Genetic risk score does not predict the outcome of obesity surgery.

BACKGROUND: We evaluated the benefit of using combined genetic risk score (GRS) of known single nucleotide polymorphisms (SNPs) for body mass index (BMI) and waist/hip ratio (WHR) in the prediction of weight loss and weight regain after obesity surgery.

METHODS: A total of 163 consecutive morbidly obese individuals undergoing Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in a single bariatric center in Finland were recruited. Fasting blood samples were drawn after 12 h of fasting before and 1 year after bariatric operation. Data for weight regain and medication were collected with a questionnaire after 3.1 ± 2.7 years (mean ± SD) follow-up. Nonalcoholic steatohepatitis (NASH) was diagnosed with liver histology. Twenty BMI- and 13 WHR-related SNPs were genotyped. Linear regression was used to identify factors predicting weight loss and weight regain.

RESULTS: Lower baseline BMI predicted greater decline in BMI (p = 0.0005) and excess weight loss (EWL) (p = 0.009). In the multiple linear regression analysis age and BMI, explained the variance of EWL during the first year while GRS, sex, fasting plasma glucose, serum insulin and NASH diagnosis did not have any effect. None of the baseline clinical variables explained BMI regain. The combined GRS did not associate with weight or BMI at baseline, with 1-year changes or with weight regain between 1 year and an average of 3.1 years follow-up.

CONCLUSIONS: In our study, we found that the genotype risk score does not predict weight loss after obesity surgery while lower baseline BMI predicted the greater weight loss.