A Polysomnography Study of Snoring and Obstructive Sleep Apnea in Relation to Chronic Bronchitis

Background and Objective Reportedly, snoring is associated with chronic bronchitis. This association warrants further studies including polysomnographic evaluations because of few epidemiologic studies on the association. Via a polysomnography study, we evaluated the associations of snoring, obstructive sleep apnea, and systemic inflammation with chronic bronchitis among 442 participants from a population-based cohort. Methods At baseline, we assessed participants’ serum levels of C-reactive protein, a biomarker of systemic inflammation. Over a 5-year period, we conducted overnight polysomnography and identified any new cases of chronic bronchitis. Results After taking into account age, smoking, and other potential risk factors, the multivariate odds ratio (95% CI) for chronic bronchitis was 2.9 (95% CI, 1.3–6.4) for snorers with cumulative duration of snoring episodes ≥ 1 hour as compared with those snoring < 1 hour. This association did not change after further adjustment for the presence of apnea. Obstructive sleep apnea had no association with chronic bronchitis. A higher level of serum C-reactive protein was associated with chronic bronchitis (p value for trend < 0.05). In a joint analysis of snoring and C-reactive protein, longer cumulative duration of snoring episodes accompanied by systemic inflammation was associated with a 10-fold (95% CI, 2.9 to 37.4) increase in the multivariate odds of chronic bronchitis. Conclusions This polysomnography study provides additional data supporting the hypothesis that snoring is associated with chronic bronchitis implying that snoring-related local and systemic inflammation may play roles in the development of chronic bronchitis.