Are Race and Sex Differences in Lung Function Explained by Frame Size

SUMMARY Using the CARDIAcohort of 20- to 32-yr-old black and white men and women, FVC and FEV 1 were standardized for standing height, sl"lng height, leg height, elbow breadth, and bl­ acromial diameter In such a way that the standardized lung function showed minimal statistical dependence on these measuresof frame size. Race and sexdifferences In lung function havebeen reported even after adjustment for height; however, these differences might depend on aspects of frame size other than height. We found that within this age group helght 2 provided robust stan­ dardization for FVC and FEV1 for all race and sex strata of the population. Height explained approxi­ mately 40% of the variance of FVC and FEV1 In whites, 30% In black women, and 20% In black men. In black men only, standardization for the combination of sl"lng height, leg height, elbow breadth, and blacromlal diameter Improved explained variance to nearly 40% for FVC and nearly 30% for FEV 1 • After standardization for height, FVC and FEV, were found to be 14 to 19% higher In whites than In blacks, and In men than In women. Standardization of FVC and FEV1 for sl"lng height, leg height, elbow breadth, and blacromlal diameter combined reduced these differences to 13-16%. Thus, race and sex differences In lung function exist even after detailed adjustment for frame size.