Table 1 Baseline characteristics of the study population
|  | Overall (n = 4039) | Male (n = 2050) | Female (n = 1989) | P value |
|---|---|---|---|---|
Cognitive function | ||||
 Episodic memory | 3.71 (1.67) | 3.72 (1.62) | 3.69 (1.73) | 0.605 |
 Mental intactness | 8.01 (2.64) | 8.46 (2.41) | 7.54 (2.78) | < 0.001 |
 Global cognition | 11.71 (3.57) | 12.18 (3.30) | 11.23 (3.76) | < 0.001 |
Physical activity |  |  |  | < 0.001 |
 None | 468 (11.6) | 211 (10.3) | 257 (12.9) |  |
 Mild | 1002 (24.8) | 471 (23.0) | 531 (26.7) |  |
 Moderate | 1263 (31.3) | 577 (28.1) | 686 (34.5) |  |
 Vigorous | 1306 (32.3) | 791 (38.6) | 515 (25.9) |  |
Age (years) | 58.12 (9.12) | 59.26 (9.01) | 56.95 (9.10) | < 0.001 |
Education level | ||||
 Primary | 2536 (62.8) | 1128 (55.0) | 1408 (70.8) | < 0.001 |
 Secondary | 1421 (35.2) | 865 (42.2) | 556 (28.0) |  |
 Third | 82 (2.0) | 57 (2.8) | 25 (1.3) |  |
Marital status |  |  |  | < 0.001 |
 Married | 3613 (89.5) | 1874 (91.4) | 1739 (87.4) |  |
 Other | 426 (10.5) | 176 (8.6) | 250 (12.6) |  |
Residence |  |  |  | < 0.001 |
 Urban | 589 (22.3) | 251 (17.5) | 338 (28.0) |  |
 Rural | 2053 (77.7) | 1186 (82.5) | 867 (72.0) |  |
BMI (kg/m2) | 23.49 (4.00) | 23.39 (3.92) | 23.59 (4.07) | 0.101 |
Health conditions | ||||
 Hypertension | 929 (23.1) | 493 (24.9) | 436 (21.4) | 0.009 |
 Diabetes | 224 (5.6) | 92 (4.5) | 132 (6.7) | 0.004 |
 Dyslipidemia | 366 (9.2) | 170 (8.4) | 196 (10.0) | 0.096 |
 Heart diseases | 447 (11.1) | 184 (9.0) | 263 (13.3) | < 0.001 |
Smoking status |  |  |  | < 0.001 |
 Current | 1298 (32.1) | 1180 (57.6) | 118 (5.9) |  |
 Former | 365 (9.0) | 327 (16.0) | 38 (1.9) |  |
 Never | 2376 (58.8) | 543 (26.5) | 1833 (92.2) |  |
Current drinking |  |  |  | < 0.001 |
 > Once a month | 1115 (27.6) | 961 (46.9) | 154 (7.7) |  |
 ≤ Once a month | 335 (8.3) | 213 (10.4) | 122 (6.1) |  |
 No current drinking | 2589 (64.1) | 876 (42.7) | 1713 (86.1) |  |
CES-D score | 6.00 [3.00, 11.00] | 6.00 [3.00, 10.00] | 7.00 [4.00, 12.00] | < 0.001 |