When they occur together, sinusitis and asthma are often thought to represent anatomically separate components of the same chronic inflammatory airway disease. Information about the effect of smoking on the interaction between sinusitis and asthma in patients who have both disorders is limited.Objectives:
To evaluate the effect of cigarette smoking on the relationship between the presence and severity of sinusitis and selected asthma-related indices in adults who have asthma.Methods:
This study included 127 patients with severe asthma and 79 patients with mild to moderate asthma. Clinical data were obtained from all subjects during a 2-day stay at Hokkaido University Hospital (Sapporo, Japan). The Lund-Mackay scoring system was used to assess the anatomic extent and severity of sinusitis as revealed by sinus computed tomographic (CT) images obtained during hospitalization. We examined associations between Lund-Mackay scores and a variety of asthma-related indices and levels of biomarkers in blood and sputum. To clarify the effect of smoking on these associations, we conducted separate analyses for nonsmoking (<10 pack-years; n = 130) and smoking subjects (≥10 pack-years; n = 76).Measurements and Main Results:
In our cohort of adults with asthma, we found significant positive relationships between the presence and severity of sinusitis as assessed by Lund-Mackay score and the severity of asthma as measured by percent predicted FEV1 or FEV1/FVC for nonsmoking subjects (<10 pack-years) but not for cigarette smokers (>10 pack-years). Lund-Mackay scores correlated with blood and sputum eosinophil counts, serum IgE levels, and fractional exhaled nitric oxide, regardless of smoking status. Lund-Mackay scores also showed significant positive associations with serum periostin and chemokine C-C motif ligand 18 levels, regardless of smoking status, whereas a positive association with plasma osteopontin level was seen only for nonsmoking subjects.Conclusions:
We found an association between the severity of sinusitis on CT imaging and the severity of concomitant asthma on spirometry for nonsmoking adults but not for smokers. In adults with asthma, CT imaging evidence of severe sinusitis indicates intense Th2-related inflammation, regardless of smoking status.