Methacholine Bronchial Hyperresponsiveness inChronic Sinusitis

Abstract

The coexistence of chronic sinusitis (CS) may deteriorate the clinical condition of lower airway diseases such as bronchial asthma (BA) or chronic bronchitis (CB). However, the bronchial hyperresponsiveness (BH) in CS without any apparent lower airway disease is not fully understood nor are the effects of treatment. We examined lower airway hyperresponsiveness to methacholine (MCh) in 42 subjects with CS but without allergic rhinitis (AR) who had normal lung functions without any pulmonary symptoms, comparing it with that of 50 subjects with stable BA, 50 subjects with simple CB and 40 subjects with AR, and further examined the effect of endoscopic sinus surgery in 7 CS subjects with BH. The BH to MCh was measured in terms of the minimum dose (Dmin), defined as the cumulative dose at the point where respiratory conductance began to decrease. A Dmin <50 units was defined as BH. Seventy-one percent of CS subjects showed BH without relation to the severity or duration of CS, or atopic status. BH in CS subjects, which was less than that in BA subjects, was similar to that in simple CB or AR in both its prevalence and degree. After the surgical treatment of CS, BH significantly decreased (p < 0.01) with improvements in both nasal symptoms and sinus lesions. These findings suggest that CS itself induces BH to a degree similar to simple CB and AR without any relationship to the clinical background, and that adequate treatment of CS reduces BH.