To investigate the annual decline of lung function in subjects with self-reported asthma, we analyzed data from a longitudinal epidemiologic study. The Copenhagen City Heart Study. The study sample consisted of 10,952 subjects (4,824 men), 20 to 90 yr of age, randomly selected from the city of Copenhagen followed over a 5-yr period. The overall prevalence of asthma was 3.7% (n = 177) in men and 3.6% (n = 219) in women. Subjects who reported asthma at the first examination had, in general, lower values for lung function than did nonasthmatic subjects, which was also the case for subjects who developed asthma during follow-up (new asthma). The annual loss of FEV1 increased with age among both asthmatics and nonasthmatics. Multiple regression analysis showed a higher decline of FEV1 in subjects with new asthma. The excess decline was, on average, 39 ml/yr in men (p = 0.002) and 11 ml/yr in women (NS), respectively, compared with that in nonasthmatic subjects. In subjects with chronic asthma, the decline was not increased compared with that in nonasthmatic subjects. Separate analyses of lifelong nonsmokers revealed that the excess decline of FEV1 in subjects with new asthma was, on average, 33 ml/yr, whereas it was not significantly increased in subjects with chronic asthma. In conclusion, this study of a large sample from the general population showed that the rate of decline of FEV1 is increased in subjects with new asthma, whereas in subjects with chronic asthma the decline of FEV1 did not differ significantly from the decline in the nonasthmatic subjects.

Current knowledge about factors determining outcome of asthma is limited, but observations over the last few decades suggest that active asthma has a negative impact on the longitudinal changes in lung function. This review aims to give an overview of the present knowledge concerning longitudinal changes in lung function, including clinical markers for distinctly poor outcome with regard to lung function, in children and adults suffering from asthma. The majority of patients with asthma have a good prognosis. However, some patients with asthma, especially those with more severe disease, are at risk of impaired growth of lung function during childhood, a lower maximally attained level of lung function and excessive decline in lung function in adulthood, which may lead to life‐threatening lung function impairment. Clinical markers of poorly controlled airway inflammation appear to have a negative impact on the longitudinal changes in lung function, and disease progression to nonreversible airflow obstruction may be observed in a minority of patients with asthma. Early intervention with anti‐inflammatory therapy may improve the short‐term outcome of asthma, but long‐term controlled studies are clearly needed in order to verify whether or not treatment, especially with inhaled corticosteroids, according to the current international guidelines alters the natural history of asthma, i.e. disease progression with regard to changes in lung function and possible development of nonreversible airflow obstruction.

Nonreversible airflow obstruction in life-long nonsmokers with moderate to severe asthma. C.S. Ulrik, V. Backer. #ERS Journals Ltd 1999. ABSTRACT: The aim of this longitudinal study was to assess the frequency of nonreversible airflow obstruction (NRAO) among adults with moderate to severe asthma, and to compare the decline of forced expiratory volume in one second (FEV1) in asthmatics with reversible and nonreversible airflow obstruction.Ninety-two (31 males) life-long nonsmokers with asthma participated in a 10-yr follow-up study; mean age 37 yrs (range 18±64) and duration of asthma 16 yrs (range 2±60) at enrolment. Case history, including use of asthma medication, was obtained, and pulmonary function, including diffusion capacity, was measured using standard techniques. At enrolment, all patients had typical symptoms and reversible airflow obstruction. (NRAO) was defined as FEV1 <80% predicted and change in DFEV1 after 5 mg salbutamol <9% pred.A total of 21 (23%) patients (mean age at enrolment 32 yrs) fulfilled the criteria for NRAO at the time of follow-up; current therapy was inhaled steroids (n=21, mean daily dose 1.5 mg), oral steroids (n=14), theophylline (n=20), oral b 2 -agonist (n=6) and inhaled b 2 -agonist. The patients with NRAO (n=21) had a steeper decline in FEV1 than the remaining patients (n=71, reversible airflow obstruction (RAO)), mean SD 53 23 mL . yr -1 and 36 21 mL . yr -1 , respectively (p<0.003). Increasing degree of bronchodilator reversibility (DFEV1% pred) at enrolment (p=0.002) and long-term treatment with oral corticosteroids (p=0.009) were associated with an increased risk for the presence of NRAO at follow-up. The comparison of data for NRAO and RAO patients (at follow-up) revealed no significant differences in mean values for total diffusion capacity (TL,CO), diffusion constant (KCO), or total lung capacity.The findings suggest that a subgroup of asthmatics may experience very steep rates of decline in forced expiratory volume in one second leading to severe nonreversible airflow obstruction, whereas no indication was found that long-standing asthma may lead to the development of emphysema.

Background: Inhaled corticosteroids (ICS) constitute the cornerstone of treatment for asthma. Many studies have reported beneficial short term effects of these drugs, but there are few data on the long term effects of ICS on the decline in forced expiratory volume in 1 second (FEV 1 ). This study was undertaken to determine whether adults with asthma treated with ICS have a less pronounced decline in FEV 1 than those not treated with ICS. Methods: Two hundred and thirty four asthmatic individuals from a longitudinal epidemiological study of the general population of Copenhagen, Denmark were divided into two groups; 44 were treated with ICS and 190 were not treated with ICS. The annual decline in FEV 1 was measured over a 10 year follow up period. Results: The decline in FEV 1 in the 44 patients receiving ICS was 25 ml/year compared with 51 ml/year in the 190 patients not receiving this treatment (p,0.001). The linear regression model with ICS as the variable of interest and sex, smoking, and wheezing as covariates showed that treatment with ICS was associated with a less steep decline in FEV 1 of 18 ml/year (p = 0.01). Adjustment for additional variables including age, socioeconomic status, body mass index, mucus hypersecretion, and use of other asthma medications did not change these results. Conclusions: Treatment with ICS is associated with a significantly reduced decline in ventilatory function.

Background Little is known about the factors that determine outcome in asthma. The purpose of this study was to describe the relation of various factors of potential importance to the rate of decline in lung function in adults with intrinsic and extrinsic asthma. Methods Of 180 asthmatic patients, 143 (79%) participated in a 10 year follow up examination. At the time of enrolment all patients underwent certain tests for asthma (case history, total IgE, skinprick tests, the radioallergosorbent test (RAST), histamine release from basophil leucocytes, and specific bronchial provocations). On the basis of these tests 94 patients had intrinsic asthma and 49 extrinsic asthma. Results Patients with intrinsic asthma had an annual decline in FEV, of 50 ml, whereas those with extrinsic asthma had a decline of 22 5 ml; the rate of decline of lung function increased with increasing age in both groups. An inverse relation between initial FEV, and decline in FEV, (the "horse racing effect") was found for the patients with extrinsic asthma but not for the patients with intrinsic asthma. There was no relation between rate of decline in lung function and number of cigarettes smoked. A high degree of airway variability-that is, reversibility in FEV1-at the time of enrolment was found to be associated with a steeper decline in lung function in patients with intrinsic asthma, whereas increasing degrees of obstruction