Asthma-COPD Overlap Phenotypes and Smoking :Comparative features of asthma in smoking or non-smoking patients with an incomplete reversibility of airway obstruction

Figures & data

Figure 1. Flowchart of study participants.

Table 1. Subjects' demographics.

	ACO	NS-IRAO	P
Number of subjects	75	40
Women/Men	47/28	15/25	0.01
Age (years), mean ± SD (range)	61 ± 10 (44–84)	64 ± 9 (44–78)	0.141
BMI (kg/m^2)	29 ± 6	28 ± 5	0.438
Smoking history, n (%)			<0.001
Never smokers	0	28 (70)
Ex-smokers	60 (80)	12 (30)
Smokers	15 (20)	0
Pack-years	36 ± 13	3 ± 2	<0.001
Asthma duration (years)	23 ± 17	35 ± 21	0.006
Asthma severity			0.862
Mild	3 (4)	1 (3)
Moderate	39 (52)	19 (48)
Severe	33 (44)	20 (50)
Dose of ICS (mcg/day, equivalent beclomethasone)	715 ± 362	801 ± 424	0.537
ICS+LABA	67 (89)	35 (88)	0.806
LABA	5 (7)	5 (0.1)	0.867
LTRA	14 (19)	11 (28)	0.173
Anti-IgE	0	0	1.0
LAMA	39 (52)	6 (15)	<0.001
SAMA	3 (4)	0	0.867
SABA^*	15 (20)	5 (13)	0.005
Prednisone	0	0	1.0
Acute care use in the previous year
mean ± SD/patient (total number of events)
Unscheduled medical visits related to respiratory problems	0.4 ± 0.8 (29)	0.3 ± 0.5 (10)	0.519
Emergency room visits (<24 hours)	0.5 ± 1.4 (39)	0.2 ±0.4 (7)	0.226
Hospitalisations (>24 hours)	0.1 ± 0.4 (8)	0.0 ± 0.2 (1)	0.315
Health care use
mean ± SD/patient (total number of events)
Oral corticosteroids in the previous year	0.8 ± 1.2 (64)	0.4 ± 0.6 (15)	0.04
Atopy (yes)	53 (71)	33 (83)	0.454
Family history of asthma (yes)	39 (52)	22 (55)	0.885
Family history of allergy (yes)	29 (39)	22 (55)	0.181

Results are presented as mean ± SD for continuous variables or as number (%) of patients for categorical variables unless stated otherwise.

^* Patients not having a SABA as rescue medication were using their combined ICS-LABA as rescue medication.

ACO: asthma-COPD overlap, ACSS: asthma control scoring system, BMI: body mass index, ICS: inhaled corticosteroid, LABA: long-acting beta-agonist, LAMA: long-acting muscarinic antagonist, LTRA: leukotriene receptor antagonist, NS-IRAO: non-smoking patients with incomplete reversibility of airway obstruction, SABA: short-acting beta-agonist, SD: standard deviation.

Table 2. Comparative scores of asthma control and asthma quality of life questionnaires.

	ACO	NS-IRAO	P
Asthma Control Questionnaire
Total	1.8 ± 0.9	1.4 ± 0.9	0.02
Asthma Control Scoring System
Clinical	76 ± 17	86 ± 17	<0.001
Daytime symptoms	17 ± 6	20 ±5	0.02
Nighttime symptoms	23 ± 4	23 ± 4	0.446
Rescue medication need	20 ± 7	22 ± 5	0.126
Activity limitation	15 ± 7	20 ± 7	<0.001
Physiologic	33 ± 16	37 ± 19	0.443
Inflammatory	59 ± 26	53 ± 30	0.518
Total	56 ± 13	60 ± 14	0.103
Asthma Quality of Life Questionnaire
Symptoms	5.4 ± 1.1	5.9 ± 1.1	0.01
Activity limitations	4.9 ± 1.2	5.8 ± 1.2	0.001
Emotions	5.3 ± 1.6	6.0 ± 1.4	0.080
Environment	5.5 ± 1.2	5.9 ± 1.3	0.091
Total	5.3 ± 1.0	5.9 ± 1.0	0.003

Results are presented as mean ± SD.

ACO: asthma-COPD overlap, NS-IRAO: non-smoking patients with incomplete reversibility of airway obstruction

Table 3. Pulmonary function in ACO and NS-IRAO.

	ACO	NS-IRAO	P
Spirometry
FEV1 (% predicted)	56 ± 13	61 ± 11	0.151
FVC (% predicted)	80 ± 14	81 ± 12	0.643
FEV1/FVC	0.56 ± 0.08	0.58 ± 0.06	0.164
Reversibility to BD (%)	14 ± 11	12 ± 10	0.827
Lung volumes
TLC (% predicted)	107 ± 16	101 ± 11	0.081
FRC (% predicted)	112 ± 25	105 ± 20	0.187
RV (% predicted)	145 ± 45	121 ± 29	0.008
DLCO (% predicted)	75 ± 19	89 ± 22	0.01
KCO (% predicted)	90 ± 22	108 ± 20	<0.001

Results are presented as mean ± SD.

ACO: asthma-COPD overlap, BD: bronchodilator, D_LCO: single-breath diffusing capacity for carbon monoxide, FEV₁: forced expiratory volume in one second, FRC: functional residual capacity, FVC: forced vital capacity, KCO: diffusing capacity for carbon monoxide corrected for alveolar volume, RV: residual volume, TLC: total lung capacity, NS-IRAO: non-smoking patients with incomplete reversibility of airway obstruction.

Table 4. Lower airway and systemic inflammation in ACO and NS-IRAO.

	ACO	NS-IRAO	P
Lower airway
FeNO (ppb)	17.9 ± 12.7	24.5 ± 19.0	0.086
Induced sputum
N	47	23
Total cell count (×10^6/mg)	9.2 (7.0–15.7)	6.1 (3.7–12.3)	0.122
Eosinophils (%)	2.3 (0.5–7.3)	4.0 (0.8–23.3)	0.245
Neutrophils (%)	54.8 (37.6–75.9)	51.2 (28.5–75.6)	0.421
Systemic
White blood cell (×10^9/L)	7.9 ± 1.7	7.5 ± 1.4	0.214
Hemoglobin (g/L)	139 ± 12	142 ± 13	0.984
Eosinophils (×10^9/L)	0.23 ± 0.17	0.26 ± 0.23	0.824
Neutrophils (×10^9/L)	5.0 ± 1.5	5.0 ± 1.2	0.928
Fibrinogen (g/L)	3.5 ± 0.9	3.5 ± 0.8	0.454
Total IgE (IU/mL)	96 (27–254)	127 (63–295)	0.475
CRP (mg/mL)	3.7 ± 3.9	2.8 ± 3.0	0.251
Alpha-1 antitrypsin (g/L)	1.1 ± 0.2	1.1 ± 0.2	0.323

Results are presented as mean ± SD except for induced sputum counts and total IgE which are presented as median (25–75 percentile).

ACO: asthma-COPD overlap, CRP: C-reactive protein, FeNO: exhaled nitric oxide, g: gram, IgE: immunoglobulin E, IU: international unit, L: liter, mg: milligram, mL: milliliter, NS-IRAO: non-smoking patients with incomplete reversibility of airway obstruction, ppb: part per billion, WBC: white blood cells.

Figure 2. Correlations between pre- and post-BD FEV₁ (% predicted) and ACSS and ACQ in smoking IRAO and non-smoking IRAO.

ACSS: asthma control scoring system, ACQ: asthma control score, BD: bronchodilator, FEV₁: forced expiratory volume in one second, NS-IRAO: non-smoking patients with incomplete reversibility of airway obstruction.