Biliopancreatic diversion with duodenal switch improves insulin sensitivity and secretion through caloric restriction.

Objective: To assess the rapid improvement of insulin sensitivity and β-cell function following biliopancreatic diversion with duodenal switch (BPD-DS) and determine the role played by caloric restriction in these changes.
Methods: Standard meals were administrated before and on day 3, 4, and 5 after BPD-DS to measure total caloric intake, glucose excursion, insulin sensitivity, and secretion in matched type 2 diabetes and normoglycemic (NG) subjects. In a second set of study, other subjects with type 2 diabetes had the same meal tests prior to and after a 3-day caloric restriction identical to that observed after BPD-DS and then 3 days after actually undergoing BPD-DS.
Results: Improvement of HOMA-IR occurred at day 3 after BPD-DS in diabetes and after 3 days of caloric restriction. The disposition index (DI) improved rapidly in diabetes after BPD-DS and to a similar extent after caloric restriction. DI was higher and did not change after BPD-DS in NG. Changes in glucagon-like peptide-1, gastric inhibitory peptide, peptide tyrosine tyrosine, ghrelin, and pancreatic polypeptide levels were not associated with modulation of DI in the participants.
Conclusions: Caloric restriction is the major mechanism underlying the early improvement of insulin sensitivity and β-cell function after BPD-DS in type 2 diabetes.
(Copyright © 2014 The Obesity Society.)