Glucose-Stimulated Insulin Secretion in Gastric Bypass Patients with Hypoglycemic Syndrome: No Evidence for Inappropriate Pancreatic β-cell Function
- 277 Downloads
Roux-en-Y gastric bypass surgery (RYGB) has been associated with a hypoglycemic syndrome characterized by postprandial hypoglycemia and hyperinsulinemia. The syndrome is believed to occur due to insulin hypersecretion from either pancreatic β-cell hyperplasia or hyperfunction.
Eight RYGB patients with hypoglycemic syndrome had insulin secretion rates determined during a 240-min graded intravenous glucose infusion. They were compared to 34 nondiabetic, nonsurgical individuals who were divided based on their insulin sensitivity status as measured by the insulin suppression test: insulin-sensitive (n = 8), insulin intermediate (n = 7), and insulin-resistant (n = 19).
RYGB patients had insulin concentrations and HOMA-IR similar to the insulin-sensitive reference group. In addition, integrated insulin secretion rates were comparable to the insulin-sensitive group and significantly lower than the insulin intermediate (p ≤ 0.046) and insulin-resistant groups (p ≤ 0.001). Pancreatic β-cell sensitivity to glucose (slope relating glucose and ISR) was lowest in the RYGB group (p ≤ 0.04).
Patients with hypoglycemic syndrome post-RYGB do not have generalized hypersecretion of insulin and appear to have appropriate insulin secretion rate in response to intravenous glucose.
KeywordsGastric bypass Hypoglycemia Hyperinsulinemia Insulin secretion
Funding support was provided by NIH Research Grants RR-00070 and K23 MH079114 (SHK).
Conflict of Interest
The authors have no conflicts of interest to disclose.
- 7.Kim SH, Liu TC, Abbasi F et al. Plasma glucose and insulin regulation is abnormal following gastric bypass surgery with or without neuroglycopenia. Obes Surg. 2009.Google Scholar