Beta cell function after weight loss: a clinical trial comparing gastric bypass surgery and intensive lifestyle intervention

Eur J Endocrinol. 2011 Feb;164(2):231-8. doi: 10.1530/EJE-10-0804. Epub 2010 Nov 15.


Objective: The effects of various weight loss strategies on pancreatic beta cell function remain unclear. We aimed to compare the effect of intensive lifestyle intervention (ILI) and Roux-en-Y gastric bypass surgery (RYGB) on beta cell function.

Design: One year controlled clinical trial ( identifier NCT00273104).

Methods: One hundred and nineteen morbidly obese participants without known diabetes from the MOBIL study (mean (s.d.) age 43.6 (10.8) years, body mass index (BMI) 45.5 (5.6) kg/m², 84 women) were allocated to RYGB (n = 64) or ILI (n = 55). The patients underwent repeated oral glucose tolerance tests (OGTTs) and were categorised as having either normal (NGT) or abnormal glucose tolerance (AGT). Twenty-nine normal-weight subjects with NGT (age 42.6 (8.7) years, BMI 22.6 (1.5) kg/m², 19 women) served as controls. OGTT-based indices of beta cell function were calculated.

Results: One year weight reduction was 30% (8) after RYGB and 9% (10) after ILI (P < 0.001). Disposition index (DI) increased in all treatment groups (all P<0.05), although more in the surgery groups (both P < 0.001). Stimulated proinsulin-to-insulin (PI/I) ratio decreased in both surgery groups (both P < 0.001), but to a greater extent in the surgery group with AGT at baseline (P < 0.001). Post surgery, patients with NGT at baseline had higher DI and lower stimulated PI/I ratio than controls (both P < 0.027).

Conclusions: Gastric bypass surgery improved beta cell function to a significantly greater extent than ILI. Supra-physiological insulin secretion and proinsulin processing may indicate excessive beta cell function after gastric bypass surgery.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Body Mass Index
  • Chromatography, High Pressure Liquid
  • Diet, Reducing
  • Exercise Therapy
  • Female
  • Gastric Bypass*
  • Glucose Tolerance Test
  • Glycated Hemoglobin / metabolism
  • Humans
  • Insulin / metabolism
  • Insulin Resistance
  • Insulin-Secreting Cells / metabolism*
  • Life Style
  • Male
  • Middle Aged
  • Obesity / metabolism
  • Obesity / therapy*
  • Statistics, Nonparametric
  • Treatment Outcome
  • Weight Loss / physiology*


  • Glycated Hemoglobin A
  • Insulin

Associated data