Total lung capacity in Andean highlanders.

Total lung capacity (TLC), residual volume (RV), and vital capacity (VC), as well as related measures of pulmonary function, were assessed in a sample of 39 male and 23 female native highlanders of Aymara ancestry (20.1-28.8 years) who were residing in La Paz, Bolivia (average altitude of about 3,600 m). After controlling for body and chest size, most measures of respiratory function were significantly larger in males than females (P < .05). Absolute TLC (1 BTPS) was significantly larger in the La Paz Aymara males than in highland Peruvian or Tibetan males (P < .05) but, after controlling for body size, TLC was only 1 and 4% larger in the La Paz Aymara than in highland Peruvians or Tibetans, respectively. Also, comparison of the body size-adjusted percentage increases in TLC, VC and RV above U.S. sea-level reference values in selected highland populations indicated that the enhanced TLCs of highlanders are primarily due to an enhancement of RV and secondarily due to an enhancement of VC. © 1994 Wiley-Liss, Inc.