Influence of FTO (Fat mass and obesity) gene and parental obesity on Brazilian children and adolescents adiposity.

Objectives: Evaluate the influence of the genetic variant rs9939609 of the FTO gene on anthropometric characteristics and whether parental obesity is related to children and adolescents being overweight. Methods: A total of 2,364 children and adolescents between 6 and 17 years old were genotyped and the lipid profile, plasma glucose level, and anthropometric characteristics were measured to assess adiposity. Results: The AA genotype (risk) was associated with higher body mass index (BMI Z-score; p = 0.006), waist circumference (WC; p = 0.001), and triglycerides (p = 0.033). The association of the participants' adiposity characteristics with the parents' BMI and FTO genotypes showed an association of the BMI Z-score when either the mother or father was overweight or obese (p = 0.028 and p = 0.029). In the overweight or obese father/eutrophic mother, we also observe an association of FTO rs9939609 with WC (p = 0.039). The effect of these variables on the risk of obesity was also tested: overweight or obese mother (OR = 1.82, p = 0.041), overweight and obese parents (OR = 3.09, p < 0.0001), and FTO rs9939609 AA genotype (OR = 2.08, p = 0.0004) were associated. With regard to altered WC and high body fat percentage (BF%), either overweight or obese parents (OR = 2.39, p < 0.0001; OR = 1.92, p < 0.002) showed an association. The FTO rs9939609 AA genotype (OR =1.99, p = 0.0002) was associated with altered WC. Conclusions: The results show that parental weight also contributes to obesity and may interact with the FTO genetic make-up.