Acclimatization to High Altitude in the Tien Shan: A Comparative Study of Indians and Kyrgyzis

Abstract Objective.—To study the changes in pulmonary function of human male volunteers from 2 different populations: Indians and Kyrgyzis before and after ascent to 3200 m and during a 4-week stay at that altitude. Methods.—Ten healthy soldiers of the Indian army (22–25 years of age) and 10 Kyrgyzis recruits (19–20 years of age ), height and weight matched, were volunteers in this study. Their pulmonary functions were evaluated at baseline (Bishkek, 760 m); on days 2, 13, and 25 at a mountain clinic at Tuya Ashuu pass (3200 m) in the northern Tien Shan Range; and on return to Bishkek. A dry spirometer was used to measure lung function at each location. Results.—Results indicated that Kyrgyzis had significantly larger forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) than those of the Indians, but their peak expiratory flow rate (PEF), forced expiratory flow rate at 25% to 75% of FVC (FEF25–75%), and maximal voluntary ventilation (MVV) measures were comparable. At high altitude (...