DEVELOPMENTAL, GENETIC, AND ENVIRONMENTAL COMPONENTS OF LUNG-VOLUMES AT HIGH-ALTITUDE

Vital capacity and residual lung volume (in terms of 1/min or ml/m(2) of body surface area) of 357 subjects (205 males, 152 females) was eva luated in La Pat, Bolivia, situated at 3,750 m. The sample included: ( 1) 37 high altitude rural natives (all male), (2) 125 high altitude ur ban natives (69 male, 58 female), (3) 85 Bolivians of foreign ancestry acclimatized to high altitude since birth (40 male, 45 female), (4) 6 3 Bolivians of foreign ancestry acclimatized to high altitude during g rowth (30 male, 33 female), and (5) 47 non-Bolivians of either Europea n or North American ancestry acclimatized to high altitude during adul thood (24 male, 23 female). Results indicate that (1) all samples stud ied, irrespective of origin or acclimatization status, have larger lun g volumes than those predicted from sea level norms; (2) the high alti tude rural natives have significantly greater lung volumes (vital capa city and residual lung volume) than the high altitude urban natives an d all the non-native high altitude samples; (3) males acclimatized to high altitude since birth or during growth attain similar lung volumes as high altitude urban natives and higher residual lung volumes than subjects acclimatized to high altitude during adulthood but lower than the high altitude rural natives; (4) females acclimatized to high alt itude since birth or during growth attain similar lung volumes as subj ects acclimatized to high altitude during adulthood; (5) age at arriva l to high altitude is inversely related to residual lung volume but no t vital capacity; (6) among subjects acclimatized to high altitude dur ing growth, approximately 20-25% of the variability in residual lung v olume can be explained by developmental factors; (7) among high altitu de rural and urban natives, it appears that approximately 20-25% of th e variability in residual lung volume at high altitude can be explaine d by genetic traits associated with skin reflectance and genetic trait s shared by siblings; and (8) vital capacity, but not the residual lun g volume, is inversely related to occupational activity level. Togethe r these data suggest that the attainment of vital capacity at high alt itude is influenced more by environmental factors, such as occupationa l activity level, and body composition than developmental acclimatizat ion. On the other hand, the attainment of an enlarged residual volume is related to bath developmental acclimatization and genetic factors. (C) 1997 Wiley-Liss, Inc.