Title | Macronutrient intake as a mediator with FTO to increase body mass index. |
Publication Type | Journal Article |
Year of Publication | 2014 |
Authors | Hardy DS, Racette SB |
Secondary Authors | Hoelscher DM |
Journal | J Am Coll Nutr |
Volume | 33 |
Issue | 4 |
Pagination | 256-66 |
Date Published | 2014 |
ISSN | 1541-1087 |
Keywords | African Americans, Aged, Alleles, Alpha-Ketoglutarate-Dependent Dioxygenase FTO, Body Mass Index, Cross-Sectional Studies, Dietary Carbohydrates, Dietary Fats, Dietary Proteins, Energy Intake, European Continental Ancestry Group, Female, Homozygote, Humans, Linear Models, Male, Middle Aged, Polymorphism, Single Nucleotide, Proteins, Surveys and Questionnaires |
Abstract | BACKGROUND: The fat mass and obesity-associated (FTO) single nucleotide polymorphisms (SNPs; rs1421085, rs17817449, rs9939609, rs8050136) and macronutrient intake (carbohydrate, protein, fat, total calories) are associated with body mass index (BMI). However, the mechanism for this relationship has not been fully elucidated. OBJECTIVE: This study examined whether macronutrient intake mediates the association between FTO SNPs and BMI. DESIGN: Baseline cross-sectional data from the Atherosclerosis Risk in Communities (ARIC) study of whites (n = 10,176) and African Americans (n = 3641) aged 45 to 64 years were analyzed. RESULTS: In linear regression models with BMI as the dependent variable, FTO SNPs were significantly associated with higher BMI after adjusting for covariates. The addition of energy-adjusted macronutrients attenuated the FTO effect estimates, indicating partial mediation. In whites, β ranged from 0.40 (95% confidence interval [CI], 0.20, 0.60) for rs17817449 heterozygous carriers to 0.93 (95% CI, 0.64, 122) for rs8050136 homozygous carriers; for African Americans rs17817449 homozygous carriers β was 0.65 (95% CI, 0.03, 1.27). In models with macronutrient intake as the dependent variable, all FTO SNPs were associated with higher protein intake for homozygous carriers after adjusting for BMI and other covariates. Among whites, β ranged from 1.44 (95% CI, 0.51, 2.37) for rs8050136 to 1.73 (95% CI, 0.85, 2.61) for rs17817449; among African American rs8050136 homozygous carriers β was 2.46 (95% CI, 0.77, 4.14). In mediation analysis, in whites only, FTO high-risk alleles were associated with higher BMI partly through their small effects on carbohydrate and protein intake. CONCLUSIONS: These findings suggest that in adults, the relationship between FTO variants and BMI is not primarily through mediation of food intake. |
DOI | 10.1080/07315724.2013.879458 |
Alternate Journal | J Am Coll Nutr |
PubMed ID | 25144299 |