Table 1.
Baseline characteristics of patients according to the 24-hour urinary sodium and protein excretion
| Characteristics | Total (N = 967) | 24-hour urinary protein excretion |
|||
|---|---|---|---|---|---|
| < 0.5 g/d |
≥ 0.5 g/d |
||||
| 24-h urinary sodium excretion | |||||
| Low <3.4 g/d |
High ≥3.4 g/d |
Low <3.4 g/d |
High ≥3.4 g/d |
||
| (n = 239) | (n = 213) | (n = 242) | (n = 273) | ||
| Demographic data | |||||
| Age, y | 55.4 ± 11.8 | 54.4 ± 13.6 | 56.1 ± 11.0 | 54.8 ± 11.5 | 56.2 ± 10.9 |
| Female, n (%) | 363 (37.5) | 117 (49.0) | 64 (30.0) | 102 (42.1) | 80 (29.3) |
| Systolic BP, mm Hg | 127.1 ± 15.3 | 124.8 ± 13.4 | 125.7 ± 14.2 | 127.6 ± 16.2 | 129.5 ± 16.5 |
| Diastolic BP, mm Hg | 76.8 ± 11.0 | 76.6 ± 10.3 | 76.8 ± 10.9 | 75.9 ± 10.5 | 77.9 ± 12.0 |
| Body mass index, kg/m2 | 24.8 ± 3.4 | 23.9 ± 3.2 | 25.4 ± 3.4 | 24.2 ± 3.2 | 25.7 ± 3.3 |
| Economic status, n (%) | |||||
| Low | 233 (24.6) | 56 (23.5) | 40 (19.2) | 57 (23.8) | 80 (30.4) |
| Middle | 487 (51.3) | 122 (51.3) | 104 (50.0) | 132 (55.0) | 129 (49.0) |
| High | 229 (24.1) | 60 (25.2) | 64 (30.8) | 51 (21.3) | 54 (20.5) |
| Primary renal disease, n (%) | |||||
| Diabetic nephropathy | 268 (27.7) | 35 (14.6) | 34 (16.0) | 104 (43.0) | 95 (34.8) |
| Hypertensive nephropathy | 187 (19.3) | 54 (22.6) | 58 (27.2) | 23 (9.5) | 52 (19.0) |
| Glomerulonephritis | 291 (30.1) | 57 (23.8) | 43 (20.2) | 97 (40.1) | 94 (34.4) |
| Polycystic kidney disease | 126 (13.0) | 70 (29.3) | 45 (21.1) | 5 (2.1) | 6 (2.2) |
| Others | 95 (9.8) | 23 (9.6) | 33 (15.5) | 13 (5.4) | 26 (9.5) |
| Comorbidities | |||||
| Hypertension, n (%) | 925 (95.7) | 218 (91.2) | 199 (93.4) | 238 (98.3) | 270 (98.9) |
| Diabetes, n (%) | 374 (38.7) | 60 (25.1) | 69 (32.4) | 115 (47.5) | 130 (47.6) |
| Myocardial infarction, n (%) | 26 (2.7) | 8 (3.3) | 3 (1.4) | 6 (2.5) | 9 (3.3) |
| Congestion heart failure, n (%) | 19 (2.0) | 3 (1.3) | 4 (1.9) | 3 (1.2) | 9 (3.3) |
| Cerebrovascular disease, n (%) | 56 (5.8) | 11 (4.6) | 17 (8.0) | 14 (5.8) | 14 (5.1) |
| DPI ≥ 0.8g/d/kg, n (%) | 718 (74.3) | 146 (61.1) | 183 (85.9) | 146 (60.3) | 243 (89.0) |
| Laboratory parameters | |||||
| Hemoglobin, g/dl | 12.9 ± 2.1 | 13.0 ± 1.9 | 13.7 ± 1.9 | 12.3 ± 2.0 | 12.9 ± 2.2 |
| Sodium, mmol/l | 140.8 ± 2.5 | 140.8 ± 2.4 | 140.8 ± 2.3 | 140.5 ± 2.6 | 141.0 ± 2.7 |
| Potassium, mmol/l | 4.7 ± 0.6 | 4.6 ± 0.5 | 4.6 ± 0.5 | 4.8 ± 0.6 | 4.7 ± 0.6 |
| Chloride, mmol/l | 105.2 ± 3.5 | 104.8 ± 3.1 | 104.5 ± 3.2 | 105.3 ± 3.7 | 105.8 ± 3.8 |
| Phosphate, mg/dl | 3.7 ± 0.7 | 3.6 ± 0.6 | 3.4 ± 0.6 | 3.9 ± 0.8 | 3.7 ± 0.6 |
| eGFR, ml/min per 1.73 m2 | 52.7 ± 29.7 | 58.3 ± 30.2 | 62.0 ± 27.2 | 42.6 ± 27.6 | 49.5 ± 29.7 |
| Albumin, g/dl | 4.2 ± 0.4 | 4.4 ± 0.3 | 4.4 ± 0.3 | 4.0 ± 0.5 | 4.0 ± 0.5 |
| Total cholesterol, mg/dl | 172.7 ± 40.4 | 168.0 ± 37.5 | 173.1 ± 34.0 | 175.7 ± 44.1 | 173.9 ± 43.8 |
| Triglyceride, mg/dl | 161.5 ± 100.4 | 145.2 ± 94.2 | 151.7 ± 83.9 | 165.7 ± 104.6 | 179.6 ± 110.6 |
| HDL-C, mg/dl | 48.3 ± 14.5 | 49.3 ± 15.8 | 48.6 ± 13.4 | 48.2 ± 15.0 | 47.3 ± 13.9 |
| LDL-C, mg/dl | 96.1 ± 32.2 | 91.3 ± 29.1 | 99.3 ± 29.7 | 97.9 ± 34.1 | 96.1 ± 34.7 |
| Urinary parameters | |||||
| Urine volume, ml | 1840.0 (1450.0–2250.0) | 1535.0 (1100.0–2000.0) | 2000.0 (1630.0–2495.0) | 1595.0 (1285.0–1900.0) | 2080.0 (1800.0–2600.0) |
| Urine protein, g/d | 0.56 (0.19–1.58) | 0.17 (0.10–0.28) | 0.18 (0.11–0.36) | 1.34 (0.73–2.47) | 1.67 (0.90–3.82) |
| Urine creatinine, g/d | 1.17 (0.89–1.47) | 0.99 (0.78–1.28) | 1.33 (1.08–1.61) | 1.00 (0.78–1.25) | 1.30 (1.05–1.60) |
| Urine sodium, g/d | 3.40 (2.46–4.51) | 2.44 (1.79–2.88) | 4.46 (3.86–5.34) | 2.50 (1.86–2.97) | 4.53 (3.90–5.47) |
| Urine potassium, g/d | 1.95 (1.44–2.57) | 1.59 (1.25–2.11) | 2.34 (1.77–2.87) | 1.56 (1.17–2.11) | 2.30 (1.87–2.96) |
| Urine chloride, g/d | 2.25 (3.78–6.93) | 3.78 (2.87–4.72) | 6.93 (6.19–8.32) | 3.87 (2.77–4.55) | 6.93 (6.01–8.65) |
| Use of medications | |||||
| RAAS blocker, n (%) | 832 (86.0) | 195 (81.6) | 175 (82.2) | 219 (90.5) | 243 (89.0) |
| Diuretics, n (%) | 309 (32.0) | 55 (23.0) | 62 (29.1) | 93 (38.4) | 99 (36.3) |
| Calcium channel blockers, n (%) | 392 (40.5) | 83 (34.7) | 80 (37.6) | 99 (40.9) | 130 (47.6) |
| Number of BP medications, n (%) | |||||
| 0 | 102 (10.5) | 42 (17.6) | 31 (14.6) | 14 (5.8) | 15 (5.5) |
| 1 | 312 (32.3) | 81 (33.9) | 66 (31.0) | 83 (34.3) | 82 (30.0) |
| 2 | 272 (28.1) | 60 (25.1) | 63 (29.6) | 67 (27.7) | 82 (30.0) |
| 3 | 185 (19.1) | 39 (16.3) | 37 (17.4) | 50 (20.7) | 59 (21.6) |
| ≥4 | 96 (9.9) | 17 (7.1) | 16 (7.5) | 28 (11.6) | 35 (12.8) |
BP, blood pressure; DPI, dietary protein intake; eGFR, estimated glomerular filtration rate; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; RAAS, renin-angiotensin-aldosterone system.
Data are presented as mean ± SD, number (percentage), or median (interquartile range).