title: FTO genotype, vitamin D status, and weight gain during childhood.
abstract: Previous evidence suggests that variants in the fat mass and obesity-associated gene (FTO) affect adiposity in an age-dependent fashion in children, and nutritional factors may modify genotype effects. We assessed the effect of FTO rs9939609 on BMI and BMI-for-age Z score changes during childhood in a population-based longitudinal study in the Brazilian Amazon and investigated whether these effects were modified by vitamin D status, an important nutritional factor related to adiposity. At baseline, 1,088 children aged <10 years had complete genotypic and anthropometric data; 796 were followed up over a median 4.6 years. Baseline vitamin D insufficiency was defined as <75 nmol/L. We observed a 0.07 kg/m(2)/year increase in BMI and a 0.03 Z/year increase in BMI-for-age Z score per rs9939609 risk allele over follow-up (P = 0.01). Vitamin D status significantly modified FTO effects (P for interaction = 0.02). The rs9939609 risk allele was associated with a 0.05 Z/year increase in BMI-for-age Z score among vitamin D-insufficient children (P = 0.003), while no significant genetic effects were observed among vitamin D-sufficient children. Our data suggest that FTO rs9939609 affects child weight gain, and genotype effects are more pronounced among children with insufficient vitamin D levels.
authors.affiliation: Public Health Nutrition Program, School of Public Health, University of São Paulo, São Paulo, Brazil.
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Lourenço
authors.forename: Lu
authors.initials: L
authors.lastname: Qi
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: Marly A
authors.initials: MA
authors.lastname: Cardoso
mesh_terms: D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D002648:Child; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005838:Genotype; D006801:Humans; D008297:Male; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D011506:Proteins; D014807:Vitamin D; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human