BACKGROUND: Most studies on the effects of temperature and humidity on exercise-induced @entity5143 (EIB) in asthmatics have been carried out under indoor conditions. However, any @entity748 @entity1 is exposed to varying climatic conditions. OBJECTIVE: To investigate whether temperature or relative humidity plays a more important role in determining the degree of EIB in asthmatics under naturally exposed climate conditions. METHODS: To exclude the effects of pollen on EIB, we enrolled 69 subjects with perennial @entity565 (mean +/- SD: 20.1 +/- 1.5 years). The subjects performed outdoor free running tests. They were divided into winter (n = 25), spring/autumn (n = 22), and summer (n = 22) groups according to the season when they performed the tests. Initial spirometry and skin prick tests were performed. @entity2710 bronchial challenge testing and, one day later, the free running tests were done. RESULTS: There were significant differences in temperature and relative humidity among the three groups: However, the relative humidity in winter did not differ from that in spring/autumn. There were no differences in pulmonary functions, airway responsiveness, and @entity402 score among the three groups. The percentage of cases of positive EIB --fall in forced expiratory volume in 1s FEV(1) of >15% from baseline --in winter (84%, p < 0.05) or spring/autumn (86.4%, p < 0.05) was higher than that in summer (50%). However, the percentage of subjects with a positive EIB in winter did not differ from that in spring/autumn. The maximal percent fall in FEV(1) after exercise in winter did not differ from that in spring/autumn. CONCLUSIONS: The occurrence of EIB is associated with environmental temperature and humidity. Under such climatic conditions as in Korea, relative humidity may be a more important factor than temperature in contributing to EIB in @entity1 with perennial @entity565 .

Seasonal difference in the occurrence of exercise-induced XXXX in asthmatics: dependence on humidity.

@entity748 :: ('MESH:D013224', 'Disease') :: ['asthmatic'] @entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity565 :: ('MESH:D001249', 'Disease') :: ['asthma'] @entity402 :: ('MESH:C564133', 'Disease') :: ['atopy'] @entity5143 :: ('MESH:D001986', 'Disease') :: ['bronchospasm'] @entity2710 :: ('MESH:D016210', 'Chemical') :: ['Methacholine']
@entity5143 :: (MESH:D001986,Disease) :: ['bronchospasm']
