Background: Genome-wide association studies on body mass index (BMI) have identified an FTO polymorphism (rs9939609) as having the strongest effect.
Aim: We examined the effect of FTO genotype on body composition at the age of 6 months using skinfold thickness measurements and dual energy X-ray absorptiometry (DXA).
Material/subjects and methods: This study was embedded in a population-based prospective cohort study from early fetal life onwards. FTO genotype was related to anthropometric measurements (weight and height), subcutaneous fat mass measured by skinfold thickness, and total, truncal, and peripheral fat mass and lean mass measured by DXA. Analyses for skinfold thickness and DXA were performed in 695 and 216 children, respectively.
Results: Genotype frequency was TT 40.3%, TA 45.5%, and AA 14.2%. No significant differences between FTO genotypes were found in weight, height or BMI. Furthermore, FTO genotype was not associated with any skinfold thickness. Finally, no associations between FTO genotype and body composition measures (fat and lean mass) assessed by DXA were found.
Conclusions: We observed no association between this FTO polymorphism and body composition at the age of 6 months. Longer follow-up studies are necessary to examine at which age and by which mechanisms FTO genotype starts to influence fat mass and body composition.