title: Potential impact of altitude on lung function.
abstract: OBJECTIVE
  The effect of altitude on lung function was evaluated in 21 healthy volunteers at 171 m and at 1580 m above sea level.
  
  
  METHODS
  Results were obtained using an open spirometry system.
  
  
  METHODS
  The parameters analyzed were forced vital capacity (FVC), forced expiration volume after 1 s (FEV1), relative 1-s capacity (FEV1/FVC), mean expiratory flows at 75%, 50% and 25% of FVC (MEF75, MEF50, MEF25), and maximal expiratory flow (peak flow, PEF).
  
  
  RESULTS
  MEF75 and MEF50 revealed a positive correlation with altitude, with mean rises of 15% and 11%, respectively. The difference was statistically significant for MEF75 (P = 0.0009) and MEF50 (P = 0.0001), whereas the other parameters revealed no significant difference.
  
  
  CONCLUSIONS
  Altitude could be a variable influencing spirometric measurements.
authors.affiliation: Department of Occupational Medicine, University of Vienna, Austria. chris.wolf@univie.ac.at
authors.forename: C
authors.initials: C
authors.lastname: Wolf
authors.forename: A
authors.initials: A
authors.lastname: Staudenherz
authors.forename: G
authors.initials: G
authors.lastname: Röggla
authors.forename: T
authors.initials: T
authors.lastname: Waldhör
mesh_terms: D000328:Adult; D000531:Altitude; D005260:Female; D006801:Humans; D008297:Male; D012123:Pulmonary Ventilation; D013147:Spirometry; D014797:Vital Capacity