[The course of pulmonary function in adults with asthma. The Osterbro study]

We studied the course of forced expiratory volume in one second (FEV1) in adults with self-reported asthma using data from a longitudinal epidemiological study of the general population, The Copenhagen City Heart Study. The study was conducted over a period of 15 years with three measurements of lung function. The data base consisted of 17,506 men and women including 1.095 participants with asthma. The unadjusted FEV1 decline in subjects with asthma was 38 ml/year compared to 22 ml/year in nonasthmatics. Similarly, the statistical analysis showed that the FEV1 normalised by height (FEV1/height2) was significantly poorer in subjects with asthma compared to nonasthmatics (p < 0.001). Smoking contributed significantly to lung function decline regardless of asthma status (p < 0.001). In a sample of the general population, adults with self-reported asthma have a significantly faster decline of ventilatory function than nonasthmatics.