Table 1.
Baseline characteristics of participants by the number of chronic diseases
| Parameters | N of chronic diseases | P value for trend | |||||
| Total | 0 | 1 | 2 | 3 | ≥4 | ||
| Number (%) of participants | 512,723 | 246,309 (48.0) | 185,330 (36.1) | 61,800 (12.1) | 14,997 (2.9) | 4287 (0.8) | – |
| Socio-demographic factors | |||||||
| Age (years) | 52.0 (10.7) | 48.1 (9.6) | 54.1 (10.3) | 58.4 (9.8) | 61.1 (9.0) | 63.1 (8.3) | <0.001 |
| Women (%) | 59.0 | 60.9 | 57.1 | 56.9 | 59.2 | 62.4 | <0.001 |
| Urban area (%) | 44.1 | 43.0 | 42.0 | 49.0 | 59.4 | 73.4 | <0.001 |
| Middle school and higher (%) | 49.2 | 49.2 | 48.8 | 49.5 | 51.8 | 55.7 | <0.001 |
| Lifestyle factors | |||||||
| Male daily smoker∗ (%) | 67.7 | 68.1 | 67.2 | 67.5 | 67.1 | 69.1 | 0.016 |
| Female daily smoker∗ (%) | 2.8 | 2.8 | 2.9 | 2.8 | 3.1 | 3.0 | 0.094 |
| Male heavy drinker† (%) | 24.6 | 21.7 | 26.3 | 28.2 | 28.6 | 31.8 | <0.001 |
| Female heavy drinker† (%) | 1.5 | 1.4 | 1.6 | 1.7 | 1.7 | 1.7 | <0.001 |
| Eat fruits daily (%) | 18.8 | 19.0 | 18.5 | 18.8 | 19.5 | 20.1 | 0.795 |
| Eat vegetables daily (%) | 94.8 | 94.8 | 94.8 | 94.7 | 95.0 | 95.1 | 0.761 |
| Eat red meat 1−6 days/week (%) | 53.4 | 54.0 | 53.1 | 52.4 | 52.5 | 53.3 | <0.001 |
| Physical activity (MET h/day) | 21.1 | 21.7 | 21.1 | 19.4 | 18.4 | 17.8 | <0.001 |
| BMI (kg/m2) | 23.7 | 23.0 | 24.1 | 24.4 | 24.7 | 25.0 | <0.001 |
| Waist circumference (cm) | 80.3 | 78.5 | 81.4 | 82.7 | 83.7 | 84.5 | <0.001 |
| Prevalence of chronic diseases (%) | |||||||
| Hypertension | 35.2 | 0 | 63.0 | 77.6 | 83.1 | 86.0 | <0.001 |
| Diabetes | 5.9 | 0 | 4.6 | 23.0 | 35.7 | 45.3 | <0.001 |
| Coronary heart disease | 3.0 | 0 | 1.8 | 9.1 | 20.9 | 36.0 | <0.001 |
| Stroke or transient ischemic attack | 1.7 | 0 | 0.7 | 6.3 | 12.6 | 19.5 | <0.001 |
| Tuberculosis | 1.5 | 0 | 1.6 | 4.3 | 8.2 | 13.2 | <0.001 |
| Asthma | 0.5 | 0 | 0.4 | 1.8 | 5.3 | 11.8 | <0.001 |
| COPD | 7.2 | 0 | 8.5 | 22.9 | 34.5 | 44.7 | <0.001 |
| Gallstone disease | 6.0 | 0 | 6.8 | 19.4 | 32.6 | 47.6 | <0.001 |
| Peptic ulcer | 3.9 | 0 | 4.8 | 12.1 | 20.0 | 29.7 | <0.001 |
| Cirrhosis/chronic hepatitis | 1.2 | 0 | 1.4 | 4.0 | 8.0 | 14.5 | <0.001 |
| Chronic kidney disease | 1.5 | 0 | 1.5 | 4.6 | 8.8 | 17.2 | <0.001 |
| Cancer | 0.5 | 0 | 0.6 | 1.5 | 2.4 | 4.1 | <0.001 |
| Neurasthenia | 1.1 | 0 | 1.0 | 3.5 | 7.9 | 17.7 | <0.001 |
| Psychiatric disorder | 1.1 | 0 | 1.2 | 4.1 | 8.6 | 16.5 | <0.001 |
| Rheumatic arthritis | 2.1 | 0 | 2.1 | 6.5 | 12.5 | 23.2 | <0.001 |
Data are presented as n (%), mean (standard deviation), mean or percentage.
∗
Included former smokers who had quit smoking due to illness.
†
Heavy drinker refers to participants who drank >30 g/day pure alcohol for men or >15 g/day pure alcohol for women or those who had quit drinking. BMI: Body mass index; COPD: Chronic obstructive pulmonary disease; MET: Metabolic equivalent tasks.