Obesidade pediátrica e polimorfismos genéticos: revisão da produção científica do gene FTO e estudo observacional de associação entre genótipo-fenótipo de múltiplos genes

Abstract

Obesity has reached epidemic proportions worldwide, affecting individuals of various age groups, both sexes, and regardless of their economic status. It is responsible for causing changes in an individual's metabolism, resulting in excess body fat and compromised health. This study aims to contribute to the understanding of the mechanisms, genes, and polymorphisms involved in the development of pediatric obesity. To this end, a scientometric analysis and a systematic review of the FTO gene were conducted, in addition to a case-control observational study to investigate polymorphisms associated with pediatric obesity. Due to the multifactorial nature of obesity, several genes are being associated with the genesis of this disease, such as: BDNF, LEPR, MC4R, ANKK1, and FTO. Among all of them, the FTO gene has been studied most frequently due to the proven influence in the Caucasian population. In the association study, it was observed that the prevalence of insulin resistance was significantly higher among obese individuals (66.9%) compared to eutrophic individuals (17.3%; p < 0.001), associated with higher serum insulin levels and compensatory hyperinsulinemia. In the lipid profile, obese individuals presented increased triglycerides and LDL and reduced HDL, composing a pattern of atherogenic dyslipidemia (p < 0.001). However, the overall prevalence of dyslipidemia was high in both groups, with no significant difference (p = 0.473). In the genetic analysis, most polymorphisms did not show a significant association with obesity, insulin resistance, or dyslipidemia. However, the rs1467568 polymorphism of the SIRT1 gene showed a significant association with obesity (OR = 2.07; 95% CI: 1.03–4.15; p = 0.041), and rs3751812 showed a statistically significant difference between the groups. The findings confirm that pediatric obesity is strongly associated with early metabolic alterations, mainly insulin resistance and an atherogenic lipid profile.