Airway responses in healthy and asthmatic subjects following exposure to low ambient air temperature.
Ventilatory capacity following exposure to low ambient air temperature (-5 degrees C) was measured in 46 male and 37 female medical students. In healthy subjects there was an increase in all test parameters during a four-hour exposure as compared to preexposure values. However, six students with bronchial asthma showed a decrease in ventilatory capacity tests following exposure to low temperature. The changes in healthy subjects as well as in asthmatics were most pronounced for the maximal flow rates at 50% and the last 25% of the vital capacity (FEF50, FEF25). The mean increase in FEF25 for healthy subjects was recorded up to a +15.1% and +6.4% increase in nonsmokers and smokers, respectively. In asthmatics, the largest decrease of FEF25 was -21.5%. Authors' data indicated that environmental exposure to low ambient air temperature caused an increase of ventilatory function tests in healthy subjects and a decrease in asthmatics, particularly in flow rates at lower lung volumes.
Zuskin
E
E
Andrija Stampar School of Public Health, Medical Faculty, University of Zagreb, Croatia.
Schachter
E N
EN
Mustajbegović
J
J
D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008449:Maximal Expiratory Flow-Volume Curves; D008450:Maximal Midexpiratory Flow Rate; D015656:Respiratory Mechanics; D012907:Smoking; D013696:Temperature; D014797:Vital Capacity