Table 1. Basic characteristics of CKB research subjects.
| Variables | Total | DM | Non-DM | P-value |
| Abbreviation: DM=diabetes mellitus; BMI=body mass index; PA=physical activity; CKB=China Kadoorie Biobank. * Low, medium, and high level of education in CKB refers to primary school and below, secondary school and college and above. † Other chronic medical history includes cardiovascular disease, chronic obstructive pulmonary disease, and hypertension. | ||||
| n | 24,494 | 3,107 | 21,387 | |
| Age (years，  ) |
65.5±9.1 | 65.5±9.1 | 65.5±9.1 | <0.001 |
| Male (%) | 35.6 | 66.9 | 36.0 | 0.001 |
| Region (%) | <0.001 | |||
| Urban | 49.7 | 39.7 | 41.0 | |
| Rural | 50.3 | 60.3 | 59.0 | |
| Education level* (%) | 0.032 | |||
| Low | 54.1 | 51.6 | 51.9 | |
| Medium | 41.9 | 43.8 | 43.6 | |
| High | 4.0 | 4.6 | 4.5 | |
| Occupation (%) | <0.001 | |||
| Employed | 24.8 | 37.5 | 36.0 | |
| Retired/unemployed | 75.2 | 62.5 | 64.0 | |
| Smoking (%) | <0.001 | |||
| Never | 74.6 | 71.1 | 71.5 | |
| Previous | 8.2 | 7.3 | 7.4 | |
| Current | 17.2 | 21.6 | 21.1 | |
| Drinking (%) | <0.001 | |||
| Never | 70.6 | 65.8 | 66.4 | |
| Previous | 4.3 | 3.2 | 3.4 | |
| Current | 25.1 | 31.0 | 30.2 | |
| Sleep duration (h, %) | <0.001 | |||
| ≤6 | 37.6 | 34.1 | 34.5 | |
| 7–8 | 42.6 | 47.0 | 46.4 | |
| ≥9 | 19.8 | 18.9 | 19.1 | |
| BMI (kg/m2, %) | <0.001 | |||
| Low and normal | 38.4 | 47.6 | 46.4 | |
| Overweight | 42.9 | 38.4 | 38.9 | |
| Obesity | 18.7 | 14.0 | 14.7 | |
| Other chronic disease history† (%) |
45.0 | 67.2 | 41.8 | <0.001 |
| Low-level PA (%) | 33.3 | 39.8 | 32.3 | <0.001 |