Alizadeh R, Ziaee V, Movafegh A, Yunesian M, Azadi Mr, Mehraein A,
Volume 64, Issue 10 (2 2006)
Abstract
Background: Both hypoxia and hypocapnia can cause broncho-constriction in humans, and this could have a bearing on performance at high altitude. The objective of this study was to examine how pulmonary ventilatory function during high-altitude trekking.
Methods: This study was a before and after study on spirometric parameters at Base line (1150 m above sea level), and after ascending at 4150 m above sea level. This study was performed in summer 2004 at Cialan Mountain in Iran. Fifty six healthy male University student volunteers were enrolled in the study. Respiratory function was assessed in participants before ascending at baseline (1150 meter) and after ascending at 4150 meter in Cialan Mount with a Spirolab II. Spirometric parameters changes were compared using paired t-test statistical analysis computations were performed by spss 11.5 and p≤0.05 was considered significant.
Results: The mean age and body mass lindex of our subjects were 22.9±5.3 years and 21.5±2.5, respectively. Forced vital capacity (FVC) was significantly decreased with increasing altitude from baseline level (P<0.01). Forced expiratory volume in 1 second to forced vital capacity ratio (FEV1/FVC) and maximal midexpiratory flow rate (FEF 25-75%) were significantly increased with increasing altitude (P=0.001). There was no significant change in forced expiratory volume in 1 second and peak flow (P>0.05). FVC fell by the average of 7.1% at 4150m (2.4% per 1000m increased altitude) in comparison to 1150m.
Conclusion: The changes in some pulmonary ventilatory parameters were proportional to the magnitude of change in altitude during a high-altitude trek.
