Document Type

Article

Publication Date

5-14-2014

Description

Background: The associations between common variants in the fat mass- and obesity-associated (FTO) gene and obesity-related traits may be age-dependent and may differ by sex. The present study aimed to assess the association of FTO rs9939609 with body mass index (BMI) and the risk of obesity from childhood to adolescence, and to determine the age at which the association becomes evident. Methods: Totally 757 obese and 2,746 non-obese Chinese children aged 6-18 years were genotyped for FTO rs9939609. Of these, a young sub-cohort (n = 777) aged 6-11 years was reexamined 6 years later. Obesity was defined using the sex- and age-specific BMI cut-offs recommended by the International Obesity Task Force. Results: The associations of FTO rs9939609 with BMI and obesity did not appear until children reached 12-14 years. The variant was associated with an increased BMI in boys (β = 1.50, P = 0.004) and girls (β = 0.97, P = 0.018), respectively. Thereafter, the magnitude of association increased in girls at ages 15-18 years (β = 2.02, P0.05). Age was found to interact with the variant on BMI (P<0.001) and obesity (P = 0.042) only in girls. In the sub-cohort, the associations of FTO rs9939609 with BMI (β = 1.07, P = 0.008) and obesity (OR = 2.09, 95% CI: 1.12, 3.91) were only observed 6 years later (ages 12-18 years) in girls, even after adjusting for baseline BMI. Conclusions: The association between FTO rs9939609 and obesity-related traits may change from childhood to adolescence in Chinese individuals, and the association may start as early as age 12 years, especially in girls.

Copyright Statement

Copyright: ß 2014 Zhang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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