Early postoperative insulin-resistance changes after sleeve gastrectomy

Biliopancreatic diversion and gastric bypass are associated with a rapid improvement in insulin resistance few days after surgery. The purpose of this study was to evaluate the short-term effects in insulin resistance following sleeve gastrectomy (SG).

Between December 2007 and September 2008, 17 consecutive obese type 2 diabetes mellitus patients (three men, mean age 51.1 years, mean BMI 44.7 kg/m(2)) were submitted to laparoscopic SG. Fasting serum glucose, insulin concentration, and homeostatic model assessment for insulin resistance (HOMA IR) were drawn preoperatively and at 5, 15, 30, and 60 postoperative days. In seven of these patients insulin sensitivity was evaluated on postoperative days 1, 2, 3, and 4. Moreover a control group of three overweight and diabetic patients (one man, mean age 52.1 years and mean BMI 26.8 kg/m(2)) submitted to laparoscopic cholecystectomy and undergoing the same diet protocol was studied.

In all obese patients, a sharp (5 days) and significant reduction of serum glucose and insulin concentration and HOMA IR values was observed after SG. In seven patients, serum glucose and insulin concentration and HOMA IR values were significantly lower at third postoperative day. At the 15th postoperative day both serum glucose and insulin concentration and HOMA IR remained significantly lower in the absence of significant weight modifications. At 30 and 60 postoperative days, these values remained substantially unchanged in spite of a greater weight loss. In the cholecystectomy patients group, at postoperative day 5, only the serum glucose concentrations were significantly reduced although with the higher values than normal in respect to the preoperative values.

After SG the improvement of insulin action occurred rapidly and independently of EWL. The results of the present study confirm that a hormonal mechanism may contribute to changes in insulin resistance following SG.