control animals but improved in the VSG mice at 80d despite weight regain. However, meal-stimulated incretin secretion decreased in VSG mice from 10 to 80 days postoperative, as did meal-stimulated and I.P. glucose-stimulated insulin secretion. This occurred over the same time period that insulin sensitivity was enhanced in VSG mice, suggesting postoperative islet output is tightly regulated by insulin demand. Conclusions These data demonstrate a dynamic, multifactorial physiology for improved glucose control after VSG, whereby rapidly elevated insulin secretion is complimented by later enhancements in insulin sensitivity. Critically, the glucose lowering effect of VSG is demonstrably larger than that of caloric-restriction, suggesting these adaptations are mediated by surgical modification of gastrointestinal anatomy and not weight-loss per se. β-cell glucose sensitivity is enhanced 90d after VSG compared to controls, coincident with improved glucose tolerance. Prandial GLP-1 and GIP are elevated 12d following VSG but return to preoperative levels 80d after VSG. Insulin sensitivity is enhanced 75d after surgery, but not 14d after surgery, in mice with VSG compared to controls. Mixed-meal glucose control is improved from 12d to 80d in VSG mice, but worsens in controls despite similar body-weight.
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