Recovery of insulin sensitivity in obese patients at short term after biliopancreatic diversion

Objective. To gain insight into the specific mechanisms by which biliopancreatic diversion (BPD) can improve insulin action. Materials and methods. Nondiabetic severely obese patients (n = 20) undergoing BPD were included. Waist-to-hip ratio and serum concentration of glucose, insulin, and leptin were determined before, at 4-day, and at 2 months after the operation. Insulin sensitivity was calculated according to the homeostatic model assessment (HOMA IR). Results. A marked increase of insulin sensitivity was observed by the fourth day after the operation; at the second postoperative month, when body weight was still in the obese range and the food intake was substantially similar to the preoperative one, a further improvement of insulin action towards normality was found. Moreover, before BPD HOMA IR data were independently correlated both to BMI and waist-to-hip ratio values, whereas at 2 months after the operation data were in positive correlation only with the BMI. Discussion. In obese patients, BPD seems to achieve recovery of insulin sensitivity by specific mechanisms independent of weight loss: the main causes of this sharp improvement might be both the intramyocellular fat depletion and the interruption of enteroinsular axis. (C) 2003 Elsevier Inc. All rights reserved.