Effect of laparoscopic mini-gastric bypass for type 2 diabetes mellitus:: Comparison of BMI >35 and <35 kg/m2

Background Laparoscopic gastric bypass resulted in significant weight loss and resolution of type 2 diabetes mellitus (T2DM). The current indication for bariatric surgery is mainly applied for patients with body mass index (BMI) > 35 kg/m(2) with comorbidity status. However, little is known concerning T2DM patients with BMI < 35 kg/m(2). Recent studies have suggested that T2DM patients with BMI < 35 kg/m(2) might benefit from gastric bypass surgery. Methods From Jan 2002 to Dec 2006, 820 patients who underwent laparoscopic mini-gastric bypass were enrolled in a surgically supervised weight loss program. We identified 201 (24.5%) patients who had impaired fasting glucose or T2DM. All the clinical data were prospectively collected and stored. Patients with BMI < 35 kg/m(2) were compared with those of BMI > 35 kg/m(2). Successful treatment of T2DM was defined by HbA1C < 7.0%, LDL < 100 mg/dl, and triglyceride < 150 mg/dl. Results Among the 201 patients, 44 (21.9%) had BMI < 35 kg/m(2), and 114 (56.7%) had BMI between 35and 45, 43 (21.4%) had BMI > 45 kg/m(2). Patients with BMI < 35 kg/m(2)are significantly older, female predominant, had lower liver enzyme and C-peptide levels than those with BMI > 35 kg/m(2). The mean total weight loss for the population was 32.1, 33.4, 31.9, and 32.8% (at 1, 2, 3, 5 years after surgery), and percentage to change in BMI was 31.9, 34.2, 32.2, and 29.5% at 1, 2, 3, and 5 years. One year after surgery, fasting plasma glucose returned to normal in 89.5% of BMI < 35 kg/m(2)T2DM and 98.5% of BMI > 35 kg/m(2) patients (p=0.087). The treatment goal of T2DM (HbA1C < 7.0%, LDL < 150 mg/dl and triglyceride < 150 mg/dl) was met in 76.5% of BMI < 35 kg/m(2) and 92.4% of BMI > 350 kg/m(2) (p=0.059). Conclusion Laparoscopic gastric bypass resulted in significant and sustained weight loss with successful treatment of T2DM up to 87.1%. Despite a slightly lower response rate of T2DM treatment, patients with BMI < 35 still had an acceptable DM resolution, and this treatment option can be offered to this group of patients.