Fat-mass and obesity-associated gene variant and changes of body mass index from ages 3 to 13 years.

Summary Objective The effect of the fat-mass and obesity-associated (FTO) gene minor allele on the change of adiposity from childhood to adolescence among Asians remains unclear, and is expected to differ among the developmental stages from childhood to adolescence. We assessed the relationship between a FTO variant and changes in body mass index (BMI) between 3 and 13 years of age among Japanese. Methods Subjects were 66 fifth graders (37 boys, 29 girls) enrolled in 2006 from Shunan City, Japan, and genotyped (rs1558902). Anthropometrics were measured at fifth grade and three years later at eighth grade, and data for these individuals recorded at 3 years of age by the health center were included. The effects on BMI and the BMI-standard deviation score (SDS) were analyzed after adjusting for age and sex. Results The minor allele of FTO was positively associated with BMI and BMI-SDS among boys at an age of 10 years ( β  = 1.779 and 0.812, respectively). The risk allele was positively associated with changes in BMI among boys between 3 and 10 years of age ( β  = 1.656). However, negative associations with changes in BMI and BMI-SDS were found among boys between 10 and 13 years of age ( β  = −0.875 and −0.512, respectively). Conclusion The increment of adiposity at 10 years of age in boys might be influenced by the FTO variant, but this influence was significantly reduced at 13 years.