Acute effects of gastric bypass versus gastric restrictive surgery on β-cell function and insulinotropic hormones in severely obese patients with type 2 diabetes

Abstract

Context: Hyperglycemia resolves quickly after bariatric surgery, but the underlying mechanism and the most effective type of surgery remains unclear. Objective: To examine glucose metabolism and b-cell function in patients with type 2 diabetes mellitus (T2DM) after two types of bariatric intervention; Roux-en-Y gastric bypass (RYGB) and gastric restrictive (GR) surgery. Design: Prospective, nonrandomized, repeated-measures, 4-week, longitudinal clinical trial. Patients: In all, 16 T2DM patients (9 males and 7 females, 52±14 years, 47±9 kg m À2 , HbA1c 7.2±1.1%) undergoing either RYGB (N ¼ 9) or GR (N ¼ 7) surgery. Outcome measures: Glucose, insulin secretion, insulin sensitivity at baseline, and 1 and 4 weeks post-surgery, using hyperglycemic clamps and C-peptide modeling kinetics; glucose, insulin secretion and gut-peptide responses to mixed meal tolerance test (MMTT) at baseline and 4 weeks post-surgery. Results: At 1 week post-surgery, both groups experienced a similar weight loss and reduction in fasting glucose (Po0.01). However, insulin sensitivity increased only after RYGB, (Po0.05). At 4 weeks post-surgery, weight loss remained similar for both groups, but fasting glucose was normalized only after RYGB (95 ± 3 mg 100 ml À1 ). Insulin sensitivity improved after RYGB (Po0.01) and did not change with GR, whereas the disposition index remained unchanged after RYGB and increased 30% after GR (P ¼ 0.10). The MMTT elicited a robust increase in insulin secretion, glucagon-like peptide-1 (GLP-1) levels and b-cell sensitivity to glucose only after RYGB (Po0.05). Conclusion: RYGB provides a more rapid improvement in glucose regulation compared with GR. This improvement is accompanied by enhanced insulin sensitivity and b-cell responsiveness to glucose, in part because of an incretin effect.

Differential Acute Impacts of Sleeve Gastrectomy, Roux-en-Y Gastric Bypass Surgery and Matched Caloric Restriction Diet on Insulin Secretion, Insulin Effectiveness and Non-Esterified Fatty Acid Levels Among Patients with Type 2 Diabetes

“…Rapid improvement of fasting glucose, insulin secretion and insulin resistance has been reported within days of Roux-en-Y gastric bypass (GBP) [3][4][5] and sleeve gastrectomy (SG) [6,7]. Hypocaloric dieting has also been shown to restore normal glucose levels [8,9].…”

Biliopancreatic diversion with duodenojejunal exclusion associated with truncal vagotomy: a new proposal for type 2 diabetes mellitus treatment

“…It has been shown that bariatric surgery promotes the control or improvement of T2DM 9,12,15,16,18,23 . Among the variations of this type of surgery, the disabsortive techniques are considered the most effective 23 .…”

“…Kashyap et al 16 studied the early effects of bariatric surgery on beta cell function and insulinotropic hormone action in obese patients with T2DM before the weight loss occurred.…”

Gender effect on vascular responsiveness after bariatric surgery

“…Comparing gastric bypass versus gastric restrictive surgery it was found that both had a similar effect on weight loss and reduction in fasting glucose. However, insulin sensitivity increased only after gastric bypass surgery and was not changed following the restrictive surgery, and there was a robust increase in insulin secretion, glucagonlike peptide 1 and beta cell sensitivity to glucose only after gastric bypass surgery [17]. A study that examined multiethnic adults showed that among 1603 adults (66% Hispanic, 77% females) who underwent bariatric surgery, 377 patients had diabetes mellitus type II, 107 had fasting plasma glucose >126 mg/dL, and 276 were pre-diabetic.…”