Table 3 The baseline characteristics of all participants in the WHZH cohort
Variables | Total (n = 4812) | Wuhan (n = 3053) | Zhuhai (n = 1759) |
|---|---|---|---|
Gender, (female, n (%)) | 3252 (67.6) | 1973 (64.6) | 1279 (72.7) |
Age (years) | 53.1 (13.0) | 53.0 (13.3) | 53.3 (12.4) |
Age (years), n (%) | Â | Â | Â |
  18-44 | 1256 (26.1) | 796 (26.1) | 460 (26.2) |
  45-59 | 2068 (43.0) | 1315 (43.1) | 753 (42.8) |
  60-80 | 1488 (30.9) | 942 (30.9) | 546 (31.0) |
Education, n (%) | Â | Â | Â |
  Primary school or illiteracy | 1219 (25.3) | 644 (21.1) | 575 (32.7) |
  Middle school | 1655 (34.4) | 1067 (34.9) | 588 (33.4) |
  High school | 1338 (27.8) | 965 (31.6) | 373 (21.2) |
  University or college or higher | 600 (12.5) | 377 (12.3) | 223 (12.7) |
Income (Yuan/year) # , n (%) | Â | Â | Â |
  ≤39999 | 2642 (54.9) | 1856 (60.8) | 786 (44.7) |
  40000-119999 | 1886 (39.2) | 1104 (36.2) | 782 (44.5) |
  ≥120000 | 201 (4.2) | 57 (1.9) | 144 (8.2) |
  Missing, n (%) | 83 (1.7) | 36 (1.2) | 47 (2.7) |
Current smoker, n (%) | 795 (16.5) | 597 (19.2) | 198 (11.3) |
Current drinker, n (%) | 666 (13.8) | 537 (17.6) | 129 (7.3) |
Physical activity, (yes, n (%)) | 2346 (48.8) | 1353 (44.3) | 993 (56.4) |
BMI (kg/m 2 ) | 24.0 (3.5) | 24.1 (3.4) | 23.7 (3.5) |
Waist circumference (cm) | 818.7 (97.6) | 820.9 (97.7) | 814.8 (97.3) |
Blood pressure (mmHg) | Â | Â | Â |
  Systolic blood pressure | 131.5 (20.3) | 131.0 (20.5) | 132.4 (20.0) |
  Diastolic blood pressure | 77.4 (15.0) | 76.6 (16.8) | 78.7 (11.2) |
  Missing, n (%) | 60 (1.2) | 37 (1.2) | 23 (1.3) |
Exhaled carbon monoxide (μg/L) | 7.7 (9.9) | 8.5 (11.0) | 6.3 (7.4) |
  Missing, n (%) | 27 (0.6) | 0 (0%) | 27 (1.5) |
Exhaled nitrogen oxide (ppb) | 24.9 (17.3) | 27.2 (16.3) | 20.9 (18.4) |
  Missing, n (%) | 228 (4.7) | 121 (4.0) | 107 (6.1) |
Lung function | Â | Â | Â |
  FVC (ml) | 2479.6 (698.9) | 2566.5 (711.7) | 2327.9 (649.0) |
  FEV1 (ml) | 2159.4 (610.7) | 2200.8 (615.1) | 2087.2 (596.4) |
  FEV1/FVC (%) | 87.5 (8.9) | 86.9 (9.2) | 89.9 (7.7) |
  Missing, n (%) | 107 (2.2) | 62 (2.0) | 45 (2.6) |
Heart rate variable | Â | Â | Â |
  TP (msec2) | 809.4 (461.8, 1413.8) | 818.0 (464.8, 1413.6) | 798.8 (450.9, 1417.3) |
  LF (msec2) | 218.8 (107.1, 418.4) | 219.0 (107.7, 426.2) | 218.8 (106.3, 406.2) |
  HF (msec2) | 119.7 (56.4, 250.8) | 125.8 (59.9, 259.9) | 110.8 (51.1, 234.6) |
  Missing, n (%) | 315 (6.5) | 203(6.6) | 112(6.4) |