Table 1.
Baseline characteristics of subjects according to the onset of depressive symptoms in the follow-up study (numbers and percentages, mean values and standard deviations).
| Characteristics | Total | CES-D ≥ 16 | CES-D < 16 | p-Value * | |||
|---|---|---|---|---|---|---|---|
| Subjects with New Onset of Depressive Symptoms | Subjects without New Onset of Depressive Symptoms | ||||||
| Mean | SD | Mean | SD | Mean | SD | ||
| No. of subjects (n) | 2335 | 515 | 1820 | ||||
| Sex (male/female) (n) | 1170/1165 (50.1/49.9%) | 227/288 (44.1/55.9%) | 943/877 (51.8/48.2%) | 0.002 | |||
| Age (years) | 56.1 | 11.9 | 56.4 | 11.6 | 56.1 | 12.0 | 0.62 |
| BMI (kg/m2) | 22.9 | 3.0 | 22.8 | 3.2 | 23.0 | 3.0 | 0.44 |
| CES-D | 5.4 | 4.2 | 8.0 | 4.2 | 4.7 | 3.9 | < 0.001 |
| Educational level (n) | |||||||
| ≤9 years | 581 (24.9%) | 150 (29.1%) | 431 (23.7%) | ||||
| 10–12 years | 950 (40.7%) | 204 (39.6%) | 746 (41.0%) | 0.032 | |||
| ≥13 years | 804 (34.4%) | 161 (31.3%) | 643 (35.3%) | ||||
| Unmarried (n) | 281 (13.7%) | 74 (14.4%) | 207 (11.4%) | 0.07 | |||
| Current smoker (n) | 481 (20.6%) | 108 (21.0%) | 373 (20.5%) | 0.81 | |||
| Energy intake (kcal/day) | 2136 | 428 | 2123 | 408 | 2140 | 433 | 0.44 |
| Alcohol consumption † (mL/day) | 9.7 | 16.1 | 8.9 | 16.5 | 10.0 | 16.0 | 0.18 |
| Total physical activity | 2.0 | 0.2 | 2.0 | 0.2 | 2.0 | 0.2 | 0.87 |
| (Mets * min/1000/day) | |||||||
| Employment (n) | |||||||
| Unemployed or household labor | 877 (37.6%) | 198 (38.5%) | 679 (37.3%) | ||||
| Nonregular employment | 407 (17.4%) | 102 (19.8%) | 305 (16.8%) | 0.15 | |||
| Regular employment | 1051 (45.0%) | 215 (41.8%) | 836 (45.9%) | ||||
| Medical history ‡ (n) | |||||||
| Stroke | 47 (2.0%) | 12 (2.3%) | 35 (1.9%) | 0.56 | |||
| Hypertension | 511 (21.9%) | 123 (23.9%) | 388 (21.3%) | 0.21 | |||
| Ischemic heart disease | 190 (8.1%) | 49 (9.5%) | 141 (7.8%) | 0.20 | |||
| Hyperlipidemia | 357 (15.3%) | 83 (16.1%) | 274 (15.1%) | 0.56 | |||
| Diabetes mellitus | 155 (6.6%) | 25 (4.9%) | 130 (7.1%) | 0.07 | |||
n, number; CES-D, Center for Epidemiologic Studies Depression Scale. * Continuous variables, Student’s t-test; categorical variables, χ2 test. † Alcohol consumption was converted into ethanol content. ‡ Past and present illness.