Clinical, physiological, and radiological features of asthma–chronic obstructive pulmonary disease overlap syndrome

Figures & data

Figure 1 Flow chart for selecting study participants.

Abbreviations: ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; COPD, chronic obstructive pulmonary disease; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 1 Patients characteristics

	COPD (N=100)	ACOS (N=40)	P-value
Age, years	69.7±8.3	67.2±10.3	0.413
Body mass index, kg/m^2	22.8±3.3	22.9±4.7	0.970
Smoking, pack years	52.8±34.4	49.4±44.0	0.412
Male sex, %	87.0	85.0
Previously treated, N (%)	48 (48.0)	20 (50.0)
LAMA use, N (%)	10 (10.0)	4 (10.0)
LABA use, N (%)	32 (32.0)	14 (35.0)
ICS/LABA use, N (%)	6 (6.0)	2 (5.0)
Post-bronchodilator
VC, %predicted	88.7±16.5	88.0±16.0	0.976
FEV1, L	1.55±0.49	1.60±0.54	0.607
FEV1 %predicted	58.0±17.3	58.1±17.6	0.676
FEV1/FVC	53.6±11.0	52.1±11.1	0.399
RV, L	2.44±0.67	2.49±0.69	0.622
TLC, L	5.59±1.07	5.56±1.11	0.944
RV/TLC, %predicted	119.3±19.3	124.6±21.7	0.229
DLCO/VA, %predicted	70.7±19.9	79.9±23.6	0.044
Response to β2-agonist
ΔFEV1, mL	46.0±62.1	137.8±107.6	<0.001
% change in FEV1, %	3.54±4.80	11.6±9.0	<0.001

Note: Data are expressed as mean ± standard deviation.

Abbreviations: ACOS, asthma-chronic obstructive pulmonary disease overlap syndrome; COPD, chronic obstructive pulmonary disease; DL_CO/VA, diffusing capacity for carbon monoxide per liter of lung volume; FEV₁, forced expiratory volume in 1 second; ΔFEV₁, increases in forced expiratory volume in 1 second; FVC, forced vital capacity; ICS, inhaled corticosteroids; LABA, long-acting β-agonist; LAMA, long-acting muscarinic antagonist; RV, residual volume; TLC, total lung capacity; VC, vital capacity.

Figure 2 Comparison of CAT scores between COPD and ACOS patients.

Notes: Results for CAT scores were compared between ACOS and COPD patients by Mann–Whitney U-tests. Bars indicate standard errors.
Abbreviations: ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; CAT, chronic obstructive pulmonary disease assessment test; COPD, chronic obstructive pulmonary disease.

Figure 3 Comparison of radiological variable results between COPD and ACOS patients.

Notes: Results for radiological variables were compared between ACOS and COPD patients by Mann–Whitney U-tests. Bars indicate standard errors.
Abbreviations: ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; COPD, chronic obstructive pulmonary disease; %CSA <5, percentage of total cross-sectional area of pulmonary vessels less than 5 mm²; LAV%, percentage of low attenuation volume; WA%, percentage of wall area.

Table 2 Characteristics of the ACOS patients treated with budesonide/formoterol

Age, years	67.7±10.8
Body mass index, kg/m^2	22.8±3.7
Smoking, pack years	52.8±36.2
Male sex, %	70.0
CAT score	13.4±8.0
Post-bronchodilator
VC, %predicted	89.4±13.1
FEV1, L	1.45±0.58
FEV1 %predicted	57.2±17.5
FEV1/FVC	51.9±10.7
RV, L	2.59±1.21
TLC, L	5.74±2.48
RV/TLC, %predicted	125.4±17.6
DLCO/VA, %predicted	78.3±26.6

Note: Data are expressed as mean ± standard deviation.

Abbreviations: ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; CAT, chronic obstructive pulmonary disease assessment test; DL_CO/VA, diffusing capacity for carbon monoxide per liter of lung volume; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; RV, residual volume; TLC, total lung capacity; VC, vital capacity.

Figure 4 Changes in clinical variables after treatment with inhaled budesonide/formoterol.

Notes: Results for pulmonary function parameters, radiological parameters, and CAT scores were compared between pretreatment and 3 months after therapy with budesonide/formoterol using nonparametric Wilcoxon rank sum tests. Bars indicate standard errors.
Abbreviations: CAT, chronic obstructive pulmonary disease assessment test; %CSA <5, percentage of total cross-sectional area of pulmonary vessels less than 5 mm²; FEV₁, forced expiratory volume in 1 second; LAV%, percentage of low attenuation volume; PEF, peak expiratory flow; Post, 3 months after treatment with budesonide/formoterol; Pre, pretreatment with budesonide/formoterol; WA%, percentage of wall area.