Review

Diabetologia

, Volume 55, Issue 7, pp 1890-1901

First online:

Mechanisms of improved glycaemic control after Roux-en-Y gastric bypass

  • C. DirksenAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of CopenhagenNovo Nordisk Foundation Centre for Basic Metabolic Research, The Panum Institute, University of Copenhagen Email author 
  • , N. B. JørgensenAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of CopenhagenNovo Nordisk Foundation Centre for Basic Metabolic Research, The Panum Institute, University of CopenhagenDepartment of Biomedical Sciences, The Panum Institute, University of Copenhagen
  • , K. N. Bojsen-MøllerAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of CopenhagenNovo Nordisk Foundation Centre for Basic Metabolic Research, The Panum Institute, University of Copenhagen
  • , S. H. JacobsenAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of CopenhagenNovo Nordisk Foundation Centre for Basic Metabolic Research, The Panum Institute, University of Copenhagen
  • , D. L. HansenAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of Copenhagen
  • , D. WormAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of Copenhagen
  • , J. J. HolstAffiliated withNovo Nordisk Foundation Centre for Basic Metabolic Research, The Panum Institute, University of CopenhagenDepartment of Biomedical Sciences, The Panum Institute, University of Copenhagen
  • , S. MadsbadAffiliated withDepartment of Endocrinology 541, Hvidovre Hospital, University of Copenhagen

Abstract

Roux-en-Y gastric bypass (RYGB) greatly improves glycaemic control in morbidly obese patients with type 2 diabetes, in many even before significant weight loss. Understanding the responsible mechanisms may contribute to our knowledge of the pathophysiology of type 2 diabetes and help identify new drug targets or improve surgical techniques. This review summarises the present knowledge based on pathophysiological studies published during the last decade. Taken together, two main mechanisms seem to be responsible for the early improvement in glycaemic control after RYGB: (1) an increase in hepatic insulin sensitivity induced, at least in part, by energy restriction and (2) improved beta cell function associated with an exaggerated postprandial glucagon-like peptide 1 secretion owing to the altered transit of nutrients. Later a weight loss induced improvement in peripheral insulin sensitivity follows.

Keywords

Bariatric surgery Beta cell function Incretin hormones Insulin sensitivity Obesity Review Roux-en-Y gastric bypass Type 2 diabetes mellitus