Changes in FVC during methacholine-induced bronchoconstriction in elderly patients with asthma - Bronchial hyperresponsiveness and aging

Study objective: We evaluated whether aging ma); produce changes in bronchial hyperresponsiveness, risk of enhanced bronchoconstriction, and changes of bronchoconstriction perception. Setting: Each subject underwent a methacholine bronchial challenge. Methacholine challenge was stopped when one of the following conditions occurred: (1) plateau of bronchoconstriction; (2) decrease of FEV1 > 4046; (3) FEV1 drop below 1 L; or (4) excessive respiratory discomfort, Methacholine dose-response curves were plotted both for FVC and FEV1, The provocative dose of methacholine causing a 20% decrease in FEV, with respect to baseline (PD20) and the fall in FVC (Delta FVC) at PD were computed. The Borg scale was used for scoring the perception of respiratory discomfort. Patients: We compared 17 young asthmatic patients (aged 22 to 45 years) with 17 older asthmatic patients (aged 63 to 78 years) selected on the basis of similar baseline pulmonary function and disease duration. Results: No significant between-group difference was found in PD20 and in plateau development. Conversely, Delta FVC was significantly higher in the older group (mean +/- SD, 15.5 +/- 3.9% vs 11.6 +/- 5.5% in younger patients). In addition, Delta FVC showed a positive linear relationship with age (p = 0,0026), Elderly subjects were less aware of bronchoconstriction during the methacholine challenge (p = 0.04), Conclusions: In elderly patients with asthma having comparable pulmonary function and disease duration, bronchial responsiveness is not different from that observed in younger asthmatic patients. Nevertheless, in such patients, an age-related tendency to an enhanced bronchoconstriction and a reduced perception of the degree of bronchoconstriction exist.