Gastric bypass surgery in non-obese patients with type 2 diabetes mellitus: a 1-year follow-up of 58 cases in Chinese.

Objective: To investigate the clinical efficacy of gastric bypass surgery in non-obese patients with type 2 diabetes.

Methods: Clinical data of 58 non-obese patients with type 2 diabetes (body mass index range from 22.1-25.8 kg/m(2)) were collected one year after gastric bypass surgery. Collected parameters included fasting plasma glucose, 2-hour postprandial blood glucose, glycosylated hemoglobin, fasting plasma glucagon-like peptide-1 and 2-hour postprandial plasma glucagon-like peptide-1. The insulin resistance index (HOMA-IR = fasting plasma glucose × fasting serum insulin/22.5) and the body mass index were calculated.

Results: Of the 58 patients, 48 had stopped taking all hypoglycemic drug treatments and had achieved complete remission (82.8%). Seven patients were unable to completely withdraw from hypoglycemic agents, although their intake of drugs was reduced at least 50% compared to pre-surgical values (12.0%). Three of the cases showed no significant change in blood glucose after surgery (5.2%). In addition, values for fasting plasma glucose, 2-hour postprandial blood glucose, glycosylated hemoglobin and HOMA-IR significantly decreased after surgery. Values for fasting plasma glucagon-like peptide-1 and 2-hour postprandial plasma glucagon-like peptide-1 significantly increased after surgery, and the body mass index at the sixth post-operative month were significantly lower than pre-operative.

Conclusions: For non-obese patients with type 2 diabetes, gastric bypass surgery has a significant clinical effect. Potential mechanisms include improvements in insulin resistance and/or increased endogenous intestinal glucagon-like peptide-1 secretion leading to improved insulin secretion.