Improvement of Insulin Resistance After Bariatric Surgery

Bariatric and weight loss surgery is an effective treatment for severe obesity. Bariatric surgery also decreases insulin resistance and improves diabetes. Our study enrolled individuals approved for bariatric surgery to collect data on modifiable predictors and laboratory outcomes. These data would allow us to systematically assess clinical outcomes over one year post bariatric surgery and elucidate how insulin resistance is decreased and diabetes is improved.

The type of surgery was selected by the subjects between Roux-en-Y gastric bypass or a laparoscopic adjustable gastric banding. Participation in the study involved having a small sample of tissue obtained from the abdomen and subjects were also given the option to have a biopsy performed in the thigh area during their elective surgical procedure (optional adipose and muscle tissue biopsies).

Subjects were examined prior to surgery and at 2, 3, 6 months after intervention. Anthropometric and body composition measurements were performed using the Bioelectrical Impendence Analysis (BIA) before surgery and 6 months post operatively. Morning blood was collected after overnight fasting during each visit. Some of the non-diabetic subjects completed a mixed nutrient stimulation study during the baseline and 6-month visit. Blood samples were collected immediately prior to drinking the liquid drink, and every 30 minutes after the meal ingestion for 2 hours.