Insulin Sensitivity and Secretion in Obese Type 2 Diabetic Women after Various Bariatric Operations

Postprandial Triglyceride, Glucose and Insulin Levels 10 Years After Bariatric Surgery in Women With Severe Obesity - A Pilot Study: Part 1 - Laparoscopic Greater Curvature Plication

The long-term effects of bariatric surgery on postprandial profiles in patients with obesity and type 2 diabetes (T2D) have not yet been investigated. Therefore, this study examined postprandial profiles before laparoscopic greater curvature plication (LGCP), and then at 2 and 10 years after surgery.The studied cohort included 10 women (mean age= 54.4±5 years) with obesity (mean BMI= 42.5±7.8 kg/m?) and T2D who underwent LGCP. All subjects underwent a standardized liquid mixed-meal test. For statistical evaluation, ANOVA with Bonferroni multiple comparison was used. Mean postprandial levels were significantly decreased 2 years after surgery. Responses 10 years after the surgery also remained significantly lower than before surgery. Changes observed during the follow-up were significant: glucose: F=34.5, p<0.001; insulin: F=49.3, p<0.001; triglycerides F=9.2, p<0.001. The long-term favorable effects of bariatric surgery on cardiometabolic health may be partly mediated by reductions in postprandial glucose, insulin, and triglyceride levels.

Postprandial Triglyceride, Glucose and Insulin Levels 10 Years After Bariatric Surgery in Women With Severe Obesity - A Pilot Study: Part 2 - Biliopancreatic Diversion

Obesity significantly increases the risk of developing metabolic and cardiovascular diseases. The most effective management tool for both obesity and type 2 diabetes (T2D) is bariatric/metabolic surgery. Delayed postprandial plasma triglyceride clearance contributes to the development of atherosclerosis in patients with T2D. Biliopancreatic diversion (BPD) was shown to be the most effective procedure in long-term T2D remission. However, the effect of BPD on postprandial metabolic profile has not been studied so far. In this pilot study, we therefore examined the changes in postprandial glucose, insulin, and triglyceride in women with severe obesity and T2D before surgery and then two and ten years after BPD. The studied cohort included 7 women (mean age at baseline=49.3±8.2 years) with severe obesity (mean BMI= 45.7±2.9 kg/m?) and T2D. A standardized liquid mixed-meal test was carried out in all subjects and the mean postprandial levels of plasma glucose, insulin, and triglyceride were analyzed by standard laboratory procedures. For statistical evaluation, ANOVA with Bonferroni multiple comparisons was used. Ten years after BPD not only a significant reduction of an average BMI (F=32.9, p<0.001) but also significant declines in mean postprandial plasma levels of glucose (F=155.3, p<0.001), insulin (F=69.8, p<0.001), and triglyceride (F=139.9, p<0.001) were demonstrated. The observed changes in postprandial metabolic profile may contribute to improved cardiometabolic health after bariatric surgery.

miR-139-5p mediates the palmitate-induced inhibition of insulin secretion by targeting neuronal pentraxin 1 in INS-1 cells

High fatty acid reduces insulin secretion in pancreatic β-cells and miR-139-5p is increased in diabetic pancreatic tissues and induces islet β-cell apoptosis. However, to date, there is no study exploring whether or not miR-139-5p is involved in high fatty acid-induced insulin secretion. In the present study, INS-1 cells were exposed to different concentrations (0.1, 0.2, and 0.4 mM) of palmitate for different time periods (12, 24, and 48 h). The expression levels of miR-139-5p and neuronal pentraxin 1 (NPTX1) were evaluated by real-time PCR and western blot analysis. The regulation of NPTX1 by miR-139-5p was examined by luciferase assay. Cell transfection was conducted using Lipo8000 or Lipofectamine RNAiMAX. Potassium or glucose-stimulated insulin secretion levels were used to verify the function of miR-139-5p or NPTX1 in insulin secretion. Insulin secretion levels were detected by radioimmunoassay. We found that miR-139-5p was increased in INS-1 cells stimulated with palmitate. In addition, miR-139-5p was also elevated in islets of high-fat diet-fed mice and db/db mice compared to those in islets of normal diet-fed mice and wild-type mice. Knockdown of miR-139-5p could reverse high fatty acid-induced insulin secretion defects in INS-1 cells. Furthermore, we demonstrated that NPTX1 is a target of miR-139-5p. miR-139-5p mediated palmitate-induced insulin secretion defects by targeting NPTX1. Moreover, palmitate treatment declined the expression of NPTX1 and the NPTX1 expression was also decreased in islets of high-fat diet-fed mice and db/db mice. Impaired NPTX1 expression is involved in fatty acid-induced insulin secretion defects. Collectively, our results illustrate that the induction of β-cell insulin secretion defects by fatty acids is mediated, at least in part, by miR-139-5p via downregulation of NPTX1 expression.

The relation between postprandial glucagon-like peptide-1 release and insulin sensitivity before and after bariatric surgery in humans with class II/III obesity

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonist treatment is beneficial for the human glucose metabolism, and GLP-1 secretion is greatly enhanced following Roux-en-Y gastric bypass (RYGB).

OBJECTIVES

To elucidate the relationship between GLP-1 concentrations and insulin sensitivity in subjects with class II/III obesity without diabetes and to assess the relation between GLP-1 and the improvements in glucose metabolism following RYGB.

SETTING

Clinical research facility in a university hospital.

METHODS

We recruited 35 patients scheduled for RYGB and assessed their plasma GLP-1, insulin, and glucose responses to a high-fat mixed meal. Basal and insulin-mediated glucose fluxes were determined during a 2-step hyperinsulinemic-euglycemic clamp with stable isotope-labeled tracers. Out of 35 subjects, 10 were studied both before surgery and at 1 year of follow-up.

RESULTS

Plasma GLP-1 increased following the high-fat mixed meal. Postprandial GLP-1 excursions correlated positively with hepatic and peripheral insulin sensitivity, but not with body mass index. At 1 year after RYGB, participants had lost 24% ± 6% of their body weight. Plasma GLP-1, insulin, and glucose levels peaked earlier and higher after the mixed meal. The positive association between the postprandial GLP-1 response and peripheral insulin sensitivity persisted.

CONCLUSIONS

Postprandial GLP-1 concentrations correlate with insulin sensitivity in subjects with class II/III obesity without diabetes before and 1 year after RYGB. Increased GLP-1 signaling in postbariatric patients may, directly or indirectly, contribute to the observed improvements in insulin sensitivity and metabolic health.

Comparing the Anti-diabetic Effect of Sleeve Gastrectomy with Transit Bipartition Against Sleeve Gastrectomy and Roux-en-Y Gastric Bypass Using a Diabetic Rodent Model

PURPOSE

Roux-en-Y gastric bypass (RYGB) has superior long-term diabetes remission outcomes to sleeve gastrectomy (SG). However, in regions with a high prevalence of gastric cancer, RYGB may not be the best option. This study aimed to investigate the anti-diabetic effect of SG with transit bipartition (SG-TB) compared with SG and RYGB.

MATERIALS AND METHODS

A total of 32 diabetic Sprague-Dawley rat models were assigned to one of four groups: SG (n = 8), RYGB (n = 8), SG-TB (n = 8), and SHAM (n = 8). Body weight, food intake, blood glucose, and hormonal changes (glucagon-like peptide-1 (GLP-1), insulin, and glucagon) were measured to investigate the effect of surgery in all groups. Oral glucose tolerance test and insulin tolerance test were performed before and 8 weeks after surgery.

RESULTS

There were no significant differences in the postoperative changes in body weight and food intake among the SG, RYGB, and SG-TB groups. Postoperatively, the RYGB and SG-TB groups had significantly higher GLP-1 levels and lower insulin levels than the SG group. Further, RYGB and SG-TB had significantly better glucose control improvements than SG. There were no significant differences in GLP-1, insulin, glucagon, and homeostasis model assessment of insulin resistance levels between RYGB and SG-TB. The preoperative and postoperative values of all variables in the SHAM group did not show significant differences.

CONCLUSION

In this study using a diabetes-induced rodent model, we found that the anti-diabetic effect of SG-TB is superior to that of SG and non-inferior to that of RYGB.

The effect of surgical gastric plication on obesity and diabetes mellitus type 2: a systematic review and meta-analysis

Introduction

All the bariatric procedures have evolved greatly over the past decades and laparoscopic greater curvature plication (LGCP) is one of the quite recently introduced techniques lacking systematic evaluation.

Aim

To compare and summarize the current data in the literature in regard to the effect of gastric plication on obesity and diabetes mellitus type 2.

Material and methods

The systematic review and meta-analysis was performed according to the PRISMA guidelines and registered at PROSPERO under the registration number CRD42018114314. The literature in English and German was searched using the MEDLINE (PubMed) and BJS databases for studies published in the last 10 years. A meta-analysis was performed focusing on the effects of this operation on weight loss, glycemia control and improvement of comorbidities.

Results

Mean preoperative body mass index (BMI) ranged from 34.42 to 46.3 kg/m². Most of the patients were female. The operation time was in the range from 50 to 192.23 min. Mean follow-up was from one month to 12 years, with most studies having a follow-up of less than 2 years. The postoperative BMI ranged from 28.59 to 38, with reported excess weight loss (EWL%) in the range 20-70%. Glycated hemoglobin (HbA_1c) values decreased by up to 5.1% after surgery, ranging from 5.1% to 7.5%.

Conclusions

Despite the quality of most of the included studies being low, the present meta-analysis revealed that, in the short term, gastric plication is an effective measure for weight loss, while the effect on diabetes mellitus type 2 is not statistically significant.