Respiratory function in normal Chinese: comparison with Caucasians.

We found that respiratory measurements in Chinese visitors to Colorado differed from those in height- and weight-matched Western residents of Denver, Colo., in the following ways (p less than 0.05): The Chinese had higher respiratory frequencies (15.5 +/- 0.93 vs. 11.4 +/- 0.85 breaths/min), lower tidal volumes (530 +/- 35.9 vs. 693 +/- 477.7 ml), lower alveolar ventilation (4.0 +/- 0.15 vs. 4.7 +/- 0.21 liters), lower forced vital capacities (4.53 +/- 0.16 vs. 5.43 +/- 0.12 liters), lower total lung capacities (6.25 +/- 0.26 vs. 7.16 +/- 0.17 liters), higher resting PaCO2 (36.3 +/- 0.94 vs. 33.6 +/- 0.74 Torr) and lower pHa (7.406 +/- 0.004 vs. 7.419 +/- 0.004). The Chinese also had lower ventilatory responses to CO2 (1.40 +/- 0.10 vs. 2.00 +/- 0.201/min/mm Hg) than did the Caucasians. The measurements made in the Chinese in Denver were similar to those reported for Chinese in China. Thus there may be differences in respiratory function between normal Chinese and normal Western subjects.