Background characteristics and diabetes remission after laparoscopic sleeve gastrectomy in Japanese patients with type 2 diabetes stratified by BMI: subgroup analysis of J-SMART.

Aim: The J-SMART study was the first national survey of Japanese patients undergoing laparoscopic sleeve gastrectomy (LSG). We performed a subgroup analysis of J-SMART focusing on the differences in patient background and diabetes remission between patients with BMI 32-34.9 kg/m and those with higher BMI.

Methods: In this multi-institutional retrospective study at 10 certified bariatric institutions, 203 Japanese with type 2 diabetes (T2D) and BMI of 32 kg/m or higher were analyzed (mean age: 49.2 years, BMI: 43.8 kg/m, HbA1c: 7.6%). Patients were stratified into five groups according to preoperative BMI.

Results: Background characteristics in BMI 32.0-34.9 group were higher adjusted HbA1c, higher visceral/subcutaneous fat area ratio, higher prevalence of diabetic retinopathy, higher frequency of insulin use and lower serum C-peptide. Although 2-year percent total weight loss (21.7%) and diabetes complete remission (CR) rate (52.4%) were lower in BMI 32.0-34.9 group, diabetes improvement rate was 81.0%, and the decrease in HbA1c and number of antidiabetic drugs were comparable or greater than those with higher BMI. Higher BMI and no insulin use were significant independent predictors of diabetes CR. No significant independent predictor was identified for diabetes improvement.

Conclusion: The patients with 32-34.9 kg/m were characterized by more severe visceral obesity, T2D and the complications, and lower intrinsic insulin secretion capacity. LSG should be considered as a treatment option for patients with BMI 32-34.9 kg/m, to improve diabetes control.