FTO Genotype Is Associated With Exercise Training–induced Changes in Body Composition

Authors

  • Tuomo Rankinen,

    Corresponding author
    1. Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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  • Treva Rice,

    1. Division of Biostatistics, Washington University School of Medicine, St Louis, Missouri, USA
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  • Margarita Teran-Garcia,

    1. Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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  • Dabeeru C. Rao,

    1. Division of Biostatistics, Washington University School of Medicine, St Louis, Missouri, USA
    2. Department of Genetics, Washington University School of Medicine, St Louis, Missouri, USA
    3. Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA
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  • Claude Bouchard

    1. Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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(rankint@pbrc.edu)

Abstract

The fat mass (FM) and obesity-associated (FTO) gene is the first obesity-susceptibility gene identified by genome-wide association scans and confirmed in several follow-up studies. Homozygotes for the risk allele (A/A) have 1.67 times greater risk of obesity than those who do not have the allele. However, it is not known whether regular exercise-induced changes in body composition are influenced by the FTO genotype. The purpose of our study was to test whether the FTO genotype is associated with exercise-induced changes in adiposity. Body composition was derived from underwater weighing before and after a 20-week endurance training program in 481 previously sedentary white subjects of the HERITAGE Family Study. FTO single-nucleotide polymorphism (SNP) rs8050136 was genotyped using Illumina GoldenGate assay. In the sedentary state, the A/A homozygotes were significantly heavier and fatter than the heterozygotes and the C/C homozygotes in men (P = 0.004) but not in women (P = 0.331; gene-by-sex interaction P = 0.0053). The FTO genotype was associated with body fat responses to regular exercise (P < 0.005; adjusted for age, sex, and baseline value of response trait): carriers of the C allele showed three times greater FM and %body fat losses than the A/A homozygotes. The FTO genotype explained 2% of the variance in adiposity changes. Our data suggest that the FTO obesity-susceptibility genotype influences the body fat responses to regular exercise. Resistance to exercise-induced reduction in total adiposity may represent one mechanism by which the FTO A allele promotes overweight and obesity.

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