Table 1 Demographic characteristics of the study population (n = 1024)
Characteristics | Exposure region (n = 611) | Reference region (n = 413) | P-value |
|---|---|---|---|
Age (years) | 54.18 ± 8.68 | 54.60 ± 8.31 | 0.447a |
Gender, n (%) | Â | Â | 0.873b |
 Male | 299 (48.9) | 200 (48.4) |  |
 Female | 312 (51.1) | 213 (51.6) |  |
Height (cm) | 162.86 ± 8.31 | 162.66 ± 10.01 | 0.728a |
Weight (kg) | 69.36 ± 11.93 | 67.84 ± 10.94 | 0.039a |
Body mass index (BMI, kg/m2) | 25.96 (23.75, 28.24) | 25.47 (23.13, 27.64) | 0.032c |
Smoking, n (%) | Â | Â | 0.013b |
 Never smoker | 410 (67.1) | 283 (68.5) |  |
 Ex-smokers/Former smoker | 38 (6.2) | 43 (10.4) |  |
 Current smoker | 163 (26.7) | 87 (21.1) |  |
Alcohol consumption, n (%) | |||
 Never drink | 431 | 281 | 0.579b |
 Ex-drinker/Former drinker | 23 | 20 |  |
 Current drinker | 157 | 112 |  |
Family monthly income level per capita (CNY), n (%) | Â | Â | < 0.001b |
  < 500 | 117 (19.2) | 199 (48.2) |  |
 500–999 | 245 (40.2) | 120 (29.1) |  |
 1000–1999 | 174 (28.5) | 61 (14.8) |  |
 2000–2999 | 33 (5.4) | 22 (5.3) |  |
  > 3000 | 41 (6.7) | 11 (2.7) |  |
Educational level, n (%) | Â | Â | 0.103b |
 Illiteracy | 26 (4.3) | 25 (6.1) |  |
 Primary school | 130 (21.3) | 100 (24.2) |  |
 Middle school | 246 (40.3) | 175 (42.4) |  |
 Secondary school or high school | 168 (27.5) | 95 (23.0) |  |
 College/university | 41 (6.7) | 17 (4.1) |  |
 Master and above | 0 (0.0) | 1 (0.2) |  |