diabetes mellitus, and much higher than the same group’s estimate for rs9939609 in UK type 2 diabetes mellitus genetics consortium controls.1 By contrast, in the more physically active OOA stratum, the associations of the FTO variants were much smaller and not statistically significant. Because the FTO genotype was not associated with physical activity, this finding suggests a strong moderating effect of physical activity on the deleterious effects of FTO variants, consistent with published findings16 based on self-reported physical activity data. When men and women were evaluated separately without consideration of covariates, the association of rs1861868 genotype reached nominal statistical significance in women only, not in men. However, there was no evidence that the effect of genotype on BMI differed substantially between men and women, particularly when the level of physical activity was included in the regression model (ie, the genotype by sex interaction term was not statistically significant; P =.17).
