Background characteristics and postoperative outcomes of insufficient weight loss after laparoscopic sleeve gastrectomy in Japanese patients

Aim: Laparoscopic sleeve gastrectomy (LSG) is becoming popular in Japan, but insufficient weight loss is often observed in patients after LSG. We investigated the effect of LSG on obesity-related comorbidities and identified the background characteristics of Japanese patients with insufficient weight loss after LSG. Methods: In this multi-institutional retrospective study at 10 certified bariatric institutions, 322 Japanese patients who underwent LSG with a follow-up period of more than 2 years were analyzed. Anthropometry, obesity-related comorbidities and psychosocial background data were collected. Weight loss was expressed as 2-year percent total weight loss (%TWL). Results: Mean age, body weight, body mass index (BMI) and glycated hemoglobin were 46.9 years, 119.2 kg, 43.7 kg/m² and 7.1%, respectively. Prevalence of mental disorders was 26.3%. Mean BMI declined to 30.3 kg/m² at 2 years and %TWL was 29.9%. Improvements in the markers and prevalence of obesity-related comorbidities were observed. Remission rates of diabetes, dyslipidemia and hypertension were 75.6%, 59.7% and 41.8%, respectively. %TWL at the respective cut-off level of diabetes remission was 20.8%. Lower remission rates of diabetes in patients with %TWL <20%, and less calorie restriction and higher prevalence of mental disorders (46.9%) in patients with %TWL <15% were observed. Frequencies of %TWL <15% and <20% were 6.5% and 18.5%, respectively. Conclusion: %TWL 20% was a candidate cut-off point of insufficient weight loss for diabetes remission after LSG, and mental disorders might be relevant to intractable obesity in Japanese patients.