Airway hyperresponsiveness and pulmonary function in adult asthma.

BACKGROUND

Airway hyperresponsiveness (AHR) is a very important factor in the pathogenesis of bronchial asthma.

OBJECTIVES

To examine the relationship between airway obstruction and AHR in adult asthma.

METHODS

This study was a retrospective study in 161 adult asthmatic patients. Nonspecific AHR to methacholine was measured. We examined the correlations between AHR and pulmonary function, severity of asthma, type of asthma and age.

RESULTS

In the moderate and severe groups, peripheral airway obstruction was more aggravated compared to the mild group, and AHR was significantly more severe. Analysis of AHR by age showed that the degree of airway obstruction increased with aging, but age did not clearly correlate with airway sensitivity. Airway reactivity decreased with aging. Aspirin-induced asthma tended to be severe. In fatal asthma, central airway obstruction was significantly more severe. Although AHR in fatal asthma did not significantly differ from that in the severe group, airway sensitivity and airway reactivity tended to be increased.

CONCLUSIONS

AHR is an important factor determining the severity of asthma, and airway obstruction is an important index for the prediction of death from asthma. An evaluation of the degree of AHR and airway obstruction is considered to be the first step in controlling asthma.