Characteristics of ventilatory function in clinical types of bronchial asthma in the elderly

Ventilatory function was examined in 55 patients with asthma (25 older patients over the age of 60 and 30 younger patients under the age of 59) in relation to four clinical types classified by clinical symptoms and signs. 1. Regarding cellular composition of bronchoalveolar lavage (BAL) fluid, number of BAL neutrophils was significantly increased in type II, bronchiolar obstruction type, of older and younger patients compared to that in type la-1 and type la-2 of same patients. In contrast, BAL eosinophilia was observed in type la-2 of both older and younger patients and in type Ib of younger patients. 2. The values of % FVC, FEV(1.0%) and % PEFR were not significantly different among four clinical types of asthma and between older and younger patients, although the values of these ventilatory parameters in type II asthma showed a tendency to be lower compared to other clinical types. 3. The values of % MMF, % V(50), and % V(25), showing ventilatory dysfunction of small airways, were lowest in type II asthma of both older and younger patients among four clinical types. A significant difference in these ventilatory parameters of type II asthma compared to type la-1 asthma was observed in younger patients, but not in older patients. These results show that ventilatory dysfunction of small airways is related to clinical asthma types in younger patients, and to aging rather than asthma types in older patients.