Changes in insulin sensitivity and secretion after sleeve gastrectomy

Background Sleeve gastrectomy is indicated for the treatment of obesity and related co-morbidity including diabetes. The dynamic changes in insulin secretion and sensitivity after sleeve gastrectomy are unknown. Methods Whole-body insulin sensitivity was measured by the euglycaemic hyperinsulinaemic clamp technique, and insulin secretion by C-peptide deconvolution after an oral glucose tolerance test (OGTT), before and 3, 6 and 12 months after sleeve gastrectomy in morbidly obese subjects. The time course of glucagon-like peptide (GLP) 1, as a marker of insulin secretion following OGTT, was also assessed. Results Ten patients were included in the study. Median (range) baseline insulin sensitivity (M-value) increased from 84\ub70 (20\ub72-131\ub74) mmol per kg per min at baseline to 122\ub78 (99\ub70-179\ub73) mmol per kg per min at 12 months after surgery (P = 0\ub7015). Fasting insulin sensitivity, measured by homeostatic model assessment of insulin resistance, which represents a surrogate index of hepatic insulin resistance, decreased from 3\ub73 (1\ub79-5\ub75) to 0\ub77 (0\ub75-1\ub71) mg/dl\ub7\u3bcunits/ml (P < 0\ub7001). Total insulin secretion, measured as incremental area under the curve (AUC), after OGTT decreased from 360\ub74 (347\ub79-548\ub70) to 190\ub71 (10\ub71-252\ub70) mmol/l\ub7180 min at 12 months (P = 0\ub7011). The AUC for GLP-1 increased from 258\ub75 (97\ub75-552\ub76) to 5531\ub78 (4143\ub70-7540\ub79) pmol/l\ub7180 min at 12 months after sleeve gastrectomy (P < 0\ub7001). In multiple regression analysis, 51 per cent of the M-value variability was explained by GLP-1 secretion. Conclusion Sleeve gastrectomy improved insulin sensitivity and reduced insulin secretion within 6 months after surgery. Although there was a correlation between insulin sensitivity and bodyweight, the major driver of the improvement in insulin sensitivity was GLP-1 secretion. Improves insulin sensitivity, reduces insulin secretio