Influence of Altitude on Pulmonary Function

Variation in lung function at high altitude (HA) impacts the working capacity of individuals and may predispose body towards hypoxia induced illness. So, we investigated the changes in pulmonary function of healthy human male volunteers belonging to two different ethnicities i.e. Indian and Kyrgyz. Twenty, age and BMI matched, volunteers (Indian=10 and Kyrgyz=10) were recruited for the study. Measurement for pulmonary functions (FVC, FEV1, FEV1/FVC ratio, PEF, FEF 25-75%, MEF 25%, MEF 50%, MEF 75%, MVV) were performed on each individual at basal (800 m) and high altitude (4,111 m) on day 3,7,14 and 21. Results indicate that Kyrgyz has comparatively higher FVC, FEV1, PEF and MVV values and lower FEV1/FVC ratio upon altitude induction than those of Indian counterparts. Mid expiratory flow FEF25-75% was significantly increased in Kyrgyz upon altitude induction indicate more proficient lung emptying while only moderate increase at day 7 in Indian. MEF25% was significantly increased in Kyrgyz, while no change is observed in Indians at high altitude which indicates that 75% of lung emptying through small airways is better in Kyrgyz. MEF 50% and MEF 75% increased with altitude in both groups. For MVV, the maximum increase was ~17% in Indian at HA14 (p<0.01) and in Kyrgyz ~33% (p<0.001) at HA14 as compared to basal. Difference in lung function response observed, indicates that Kyrgyz has better pulmonary dynamics during altitude exposure as compared to Indian counterparts. The varied result observed may be due to different ethnic origin of the groups