Remission of type 2 diabetes after Roux-en-Y gastric bypass or sleeve gastrectomy is associated with a distinct glycemic profile

Comparative impact of Roux-en-Y gastric bypass, sleeve gastrectomy or diet alone on beta-cell function in insulin-treated type 2 diabetes patients

Although bariatric surgery is an effective treatment for type 2 diabetes by inducing weight loss and augmenting gut hormone secretion, the immediate effect on beta-cell function itself remains to be elucidated in type 2 diabetes. Therefore, a prospective, randomized trial was performed in 30 patients with insulin-treated type 2 diabetes and a body mass index ≥ 35 kg/m2. Patients were randomly assigned (1:1:1) to Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in combination with protein-sparing modified fast (PSMF), or to PSMF alone. Eu- and hyperglycemic clamps were performed before and 3 weeks after surgery and/or PSMF initiation. The primary outcome was the evolution of insulin sensitivity and beta-cell function after surgery, calculated using the composite measures of glucose disposal rate, insulin secretion rate, and disposition index (DI). Results revealed that markers of insulin sensitivity increased similarly in all arms (p = 0.43). A higher marker for maximal beta-cell function was observed when comparing SG to PSMF (p = 0.007). The DI showed a clear positive evolution after RYGB and SG, but not after PSMF alone. Altogether, these findings indicate that bariatric surgery results in an immediate beta-cell function recovery in insulin-treated type 2 diabetes.

Analysis of Changes in Glucose and Lipid Metabolism in Patients with Clinically Severe Obesity and Type 2 Diabetes Mellitus Undergoing Laparoscopic Sleeve Gastrectomy-Prospective Observational Study

INTRODUCTION

We still lack studies providing analysis of changes in glucose and lipid metabolism after laparoscopic sleeve gastrectomy (LSG) in patients with type 2 diabetes mellitus (DM2). We aimed to investigate postoperative changes in glucose and lipid metabolism after LSG in patients with DM2.

MATERIAL AND METHODS

Prospective, observational study included patients with BMI ≥ 35 kg/m2 and ≤ 50 kg/m2, DM2 < 10 years of duration, who were qualified for LSG. Perioperative 14-day continuous glucose monitoring (CGM) began after preoperative clinical assessment and OGTT, then reassessment 1 and 12 months after LSG. Thirty-three patients in mean age of 45 ± 10 years were included in study (23 females).

RESULTS

EBMIL before LSG was 17 ± 11.7%, after 1 month-36.3 ± 12.8%, while after 12 months-66.1 ± 21.7%. Fifty-two percent of the patients had DM2 remission after 12 months. None required then insulin therapy. 16/33 patients initially on oral antidiabetics still required them after 12 months. Significant decrease in HbA1C was observed: 5.96 ± 0.73%; 5.71 ± 0.80; 5.54 ± 0.52%. Same with HOMA-IR: 5.34 ± 2.84; 4.62 ± 3.78; 3.20 ± 1.99. In OGTT, lower increase in blood glucose with lesser insulin concentrations needed to recover glucose homeostasis was observed during follow-ups. Overtime perioperative average glucose concentration in CGM of 5.03 ± 1.09 mmol/L significantly differed after 12 months, 4.60 ± 0.53 (p = 0.042). Significantly higher percentage of glucose concentrations above targeted compartment (3.9-6.7 mmol/L) was observed in perioperative period (7% ± 4%), than in follow-up (4 ± 6% and 2 ± 1%). HDL significantly rose, while triglyceride levels significantly decreased.

CONCLUSIONS

Significant improvement in glucose and lipid metabolism was observed 12 months after LSG and changes began 1 month after procedure.

Roux-en-Y Gastric Bypass vs Vertical Sleeve Gastrectomy in the Remission of Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

<b><br>Introduction:</b> Obesity's associated comorbidities and treatment costs have risen significantly, highlighting the importance of early weight loss strategies. Bariatric surgeries like Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) have been effective in promoting weight loss and improving type 2 diabetes mellitus (T2DM) management.</br> <b><br>Aim:</b> The aim was to determine whether Roux-en-Y gastric bypass is more effective than vertical sleeve gastrectomy in the remission of type 2 diabetes mellitus (T2DM).</br> <b><br>Methods:</b> A systematic review and meta-analysis was performed. A literature search was performed in the databases Web of Science, Medline/PubMed, Embase, Scopus, and Medline/Ovid. A total of 1323 results were identified; after screening, 14 articles were selected and included in the systematic review. Primary and secondary outcomes were measured by RR with a 95% CI.</br> <b><br>Results:</b> The primary outcome of T2DM remission was 15% in favor of VSG (RR: 1.15, [95% CI: 1.04-1.28]). For secondary outcomes, hypertension remission was 7% in favor of VSG (RR: 1.07, [95% CI: 1.00-1.16]). Remission of dyslipidemia was 16% in favor of VSG (RR: 1.16, [95% CI: 1.06-1.26]). BMI after surgery was in favor of RYGB (MD: -1.31, [95% CI: -1.98 to -0.64]). For weight loss, the results favored VSG (MD: 6.50, [95% CI: 4.99-8.01]). In relation to total cholesterol, they were 65% favorable for RYGB (MD: -0.35, [95% CI: -0.46 to -0.24]), with a value of p <0.05. For LDL values, our results were 69% favorable for RYGB (MD: -0.31, [95% CI: -0.45 to -0.16]), p <0.01 value.</br> <b><br>Conclusions:</b> Laparoscopic sleeve gastrectomy is more effective in T2DM remission, hypertension remission, dyslipidemia remission, and weight loss compared to Roux-en-Y gastric bypass. Roux-en-Y gastric bypass is more effective at lowering BMI, total cholesterol, LDL, and TG compared to laparoscopic sleeve gastrectomy.</br>.

Use of Continuous Glucose Monitoring in Patients Following Bariatric Surgery: A Scoping Review

The objective of this scoping review was to summarize the emerging literature on the use of continuous glucose monitoring (CGM) in post-bariatric surgery patients, with a focus on its features (e.g., device, mode, and accuracy), as well as purposes and outcomes of utilization. Three databases (PubMed, EMBASE, and Web of Science) were searched to obtain relevant studies. Results suggested that most studies used CGM for 3-7 days under blinded mode. Accuracy data were available in only one study, which reported a mean absolute relative difference of 21.7% for Freestyle Libre. The primary applications of CGM were for elucidating glucose patterns and assessing glycemic treatment outcomes. No study has tested the effect of CGM as an intervention strategy to enhance glucose control.

Utility of Continuous Glucose Monitoring vs Meal Study in Detecting Hypoglycemia After Gastric Bypass

CONTEXT

Gastric bypass (GB) increases postprandial glucose excursion, which in turn can predispose to the late complication of hypoglycemia. Diagnosis remains challenging and requires documentation of symptoms associated with low glucose and relief of symptom when glucose is normalized (Whipple triad).

OBJECTIVE

To compare the yield of mixed meal test (MMT) and continuous glucose monitoring system (CGMS) in detecting hypoglycemia after GB.

SETTING

The study was conducted at General Clinical Research Unit, Cincinnati Children's Hospital (Cincinnati, OH, USA).

METHODS

Glucose profiles were evaluated in 15 patients with documented recurrent clinical hypoglycemia after GB, 8 matched asymptomatic GB subjects, and 9 healthy weight-matched nonoperated controls using MMT in a control setting and CGMS under free-living conditions.

RESULTS

Patients with prior GB had larger glucose variability during both MMT and CGMS when compared with nonsurgical controls regardless of their hypoglycemic status. Sensitivity (71 vs 47%) and specificity (100 vs 88%) of MMT in detecting hypoglycemia was superior to CGMS.

CONCLUSIONS

Our findings indicate that a fixed carbohydrate ingestion during MMT is a more reliable test to diagnose GB-related hypoglycemia compared with CGMS during free-living state.

Rate of post-bariatric hypoglycemia using continuous glucose monitoring: A meta-analysis of literature studies

AIMS

Hypoglycemia is a serious complication of bariatric surgery. The aim of the present meta-analysis was to evaluate the rate and the timing of post-bariatric hypoglycemia (PBH) with different bariatric procedures using reliable data from continuous glucose monitoring (CGM).

DATA SYNTHESIS

Studies were systematically searched in the Web of Science, Scopus and PubMed databases according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The prevalence of PBH was expressed as weighted mean prevalence (WMP) with pertinent 95% confidence intervals (95%CI). A total of 8 studies (16 datasets) enrolling 280 bariatric subjects were identified. The total WMP of PBH was 54.3% (95%CI: 44.5%-63.8%) while the WMP of nocturnal PBH was 16.4% (95%CI: 7.0%-34%). We found a comparable rate of PBH after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) (OR 1.62, 95%CI: 0.71-3.7; P = 0.248); likewise, the percent time spent in hypoglycemia was similar with the two procedures (mean difference 5.3%, 95%CI: -1.4%-12.0%; P = 0.122); however, RYGB was characterized by a higher glycemic variability than SG. Regression models showed that the time elapsed from surgical intervention was positively associated with a higher rate of both total PBH (Z-value: 3.32, P < 0.001) and nocturnal PBH (Z-value: 2.15, P = 0.013).

CONCLUSIONS

PBH, both post-prandial and nocturnal, is more prevalent than currently believed. The rate of PBH increases at increasing time from surgery and is comparable after RYGB and SG with a higher glucose variability after RYGB.

Acute Effects of Sleeve Gastrectomy on Glucose Variability, Glucose Metabolism, and Ghrelin Response

PURPOSE

This study aims to examine the changes of glucose metabolism, glucose variability (GV), and ghrelin secretion within 1 week following SG in Chinese patients with obesity.

MATERIALS AND METHODS

Forty-nine patients with obesity (15 with type 2 diabetes) were enrolled to undergo SG. Within 1 week before and after surgery, liquid meal tests were performed in all subjects, and continuous glucose monitoring (CGM) was performed in diabetic patients. Blood samples were collected at 0, 15, 30, 45, 60, 120, and 180 min for glucose, C-peptide, insulin, and ghrelin analysis in liquid meal test. Mean amplitude of glucose excursions (MAGE), standard deviations (SD), and percent time-in-range (%TIR) determined by CGM were analyzed.

RESULTS

Both in diabetic and non-diabetic groups, significant decrease was observed in glucose, insulin, C-peptide, and ghrelin. Homeostasis model assessment-insulin resistance and liver fat content was decreased. In diabetic group, MAGE and SD were decreased significantly, and the percent time-in-range was higher. The decrease in blood glucose was positively correlated with the decrease in ghrelin concentration in non-diabetic group.

CONCLUSION

Within 1 week after SG, both glucose metabolism and glucose variability were improved significantly. Suppression of ghrelin secretion postoperatively might be a driver of this early improved glycemia homeostasis.

Continuous glucose monitoring in patients with remission of type 2 diabetes after laparoscopic sleeve gastrectomy without or with duodenojejunal bypass

Bariatric surgery is associated with a high remission rate of type 2 diabetes mellitus. However, it is unclear whether patients showing remission of diabetes actually have normal blood glucose levels throughout the day. We therefore performed continuous glucose monitoring (CGM) in 15 ambulatory patients showing remission of diabetes after laparoscopic sleeve gastrectomy (LSG) without or with duodenojejunal bypass (DJB) at the time of diabetic remission (12.9 ± 1.8 months after bariatric surgery). The definition of remission of diabetes was based on the American Diabetes Association criteria. The mean, SD, and coefficient of variation (CV) of glucose calculated from CGM were 6.2 ± 0.6 mmol/L, 1.5 ± 0.4 mmol/L, and 23.7 ± 6.2%, respectively. These values were higher than those of healthy participants without diabetes previously reported. The percentages of time spent above 10.0 mmol/L and below 3.9 mmol/L were 2.6 (IQR 0-5.0)% and 0 (IQR 0-8.0)%, respectively. Thus, patients with remission of diabetes after LSG or LSG/DJB still had substantial periods of hyperglycemia and hypoglycemia throughout the day. Therefore, we must manage patients with diabetes carefully, even after apparent remission of type 2 diabetes in response to bariatric surgery.

Remission of Type 2 Diabetes and Sleeve Gastrectomy in Morbid Obesity: a Comparative Systematic Review and Meta-analysis

BACKGROUND

The sleeve gastrectomy (SG) has gained popularity which has resulted in a rising number of patients with T2DM to undergo this procedure. This systematic review and meta-analysis aimed to compare the long-term effects of SG on T2DM remission with remission seen after Roux-en-Y gastric bypass (RYGB) or gastric banding (GB).

METHODS

A literature search was performed in PubMed and Cochrane Library using the following search terms: 'sleeve gastrectomy', 'diabetes', 'gastric bypass' and 'gastric banding'. Studies published between January 2000 and April 2018, and with following inclusion criteria were selected for this review: BMI ≥ 35 kg/m2, age ≥ 18 years, follow-up ≥ 1 year, T2DM. Data was statistically analysed using a random-effects model and results were expressed as odds ratio with 95% confidence interval.

RESULTS

After exclusion, 35 out of an initial 748 studies, consisting of 18 138 T2DM patients, remained for inclusion. Of these patients, 2480 underwent a SG. The remaining patients underwent a RYGB (n = 10,597) or GB (n = 5061). One year postoperatively, SG patients reached significantly (OR 0.71, p = 0.003) less T2DM remission than RYGB. After stratifying for different criteria for remission, RYGB still tended to result in higher remission rates, but the difference was not statistically significant. Beyond 1 year of follow-up, the difference between RYGB and SG in terms of T2DM remission decreased. SG was superior to the GB (OR 2.17, p = 0.001) after 1 year of follow-up.

CONCLUSION

This review demonstrates important remission of T2DM following SG. Nevertheless, as remission was significantly more often observed following RYGB surgery, the latter procedure remains the gold standard for reaching T2DM remission in patients with concurrent obesity.

Continuous glucose monitoring reveals glycemic variability and hypoglycemia after vertical sleeve gastrectomy in rats

Objective

Post–bariatric surgery hypoglycemia (PBH) is defined as the presence of neuroglycopenic symptoms accompanied by postprandial hypoglycemia in bariatric surgery patients. Recent clinical studies using continuous glucose monitoring (CGM) technology revealed that PBH is more frequently observed in vertical sleeve gastrectomy (VSG) patients than previously recognized. PBH cannot be alleviated by current medication. Therefore, a model system to investigate the mechanism and treatment is required.

Methods

We used CGM in a rat model of VSG and monitored the occurrence of glycemic variability and hypoglycemia in various meal conditions for 4 weeks after surgery. Another cohort of VSG rats with CGM was used to investigate whether the blockade of glucagon-like peptide-1 receptor (GLP-1R) signaling alleviates these symptoms. A mouse VSG model was used to investigate whether the impaired glucose counterregulatory system causes postprandial hypoglycemia.

Results

Like in humans, rats have increased glycemic variability and hypoglycemia after VSG. Postprandial hypoglycemia was specifically detected after liquid versus solid meals. Further, the blockade of GLP-1R signaling raises the glucose nadir but does not affect glycemic variability.

Conclusions

Rat bariatric surgery duplicates many features of human post–bariatric surgery hypoglycemia including postprandial hypoglycemia and glycemic variability, while blockade of GLP-1R signaling prevents hypoglycemia but not the variability.

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VSG causes glycemic variability during ad lib feeding condition.

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Single liquid meal ingestion causes post-VSG hypoglycemia.

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Blockade of GLP-1 receptor prevents post-VSG hypoglycemia.

Safety of Blood Glucose Response Following Exercise Training After Bariatric Surgery

INTRODUCTION

Safety of exercise training in relationship with the risk of hypoglycemia post-bariatric surgery is unknown.

OBJECTIVE

To evaluate the safety and magnitude of changes in blood glucose levels during exercise training following bariatric surgery.

MATERIAL AND METHODS

Twenty-nine severely obese patients undergoing either sleeve gastrectomy (SG) (n = 16) or biliopancreatic diversion with duodenal switch (BPD-DS) (n = 13) were prospectively enrolled. Three months after surgery, patients participated in a 12-week supervised exercise training program, (35-min aerobic training with a 25-min resistance exercises) three times a week. Capillary blood glucose (CBG) levels were measured immediately before and after each exercise session.

RESULTS

Seven patients (24%) had type 2 diabetes before surgery (mean duration: 10 years); four patients still have type 2 diabetes 3 months post-bariatric surgery. A total of 577 exercise training sessions with CBG monitoring were recorded. Only seven sessions (1.2%) were associated with an episode of asymptomatic hypoglycemia (CBG ≤ 3.9 mmol/L). Patients with type 2 diabetes at baseline showed a larger decrease in CBG with pre-exercise CBG being between 6.1 and 8.0 mmol/L (- 1.6 ± 1.2 vs. - 1.1 ± 0.9 mmol/L, p = 0.02). BPD-DS patients with CBG ≥ 6.1 mmol/L showed higher reduction in CBG following exercise vs. SG patients (- 1.7 ± 1.0 vs. - 1.1 ± 1.1 mmol/L; p < 0.001 and - 4.3 ± 1.0 vs. - 2.2 ± 1.4 mmol/L, p < 0.001, respectively).

CONCLUSION

Three months after bariatric surgery, exercise training program in patients without and with type 2 diabetes is safe, and is associated with a desirable glycemic profile, with few episodes of asymptomatic hypoglycemia.

Intestinal Glucose Absorption Was Reduced by Vertical Sleeve Gastrectomy via Decreased Gastric Leptin Secretion

BACKGROUND

The unique effects of gastric resection after vertical sleeve gastrectomy (VSG) on type 2 diabetes mellitus remain unclear. This work aimed to investigate the effects of VSG on gastric leptin expression and intestinal glucose absorption in high-fat diet-induced obesity.

METHODS

Male C57BL/6J mice were fed a high-fat diet (HFD) to induce obesity. HFD mice were randomized into VSG and sham-operation groups, and the relevant parameters were measured at 8 weeks postoperation.

RESULTS

Higher gastric leptin expression and increased intestinal glucose transport were observed in the HFD mice. Furthermore, VSG reduced gastric leptin expression and the intestinal absorption of alimentary glucose. Both exogenous leptin replenishment during the oral glucose tolerance test (OGTT) and the addition of leptin into the everted isolated jejunum loops in vitro restored the glucose transport capacity in VSG-operated mice, and this effect was abolished when the glucose transporter GLUT2 was blocked with phloretin. Moreover, phloretin almost completely suppressed glucose transport in the HFD mice. Intestinal immunohistochemistry in the obese mice showed increased GLUT2 and diminished sodium glucose co-transporter 1 (SGLT-1) in the apical membrane of enterocytes. Decreased GLUT2 and enhanced SGLT1 were observed following VSG. VSG also reduced the phosphorylation status of protein kinase C isoenzyme β II (PKCβ II) in the jejunum, which was stimulated by the combination of leptin and glucose.

CONCLUSION

Our data demonstrated that the decreased secretion of gastric leptin in VSG results in a decrease in intestinal glucose absorption via modulation of GLUT2 translocation.

The Effects of Bariatric Surgery on Islet Function, Insulin Secretion, and Glucose Control

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.

Metabolic surgery for the treatment of type 2 diabetes in patients with BMI lower than 35 kg/m2 : Why caution is still needed

Bariatric surgery has shifted from being a risky procedure to an evidence-based one, with proven benefits on all-cause mortality, cardiovascular disease, cancer, and diabetes control. The procedure has an overall positive result on type 2 diabetes mellitus (T2DM), with a substantial number of patients achieving disease remission. This has resulted in several studies assessing possible weight-independent effects of bariatric surgery on glycemic improvement, in addition to recommendation of the procedure to patients with class 1 obesity and T2DM, for whom the procedure was classically not indicated, and adoption of a new term, "metabolic surgery," to highlight the overall metabolic benefit of the procedure beyond weight loss. Recently, the Diabetes Surgery Summit (DSS) has included metabolic surgery in its T2DM treatment algorithm. Although the discussion brought by this consensus is highly relevant, the recommendation of metabolic surgery for patients with uncontrolled T2DM and a body mass index of 30 to 35 kg/m² still lacks enough evidence. This article provides an overall view of the metabolic benefits of bariatric/metabolic surgery in patients with class 1 obesity, compares the procedure against clinical treatment, and presents our rationale for defending caution on recommending the procedure to less obese individuals.

Mechanisms for the metabolic success of bariatric surgery

To date, bariatric surgery remains the most effective strategy for the treatment of obesity and its comorbidities. However, given the enormity of the obesity epidemic, and sometimes variable results, it is not a feasible strategy for the treatment of all obese patients. A simple PubMed search for 'bariatric surgery' reveals over 28 000 papers that have been published since the 1940s when the first bariatric surgeries were performed. However, there is still an incomplete understanding of the mechanisms for the weight loss and metabolic success of surgery. An understanding of the mechanisms is important because it may lead to greater understanding of the pathophysiology of obesity and thus surgery-alternative strategies for the treatment of all obese patients. In this review, the potential mechanisms that underlie the success of surgery are discussed, with a focus on the potential endocrine, neural and other circulatory factors (eg, bile acids) that have been proposed to play a role.

Association of Time in Range, as Assessed by Continuous Glucose Monitoring, With Diabetic Retinopathy in Type 2 Diabetes

OBJECTIVE

Continuous glucose monitoring (CGM) has provided new measures of glycemic control that link to diabetes complications. This study investigated the association between the time in range (TIR) assessed by CGM and diabetic retinopathy (DR).

RESEARCH DESIGN AND METHODS

A total of 3,262 patients with type 2 diabetes were recruited. TIR was defined as the percentage of time spent within the glucose range of 3.9-10.0 mmol/L during a 24-h period. Measures of glycemic variability (GV) were assessed as well. DR was determined by using fundus photography and graded as 1) non-DR; 2) mild nonproliferative DR (NPDR); 3) moderate NPDR; or 4) vision-threatening DR (VTDR).

RESULTS

The overall prevalence of DR was 23.9% (mild NPDR 10.9%, moderate NPDR 6.1%, VTDR 6.9%). Patients with more advanced DR had significantly less TIR and higher measures of GV (all P for trend <0.01). The prevalence of DR on the basis of severity decreased with ascending TIR quartiles (all P for trend <0.001), and the severity of DR was inversely correlated with TIR quartiles (r = -0.147; P < 0.001). Multinomial logistic regression revealed significant associations between TIR and all stages of DR (mild NPDR, P = 0.018; moderate NPDR, P = 0.014; VTDR, P = 0.019) after controlling for age, sex, BMI, diabetes duration, blood pressure, lipid profile, and HbA_1c. Further adjustment of GV metrics partially attenuated these associations, although the link between TIR and the presence of any DR remained significant.

CONCLUSIONS

TIR assessed by CGM is associated with DR in type 2 diabetes.

Glucose Variability After Bariatric Surgery: Is Prediction of Diabetes Remission Possible?

We aimed to corroborate glycemic control after bariatric surgery (BS) using continuous glucose monitoring (CGM) and analyze if data could predict long-term outcome. We evaluated 24 of our patients with type 2 diabetes who underwent BS (12 Roux-en-Y gastric bypass, RYGB, and 12 single-anastomosis duodeno-ileal bypass with sleeve gastrectomy, SADI-S) and who were in remission after 18-24 months' follow-up. At this time, a CGM device was placed for 7 days. Patients were reevaluated thereafter for at least 5 years. Glucose variability (GV) was lower in patients after SADI-S and in the 18 patients who were still in remission after 5 years, and provided more information on long-term status than classical diabetes-related characteristics.

Long-Term Results After Sleeve Gastrectomy for Gastroesophageal Reflux Disease: a Single-Center French Study

BACKGROUND

Many studies have analyzed the impact of sleeve gastrectomy (SG) on weight loss and/or the evolution of obesity-related comorbid conditions, but few have reported the long-term outcomes after surgery. The objective of this study was to investigate the outcomes after SG on weight loss, obesity-related comorbid conditions, quality of life (QoL), and GERD symptoms (GERDS) beyond 5 years.

METHODS

A prospective database was retrospectively searched for the following factors: gender, age, anthropometrics, presence of comorbid conditions, QoL (BAROS questionnaire), and presence of GERDS. The data were analyzed before and at 1 and 6 years after surgery.

RESULTS

Of the 64 patients included, 32.8% were lost to follow-up (76% during the first postoperative year). A complete follow-up of >5 years was obtained for 41 patients. Before surgery, mean excess BMI was 22 ± 7 kg/m², and 26.8% of patients had GERDS. Percent excess BMI loss was 55 ± 30% at 1 year and 48 ± 27% at 6 years. Preoperative BMI and absence of type 2 diabetes (T2D) before surgery were the only independent variables for long-term failure. Six years after SG, remission from metabolic comorbidities was as follows: 50% for T2D, 28% for blood hypertension, 58% for dyslipidemia, and 33% for sleep-apnea syndrome. Thirty percent of patients with preoperative GERD had resolution of symptoms at 6 years whereas 9 patients (32%) had de novo GERD. QoL was improved for 62% of patients at 6 years.

CONCLUSION

The benefits of SG on weight loss, resolution of comorbidities, and QoL were maintained in the long term for most patients.

Gastric Bypass-Related Effects on Glucose Control, β Cell Function and Morphology in the Obese Zucker Rat

BACKGROUND

Roux-en-Y gastric bypass (RYGB) may improve beta cell function by mechanisms other than caloric restriction and body weight loss. We aimed to assess the impact of anatomical and hormonal alterations specific to RYGB on glucose homeostasis, β cell function and morphology.

METHODS

Male Zucker(fa/fa) rats underwent either RYGB (n = 11) or sham surgeries (n = 10). Five of the shams were then food restricted and body weight matched (BWM) to the RYGB rats. Six male Zucker(fa/+) rats underwent sham surgery and served as additional lean controls. Twenty-seven days after surgery, an oral glucose tolerance test (OGTT) was performed and plasma levels of glucose, insulin and glucagon-like peptide-1 (GLP-1) were measured. Immunohistological analysis of pancreatic islets was performed, and GLP-1 receptor and PDX-1 mRNA content were quantified.

RESULTS

Shams consumed more food and gained more weight compared to both RYGB and BWM (p < 0.001). Hyperglycaemia was evident in ad libitum-fed shams, whilst postprandial glucose levels were lower in RYGB compared to the BWM sham group (p < 0.05). During the OGTT, RYGB rats responded with >2.5-fold increase of GLP-1. Histology revealed signs of islet degeneration in ad libitum-fed shams, but not in RYGB and sham BWM controls (p < 0.001). GLP-1 receptor and PDX-1 mRNA content was similar between the RYGB and BWM shams but higher compared to ad libitum shams (p < 0.05).

CONCLUSIONS

Combined molecular, cellular and histological analyses of pancreatic function suggest that weight loss alone, and not the enhancement of GLP-1 responses, is predominant for the short-term β cell protective effects of RYGB.

Long-Term Outcomes of Three Types of Bariatric Surgery on Obesity and Type 2 Diabetes Control and Remission

BACKGROUND

Different bariatric surgeries have demonstrated different effectiveness for weight loss and glucose control in obese persons with diabetes, over a short follow-up time. The aim of this study was to compare weight loss, glucose control, and diabetes remission in individuals with type 2 diabetes, after three types of bariatric surgery: gastric banding (GB), sleeve gastrectomy (SG), and Roux-en-Y gastric bypass (RYGB), with 5 years follow-up.

METHODS

A retrospective study was conducted on bariatric surgeries performed during 2002-2011 in a large nationwide healthcare organization.

RESULTS

Of 2190 patients, 64.8 % were women. The operations performed were 1027 GB, 1023 SG, and 140 RYGB. Mean BMI ± SD at baseline, 1 year postoperatively, and 5 years postoperatively were 43.5 ± 6.18, 37.1 ± 6.35, and 35.5 ± 6.48 for GB; 43.6 ± 6.42, 34.4 ± 6.08, and 35.3 ± 6.7 for SG; and 42.8 ± 5.81, 32.8 ± 4.9, and 34.1 ± 5.09 for RYGB. Mean HbA1c ± SD at baseline, 1 year postoperatively, and 5 years postoperatively were 7.6 + 1.58, 6.5 + 1.22, and 6.8 + 1.48 for GB; 7.7 + 1.63, 6.4 + 1.18, and 6.7 + 1.57 for SG; and 8.0 + 1.78, 6.3 + 0.98, and 7.04 + 1.42 for RYGB. At 1 year follow-up, 53.2 % had achieved remission; at 5 years, 54.4 %. Remission rates at 5 years were similar for the three surgeries. Five-year remission was inversely associated with baseline HbA1c and with treatment with insulin at baseline and positively associated with BMI.

CONCLUSIONS

For all three surgeries, diabetes remission was higher than the baseline after 5 years; mean BMI and HbA1c decreased considerably during the first year postoperatively and remained lower than basal values throughout follow-up. Early improvements were greatest for RYGB, though the advantage over the other operations diminished with time.

Defining and Using Preoperative Predictors of Diabetic Remission Following Bariatric Surgery

BACKGROUND

Diabetes remission is defined as the return of glycemic control in the absence of medication or insulin use after bariatric surgery. We sought to identify and assess the clinical utility of a predictive model for remission of type 2 diabetes mellitus in a population seeking bariatric surgery.

METHOD

A retrospective cohort design was applied to presurgical data on patients referred for Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG). The model developed from logistic regression was compared with a published model through receiver operating characteristic analyses.

RESULTS

At 12 months postoperatively, 59.7% of the cohort was remitted, with no differences between RYGB and VSG. Logistic regression analyses yielded a model in which 4 preoperative variables reliably predicted remission. A Hosmer-Lemeshow goodness-of-fit test result of 0.204 indicated good fit of the developed prediction model to our outcome data. The predictive accuracy of this prediction model was compared with a published model, and an associated variation with diabetes years was substituted for age in our patient population. Our model was the most accurate.

CONCLUSIONS

Using these predictors, healthcare providers may be able to better counsel patients who are living with diabetes and considering bariatric surgery on the likelihood of achieving remission from the intervention. This refined prediction model requires further testing in a larger sample to evaluate its external validity.

Differences in Anthropometric and Metabolic Parameters Between Subjects with Hypoglycaemia and Subjects with Euglycaemia After an Oral Glucose Tolerance Test Six Months After Laparoscopic Sleeve Gastrectomy

BACKGROUND

Hypoglycaemia after an oral glucose tolerance test (OGTT) can occur in up to 33 % of subjects after laparoscopic sleeve gastrectomy (LSG). The underlying pathophysiology is not well understood. We aimed to compare the anthropometric and metabolic characteristics of subjects with post-OGTT hypoglycaemia (HYPO) to subjects with post-OGTT euglycaemia (EU) 6 months after LSG.

METHODS

Eighteen morbidly obese patients with normal glucose tolerance (NGT) were evaluated with an OGTT before and 6 months after LSG. Serum glucose and insulin were measured before and every 30 min after glucose ingestion up to 120'. The patients were categorized as HYPO or EU based on lowest glucose levels 90' to 120' post-OGTT 6 months after LSG (hypoglycaemia defined as glucose levels <60 mg/dl). OGTT derived indices of insulin secretion; insulin sensitivity and beta cell function were also evaluated.

RESULTS

Eight patients (44.4 %) were categorized as HYPO. Preoperatively, subjects with HYPO had lower BMI (p = 0.02) compared to that with EU. Postoperatively, subjects with HYPO had lower BMI (p = 0.01), lower weight (p = 0.01), and higher percentage of total weight loss (%TWL) (p = 0.03) compared to that with EU. The beta cell function index was higher in the HYPO group postoperatively compared to EU (p = 0.02)-especially during the latter portion of the OGTT. No difference was detected in insulin secretion and insulin sensitivity indices between the two groups preoperatively or postoperatively.

CONCLUSIONS

Subjects with NGT who developed HYPO 6 months after LSG are leaner, with higher TWL% and higher beta cell function at the latter portion of the OGTT compared to those with EU.

[Quality indicators for metabolic and bariatric surgery in Germany : Evidence-based development of an indicator panel for the quality of results, indications and structure]

An expert committee was appointed by the German Society for General and Visceral Surgery to develop a panel of appropriate quality indicators to collate the quality of results, indications and structure in metabolic and bariatric surgery. This entailed assimilating the available evidence (systematic literature search), results from the national registry of the society (StuDoQ|MBE) and specific socioeconomic aspects (e. g. severely limited access to metabolic and bariatric surgery in Germany). These quality parameters were to be incorporated into the national guidelines and the rules of procedure for certification in the future. The committee concluded that mortality, MTL30 and severe complications needing intervention (Clavien-Dindo ≥ 3b) are suitable indicators to measure surgical outcome quality due to their relevance, scientific soundness and practicability. As a systematic follow-up is mandatory after bariatric surgery, a minimum follow-up quota is now required using reported quality of life data as an indicator of process quality. As intestinal bypass procedures have been shown to be superior in the treatment of type 2 diabetes, these procedures should be offered to eligible patients and also be performed. The proposed threshold values based on the results of the available literature and StuDoQ registry are to be considered as preliminary and need to be validated and adjusted if necessary in the future. The StuDoQ|MBE is considered a valuable tool to gather this information and also represents the appropriate infrastructure for the collation of relevant risk adjustors.

The Role of GLP-1 in the Metabolic Success of Bariatric Surgery

Two of the most popular bariatric procedures, vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB), are commonly considered metabolic surgeries because they are thought to affect metabolism in a weight loss-independent manner. In support of this classification, improvements in glucose homeostasis, insulin sensitivity, and even discontinuation of type 2 diabetes mellitus (T2DM) medication can occur before substantial postoperative weight loss. The mechanisms that underlie this effect are unknown. However, one of the common findings after VSG and RYGB in both animal models and humans is the sharp postprandial rise in several gut peptides, including the incretin and satiety peptide glucagonlike peptide-1 (GLP-1). The increase in endogenous GLP-1 signaling has been considered a primary pathway leading to postsurgical weight loss and improvements in glucose metabolism. However, the degree to which GLP-1 and other gut peptides are responsible for the metabolic successes after bariatric surgery is continually debated. In this review we discuss the mechanisms underlying the increase in GLP-1 and its potential role in the metabolic improvements after bariatric surgery, including remission of T2DM. Understanding the role of changes in gut peptides, or lack thereof, will be crucial in understanding the critical factors necessary for the metabolic success of bariatric surgery.

Cross-Talk Between Bile Acids and Gastro-Intestinal and Thermogenic Hormones: Clues from Bariatric Surgery

Obesity is rapidly increasing and has reached epidemic features worldwide. It´s linked to insulin resistance, systemic low-grade inflammation and common pathogenic pathways with a number of comorbidities (including cancer), leading to high mortality rates. Besides change of lifestyles (diet and physical exercise) and pharmacological therapy, bariatric surgery is able to rapidly improve several metabolic and morphologic features associated with excessive fat storage, and currently represents an in vivo model to study the pathogenic mechanisms underlying obesity and obesity-related complications. Studies on obese subjects undergoing bariatric surgery find that the effects of surgery are not simply secondary to gastric mechanical restriction and malabsorption which induce body weight loss. In fact, some surgical procedures positively modify key pathways involving the intestine, bile acids, receptor signaling, gut microbiota, hormones and thermogenesis, leading to systemic metabolic changes. Furthermore, bariatric surgery represents a suitable model to evaluate the gene-environment interaction and some epigenetic mechanisms linking obesity and insulin resistance to metabolic diseases.

Diabetes remission after bariatric surgery is characterized by high glycemic variability and high oxidative stress

BACKGROUND AND AIM

To evaluate glycemic variability (GV) and oxidative stress in patients who achieved type 2 diabetes (T2DM) remission after bariatric surgery (BS).

METHODS AND RESULTS

Twenty-two patients (M/F10/12, age 50 ± 9 years, BMI 31 ± 6 kg/m²) who were in remission of T2DM (T2DM remitters) after BS since at least 1 year and 22 age-, sex- and BMI-matched control subjects were studied. Of the BS group, eleven subjects had undergone Roux-en-Y gastric bypass (RYGB) and eleven subjects sleeve gastrectomy (SG). Oral glucose tolerance test (OGTT), 7 days-continuous glucose monitoring, 24-h urinary excretion of 8-isoprostaglandin F2α (8-isoPGF2α) and dietary intake evaluation were performed. According to general linear model for repeated measures, glucose and insulin response during OGTT were significantly different in T2DM remitter than in control subjects (p < 0.001, for both). All measures of GV (standard deviation, coefficient of variation and mean amplitude of glucose excursions) were significantly higher in T2DM remitters than in controls, (p < 0.001 for all). These indexes were higher among RYGB than SG patients (p < 0.05). The time spent out of the 60-160 mg/dl range was significantly longer in T2DM remitters undergoing RYGB than in controls (p < 0.02). Mean 24-h urinary 8-isoPGF2α excretion was significantly higher in T2DM remitters than that of control subjects (p = 0.04). All GV indexes were directly correlated with blood glucose levels at 30 and 60 min during OGTT (p < 0.05-0.001).

CONCLUSION

Remission of T2DM after BS is characterized by high GV and high oxidative stress in the face of fasting blood glucose and HbA1c within the normal range.

Intestinal Adaptations after Bariatric Surgery: Consequences on Glucose Homeostasis

The gastrointestinal (GI) tract can play a direct role in glucose homeostasis by modulating the digestion and absorption of carbohydrates and by producing the incretin hormones. In recent years, numerous studies have focused on intestinal adaptation following bariatric surgeries. Changes in the number of incretin (glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide) producing cells have been reported, which could result in the modified hormonal response seen after surgery. In addition, the rate of absorption and the intestinal regions exposed to sugars may affect the time course of appearance of glucose in the blood. This review gives new insights into the direct role of the GI tract in the metabolic outcomes of bariatric surgery, in the context of glucose homeostasis.

Comparison of glucose homeostasis parameters between patients with high and low risk of diabetes at 6 weeks and 6 months after sleeve gastrectomy

BACKGROUND

The changes in glucose homeostasis after sleeve gastrectomy (SG) for patients with high (HRD) and low risk (LRD) of developing diabetes have not been investigated.

OBJECTIVE

To compare the glucose homeostasis parameters between patients with HRD and LRD after SG.

SETTING

University hospital in Greece.

METHODS

Thirteen patients were categorized as HRD (9 females, mean body mass index 46.3±1.6 kg/m²) and 10 as LRD (8 females, mean body mass index 45.4±1.7 kg/m²) based on a preoperative 2-hour oral glucose tolerance test (OGTT). OGTT was repeated 6 weeks and 6 months postoperatively. OGTT-derived indices of insulin secretion, insulin sensitivity, and β-cell function (oral disposition index [ODI]) were calculated.

RESULTS

Preoperatively, in the HRD group, fasting and postload glucose levels were higher and the ODIs were lower compared with those in the LRD group. Six weeks postoperatively, glucose levels and ODIs were not different between the 2 groups. However, 6 months postoperatively, the HRD group had demonstrated higher postload glucose levels and lower ODI (0-30) and ODI (0-120) compared with the LRD group. Six weeks postoperatively, insulin levels, early insulin secretion, and insulin resistance indices were decreased compared with preoperative levels only in the HRD group. Six months postoperatively, ODIs and insulin sensitivity indices improved in both groups compared with baseline.

CONCLUSION

Six months after SG, glucose levels and ODIs improved for both HRD and LRD patients; however, postprandial glucose levels and ODI (0-30) and ODI (0-120) in HRD patients did not return to LRD levels. Moreover, during the first 6 postoperative weeks, the changes in glucose homeostasis parameters compared with preoperative levels were different for HRD and LRD patients.

How do patients' clinical phenotype and the physiological mechanisms of the operations impact the choice of bariatric procedure?

Bariatric surgery is currently the most effective option for the treatment of morbid obesity and its associated comorbidities. Recent clinical and experimental findings have challenged the role of mechanical restriction and caloric malabsorption as the main mechanisms for weight loss and health benefits. Instead, other mechanisms including increased levels of satiety gut hormones, altered gut microbiota, changes in bile acid metabolism, and/or energy expenditure have been proposed as explanations for benefits of bariatric surgery. Beside the standard proximal Roux-en-Y gastric bypass and the biliopancreatic diversion with or without duodenal switch, where parts of the small intestine are excluded from contact with nutrients, resectional techniques like the sleeve gastrectomy (SG) have recently been added to the armory of bariatric surgeons. The variation of weight loss and glycemic control is vast between but also within different bariatric operations. We surveyed members of the Swiss Society for the Study of Morbid Obesity and Metabolic Disorders to assess the extent to which the phenotype of patients influences the choice of bariatric procedure. Swiss bariatric surgeons preferred Roux-en-Y gastric bypass and SG for patients with type 2 diabetes mellitus and patients with a body mass index >50 kg/m², which is consistent with the literature. An SG was preferred in patients with a high anesthetic risk or previous laparotomy. The surgeons’ own experience was a major determinant as there is little evidence in the literature for this approach. Although trends will come and go, evidence-based medicine requires a rigorous examination of the proof to inform clinical practice.

Metabolic Surgery in Type 2 Diabetes: Roux-en-Y Gastric Bypass or Sleeve Gastrectomy as Procedure of Choice?

In recent years, a marked increase in the relative use of sleeve gastrectomy (SG) has occurred. However, long-term head-to-head comparison of the impact of this bariatric surgery (BS) procedure with the still considered "gold standard" Roux-en-Y gastric bypass (GBP) in subjects with type 2 diabetes mellitus (T2DM) is surprisingly low. The aim of this review manuscript is to appraise current evidence on the potential of GBP and SG as long-term therapeutic tool for subjects with T2DM. In our opinion, unfortunately, review of current literature does not allow to properly answer which of the two surgeries would be better as procedure of choice for subjects with T2DM. Arguably, the apparent superiority of GBP over SG could be overcome by the addition of a malabsortive component to SG in a staged approach restricted to those failing to achieve the desired metabolic outcomes. Nonetheless, whether this serves as basis for the election of SG as primary strategy for those with T2DM is questionable.

Differences in Alimentary Glucose Absorption and Intestinal Disposal of Blood Glucose After Roux-en-Y Gastric Bypass vs Sleeve Gastrectomy

BACKGROUND & AIMS

Bariatric procedures, such as Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG), are the most effective approaches to resolve type 2 diabetes in obese individuals. Alimentary glucose absorption and intestinal disposal of blood glucose have not been directly compared between individuals or animals that underwent RYGB vs VSG. We evaluated in rats and humans how the gut epithelium adapts after surgery and the consequences on alimentary glucose absorption and intestinal disposal of blood glucose.

METHODS

Obese male rats underwent RYGB, VSG, or sham (control) operations. We collected intestine segments from all rats; we performed histologic analyses and measured levels of messenger RNAs encoding the sugar transporters SGLT1, GLUT1, GLUT2, GLUT3, GLUT4, and GLUT5. Glucose transport and consumption were assayed using ex vivo jejunal loops. Histologic analyses were also performed on Roux limb sections from patients who underwent RYGB 1-5 years after surgery. Roux limb glucose consumption was assayed after surgery by positron emission and computed tomography imaging.

RESULTS

In rats and humans that underwent RYGB, the Roux limb became hyperplasic, with an increased number of incretin-producing cells compared with the corresponding jejunal segment of controls. Furthermore, expression of sugar transporters and hypoxia-related genes increased and the nonintestinal glucose transporter GLUT1 appeared at the basolateral membrane of enterocytes. Ingested and circulating glucose was trapped within the intestinal epithelial cells of rats and humans that underwent RYGB. By contrast, there was no hyperplasia of the intestine after VSG, but the intestinal absorption of alimentary glucose was reduced and density of endocrine cells secreting glucagon-like peptide-1 increased.

CONCLUSIONS

The intestine adapts differently to RYGB vs VSG. RYGB increases intestinal glucose disposal and VSG delays glucose absorption; both contribute to observed improvements in glycemia.

Effects of meal composition on postprandial incretin, glucose and insulin responses after surgical and medical weight loss

Background

Meal tolerance tests are frequently used to study dynamic incretin and insulin responses in the postprandial state; however, the optimal meal that is best tolerated and suited for hormonal response following surgical and medical weight loss has yet to be determined.

Objective

To evaluate the tolerability and effectiveness of different test meals in inducing detectable changes in markers of glucose metabolism in individuals who have undergone a weight loss intervention.

Methods

Six individuals who underwent surgical or medical weight loss (two Roux‐en‐Y gastric bypass, two sleeve gastrectomy and two medical weight loss) each completed three meal tolerance tests using liquid‐mixed, solid‐mixed and high‐fat test meals. The tolerability of each test meal, as determined by the total amount consumed and palatability, as well as fasting and meal‐stimulated glucagon‐like peptide, glucose‐dependent insulinotropic polypeptide, insulin and glucose were measured.

Results

Among the six individuals, the liquid‐mixed meal was better and more uniformly tolerated with a median meal completion rate of 99%. Among the four bariatric surgical patients, liquid‐mixed meal stimulated on average a higher glucagon‐like peptide (percent difference: 83.7, 89), insulin secretion (percent difference: 155.1, 158.7) and glucose‐dependent insulinotropic polypeptide (percent difference: 113.5, 34.3) compared with solid‐mixed and high‐fat meals.

Conclusions

The liquid‐mixed meal was better tolerated with higher incretin and insulin response compared with the high‐fat and solid‐mixed meals and is best suited for the evaluation of stimulated glucose homeostasis.

[Dumping syndrome: Diagnostics and therapeutic options]

BACKGROUND

Dumping syndrome is a common complication after surgery of the upper gastrointestinal tract with symptoms ranging from mild gastrointestinal discomfort and moderate vasomotor disturbances, to severe hyperinsulinemic hypoglycemia. Due to the increasing number of bariatric procedures being performed worldwide, bariatric surgery has become the most common cause for this disease entity.

OBJECTIVE

The aim of this review is to highlight the evidence for the physiological mechanisms contributing to dumping syndrome after the two most common bariatric surgery procedures, Roux-en-Y gastric bypass and sleeve gastrectomy, to discuss technical aspects of the procedures underlying the development of the syndrome, patient-related predictive factors and other differential diagnoses, together with diagnostic and therapeutic algorithms.

Is type 2 diabetes really resolved after laparoscopic sleeve gastrectomy? Glucose variability studied by continuous glucose monitoring

The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (<140 mg/dL) at 120 minutes OGTT. These interesting data could help clinicians to better individualize patients in which diabetes is not resolved and who could need more attention in order to prevent chronic complications of diabetes.

Anti-incretin, Anti-proliferative Action of Dopamine on β-Cells

Human islet β-cells exploit an autocrine dopamine (DA)-mediated inhibitory circuit to regulate insulin secretion. β-Cells also express the DA active transporter and the large neutral amino acid transporter heterodimer enabling them to import circulating DA or its biosynthetic precursor, L-3,4-dihydroxyphenylalanine (L-DOPA). The capacity to import DA or L-DOPA from the extracellular space possibly indicates that DA may be an endocrine signal as well. In humans, a mixed meal stimulus is accompanied by contemporary serum excursions of incretins, DA and L-DOPA, suggesting that DA may act as an anti-incretin as postulated by the foregut hypothesis proposed to explain the early effects of bariatric surgery on type 2 diabetes. In this report, we take a translational step backwards and characterize the kinetics of plasma DA and incretin production after a mixed meal challenge in a rat model and study the integration of incretin and DA signaling at the biochemical level in a rodent β-cell line and islets. We found that there are similar excursions of incretins and DA in rats, as those reported in humans, after a mixed meal challenge and that DA counters incretin enhanced glucose-stimulated insulin secretion and intracellular signaling at multiple points from dampening calcium fluxes to inhibiting proliferation as well as apoptosis. Our data suggest that DA is an important regulator of insulin secretion and may represent 1 axis of a gut level circuit of glucose and β-cell mass homeostasis.