Effect of Roux-en-Y Gastric Bypass with Different Pouch Size in Chinese T2DM Patients with BMI 30-35 kg/m2

Background The purpose of this study was to assess the effect of Roux-en-Y gastric bypass (RYGB) with different pouch size in Chinese type 2 diabetes mellitus (T2DM) patients with measured body mass index (BMI) 30-35 kg/m(2). Methods In this randomized and prospective study, we evaluated the efficacy of RYGB with smaller size pouch (10-20 ml) versus larger pouch size (25-35 ml) in 76 Chinese obese patients (33 F, 43 M) with T2DM. According to protocol, all patients were divided into two groups, smaller pouch size group and larger pouch size group, and underwent RYGB surgery. Primary inclusion criteria of study were (a) a diagnosis of type 2 diabetes (glycated hemoglobin level >7.0 %), (b) measured BMI of at least 30 kg/m(2) and not yet 35 kg/m(2), and (c) age between 25 and 60 years old, and (d) patients were excluded if they had previously undergone complex abdominal surgery or bariatric surgery. Weight loss, BMI, percentage of excess weight loss (% EWL), glycated hemoglobin, and fasting plasma glucose were obtained at 3, 6, 9, and 12 months after surgery. Results Of these 76 patients, 69 (91 %) patients completed follow-up postoperative 12 months. Weight loss and % EWL at 12 months was greater in smaller pouch size group (mean 15.8 kg, 95 % CI -17.2 to -14.4 and mean 68.9, 95 % CI 62.5-75.2 %) than in larger pouch size group (mean -13.7 kg, 95 % CI -15.3 to -12.1, and mean 59.1, 95 % CI 52.8-65.5) (P=0.046, P=0.033, respectively). Glycemic control improved in both two groups, with a mean glycated hemoglobin level of 6.2 % (95% CI 6.0-6.5 %) in smaller size group, and 6.7 % (95 % CI 6.4-7.0 %) in larger size group (P=0.025, P<0.05). The fasting plasma glucose level decreased significantly after surgery, with a mean level of 5.4mmol/L (95% CI 5.2-5.5 mmol/L) and 5.6 mmol/L (95 % CI 5.5-5.8 mmol/L) respectively, (P=0.040, P<0.05). Conclusions In this short-term study, in Chinese T2DM patients with BMI 30-35 kg/m(2), we observed a greater efficiency on weight loss and glycemic control with smaller pouch size compared to larger pouch size. In the future, long-term follow-up and large sample study will be necessary to confirm these outcomes.