2083-P: Monogenic Obesity Mutations Lead to Less Weight Loss after Bariatric Surgery: A 6-Year Follow-Up Study.

Objectives: Bariatric surgery is emerging as the most effective treatment option for patients with obesity. Hypothalamic arcuate nucleus plays an important role in metabolic homeostasis. However, the influence of mutations related to the feeding center on weight loss after bariatric surgery is still unclear. We aimed to diagnose monogenic obesity by whole-exome sequencing (WES) and explore whether monogenic mutations influence the effectiveness of bariatric surgery. Methods: We collected obese patients aged 15 to 55 with a BMI >28 kg/m2 and who underwent laparoscopic sleeve gastrectomy from March 2011 to June 2017 in Shanghai. Data related to weight loss and metabolic characteristics preoperatively and postoperatively were collected, including fasting blood glucose (FBG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides. WES was performed in obese patients using genomic DNA from whole blood samples. Results: We investigated the proportion of 131 obese adults with one mutation as high as to 8.4% and then evaluated the association between these mutations and weight loss. Mutation carriers had less weight loss over both short-term and long-term periods. Survival analyses indicated it was harder to attain the goal of 20% weight loss for mutation carriers (Plog-rank=0.001; Pbreslow<0.001), and the difference remained significant with a Cox regression model. Improvement in FBG, HDL cholesterol and triglycerides postoperatively were observed in both groups, while there were significant differences between the two groups. Conclusions: Our data indicated that 8.4% of obesity cases were caused by change in genetics, and mutations had negative effects on the efficacy of bariatric surgery. Disclosure: C. Hu: None. [ABSTRACT FROM AUTHOR]