THE INFLUENCE OF INCREASED BRONCHIAL RESPONSIVENESS, ATOPY, AND SERUM IGE ON DECLINE IN FEV(1) - A LONGITUDINAL-STUDY IN THE ELDERLY

We have performed a 4-yr prospective survey of the association of allergen skin test positivity, total serum immunoglobulin E (IgE), and bronchial responsiveness to methacholine, with longitudinal decline in FEV(1), in subjects over 65 yr of age. In 1987, 324 subjects completed a respiratory questionnaire, and underwent measurement of FEV(1) and FVC, methacholine challenge, skin prick testing (to Dermatophagoides pteronyssinus, cat fur, mixed grasses, and Aspergillus fumigatus) and estimation of total serum IgE. After an interval of 4 yr, 212 subjects were reexamined. The mean annual decline in FEV(1) was significantly higher in males than in females, but was not significantly influenced by smoking habits defined at the start of the study. The relation of atopy (skin test reaction to allergen greater than or equal to 3 mm greater than saline control), increased bronchial responsiveness (PD(20)FEV(1) less than or equal to 6.4 mu moles methacholine) and serum IgE > 80 IU/ml, to annual decline in FEV(1) was examined for each risk factor individually with adjustment for age, sex, height, and initial FEV(1), by multiple linear regression. Both atopy and bronchial responsiveness were significantly associated with accelerated decline in FEV(1). Elevated IgE was correlated with faster FEV(1) decline in subjects who were current smokers at the start of the study. In a multiple regression model examining the mutually adjusted associations of all relevant variables with annual decline in FEV(1), male sex was the most important predictor (B = 38.6 ml/yr, 95% Cl = 4.3, 72.9). Increased bronchial responsiveness also tended to be associated with accelerated decline in FEV(1). In further analyses incorporating the same variables, but restricted to specific smoking categories, age was the only significant factor in the never-smokers, whereas both atopy (B = 44.5 ml/yr, 95% Cl = 3.8, 85.3) and increased bronchial responsiveness (B = 43.5 ml/yr, 95% Cl = 4.6, 82.3) were significant predictors of accelerated FEV(1) decline in former and current smokers combined. In conclusion, allergy and increased bronchial responsiveness are risk factors for a more rapid decline in lung function in the elderly, particularly in former and current smokers.