Multinational Andean genetic and health program. VII. Lung function and physical growth - multivariate analyses in high- and low-altitude populations

Previous studies of the association between lung function and body measurements have relied on univariate methods of analysis which can only assess the importance of the factor common to all body measurements-size. Studies of this kind in high-altitude populations have found higher correlations of chest measurements with lung function, while pulmonary efficiency in sea level societies appears more related to height. However, ethnic differences as yet have not been controlled. The association of lung function (forced vital capacity, forced expiratory volumes at 3 s and 1 s and peakflow rate) and 14 body measurements of child and adult permanent residents of an altitudinal gradient in northern Chile, is explored by principal components and canonical correlation, multivariate methods with which we may assess the importance, of both size and body proportion in physiological efficiency. Results indicate that physical growth is different at high and low altitudes, higher altitude children having greater chest development (circumference and transverse) relative to height. The first two canonical correlations, out of a possible four, were significant. Both indicate chest measurements as the major physical correlates of lung function irrespective of altitude, sex, or age group. However, these correlations depend on ethnicity (Spanish-Amerindian ancestry) as they increase substantially when this factor is held constant.