Analysis of pulmonary function characteristics between stable chronic obstructive pulmonary disease and asthma-chronic obstructive pulmonary disease overlap in the elderly males

Abstract

Objective To compare the characteristics of pulmonary function between stable chronic obstructive pulmonary disease (COPD) and asthma- COPD overlap syndrome (ACO) in the elderly males. Methods Three hundred and eighteen elderly male patients with stable COPD were followed up between January 2014 and December 2017. A11 patients underwent pulmonary function tests and bronchial dilation test (BDT) in the stable condition. According to the occurrence of ACO, the patients were divided into ACO group (54 cases) and non-ACO group (264 cases). The indexes of pulmonary function before and after BDT (T0 and T1) in two groups were statistically compared. Results Among 318 elderly male patients with stable COPD, ACO patients accounted for 17.0%(54/318). Compared with non-ACO group, at T0 ACO group had significantly lower values in forced vital capacity (FVC) pred [(83.5 ± 15.4)%vs. (93.9 ± 5.6)%], in forced expiratory volume in 1 second (FEV1) pred [(61.1 ± 13.6)% vs. (74.5 ± 12.0)%], in forced expiratory volume in 3 seconds (FEV3) pred [(70.5 ± 13.4)% vs. (81.8 ± 12.9)%] and in forced expiratory flow rat (FEF25%-75%) pred [(26.7 ± 8.5)%vs.(36.7 ± 10.2)%](P 0.05). And ACO group also had significantly higher values in residual volume pred [(138.9 ± 25.7)% vs. (117.5 ± 26.6)%] and in residual volume/total lung capacity [(55.8 ± 9.7)% vs. (45.1 ± 8.9)%] (P<0.05). Conclusions ACO is common in the elderly male patients with stable COPD, and ACO patients have lower time vital capacity as compared with non-ACO patients. But after bronchodilation test, the two groups have similar ventilation function, and the small airway function in ACO patients improves more significantly. Key words: Asthma; Pulmonary disease, chronic obstructive; Respiratory function tests