Indoor allergens and longitudinal FEV1 decline in older adults: The Normative Aging Study

We investigated the relationship between home allergen exposure and decline in FEV₁ in 10 asthmatic and 30 randomly selected, age-matched, nonasthmatic participants in the Normative Aging Study. We defined asthma as subject-reported wheezing apart from colds, with either a physician's diagnosis of asthma or a methacholine PD₂₀ FEV₁ of 8.6 μmol or less. We examined the relationship between the annual decline in FEV ₁ and the concentrations of the cockroach (Blattella germanica) allergens Bla g 1 and Bla g 2, the dust mite (Dermatophagoides pteronyssinus and Dermatophagoides farinae) allergens Der p 1 and Der f 1, and the cat (Felis domesticus) allergen Fel d 1 in house dust specimens. Bla g 1 (–79.8 ml/yr, p = 0.0006) and Bla g 2 (–40.81 ml/yr, p = 0.0004) were significant predictors of decline in FEV₁ after adjustment for age, smoking, and baseline FEV₁. These results were unchanged after elimination of the asthmatic subjects from the analysis. We conclude that cockroach allergen levels in homes is a risk factor for accelerated decline in FEV₁ independent of airway responsiveness. (J Allergy Clin Immunol 1998;101:720–5.)