Racial/ethnic Differences in Body Composition Measures and Exercise Parameters in the TIGER Study (P21-046-19)

Abstract

Abstract Objectives Although current adult anthropometric cut points (e.g., BMI, waist circumference (WC), etc.) are applied universally, a growing body of research suggests that these measures, along with their relation to body fat percentage, may differ across racial/ethnic groups. In this study we investigated the presence of racial/ethnic differences among anthropometric measures and exercise parameters. Racial/ethnic specific prediction of body fat percentage (DXA-BF%) by these body composition measures was also examined. Methods Data from 1789 participants from the Training Intervention and Genetics of Exercise Response (TIGER) Study (n = 1154 females, 635 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 multivariate regression, stratified by gender, were used to compare the relationship between race/ethnicity, DXA-BF%, and body composition. Results Both African American (AA) males and females exhibited lower levels of DXA-BF% per unit BMI, waist circumference (WC), and hip circumference (HC) when compared to NHW. Similarly, Hispanic White (H) of both genders showed less DXA-BF% per unit BMI and WC compared to NHW. AA and H males also showed significantly lower levels of DXA-BF% per unit waist-to-hip ratio (WHR). Conversely, Asian Indians of both genders had higher levels of DXA-BF% per unit BMI, WC, and HC compared to NHW. Asians also had greater levels of DXA-BF% compared to NHW, with significant differences in HC for both genders and WHR in females. Racial/ethnic differences were observed among females for exercise duration, with AA (37.9 ± 3.9 minutes; P < 0.05), H (38.9 ± 4.0 minutes; P < 0.001), and Asians (38.9 ± 5.4 minutes; P < 0.01) all having significantly longer duration compared to NHW (37.1 ± 3.5 minutes). In males, values for exercise heart rate (AA 154.3 ± 7.6 bpm; H 157.7 ± 8.3 bpm; P < 0.05) and intensity (AA 66.6 ± 5.6%; H 69.4 ± 6.0%; P < 0.01) were significantly lower in AA compared to H. Conclusions Our data provide evidence of racial/ethnic biases in anthropometric measures and their relationship to DXA-BF%, further supporting the need for race/ethnicity-specific cut points. Significant racial/ethnic differences in exercise parameters were also observed. Funding Sources TIGER Study funded by NIH/NIDDK.