Table 1. Baseline characteristics of never-smoker asthma patients with and without exposure to HD.
| Characteristics | HDA (n = 70) | Asthma without exposure to HD (n = 79) | P value | |
|---|---|---|---|---|
| Age, yr | 46.6 ± 15.3 | 51.8 ± 16.9 | 0.051 | |
| Sex (male) | 17a (24.3) | 14a (17.7) | 0.325 | |
| BMI, kg/m2 | 24.4 ± 4.3 | 25.1 ± 4.0 | 0.293 | |
| FEV1/FVC, % | 73.1 ± 13.8 | 70.6 ± 9.0 | 0.195 | |
| FVC% predicted | 83.2 ± 17.5 | 89.9 ± 16.4 | 0.018 | |
| FEV1% predicted | 75.8 ± 22.1 | 79.7 ± 15.5 | 0.208 | |
| FEF25-75% predicted | 66.1 ± 36.3 | 58.1 ± 26.8 | 0.132 | |
| DLCO% predicted | 81.9 ± 21.5 | 88.6 ± 13.2 | 0.021 | |
| DLCO/VA% | 101.5 ± 21.8 | 102.6 ± 14.1 | 0.748 | |
| DLCO/VA%, n (%) | 53 (75.7) | 79 (100.0) | ||
| TLC% predicted | 93.6 ± 13.1 | 98.7 ± 20.5 | 0.388 | |
| TLC% predicted, n (%) | 32 (45.7) | 15 (19.0) | ||
| RV/TLC (%) | 36.2 ± 15.7 | 32.4 ± 10.7 | 0.403 | |
| RV/TLC (%) | 32 (45.7) | 15 (19.0) | ||
| BPT positive%, n (%) | 14/25 (56.0) | 79/79 (100.0) | N/A | |
Data are presented as means ± standard deviation or absolute number (%). Bold font indicates statistical significance.
HD = humidifier disinfectant, HDA = humidifier disinfectant-associated asthma, BMI = body mass index, FEV1 = forced expiratory volume in one second, FVC = forced vital capacity, FEF25-75 = forced expiratory flow between 25% and 75% of vital capacity, DLCO = diffusing capacity of the lung for carbon monoxide, VA = alveolar volume, TLC = total lung capacity, RV = residual volume, BPT = bronchial provocation test, N/A = not applicable.
aNumber of patients with pulmonary function test results, i.e., number of patients who were able to obtain results.