EFFECT OF WHOLE-BODY EXPOSURE TO COLD AND WIND ON LUNG-FUNCTION IN ASTHMATIC-PATIENTS

To assess the effect of subfreezing temperature and wind on lung funct ion in asthmatic patients, an exposure to subfreezing temperature at r est, a moderate exercise challenge at subfreezing temperature, and a s imilar exercise challenge at room temperature mere performed in 19 sta ble asthmatic subjects in an environmental chamber with an artificial wind. The mean maximal falls in FEV(1) were 5.3, 11.7, and 4.8 percent , respectively. The two challenges at subfreezing temperature caused s tatistically significant changes in FEV(1), but the exercise challenge at room temperature had no effect. A large variation in the sensitivi ty to cold was found. The time courses of the responses varied between the challenges, suggesting at least partially different mechanisms. T he results indicate that even moderate exercise can cause severe bronc hoconstriction in certain stable asthmatic subjects at climatic condit ions similar to the Scandinavian winter. The importance of reflex mech anisms causing bronchoconstriction in physiologic conditions is discus sed.