Objectives To investigate the
incidence rate of
asthma and
chronic obstructive pulmonary disease (
COPD) overlap
syndrome(ACOS)in
elderly male patients with stable
COPD by following-up,and to explore the characteristics and
clinical significance of pulmonary function for ACOS.
Methods According to
GOLD and
Spain's guidelines for the
diagnosis and
treatment of
COPD,we screened ACOS
patients in 299
elderly male patients with stable
COPD by following up in
Beijing Hospital between 2003 and 2014.All
patients were divided into 2 groups of 51 ACOS
patients and 248 non-ACOS
patients with
COPD.All
patients underwent
pulmonary function tests and bronchial
dilation test in the stable condition.The differences in pulmonary functions were compared between stable ACOS
patients and non-ACOS
patients with
COPD.Results Among 299
elderly male patients with stable
COPD,ACOS
patients accounted for 17.1 % (51/299).Compared with nonACOS
patients with stable
COPD,ACOS
patients had significantly lower baseline values in
forced expiratory volume in 1 seconds(FEV1) [(61.0 ± 14.5) % pred vs.(74.4 ± 20.0) % pred],in
forced expiratory volume in 3 seconds(FEV3) [(71.6± 14.3)% pred vs.(82.7± 19.6)% pred]and in
forced vital capacity(FVC) [(84.6 ± 16.4)% pred vs.(93.8 ± 20.6)% pred],and also had significantly higher values in
residual volume(RV)[(139.4±55.8)% pred vs.(118.8±46.6)% pred]and in RV/
total lung capacity(TLC) [(52.7±10.7)% pred vs.(48.1±10.9)% pred],all P<0.05.After bronchodilation test,there was no significant difference in FEV1,FEV3 and FVC between the two groups(all P>0.05).
Patients with stable ACOS had lower value in forced expiratory flow
rat (FEF25%±75%)than those with non-ACOS in baseline [FEF25%-75% % pred(26.8± 11.5) % vs.(36.1 ±17.5) % (P<0.05)],and the improvement of small
airway function was significantly better in ACOS
patients than in non-ACOS
patients after bronchodilation test (P<0.05).Conclusions ACOS is very common in the
elderly patients with
COPD,stable ACOS
patients have lower
time vital capacity as compared with non-ACOS
patients with stable
COPD.But after bronchodilation test,the two groups have
similar ventilation function,and the small
airway function in ACOS
patients improves more significantly.The ACOS
patients have unique characteristics of pulmonary functions and suitable
treatment may improve the
prognosis.