Background
Obesity is the largest global public health epidemic, increasingly affecting children and adolescents. Studies suggest that this single nucleotide polymorphisms (SNP) is associated with the development of obesity. Obesity susceptibility genes identified include alpha-ketoglutarate-dependent dioxygenase (FTO) and endothelial nitric oxide (NOS3). Furthermore genetic predisposition can interact with other environmental factors, such as clinical risk factors for obesity. In this context, the potential interaction between the FTO and NOS3 SNPs and clinical risk factors such as non-exclusive breastfeeding, high birth weight, and a family history of chronic diseases warrants investigation.There is a clear need for more research on the FTO and NOS3 genes in Brazilian children. The purpose of this study was to evaluate the associations between single nucleotide polymorphisms (SNPs) in the FTO (rs1121980) and NOS3 (rs1799983) genes and obesity in children and adolescents in Ouro Preto, Minas Gerais, Brazil.
Methods
A cross-sectional population-based study was conducted with elementary school students aged 6–17 years in Ouro Preto, Minas Gerais, between April and December 2021. The study evaluated sociodemographic, clinical, and biochemical variables and the SNPs rs1121980 and rs1799983 in the FTO and NOS3 genes, respectively, for associations with obesity.
Results
The study revealed that the prevalence of obesity was notably high, reaching 8.5% in the study population. Homozygotes for the risk alleles of the FTO and NOS3 genes (genotypes AA and TT, respectively) remained significant, with both showing a more than twofold increased likelihood of being obese [OR: 2.12 (CI: 1.40–4.31) and 2.64 CI: (1.40–6.09), respectively]. The same combination of alleles associated with clinical risk factors (nonexclusive breastfeeding, high birth weight, family history of diabetes, obesity and dyslipidemia) was associated with a significantly greater chance of being obese at a young age.
Conclusions
Our results support the idea that the SNP rs1121980 in the FTO gene and rs1799983 in the NOS3 gene can affect the occurrence of obesity in Brazilian children and adolescents living in urban areas.
