Table 1 Demographic characteristics of participators at baseline
Characteristic | All participators | Tertile of blood Co (ppm) | P | ||
|---|---|---|---|---|---|
Tertile 1 (<0.635) | Tertile 2 (0.635 ~ 1.230) | Tertile 3 (>1.230) | |||
N | 771 | 257 | 257 | 257 | Â |
Age, years | 74.0 ± 0.32 | 74.15 ± 0.54 | 74.19 ± 0.56 | 73.67 ± 0.54 | 0.756 |
Male, n (%) | 567 (73.54) | 193 (75.10) | 193 (73.10) | 181 (70.43) | 0.383 |
BMI (kg/m2) | 22.19 ± 0.33 | 23.06 ± 0.33 | 22.68 ± 0.46 | 22.13 ± 0.16 | 0.095 |
Enrolled season, n (%) | Â | Â | Â | Â | 0.002 |
Spring | 176 (22.83) | 58 (22.57) | 70 (27.24) | 48 (18.68) | Â |
Summer | 119 (15.43) | 45 (17.51) | 39 (15.18) | 35 (13.62) | Â |
Autumn | 228 (29.57) | 63 (24.51) | 63 (24.51) | 102 (39.69) | Â |
Winter | 247 (32.04) | 90 (35.02) | 85 (33.07) | 72 (28.02) | Â |
Smoking status, n (%) | Â | Â | Â | Â | 0.019 |
None | 330 (42.80) | 118 (52.85) | 109 (41.06) | 103 (39.93) | Â |
Former | 230 (29.83) | 87 (28.14) | 75 (24.34) | 68 (34.60) | Â |
Current | 211 (26.37) | 52 (19.01) | 73 (34.60) | 86 (25.47) | Â |
Smoking amount, pack-year | 41.38 ± 0.58 | 35.26 ± 0.91 | 43.07 ± 0.85 | 46.36 ± 1.11 | 0.001 |
Self-cooking, n (%) | 594 (78.04) | 180 (70.04) | 203 (78.99) | 211 (82.10) | 0.003 |
Drinkers, n (%) | 245 (31.78) | 81 (31.52) | 80 (31.13) | 84 (32.68) | 0.925 |
Comorbidities, n (%) | Â | Â | Â | Â | Â |
Hypertension | 280 (36.32) | 88 (34.34) | 94 (36.58) | 98 (38.13) | 0.653 |
Diabetes mellitus | 78 (9.86) | 26 (10.12) | 16 (6.23) | 36 (14.01) | 0.014 |
Coronary disease | 119 (15.43) | 35 (13.62) | 45 (17.51) | 49 (19.07) | 0.227 |
Cerebrovascular diseases | 90 (11.67) | 24 (9.34) | 26 (10.12) | 40 (15.560) | 0.065 |
Inhaled drug for COPD, n (%) | Â | Â | Â | Â | Â |
SABA | 426 (55.25) | 116 (45.14) | 117 (45.53) | 193 (75.10) | <0.001 |
SAMA | 75 (9.73) | 21 (8.17) | 22 (8.26) | 32 (12.45) | 0.228 |
LABA | 321 (41.63) | 104 (40.47) | 104 (40.47) | 113 (43.97) | 0.649 |
LAMA | 132 (17.12) | 47 (18.29) | 47 (18.29) | 38 (14.79) | 0.493 |
ICS | 626 (81.19) | 202 (78.60) | 207 (80.54) | 217 (84.44) | 0.226 |
CC16 (pg/mL) | 0.55 (0.29, 1.04) | 0.98 (0.62, 1.35) | 0.50 (0.26, 0.89) | 0.34 (0.18, 0.54) | <0.001 |
Pulmonary function | Â | Â | Â | Â | Â |
FVC (L) | 2.29 ± 0.05 | 2.71 ± 0.07 | 2.36 ± 0.07 | 1.82 ± 0.07 | <0.001 |
FEV1 (L) | 1.80 ± 0.04 | 2.23 ± 0.08 | 1.73 ± 0.08 | 1.47 ± 0.06 | <0.001 |
FEV1/FVC (%) | 59.55 ± 0.82 | 65.67 ± 1.59 | 59.78 ± 1.43 | 54.37 ± 1.07 | <0.001 |
FEV1 (%) | 61.99 ± 1.74 | 79.29 ± 2.63 | 62.71 ± 2.40 | 43.50 ± 2.77 | <0.001 |