The Air We Breathe: Respiratory Impact of Indoor Air Quality in Chronic Obstructive Pulmonary Disease

RATIONALE: Environmental exposures have been associated with adverse outcomes in chronic obstructive pulmonary disease (COPD). Approximately one-third of individuals with COPD have allergic sensitization, but it is unknown whether exposure to allergens in the home is associated with outcomes. OBJECTIVES: To determine the prevalence and associations of allergen sensitization with exposure to common indoor allergens with symptoms and exacerbation risk in COPD. METHODS: Allergen sensitization to five common indoor allergens was assessed in former smokers with COPD. Home settled dust was assessed for presence of corresponding allergens. Sensitization and exposure status was determined and associations evaluated in adjusted models with longitudinal outcomes including symptoms, lung function, and exacerbations. Interactions were assessed between sensitization/exposure status and lung function. MEASUREMENTS AND MAIN RESULTS: One hundred eighty-three individuals studied were on average 67.3 years of age (SD, 8.22) with average FEV(1) of 53.2% (SD, 17.6%). Seventy-seven percent of participants were exposed to at least one tested allergen, and 17% had sensitization with corresponding allergen exposure. After adjustment, sensitization with exposure was associated with lower lung function (β, −8.29; 95% confidence interval [CI], −14.80 to −1.77), higher St. George’s Respiratory Questionnaire Total Score (β, 6.71; 95% CI, 0.17 to 13.25), and higher exacerbation risk (odds ratio, 2.31; 95% CI, 1.11 to 4.79). Associations appeared to be more pronounced among individuals with lower lung function. CONCLUSIONS: Allergen exposures are common in COPD and associated with adverse outcomes among those with concomitant allergen sensitization. This study establishes allergens as an important home exposure that potentially could be addressed with comprehensive home environmental modification strategies to improve COPD outcomes.