Genetic Underpinnings of Regional Adiposity Distribution in African Americans: Assessments from the Jackson Heart Study

BackgroundAfrican ancestry individuals with comparable overall anthropometric measures to Europeans have lower abdominal adiposity. To explore genetic underpinning of different adiposity patterns, we investigated if genetic risk scores for well-studied adiposity phenotypes also predict other adiposity measures in 2420 African American individuals from the Jackson Heart Study. MethodsPolygenic risk scores (PRS) for BMI, WHR adjusted for BMI (WHRBMIadj), WCBMIadj, and body fat percentage (BF%) were calculated using GWAS significant variants from mostly European ancestry studies. Associations between each PRS and adiposity measures were examined using multivariable linear regression. ResultsThe BMI-PRS was found to be a positive predictor of BF% ({beta}=0.005 per allele, 95% CI: 0.002, 0.008) and subcutaneous adiposity ({beta}=0.004, CI: 0.002, 0.008). The BF%-PRS was associated with subcutaneous ({beta}=0.022, CI: 0.010, 0.032) but not visceral adiposity; neither BMI nor BF%-PRS were predictors of central obesity measures. Other PRS were not associated with BF%. ConclusionThese analyses suggest: (a) genetically driven increases in BF% strongly associate with subcutaneous but not visceral adiposity; (b) BF% is strongly associated with BMI but not central adiposity associated genetic variants. How these variants may contribute to observed differences in adiposity patterns between African and European ancestry individuals requires further study.