Table 3.
Socio-Demographic and Clinical Characteristics of the Participants at Stage 2
| Total (N = 148) | Asthma (N = 46) | No Asthma (N = 102) | P-value | |
|---|---|---|---|---|
| Age, median (IQR, range) | 60 (46–68) [19–89] | 51 (39–67) [19–82] | 63 (48–68) [19–89] | 0.02* |
| Male, N (%) | 64 (43.2) | 20 (43.4) | 44 (43.1) | 0.31 |
| Marital status, N (%) | 0.46 | |||
| Married/partnership | 105 (71.0) | 29 (63.0) | 76 (74.5) | |
| Single | 20 (13.5) | 9 (19.6) | 11 (10.8) | |
| Divorced/separated | 11 (7.4) | 4 (8.7) | 7 (6.8) | |
| Widowed | 12 (8.1) | 4 (8.7) | 8 (7.8) | |
| Education, grade, N (%) | 0.47 | |||
| ≤9th | 56 (37.8) | 14 (30.4) | 42 (41.2) | |
| 10th–12th | 58 (39.2) | 18 (39.1) | 39 (38.2) | |
| >12th | 34 (23.0) | 14 (30.4) | 20 (19.6) | |
| Occupational status, N (%) | 0.18 | |||
| Employee | 68 (45.9) | 26 (56.5) | 42 (41.1) | |
| Retired | 58 (39.2) | 15 (32.6) | 43 (42.2) | |
| Unemployed | 17 (11.5) | 2 (4.3) | 13 (13.0) | |
| Student | 3 (2.0) | 2 (4.3) | 1 (1.0) | |
| Other | 2 (1.5) | 1 (2.2) | 3 (3.0) | |
| BMI, kg/m2 median (IQR) | 27 (24–30) | 28 (24–30) | 26 (24–30) | 0.48 |
| BMI, classification N (%) | 0.74 | |||
| Underweight (<18.5) | 1 (0.7) | - | 1 (1.0) | |
| Normal weight (18.5–24.9) | 50 (33.8) | 17 (37) | 33 (32.4) | |
| Overweight (25–29.9) | 58 (39.2) | 15 (32.6) | 43 (42.2) | |
| Obese (>30) | 39 (26.4) | 14 (30.4) | 25 (24.5) | |
| Insufficiently active, N (%) | 90 (60.8) | 25 (54.3) | 65 (64.0) | 0.28 |
| Smoking status, N (%) | 0.26 | |||
| Former smoker | 45 (30.4) | 14 (30.4) | 31 (30.3) | |
| Current smoker | 34 (23.0) | 5 (10.9) | 29 (28.4) | |
| Never-smoked | 69 (46.6) | 27 (58.7) | 42 (41.2) | |
| ETS, N (%) | 39 (26.4) | 9 (19.6) | 30 (29.4) | 0.23 |
| Asthma family History, N (%) | 79 (53.4) | 31 (67.4) | 48 (47.0) | 0.39 |
| Comorbidities, N (%) | ||||
| Atopic dermatitis | 19 (12.8) | 6 (13.0) | 13 (12.7) | 0.31 |
| OSA | 10 (6.8) | 2 (4.3) | 8 (7.8) | 0.20 |
| GERD | 39 (26.4) | 9 (19.6) | 30 (29.4) | 0.23 |
| Heart failure | 10 (6.8) | 1 (2.2) | 9 (8.8) | 0.10 |
| Anxiety/depression | 60 (40.5) | 16 (34.8) | 44 (43.1) | 0.26 |
| Others | 98 (66.2) | 31 (67.4) | 67 (66.0) | 0.34 |
| Childhood respiratory symptoms, N (%) | 33 (22.3) | 19 (41.3) | 14 (13.7) | 0.58 |
| FeNO (ppb), N (%)a | <0.01* | |||
| <25 | 87 (58.8) | 14 (30.4) | 73 (71.6) | |
| [25–50] | 41 (27.7) | 20 (43.5) | 21 (20.6) | |
| >50 | 12 (8.1) | 9 (19.6) | 3 (2.9) | |
| Eosinophils, N (%)b | <0.01* | |||
| >0.3 × 109/L | 12 (8.1) | 9 (19.6) | 3 (2.9) | |
| ≤0.3 × 109/L | 88 (59.5) | 25 (54.3) | 63 (61.8) | |
| Spirometry parametersc | ||||
| Pre-bronchodilator, mean (SD) | ||||
| FEV1% predicted | 90 (20.0) | 86 (23.9) | 91 (17.9) | 0.25 |
| FVC % predicted | 90 (20.1) | 91 (24.2) | 90 (16.2) | 0.84 |
| FEV1/FVC (%) | 79 (7.8) | 77 (8.7) | 79 (7.7) | 0.13 |
| Post-bronchodilator, mean (SD) | ||||
| FEV1% predicted | 93 (19.0) | 92 (23.7) | 93 (16.6) | 0.79 |
| FVC % predicted | 92 (18.1) | 93 (24.7) | 91 (14.4) | 0.57 |
| FEV1/FVC (%) | 80 (8.0) | 79 (8.9) | 81 (7.5) | 0.32 |
| Positive bronchodilator response, N (%) | 10 (6.8.) | 6 (13.0) | 4 (3.9) | 0.60 |
Notes: *p<0.05; aParticipant refused test or experienced test fatigue (N = 8); bEquipment failure did not record value (N = 48); cParticipants did not meet the absolute contraindications for performing spirometry (N = 5). Positive bronchodilator response was defined as post-bronchodilator increase of ≥12% and an absolute change of >200 mL from the baseline FEV1.
Abbreviations: BMI, body mass index; ETS, environmental tobacco smoke; OSA, obstructive sleep apnoea; GERD, gastroesophageal reflux disease; FeNO, concentration of exhaled nitric oxide; FEV1, forced exhalation volume in one second; FVC, forced vital capacity.