Table 1. Characteristics of the participants.
| All (n = 1668) | Male (n = 779) | Female (n = 889) | P | |
|---|---|---|---|---|
| Age (years), Mean ± SD | 46.5 ± 12.3 | 46.5 ± 12.1 | 46.6 ± 12.5 | 0.8934 |
| Age (years) group, (%) | 0.5368 | |||
| 30~ | 35.7 | 35.3 | 36.1 | |
| 40~ | 27.9 | 29.0 | 26.6 | |
| 50~ | 19.8 | 18.6 | 21.2 | |
| 60~ | 11.3 | 11.3 | 11.3 | |
| 70~ | 5.4 | 5.9 | 4.9 | |
| Occupation, (%) | 0.0063 | |||
| Nomad | 38.2 | 38.4 | 38.0 | |
| Farmer | 50.2 | 52.6 | 48.1 | |
| Citizen | 11.6 | 9.0 | 13.8 | |
| Education attainment, (%) | 0.0010 | |||
| Primary school or below | 30.3 | 30.8 | 29.8 | |
| Middle school | 45.3 | 48.8 | 42.2 | |
| High school and above | 24.4 | 20.4 | 28.0 | |
| Family annual income (RMB), (%) | 0.6685 | |||
| <10 000 | 53.2 | 52.0 | 54.2 | |
| 10 000–39999 | 41.2 | 42.0 | 40.4 | |
| ≥40 000 | 5.7 | 6.0 | 5.5 | |
| BMI group, (%)* | <0.0001 | |||
| Normal | 35.5 | 40.0 | 31.6 | |
| Overweight | 32.0 | 33.7 | 30.5 | |
| Obesity | 32.5 | 26.3 | 37.8 | |
| Salt intake (g), Median (IQR) | 16.5 (12.9–19.0) | 17.5 (13.8–20.1) | 15.7 (12.1–17.9) | <0.0001 |
| Smoking, (%) | <0.0001 | |||
| Yes | 35.9 | 73.0 | 3.5 | |
| No | 64.1 | 27.0 | 96.5 | |
| Drinking, (%) | <0.0001 | |||
| Yes | 13.4 | 28.4 | 0.2 | |
| No | 86.6 | 71.6 | 99.8 | |
| Family history of hypertension, (%) | 0.5303 | |||
| Yes | 55.3 | 54.2 | 56.2 | |
| No | 40.6 | 41.2 | 40.1 | |
| Unknown | 4.2 | 4.7 | 3.7 | |
| Personal history of Cardiac disease, (%) | <0.0001 | |||
| Yes | 12.8 | 7.6 | 17.4 | |
| No | 87.2 | 92.4 | 82.6 |
BMI: body mass index; RMB: renminbi; SD: standard deviation. *BMI groups: Normal < 24 kg/m2; Overweight 24–27.9 kg/m2; Obese ≥ 28 kg/m2.