The effect of sex, age and race on estimating percentage body fat from body mass index: The Heritage Family Study
The effect of sex, age and race on estimating percentage body fat from body mass index: The Heritage Family Study
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DOI：
10.1038/sj.ijo.0802006
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发表时间：
2002-06-01
影响因子：
4.9
通讯作者：
Wilmore, JH
中科院分区：
文献类型：
--
作者：
Jackson, AS;Stanforth, PR;Wilmore, JH
目的：研究性别、年龄和种族对体重指数（BMI）和测量的体脂百分比（%fat）之间关系的影响。设计：对久坐个体的横断面验证研究。受试者：传统家族研究队列，包括665名黑人和白色男性和女性，年龄从17岁到65岁不等。用性别和种族特异性二室模型测定的体脂百分比。结果：多项式回归分析显示，男性和女性的脂肪百分比与BMI之间均呈二次曲线关系。BMI的自然对数转换，针对非线性进行调整。对数转换的BMI和性别的同质性检验表明，男性-女性斜率在随机方差内，但截距不同。对于相同的BMI，女性的脂肪百分比比男性高10.4%。对女性数据的一般线性模型分析表明，年龄、种族和种族与BMI的相互作用与%脂肪独立相关。同样的分析应用于男性的数据表明，%脂肪不仅是BMI的函数，而且是年龄和年龄与BMI的相互作用。多元回归分析提供的模型，定义的bias.CONCLUSIONS：这些数据和结果发表在文献中表明，BMI和%脂肪的关系是不独立的年龄和性别。这些数据表明，种族效应对女性，但不是男性。由于未能对这些偏倚来源进行调整，导致通过测量的%脂肪定义为肥胖的受试者比例存在显著差异。
OBJECTIVE: To study the effects of sex, age and race on the relation between body mass index (BMI) and measured percent body fat (%fat).DESIGN: Cross-sectional validation study of sedentary individuals.SUBJECTS: The Heritage Family Study cohort of 665 black and white men and women who ranged in age from 17 to 65y.MEASUREMENTS: Body density determined from hydrostatic weighing. Percentage body fat determined with gender and race-specific, two-compartment models. BMI determined from height and weight, and sex and race in dummy coded form.RESULTS: Polynomial regression showed that the relationship between %fat and BMI was quadratic for both men and women. A natural log transformation of BMI adjusted for the non-linearity. Test for homogeneity of log transformed BMI and gender showed that the male-female slopes were within random variance, but the intercepts differed. For the same BMI, the %fat of females was 10.4% higher than that of males. General linear models analysis of the women's data showed that age, race and race-by-BMI interaction were independently related to %fat. The same analysis applied to the men's data showed that %fat was not just a function of BMI, but also age and age-by-BMI interaction. Multiple regression analyses provided models that defined the bias.CONCLUSIONS: These data and results published in the literature show that BMI and %fat relationship are not independent of age and gender. These data showed a race effect for women, but not men. The failure to adjust for these sources of bias resulted in substantial differences in the proportion of subjects defined as obese by measured %fat.