LAUSR

Background: COPD exacerbations are important to disease progression and quality of life. Although exacerbation frequency increases with disease severity, other contributors are also important in determining the risk of exacerbations. Haptoglobin (Hp) polymorphism has been associated with various clinical conditions and outcomes. The Hp 2-2 phenotype has been found to have bacteriostatic properties while the 1-1 phenotype was found to be associated with infections. In light of these findings, we tested the hypothesis that COPD patients who possess the Hp 1-1 phenotype are at a higher risk of becoming frequent exacerbators. Methods: Patients with COPD (FEV1 Results: The multivariate logistic regression yielded a model in which current smoking status was negatively related with the frequent exacerbator status (odds ratio, 0.240; 95% CI, 0.068 to 0.843; p-value = 0.03). Number of pack-years was also negatively related to being a frequent exacerbator. (odds ratio, 0.979; 95% CI, 0.962 to 0.996; p-value = 0.02). Haptoglobin phenotype did not have a statistically significant association with frequent exacerbator status. Conclusions: Current smokers report significantly less exacerbations. A possible explanation may be reduced awareness of exacerbations and reduced health care utilization of active smokers.