4 2 ) 0 g k ( ass -2 m e e r ftfa -4 n i s cen -6 e r e f f iD -8 -10 -12 Vs 45-50 Vs 51-54 Vs 55-59 Vs 60-64 Vs 65-69 Vs 70-74 Vs 75-79 Vs > 80 White men Black men White w omen Black w omen BMC Public Health 2005, 5:41 http://www.biomedcentral.com/1471-2458/5/41 Age-related changes FAiggeu-rreela1ted changes in fat free mass in older white and black men and women Age-related changes in fat free mass in older white and black men and women. The Third National Health and Nutrition Exam- ination Survey (NHANES III 1988–94) combined, both FFM and FFMI peaked earlier in men (at age 51–54 yrs) than in women (at age 55–59 yrs). In black men, the decline in FFM started about 5 years earlier (at age 51–54 years) compared to white men (at age 55–59 years), and reached significance level at age 65–69 in black men and age 70–74 in white men. Although FFM peaked earlier in white women compared to black women, statistically significant decline was reached earlier in black women at age 70–74 (p = 0.025) compared to age 75–79 in white women (p = 0.01). Initial onset of decline in FFM occurred almost a decade after that of men of similar ethnic background. In both white and black women, decline in FFMI was also noted, but did not attain significance level. Furthermore, decline in FFMI was noted in black men starting at age 60–64 and reach- ing significance at age 70–74 (p = 0.047). In white men, decline started at age 70–74, and reached significant level in the eight decade (of life (p < 0.01). Multiple regression analyses In multivariate analysis for the entire group including eth- nicity, age and gender, while adjusting for BMI, FFM sig- nificantly associated with ethnicity (p < 0.043), age (p < 0.001), and gender (p < 0.001). In separate analyses for men and for women, FFM significantly associated with ethnicity (p < 0.012) and age (p < 0.001) in women, but only with age (p < 0.001) in men (Table 3). This con- firmed our preliminary observation of higher FFM in black women compared to white women, and significant age-related changes in FFM. However, black and white men were similar in FFM. Because FFMI was already adjusted for height, the multivariate model for FFMI was adjusted for body weight instead of BMI. The association of FFMI with ethnicity, age and gender in the entire group was similar to that observed for FFM (all p < 0.001). In men and in women, FFMI significantly associated with ethnicity (p < 0.001; p = 0.003 respectively) and with age (p < 0.001; p = 0.004 respectively) (Table 3). Discussion Based on a representative national epidemiological data, we observed significantly higher FFM and FFMI in black compared to white women, but not between black and white men. These differences were independent of body weight. Important differences in age-related decline in FFM and FFMI were also noted, starting earlier in black men than white men, but earlier in white women than black women despite a higher decline in black women. Despite the earlier onset of decline of FFM and FFMI in Page 4 of 9 (page number not for citation purposes)