Characteristics of Childhood Onset and Post-Puberty Onset Obesity and Weight Regain after Laparoscopic Sleeve Gastrectomy in Japanese Subjects: A Subgroup Analysis of J-SMART

Introduction: The psychosocial background of subjects with severe obesity developed from childhood onset obesity (CO) and their outcomes after bariatric surgery have not been fully investigated. Methods: 305 subjects were enrolled in the J-SMART study, which examined the effects of laparoscopic sleeve gastrectomy (LSG) in Japan, and categorized into two groups: CO defined as onset up to 13 years of age (CO group) and post-puberty onset obesity defined as onset after 13 years of age (PPO group). The subjects were followed up for at least 2 years and up to 5 years after LSG. Changes in physical parameters and remission of obesity-related comorbidities were assessed at 2 years after LSG. Weight regain (WR) was also assessed by evaluating the nadir weight after LSG and maximum weight thereafter during follow-up period. Results: The mean postoperative follow-up period was 3.0 ± 1.1 years. 40.0% of the subjects had CO and these subjects had higher BMI and HOMA-β and lower age, HbA1c, HDL cholesterol, and visceral/subcutaneous fat area ratio compared to those with PPO. The CO group was also characterized by having higher rates of mental retardation, developmental disorders, and obesity in either parent and lower rate of marriage compared to the PPO group. Two years after LSG, there were no differences in total weight loss and remission rates of diabetes, dyslipidemia, and sleep apnea syndrome between the two groups, although remission rate of hypertension was higher in the CO group. The CO group also had a higher rate of WR after LSG than the PPO group, with CO, BMI, mental disorder, and binge eating contributing to WR. Conclusion: This study suggests that CO might be associated with genetic and psychosocial factors. CO and PPO probably differ in pathogenesis and may require different treatment strategies.