Association of FTO gene polymorphisms with weight loss in bariatric surgery patients

Obesity is a multifactorial disease defined as the excessive accumulation of fat that can impair human health. In contemporary times, bariatric surgery plays a significant role in the treatment of obesity. Recent studies indicate that genetic factors influence early weight loss after bariatric surgery. The Fat Mass and Obesity-Related (FTO) gene is the first gene associated with susceptibility to obesity, and it is suggested that FTO gene variants may be linked to early weight loss following bariatric surgery. Aim: This study aims to figure out the relationship between the FTO gene rs9939609 and rs9930506 variants and post-operative weight loss in patients who have undergone bariatric surgery. Method: This study included 104 obese individuals who had undergone bariatric surgery and 149 control individuals. DNA isolation from peripheral blood samples was performed. Single nucleotide polymorphisms were determined through real-time polymerase chain reaction using TaqMan assays. Results: The carrying of the FTO gene rs9939609 A allele, the rs9930506 GG genotype, and the AA+GG genotype combination have been found to predispose to obesity development. While no statistically significant relationship was found between FTO rs9939609 and rs9930506 variants and the rate of weight loss after bariatric surgery in the cases, categorical component analysis results have revealed an association between FTO rs9939609 A allele carriers and weight loss. Additionally, the most common genotype determined among cases in the 6th-month post-bariatric surgery controls was AA+GG. Categorical component analyses have shown an association between rs9939609 A allele carriage and rs9930506 G allele carriage combined genotypes with the rate of weight loss in the first month post-surgery among cases. Conclusion: In this study, it has been shown that the variants of the FTO gene, rs9939609 and rs9930506, predispose to obesity development in the Turkish population, and the combined effects of these genotypes are associated with the average weight loss in the first month after bariatric surgery.