Incretin hormones likely affect diabetes response to bariatric procedures vs. medical weight loss
NEW ORLEANS — Patients with obesity and type 2 diabetes can expect different changes in glucose homeostasis following weight loss from surgical vs. medical interventions, likely due to effects on insulin, glucagon-like peptide 1 and gastrointestinal inhibitory peptide secretion, according to a presenter here.
Nisa Maruthur, MD, MHS, professor of medicine at Johns Hopkins Medicine in Baltimore, and colleagues randomly assigned 12 women (median age, 52.2 years; 75% black) with obesity and type 2 diabetes 1:1:1 to laparoscopic Roux-en-Y gastric bypass surgery (RYGB), adjustable gastric binding (AGB) or medical weight loss (MWL) to determine changes in early and late glucose, insulin, GLP-1 and GIP response to a mixed-meal tolerance test from baseline prior to intervention to 10% weight loss or 9 months.
Using nonparametric tests, the researchers observed greater median percent weight loss in the surgical groups (RYGB, 10.3%; AGB, 9.2%) compared with the MWL group (4%; P = .05); reductions in waist circumference and HbA1c were similar across groups. Using the trapezoidal rule to calculate area under the curve, they observed reductions in all groups for meal-stimulated glucose AUC at 60 minutes and at 300 minutes, and similar changes across groups in AUC at 60 minutes for insulin, GLP-1 and GIP. AUC at 300 minutes for insulin was decreased for the RYGB group (P = .046) and not significantly increased for the AGB and MWL groups. A greater decrease in AUC at 300 minutes for GLP-1 was observed in the AGB group (P = .049) and the RYGB group (P = .096) than in the MWL group (P across groups = .51). GIP AUC at 300 minutes was significantly decreased in the RYGB group (P = .04); however, the difference across arms was not significant.
“Incretin hormones do not explain all of the differential effects of bariatric surgery (especially in RYGB) on diabetes/glucose control,” Maruthur told Endocrine Today. “Although incretin hormones likely play a role in diabetes improvement after bariatric surgery, based on findings from our small study, it’s not clear that we should steer patients to a particular surgery if they have diabetes. We do not have data on the effects of the sleeve gastrectomy on incretin hormones on mixed-meal tolerance testing.”
Maruthur N. T-OR-2079. Presented at: ObesityWeek 2016; Oct. 31-Nov. 4, 2016; New Orleans.
Disclosure: Maruthur reports no relevant financial disclosures.