Table 1. Baseline characteristics by level of education.
| Variable* | Highest education |
|||||
|---|---|---|---|---|---|---|
| No formal school (n=95,221) | Primary school (n=165,216) | Middle school (n=144,913) | High school (n=77,527) | Technical/college (n=18,294) | University (n=11,720) | |
| Age (SD), year | 52.3 (10.2) | 51.8 (4.4) | 51.1 (3.6) | 51.2 (5.0) | 51.0 (8.1) | 50.9 (8.1) |
| Female, % | 83.3 | 60.4 | 47.1 | 43.6 | 33.2 | 27.1 |
| Socioeconomic and lifestyle factors | ||||||
| Urban region, % | 20.5 | 26.5 | 56.1 | 74.6 | 89.9 | 93.9 |
| Household income ≥35 000 RMB/year, % | 9.6 | 12.3 | 17.8 | 27.3 | 43.6 | 54.8 |
| Ever regular smoking, % | ||||||
| Male | 69.6 | 71.5 | 68.6 | 61.8 | 51.5 | 43.2 |
| Female | 5.3 | 4.0 | 2.4 | 1.5 | 1.2 | 0.2 |
| Weekly drinking, % | ||||||
| Male | 31.9 | 33.7 | 33.7 | 31.2 | 30.3 | 29.5 |
| Female | 2.3 | 1.8 | 2.0 | 1.8 | 2.0 | 2.0 |
| Total physical activity (SD), MET-h/day | 20.4 (14.3) | 21.1 (14.3) | 20.7 (14.3) | 19.3 (12.7) | 17.3 (9.0) | 17.3 (8.1) |
| Sedentary leisure time (SD), h/day | 2.8 (1.7) | 3.0 (1.5) | 3.2 (1.5) | 3.3 (1.5) | 3.4 (1.5) | 3.3 (1.5) |
| Daily intake, % | ||||||
| Fresh fruits | 11.7 | 14.6 | 21.0 | 28.2 | 40.0 | 41.7 |
| Fresh vegetables | 93.1 | 94.3 | 95.3 | 95.9 | 97.1 | 98.3 |
| Red meat | 23.8 | 26.8 | 30.6 | 35.4 | 43.7 | 46.0 |
| Blood pressure and anthropometry | ||||||
| SBP (SD), mmHg | 133.3 (23.3) | 131.6 (21.4) | 130.4 (19.4) | 129.3 (19.2) | 127.6 (19.2) | 126.1 (19.3) |
| RPG (SD), mmol/L | 6.2 (2.5) | 6.1 (2.4) | 6.1 (2.3) | 6.0 (2.1) | 6.1 (2.2) | 6.0 (2.2) |
| BMI (SD), kg/m2 | 23.7 (3.5) | 23.7 (3.4) | 23.7 (3.3) | 23.7 (3.3) | 23.8 (3.2) | 23.9 (3.2) |
| Waist circumference (SD), cm | 80.3 (10.0) | 80.6 (9.7) | 80.5 (9.6) | 80.4 (9.7) | 80.7 (9.9) | 81.1 (10.0) |
| Hip circumference (SD), cm | 90.5 (6.8) | 90.9 (6.7) | 91.2 (6.8) | 91.4 (6.6) | 92.0 (6.2) | 92.5 (6.3) |
| Waist to hip ratio (SD) | 0.89 (0.07) | 0.89 (0.07) | 0.88 (0.07) | 0.88 (0.07) | 0.88 (0.08) | 0.88 (0.07) |
| Body fat percentage (SD), % | 28.1 (8.8) | 28.1 (8.9) | 28.1 (8.1) | 27.9 (7.6) | 28.2 (6.9) | 27.8 (6.8) |
| BMI at age 25, kg/m2 | 22.2 (2.8) | 22.2 (2.6) | 21.9 (2.5) | 21.6 (2.5) | 21.3 (2.4) | 21.2 (2.4) |
| Height (SD), cm | 157.3 (7.2) | 158.1 (7.8) | 159.0 (8.0) | 159.8 (8.0) | 160.8 (7.8) | 161.3 (7.9) |
| HBsAg positive, % | 3.3 | 3.3 | 3.0 | 2.8 | 2.6 | 1.9 |
Abbreviations: BMI=body mass index, MET=metabolic equivalent of task, RPG=random plasma glucose, SBP=systolic blood pressure.
*
Results were standardised by age, sex, and region (where appropriate). Values are means unless otherwise stated.
P-values for trend: all <0.001 except for weekly drinking in females (0.38).