Table 1.
Demographics of subjects according to the group
| Normal | PRISm | Unrevealed COPD | P-value | P-value* | P-value+ | P-value‡ | |
|---|---|---|---|---|---|---|---|
| Age | 54.57 ± 10.52 | 55.97 ± 10.85 | 64.48 ± 9.54 | < 0.001 | 0.083 | < 0.001 | < 0.001 |
| Male, n (%) | 1560 (93.6) | 286 (91.4) | 654 (95.2) | 0.063 | 0.426 | 0.432 | 0.054 |
| Height (cm) | 167.14 ± 6.94 | 166.79 ± 6.94 | 165.97 ± 6.56 | < 0.001 | 0.998 | <.0.001 | 0.236 |
| Weight (kg) | 68.29 ± 9.91 | 68.66 ± 11.6 | 63.7 ± 9.8 | < 0.001 | 0.998 | < 0.001 | < 0.001 |
| Smoking history | |||||||
| Current smoking, n (%) | 858 (51.5) | 193 (61.7) | 367 (53.4) | 0.004 | 0.003 | 0.999 | 0.045 |
| Pack-years | 28.62 ± 17.11 | 33.20 ± 20.34 | 36.58 ± 21.14 | < 0.001 | < 0.001 | < 0.001 | 0.026 |
| Co-morbidity, n (%) | |||||||
| Hypertension | 453 (27.2) | 91 (29.1) | 209 (30.4) | 0.269 | 0.998 | 0.336 | 0.999 |
| Hyperlipidemia | 166 (10.0) | 34 (10.9) | 47 (6.8) | 0.035 | 0.998 | 0.048 | 0.092 |
| Stroke | 48 (2.9) | 14 (4.5) | 18 (2.6) | 0.252 | 0.414 | 0.999 | 0.368 |
| Acute coronary syndrome | 17 (1.0) | 8 (2.6) | 16 (2.3) | 0.019 | 0.077 | 0.042 | 0.999 |
| Diabetes mellitus | 174 (10.4) | 63 (20.1) | 84 (12.2) | < 0.001 | < 0.001 | 0.624 | 0.003 |
| Pulmonary tuberculosis | 124 (7.4) | 21 (6.7) | 109 (15.9) | < 0.001 | 0.999 | < 0.001 | < 0.001 |
| Asthma | 20 (1.2) | 15 (4.8) | 65 (9.5) | < 0.001 | < 0.001 | < 0.001 | 0.024 |
| Lung function test | |||||||
| FVC % predicted | 92.96 ± 10.02 | 72.55 ± 9.45 | 88.51 ± 15.02 | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
| FEV1% predicted | 94.66 ± 9.14 | 72.8 ± 6.72 | 74.18 ± 16.57 | < 0.001 | < 0.001 | < 0.001 | 0.035 |
| FEV1/FVC | 0.79 ± 0.05 | 0.77 ± 0.06 | 0.61 ± 0.09 | < 0.001 | < 0.001 | < 0.001 | 0.006 |
| Respiratory symptoms, n (%) | |||||||
| Cough for more than 3 months | 1 (0.1) | 2 (0.6) | 19 (2.8) | < 0.001 | 0.047 | < 0.001 | 0.091 |
| Sputum for more than 3 months | 4 (0.2) | 2 (0.6) | 18 (2.6) | < 0.001 | 0.999 | < 0.001 | 0.104 |
| Dyspnea | 10 (0.6) | 3 (1.0) | 31 (4.5) | < 0.001 | 0.999 | < 0.001 | 0.012 |
| Wheezing | 116 (7.0) | 37 (11.8) | 154 (22.4) | < 0.001 | 0.009 | < 0.001 | < 0.001 |
| Chronic bronchitis | 4 (0.2) | 2 (0.6) | 21 (3.1) | < 0.001 | 0.717 | < 0.001 | 0.054 |
| Total | 1666 | 313 | 687 | ||||
Data are presented as mean ± standard deviation or number (percentage)
* P-value for comparison between normal and PRISm group; + P-value for comparison between normal and unrevealed COPD group; ‡ P-value for comparison between PRISm and unrevealed COPD group
PRISm preserved ratio impaired spirometry, COPD chronic obstructive pulmonary disease, FEV1 forced expiratory volume for 1 s, FVC forced vital capacity