2009 SSAT Plenary Presentation

Journal of Gastrointestinal Surgery

, Volume 14, Issue 1, pp 15-23

Open Access This content is freely available online to anyone, anywhere at any time.

Improvement in Peripheral Glucose Uptake After Gastric Bypass Surgery Is Observed Only After Substantial Weight Loss Has Occurred and Correlates with the Magnitude of Weight Lost

  • Guilherme M. CamposAffiliated withDepartment of Surgery, University of California San FranciscoDepartment of Surgery, School of Medicine and Public Health, University of Wisconsin Email author 
  • , Charlotte RablAffiliated withDepartment of Surgery, University of California San Francisco
  • , Sofia PeevaAffiliated withDepartment of Surgery, University of California San Francisco
  • , Ruxandra CiovicaAffiliated withDepartment of Surgery, University of California San Francisco
  • , Madhu RaoAffiliated withDepartment of Medicine, University of California San Francisco
  • , Jean-Marc SchwarzAffiliated withDepartment of Medicine, University of California San Francisco
  • , Peter HavelAffiliated withDepartment of Nutrition, University of California Davis
  • , Morris SchambelanAffiliated withDepartment of Medicine, University of California San Francisco
  • , Kathleen MulliganAffiliated withDepartment of Medicine, University of California San Francisco

Abstract

Introduction

Altered gut and pancreatic hormone secretion may bolster resolution of insulin resistance after Roux-en-Y gastric bypass (RYGB), but the independent effects of weight loss and hormonal secretion on peripheral glucose disposal are unknown.

Methods

Two groups of nondiabetic morbidly obese patients were studied: RYGB followed by standardized caloric restriction (RYGB, n = 12) or caloric restriction alone (diet, n = 10). Metabolic evaluations (euglycemic–hyperinsulinemic clamp, meal tolerance test) were done at baseline and 14 days (both groups) and 6 months after RYGB.

Results

At baseline, body composition, fasting insulin, and glucose and peripheral glucose disposal did not differ between groups. At 14 days, excess weight loss (EWL) was similar (RYGB, 12.7% vs. diet, 10.9%; p = 0.12), fasting insulin and glucose decreased to a similar extent, and RYGB subjects had altered postmeal patterns of gut and pancreatic hormone secretion. However, peripheral glucose uptake (M value) was unchanged in both groups. Six months after RYGB, EWL was 49.7%. The changes in fasting glucose and insulin levels and gut hormone secretion persisted. M values improved significantly, and changes in M values correlated with the % EWL (r = 0.68, p = 0.02).

Conclusions

Improvement in peripheral glucose uptake following RYGB was observed only after substantial weight loss had occurred and correlated with the magnitude of weight lost.

Keywords

Bariatric surgery Insulin resistance Obesity Morbid obesity Gastric bypass Weight loss GLP-1 Insulin Type 2 diabetes Diabetes Calorie restriction Incretin