POTENTIAL IMPACT OF ALTITUDE ON LUNG-FUNCTION

Object. The effect of altitude on lung function was evaluated in 21 he althy volunteers at 171 m and at 1580 m above sea level. Method. Resul ts were obtained using an open spirometry system. Design. The paramete rs analyzed were forced vital capacity (FVC), forced expiration volume after 1 s (FEV1), relative 1-s capacity (FEV1/FVC), mean expiratory f lows at 75%, 50% and 25% of FVC (MEF75, MEF50, MEF25), and maximal exp iratory flow (peak flow, PEF). Results. MEF75 and MEF50 revealed a pos itive correlation with altitude, with mean rises of 15% and 11%, respe ctively. The difference was statistically significant for MEF75 (P = 0 .0009) and MEF50 (P = 0.0001), whereas the other parameters revealed n o significant difference. Conclusion. Altitude could be a variable inf luencing spirometric measurements.