Influência do polimorfismo rs9939609 do gene FTO nos dados clínicos e comportamento nutricional de pacientes submetidos à cirurgia bariátrica em um hospital público de referência no Maranhão

Abstract

Introduction: Obesity is a multifactorial condition resulting from the interaction between genetic predisposition and environmental factors. Among genetic markers, the Fat Mass and Obesity-Associated (FTO) gene stands out due to its strong association with increased Body Mass Index (BMI) and risky eating behaviors. Objective: To investigate the influence of the rs9939609 polymorphism of the FTO gene on clinical aspects and eating behavior in patients undergoing bariatric surgery at a public referral hospital in Maranhão. Methods: This was an ambispective longitudinal cohort study including 98 patients who underwent bariatric surgery. Preoperative clinical and anthropometric data were obtained from medical records, while postoperative data were collected through direct assessment to calculate weight loss and weight regain indicators. Behavioral factors were assessed using a structured questionnaire based on the Three-Factor Eating Questionnaire (TFEQ-R21) and a Food Frequency Questionnaire. Oral mucosa samples were collected for DNA extraction and genotyping of the rs9939609 polymorphism of the FTO gene using qPCR. Statistical analyses included association tests, comparisons between genotype groups, and assessment of Hardy–Weinberg equilibrium (p<0.05). Results: The frequency of the risk allele “A” was 40.8%, with a predominance of the heterozygous genotype AT (51.0%). No statistically significant associations were observed between genotypes (AA/AT vs. TT) and percentage weight loss or postoperative BMI (p>0.05). However, a trend toward greater weight regain was identified in carriers of the risk allele (9.9% ± 5.5%) compared to the wild-type genotype (7.2% ± 8.3%), although strongly correlated with follow-up time (p<0.001). Conclusion: The rs9939609 polymorphism of the FTO gene showed an influence on weight regain after bariatric surgery, with no significant impact observed on eating behavior, clinical characteristics, weight loss, or remission of comorbidities in this population.