[Measurement of peak expiratory flow and altitude].

Readings of peak-expiratory flow rate (PEFR) in twelve healthy alpinists at sea level (Lima) and at 3800 m (Yanganugo) show a significant slight fall with altitude (p less than 0.05). This study corroborates previous reports (Singh et al., 1969; Stockley et al., 1979). However, Forster (1983) taking in account the effect of air density on the functioning of peak-flow meter suggested that actual PEFR increases slightly with altitude. In the present study, corrected data show an increase of PEFR by about 3% at 3800 m, similar to Forster's results (at 4200 m). Air density must be considered in future studies in altitude and in estimation of clinical improvement of asthmatic people living in mountain health resort.