title: The relationship of nonspecific bronchial responsiveness to the occurrence of respiratory symptoms and decreased levels of pulmonary function. The Normative Aging Study.
abstract: Nonspecific bronchial responsiveness was assessed by an abbreviated methacholine challenge test in 458 male participants of the Normative Aging Study, who also completed a respiratory questionnaire and spirometry. A positive response to the methacholine challenge test was defined as a greater than or equal to 20% decline in FEV1 during the test. Cigarette smoking was significantly associated with a positive methacholine response (p less than 0.001). Logistic regression analyses indicated that there was a significant association between a positive response to methacholine and both any wheeze (p = 0.002) and persistent wheeze (p less than 0.001) after taking into account smoking status and age; an association between responsiveness and chronic cough was of borderline significance (p = 0.06). Multiple linear regression analyses indicated that positive methacholine responsiveness was independently associated with lower levels of FEV1 (p less than 0.001) and FEF25-75 (p less than 0.001). Using the log of the dose-response slope rather than a dichotomous variable to characterize responder status yielded very similar results in the linear and logistic models. The findings of this cross-sectional study suggest that increased level of nonspecific responsiveness is significantly associated with wheeze and cough symptoms and decreased levels of pulmonary function in adult men. Longitudinal follow-up of these men should shed light on the importance of nonspecific responsiveness as a risk factor for the subsequent development of chronic obstructive pulmonary disease.
authors.forename: D
authors.initials: D
authors.lastname: Sparrow
authors.forename: G
authors.initials: G
authors.lastname: O'Connor
authors.forename: T
authors.initials: T
authors.lastname: Colton
authors.forename: C L
authors.initials: CL
authors.lastname: Barry
authors.forename: S T
authors.initials: ST
authors.lastname: Weiss
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001980:Bronchi / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D003430:Cross-Sectional Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000503:physiopathology*; D008297:Male; D016210:Methacholine Chloride; D008688:Methacholine Compounds; D008875:Middle Aged; D012120:Respiration Disorders / Q000503:physiopathology*; D012135:Respiratory Sounds / Q000503:physiopathology; D012907:Smoking; D014797:Vital Capacity
chemical_list: D008688:Methacholine Compounds; D016210:Methacholine Chloride