Original articleEffect of Roux-en-Y gastric bypass on the remission of type 2 diabetes: a 3-year study in Chinese patients with a BMI <30 kg/m2

BackgroundRoux-en-Y gastric bypass (RYGB) is an effective treatment for patients with type 2 diabetes (T2D) and morbid obesity. However, T2D remission after surgery has not been adequately studied in Chinese patients with a body mass index (BMI)<30 kg/m2.ObjectivesThe objective of this study was to evaluate the 3-year effect of RYGB among patients with T2D with a BMI<30 kg/m2 and elucidate the predictors of T2D remission.SettingDepartment of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.MethodsSixty-six Chinese patients with T2D and a BMI 25-30 kg/m2 were retrospectively examined for metabolic outcomes 3 years after RYGB. Remission was defined as glycated hemoglobin (HbA1C)<6.5% and no medications. Binary logistic regression analysis was used to identify preoperative parameters independently predictive of diabetes remission at 1 and 3 years postoperatively [variables: sex, age, BMI, T2D duration, plasma glucose 2 hours after meal, HbA1C, fasting C-peptide, visceral fat area, free triiodothyronine, and thyroid-stimulating hormone. There was no significant difference in fasting insulin or glucose between the remission and no remission groups.ResultsPatients were a mean 50.4±11.4 years of age at baseline, and 57.6% were female. Mean T2D duration was 8.9±5.2 years, baseline HbA1C level was 8.3±1.9%, and baseline BMI was 28.2±1.2 kg/m2 (range: 25.5-30.0). BMI was 22.5±1.8 kg/m2 (range: 19.1-28.0) at 1 year and 23.0±1.76 kg/m2 (range: 19.7-28.0) at 3 years. Remission was achieved in 49 patients (74.2%) at 1 year and 38 patients (57.6%) at 3 years. There was a significant reduction in medication for diabetes, hypertension, and hyperlipidemia (P<.01). Compared with patients in the no remission group, patients in the remission group had higher fasting C-peptide levels (P<.01) and free triiodothyronine levels (P = .01) at 1 year. Multiple logistic regression analysis confirmed that fasting C-peptide (odds ratio = 3.795, P = .007) and free triiodothyronine (odds ratio = 4.661, P = .019) levels were predictors of T2D remission at 1 year. No significant difference was found between the 2 groups at 3 years.ConclusionsRYGB resulted in significant clinical and biochemical improvements in Chinese patients with BMI 25-30 kg/m2 and T2D. Appropriate patient selection (better β-cell function) may produce better outcomes.