Table 1. Basal characteristics of elderly population at baseline study according to age.
| All | Age<75 years | Age≥75 years | p-value | |
| Number | 949 | 534 | 415 | |
| Age (years) | 75.8±9.0 | 68.8±2.9 | 84.8±5.6 | <0.001 |
| Gender (Male, %) | 45.4 | 45.5 | 45.3 | 0.950 |
| BMI (kg/m2) | 24.0±3.3 | 24.6±3.2 | 22.9±3.2 | <0.001 |
| DBP (mmHg) | 82.7±10.6 | 83.5±10.3 | 81.5±10.9 | 0.003 |
| SBP (mmHg) | 132.3±17.9 | 132.3±16.8 | 132.3±19.2 | 0.973 |
| Smoking (%) | 0.202 | |||
| Never | 58.9 | 59.9 | 57.6 | |
| Ex-smoker | 29.6 | 27.5 | 32.3 | |
| Current smoker | 11.5 | 12.5 | 10.1 | |
| Diabetes mellitus (%) | 24.2 | 25.7 | 22.4 | 0.328 |
| Hypertension (%) | 73.8 | 72.6 | 75.4 | 0.279 |
| Hemoglobin (g/dL) | 13.7±1.5 | 14.0±1.4 | 13.3±1.5 | <0.001 |
| Anemia (%) | 8.6 | 4.3 | 14.3 | <0.001 |
| Creatinine (mg/dL) | 0.93±0.37 | 0.89±0.35 | 0.98±0.40 | 0.001 |
| GFR (ml/min/1.73 m2) | 72.2±17.0 | 78.1±14.5 | 64.6±17.0 | <0.001 |
| ≥90 | 15.2 | 24.2 | 3.6 | <0.001 |
| 60–89 | 60.5 | 64.6 | 55.2 | |
| 45–59 | 16.5 | 8.2 | 27.2 | |
| <45 | 7.8 | 3.0 | 14.0 | |
| Proteinuria by dipstick (%) | 0.012 | |||
| none | 83.6 | 86.7 | 79.5 | |
| trace | 8.2 | 6.6 | 10.4 | |
| 1+ or more | 8.2 | 6.7 | 10.1 | |
| Hematuria (%) | 10.5 | 9.7 | 11.6 | 0.363 |
| Medication (%) | ||||
| ACEI or ARB | 14.4 | 12.7 | 16.6 | 0.091 |
| Anti-platelet agent | 21.1 | 20.6 | 21.7 | 0.686 |
| Statin | 8.1 | 9.4 | 6.5 | 0.110 |
| No of AntiHTN (%) | 0.196 | |||
| 0 | 53.5 | 55.4 | 51.1 | |
| 1 | 28.9 | 28.5 | 29.4 | |
| 2 | 10.7 | 9.4 | 12.5 | |
| ≥3 | 6.9 | 7.7 | 7.0 |
GFR: Calculated by CKD-EPI equation, BMI: body mass index, Proteinuria: measured by dipstick test, Anemia: defined in female with hemoglobin less than 12 g/dL and, in male, less than 13 g/dL. Hematuria: RBC≥5/HPF, Anti-platelet agent: aspirin 100 mg, triflusal, sarpogrelate, or clopidogrel, No of AntiHTN: number of antihypertensive medication.