A multinational Andean genetic and health program: VI. Physiological measurements of lung function in an hypoxic environment

In 1972 a multidisciplinary study sought to assess the health status of the indigenous people of northern Chile, the Aymara, and relate morphological, physiological and biochemical variation to the striking changes in altitude of the region. This report describes the development of lung function (FVC, FEV₃, FEV₁ and peakflow) in individuals of both sexes ages 6 to 80 years (N = 614), permanent residents of an altitudinal gradient (coast, sierra (3000 m) and altiplano (over 4000 m)), and the relationship of these measurements to physical size and shape, environment (hypoxia) and ethnicity (Spanish-Aymara ancestry). In children (6-18 years old) high altitude residents had larger lung function measurements in both sexes, an effect which increased after adjusting for smaller body size at higher altitude and was independent of ethnicity. In adults, ethnicity also exerted an effect, which, however, was not easily separable from that of altitude. These results suggest that altitude has a direct positive effect on lung function measurements, whereas growth rate of the physiological measurements relative to stature may be under genetic control. Of five anthropometrics, maximum chest circumference was the best predictor of lung function in children, but stature accounted for more of the variation in adults. Indices of chest mobility (chest expansion) and chest shape (anterior-posterior/transverse chest) were also significantly related to lung function independent of the contributions of stature and chest circumference. The characteristic morphology of high altitude Andean populations (expansive and rounder chests) appears to have functional significance.