Clinical characteristics of the overlap syndrome of asthma and COPD in older adults

BACKGROUND: There is little information about the overlapping diagnoses of asthma and COPD (overlap syndrome) in older people with asthma. Some of the refractory asthma in elderly could be associated with complication with COPD. We therefor examined the clinical features and treatment of patients with overlap syndrome in elderly. METHODS: In 52 outpatients with physician-diagnosed asthma aged 75 years and older, we performed chest high-resolution CT and assessed the presence of pulmonary emphysema (low attenuation area) according to the method of Bergin. For pulmonary function test, pre- and post-bronchodilator FEV 1 , peak expiratory flow (PEF), and carbon monoxide diffusing capacity of the lung (DLCO) were measured. In addition, the efficacy of adding tiotropium bromide to the treatment was examined. RESULTS: Of 52 patients, 29 had emphysema, where the frequency was higher in men than women (71% vs. 28%). Values for FEV 1 were not different between patients with and without COPD, but COPD (+) patients with moderate and severe asthma had significantly lower DLCO and reversibility of FEV 1 compared with COPD (–) patients. The duration of asthma was not related to FEV 1 or PEF, but inversely correlated with post-bronchodilator FEV 1 (p = 0.029) and with reversibility of FEV 1 (p = 0.037). Treatment with tiotropium for 8 weeks increased FEV 1 by 136 ± 29 ml. CONCLUSIONS: In our patient group, aging and asthma duration results in “fixed” or irreversible airflow obstruction, and addition of anticholinergic agent to the treatment should be considered.