Study objectives: The objective of this study was to determine differences in airway responsiveness to adenosine 5′-monophosphate (AMP) between smokers and nonsmokers with allergic rhinitis.
Methods: A total of 41 adults with allergic rhinitis (16 smokers and 25 nonsmokers) were challenged with increasing concentrations of methacholine and AMP. Airflow was assessed after each concentration, and the response to each bronchoconstrictor agent was measured by the provocative concentration required to produce a 20% fall in FEV1 (PC20).
Results: The geometric mean PC20 AMP values were significantly lower in smokers than in nonsmokers: 72.4 mg/mL (95% confidence interval [CI], 33.9 to 154.9) vs 204.2 mg/mL (95% CI, 120.2 to 346.7) [p = 0.021]. The proportion of subjects with bronchoconstriction in response to AMP was higher in smokers (12 of 16 subjects) than in nonsmokers (7 of 25 subjects) [p = 0.005].
Conclusions: We conclude that smokers with allergic rhinitis have a greater AMP sensitivity than nonsmokers.