Most of the subjects who ever had asthma had at least one positive histamine test result, but 64 subjects (16% of the sample) had asymptomatic BHR at either one or both of the surveys. A substantial proportion of hyperresponsive subjects therefore may seem to have transient BHR of probably only minor clinical significance. BHR in […]

In keeping with previous reports, the crosssectional analyses of data from the two surveys showed a strong association between atopy to HDMs and degree of histamine responsiveness, irrespective of the presence or absence of symptomatic asthma. Furthermore, the longitudinal analysis revealed that persistent or new atopy to HDM had significant impact on the degree of […]

The present study showed an overall decline in BR to inhaled histamine from childhood to early adulthood, possibly reflecting the growth-related increase in airway caliber, and furthermore, the level of FEV1 %pred, as an index of airway caliber, and atopy, especially to HDMs, are important determinants for changes over time in degree of histamine responsiveness […]

The results of the multiple regression analysis predicting histamine DRS at the second survey as a function of variables measured at the first survey and changes in these variables during the observation period are shown in Table 4. Preliminary analyses of the data showed that atopy to HDM was associated closer with histamine responsiveness than […]

Complete data were available for 408 subjects, 199 male and 209 female; characteristics of the examined subjects are displayed in Table 1. The proportion of subjects with current asthma increased from 5% at the first survey to 15% at the second survey (Table 2); and likewise did the point prevalence of a positive SPT increase […]

BR to inhaled histamine was measured using the method described by Cockcroft et al. Aerosols of the test solution were generated by a nebulizer (Wright; Aerosol Products Ltd; London, UK) operated to give an output of 0.14 mL/min. Each aerosol was inhaled through the mouth by tidal breathing for 2 min. The first aerosol was […]

The FEVX and FVC were measured with a 7-L diy wedge spirometer (Vitalograph) that was calibrated weekly. Each measurement consisted of at least three maximal expiratory maneuvers from total lung capacity to residual volume with a variation of <5%. The highest FEV1 and FVC were used in the analyses. Data on pulmonary function were also […]