Table 1.
Baseline characteristics of study participants according to depressive symptoms at baseline
| Characteristics | Total sample | Depressive symptoms | ||
|---|---|---|---|---|
| (n = 1440) | No (n = 1124) | Yes (n = 316) | p-value | |
| Female, n (%) | 864 (60.0) | 650 (75.2) | 214 (24.8) | 0.002 |
| Age (years), mean (SD) | 68.5 (4.9) | 68.3 (4.9) | 69.4 (5.1) | 0.001 |
| Education (years), mean (SD) | 3.9 (3.4) | 4.0 (3.4) | 3.7 (3.3) | 0.180 |
| BMI (kg/m2), mean (SD) | 26.4 (8.1) | 26.5 (8.9) | 26.2 (4.2) | 0.599 |
| Current smokinga, n (%) | 206 (14.3) | 162 (14.4) | 44 (13.9) | 0.970 |
| Alcohol consumptiona, n (%) | 299 (20.8) | 247 (22.0) | 52 (16.5) | 0.018 |
| Hypertension, n (%) | 768 (53.3) | 573 (51.0) | 195 (61.7) | 0.001 |
| Diabetes, n (%) | 322 (22.4) | 246 (21.9) | 76 (24.1) | 0.415 |
| Heart diseasea, n (%) | 486 (33.8) | 357 (31.8) | 129 (40.8) | 0.009 |
| Strokea, n (%) | 124 (8.6) | 86 (7.7) | 38 (12.0) | 0.044 |
| Cataract, n (%) | 200 (13.9) | 145 (12.9) | 55 (17.4) | 0.041 |
| COPDa, n (%) | 199 (13.8) | 142 (12.6) | 57 (18.0) | 0.029 |
| Arthritisa, n (%) | 518 (36.0) | 384 (34.2) | 134 (42.4) | 0.015 |
| Nephritisa, n (%) | 69 (4.8) | 52 (4.6) | 17 (5.4) | 0.763 |
| Tumor, n (%) | 51 (3.5) | 37 (3.3) | 14 (4.4) | 0.333 |
| cysC (mg/L), mean (SD) | 0.99 (0.29) | 0.97 (0.29) | 1.09 (0.26) | < 0.001 |
| HDL (mmol/L), mean (SD) | 1.49 (0.44) | 1.50 (0.42) | 1.44 (0.49) | 0.023 |
| LDL (mmol/L), mean (SD) | 2.69 (0.85) | 2.67 (0.85) | 2.78 (0.87) | 0.045 |
| Creatinine (μmol/L), mean (SD) | 70.5 (21.8) | 69.7 (22.8) | 73.3 (17.7) | 0.010 |
| eGFR (ml/min/1.73 m2), mean (SD) | 81.3 (30.6) | 84.2 (31.7) | 71.2 (23.4) | < 0.001 |
| MMSE score, mean (SD) | 26.2 (4.5) | 26.4 (4.4) | 25.5 (4.8) | 0.002 |
| ADL-disability, n (%) | 32 (2.2) | 12 (1.1) | 20 (6.3) | < 0.001 |
Abbreviations: BMI body mass index, COPD chronic obstructive pulmonary disease, cysC cystatin C, HDL high-density lipoprotein, LDL low-density lipoprotein, eGFR estimated glomerular filtration rate, MMSE mini-mental state examination, ADL activities of daily living
aNumbers of subjects with missing values were 5 for smoking, 11 for alcohol consumption, 1 for stroke, 3 for heart disease, 4 for COPD, 2 for arthritis, and 3 for nephritis. In the subsequent analyses, subjects with missing values were placed in the non-exposure group