Racial/ethnic differences in body composition measures and exercise parameters in the TIGER Study

Background/Objectives: Although current adult anthropometric cut-points (e.g., BMI, waist circumference (WC), and waist-to-hip ratio (WHR)) are applied universally, a growing body of research suggests that these measures, along with their relation to adiposity, may differ across racial/ethnic groups. In this study, we investigated the presence and persistence of racial/ethnic differences among anthropometric and body composition measures. Racial/ethnic-specific prediction of total percent body fat (BF%) and percent trunk fat (TF%) by these anthropometric measures was also examined. Exercise parameters were also compared across racial/ethnic groups Subjects/Methods: Data from 1783 participants from the Training Intervention and Genetics of Exercise Response (TIGER) Study, (n=1151 females, 632 males) were used. Subjects underwent 15 weeks of aerobic exercise training at 65 – 85% heart rate reserve. Only subjects who completed the protocol were included in these analyses. One-way ANOVA and multiple regression, stratified by sex, were used to compare the relationship between race/ethnicity, BF% or TF%, and anthropometric measures, and exercise parameters across racial/ethnic groups. Results: African American (AA) of both sexes exhibited lower levels of BF% per unit BMI, WC, and hip circumference (HC) and TF% per unit WC and WHR when compared to NHW. Similarly, Hispanic males and females showed less BF% per unit BMI and WC compared to NHW, but greater TF% per unit WC. Conversely, Asian Indians of both sexes had higher levels of BF% per unit BMI, WC, and HC compared to NHW. Both Asian males and females had greater levels of BF% per unit HC and TF% per unit WC compared to NHW. In females, AA (p<0.05), Hispanics (p<0.001), and Asians (p<0.01) all had significantly longer exercise duration compared to NHW. In males, exercise intensity was significantly higher in Hispanics compared to AA (p<0.005) and Asian Indians (p