The effect of rs9939609 FTO gene polymorphism on weight loss after laparoscopic sleeve gastrectomy

Remarkable differences in weight loss have been observed in obese patients undergoing laparoscopic sleeve gastrectomy (LSG). These high variations might be partly explained by genetic factors. The rs9939609 fat mass and obesity-associated gene (FTO) polymorphism has been implicated in the susceptibility of obesity. We aimed to explore the effects of the rs9939609 FTO gene polymorphism on weight loss among severely obese patients applying for LSG.

All individuals were analyzed for the FTO rs9939609 gene polymorphism. A total of 74 morbid obese patients (20 male, 54 female) were operated. Body weight and body mass index (BMI) were measured at before LSG and after surgery at the sixth month.

Twenty-eight patients (37.8%) had genotype TT (wild-type allel), 36 patients (48.6%) had genotype TA, and 10 patients (13.5%) had genotype AA. In both wild-type group and mutant group, BMI and weight levels decreased at the sixth month after surgery. Percent of excess weight loss (EWL) at 6 months of follow-up was similar in both groups. There were no differences between the mutant and wild-type groups percent of EWL at the sixth month after applying LSG.

Our data showed that the rs9939609 FTO gene polymorphism is not a useful genetic test prior to LSG to help clinicians predicting the weight loss for severely obese patients in short-term follow-up.