چكيده لاتين :
Hypoxia and hypocapnia can cause broncho-constriction in human subjects, and this
could have a bearing on performance at high altitude. The object of this study was to
examine how pulmonary ventilatory functions during high-altitude trekking.
This study is a cohort study on spirometric parameters at different altitudes. Fifty six
healthy male volunteers from a university student population were enrolled in the study (ages
22.9(PLUS-MINUS)5.3 years). Pulmonary function was assessed with a Spirolab II in all participants before
ascending at baseline (1150 meter), after ascending at different altitudes (2850, 4150 meter),
and after descending at sea level during a 3-day trek in Sialan Mount.
This study indicates that in an actual trek, ascending results in significant decrease in
forced vital capacity (FVC). FVC significantly decreased with increasing altitude from
baseline level and at the sea level it was significantly less than baseline level. Peak flow
increased with increasing altitude from baseline (1150 m) to 2850 m and decreased with
decreasing altitude (p(LESS THAN)0.01). Maximal midexpiratory flow rate (FEF 25-75%) and forced
expiratory volume in 1 second to forced expiratory volume ratio (FEVl.0%) significantly
increased with increasing and decreasing altitude from baseline level (p(LESS THAN)0.001). There was no
significant change in FEVI.
It could be concluded that changes in some pulmonary ventilatory parameters were
proportional to the magnitude of change in altitude during a high-altitude trek. These
changes are significant at the beginning of ascending.
