This article was originally published as Integrative Physiology.
Admixture Mapping of Obesity-related Traits in African Americans: The Atherosclerosis Risk in Communities (ARIC) Study
Article first published online: 6 SEP 2012
2010 North American Association for the Study of Obesity (NAASO)
Volume 18, Issue 3, pages 563–572, March 2010
How to Cite
Cheng, C.-Y., Reich, D., Coresh, J., Boerwinkle, E., Patterson, N., Li, M., North, K. E., Tandon, A., Bailey-Wilson, J. E., Wilson, J. G. and Kao, W.H. L. (2010), Admixture Mapping of Obesity-related Traits in African Americans: The Atherosclerosis Risk in Communities (ARIC) Study. Obesity, 18: 563–572. doi: 10.1038/oby.2009.282
- Issue published online: 6 SEP 2012
- Article first published online: 6 SEP 2012
- Received 21 September 2008; accepted 17 July 2009
Obesity is an important cause of morbidity and mortality worldwide. In the United States, the prevalence of obesity is higher in African Americans than whites, even after adjustment for socioeconomic status (SES). This leads to the hypothesis that differences in genetic background may contribute to racial/ethnic differences in obesity-related traits. We tested this hypothesis by conducting a genome-wide admixture mapping scan using 1,350 ancestry-informative single-nucleotide polymorphisms (SNPs) in 3,531 self-identified blacks from the Atherosclerosis Risk in Communities (ARIC) study. We used these markers to estimate the overall proportions of European ancestry (PEAs) for each individual and then scanned for the association between PEA and obesity-related traits (both continuous and dichotomous) at each locus. The median (interquartile range) PEA was 0.151 (0.115). PEA was inversely correlated with continuous BMI, weight, and subscapular skinfold thickness, even after adjusting for socioeconomic factors. In contrast, PEA was positively correlated with BMI-adjusted waist circumference. Using admixture mapping on dichotomized traits, we identified a locus on 2p23.3 to be suggestively associated with BMI (locus-specific lod = 4.11) and weight (locus-specific lod = 4.07). After adjusting for global PEA, each additional copy of a European ancestral allele at the 2p23.3 peak was associated with a BMI decrease of ∼0.92 kg/m2 (P = 2.9 × 10−5). Further mapping in this region on chromosome 2 may be able to uncover causative variants underlying obesity, which may offer insights into the control of energy homeostasis.