Adding glimepiride to current insulin therapy increases high-molecular weight adiponectin levels to improve glycemic control in poorly controlled type 2 diabetes

BACKGROUND To observe the efficacy and safety of adding glimepiride to established insulin therapy in poorly controlled type 2 diabetes (T2D) and to assess the relationship of changes in the serum high-molecular weight (HMW) adiponectin levels and glycemic control after glimepiride treatment. METHODS Fifty-six subjects with poorly controlled insulin-treated T2D were randomly assigned to either the glimepiride-added group (the group A, n = 29) or the insulin-increasing group (the group B, n = 27) while continuing current insulin-based therapy. Glycosylated hemoglobin (HbA1c) value, daily insulin dose, body weight, waist circumference, plasma lipid concentration, serum HMW adiponectin level and the number of hypoglycemic events were evaluated before and after treatment. RESULTS At the end of study, insulin doses were significantly reduced, and the mean HbA1c, fasting blood glucose (FBG) and 2-hour postprandial blood glucose (P2BG) were improved greater in the group A compared with the group B. The serum HMW adiponectin levels were significantly increased in the group A compared with the group B. Most importantly, we found that changes in HbA1c were inversely correlated with changes in serum HMW adiponectin in the group A (r = -0.452, p = 0.02). CONCLUSIONS Adding glimepiride to current insulin treatment led to better improvement in glycemic control with a significant smaller daily insulin dose, and the increases in the serum HMW adiponectin levels may directly contribute to improvement glycemic control.