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/m2 with comorbidity status. However, little is known concerning T2DM patients with BMI<35 kg/m2. Recent studies have suggested that T2DM patients with BMI<35 kg/m2 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/m2 were compared with those of BMI>35 kg/m2. 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/m2, and 114 (56.7%) had BMI between 35 and 45, 43 (21.4%) had BMI>45 kg/m2. Patients with BMI<35 kg/m2 are significantly older, female predominant, had lower liver enzyme and C-peptide levels than those with BMI>35 kg/m2. 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/m2 T2DM and 98.5% of BMI>35 kg/m2 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/m2 and 92.4% of BMI>350 kg/m2 (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.