EFFECTS OF ETHNICITY, GENDER, OBESITY, AND AGE ON CENTRAL FAT DISTRIBUTION - COMPARISON OF DUAL X-RAY ABSORPTIOMETRY MEASUREMENTS IN WHITE,BLACK, AND PUERTO-RICAN ADULTS

Population based studies relying primarily upon anthropometric surroga tes of fat distribution have shown that central or upper-body adiposit y is related to ethnicity, gender, age, and total body fatness. As an improvement over anthropometry, dual x-ray absorptiometry (DXA) provid es more precise measurements of fat mass (FM) in the total body and tr unk. DXA was performed on 510 apparently healthy White (81 females (f) , 64 males (m)), Black (94 f, 79 m), and Puerto Rican (102 f, 100 m) a dults aged 20-75 years in order to determine and compare the effects o f race, gender, age, and total FM on trunk FM. Trunk FM was greater fo r Blacks and Puerto Ricans than Whites, irrespective of gender (P < 0. 014), Puerto Rican males and females had a greater proportion of fat i n the trunk (%TrFM) than Whites or Blacks (P < 0.001), and Whites and Blacks were similar with respect to %TrFM (P > 0.67). Females had less %TrFM than males in all three ethnic groups tall P < 0.001). Based on multiple regression analysis; ethnicity did not affect the relationsh ip of trunk and total FM among males (P > 0.16), but the coefficient f or total FM was larger for Puerto Rican compared to Black females (P = 0.043), Trunk FM increased with age in Whites and Puerto Ricans (P < 0.02), but not Blacks (P > 0.24), The effects of age did not differ by gender or ethnicity among Whites and Puerto Ricans (P > 0.10), Adjust ment for total FM and age eliminated ethnic and gender differences in trunk FM tall P > 0.37). The results suggest that the high levels of c entral adiposity observed among Blacks and Hispanics relative to White s reflect patterns of generalized obesity observed in the respective p opulations. Patterns of accumulation of truncal FM with increasing age and obesity may not be generalizable to all ethnic groups. (C) 1998 W iley-Liss, Inc.