Table 1. Clinical characteristics of the study subjects stratified by time-averaged serum sodium level.
| Time-averaged serum sodium (mEq/L; number of subjects) | |||||
| Total(n = 441) | <137(n = 145) | 137 to <139(n = 148) | ≥139(n = 148) | p for trend | |
| Age (years) | 59.2±13.8 | 60.6±13.4 | 58.3±14.2 | 58.8±13.8 | 0.251 |
| Gender (male) | 240 (54.4) | 76 (52.4) | 79 (53.4) | 85 (57.4) | 0.388 |
| Body massindex (kg/m2) | 22.9±6.7 | 22.4±2.6 | 23.5±7.7 | 22.6±3.3 | 0.846 |
| Presence ofdiabetes mellitus | 227 (51.5) | 73 (50.3) | 73 (49.3) | 81 (54.7) | 0.446 |
| Presence ofcoronary arterydisease | 70 (15.9) | 27 (18.6) | 24 (16.2) | 19 (12.8) | 0.176 |
| CharlsonComorbidityIndex score | 3.0±1.0 | 3.2±1.0 | 3.0±1.1 | 3.0±0.9 | 0.065 |
| Laboratoryfindings* | |||||
| Serumsodium (mEq/L) | 137.7±2.7 | 134.5±2.1 | 138.0±0.6 | 140.3±0.9 | <0.001 |
| Serumpotassium(mEq/L) | 4.1±0.7 | 4.2±0.8 | 4.1±0.6 | 4.1±0.7 | 0.274 |
| Serumbicarbonate(mEq/L) | 25.9±2.4 | 25.7±2.3 | 26.1±2.3 | 26.0±2.5 | 0.206 |
| Serumalbumin (g/dL) | 3.1±0.5 | 2.9±0.5 | 3.1±0.6 | 3.2±0.5 | <0.001 |
| Serumferritin (ng/mL) | 274.3 [52–521] | 294.7 [52–509] | 258.3 [59–521] | 271.2 [56–514] | 0.314 |
| C-reactive protein(mg/dL) | 0.7 [0.01–16.2] | 0.8 [0.01–14.2] | 0.4 [0.01–6.3] | 0.8 [0.01–16.2] | 0.623 |
| Residual GFR(mL/min/1.73m2)* | 4.0 [0.2–29.3] | 3.9 [0.2–18.9] | 4.0 [0.3–29.3] | 4.4 [0.3–19.0] | 0.004 |
| Dailyultrafiltration(mL)* | |||||
| Peritoneal dialysis | 731.6±569.3 | 811.2±601.6 | 751.2±563.1 | 634.1±531.4 | 0.008 |
| Total | 1827.6±691.4 | 1847.6±706.0 | 1794.2±700.2 | 1841.4±671.3 | 0.943 |
| Automatedperitoneal dialysis | 5 (1.1) | 1 (0.7) | 2 (1.4) | 2 (1.4) | 0.594 |
| Icodextrin usedaily | 35 (7.9) | 25 (17.2) | 10 (6.8) | 0 (0.0) | <0.001 |
| 2.5% and/or4.25% dialysateuse daily | 105 (23.8) | 38 (26.2) | 41 (27.7) | 26 (17.6) | 0.081 |
| Total weeklyKt/V urea* | 2.3±0.8 | 2.2±0.7 | 2.3±0.9 | 2.4±0.8 | 0.061 |
| nPCR (g/Kg/day)* | 0.9±0.3 | 0.9±0.3 | 0.9±0.3 | 1.0±0.2 | 0.012 |
| Lean body mass(% body weight)* | 66.4±12.4 | 61.4±11.9 | 66.8±13.8 | 67.4±14.2 | <0.001 |
| Anti-hypertensivemedications | |||||
| ACE inhibitoror ARB | 302 (68.5) | 98 (67.6) | 104 (70.3) | 100 (67.6) | 0.995 |
| Alpha and/or beta blocker | 217 (49.2) | 72 (49.7) | 78 (52.7) | 67 (45.3) | 0.450 |
| Calciumchannel blocker | 265 (60.1) | 86 (59.3) | 91 (61.5) | 88 (59.5) | 0.981 |
| Thiazideor thiazide-likediuretics | 48 (10.9) | 19 (13.1) | 13 (8.8) | 16 (10.8) | 0.534 |
| Lasix orother loopdiuretics | 200 (45.4) | 64 (44.1) | 71 (48.0) | 65 (43.9) | 0.966 |
| Dose offurosemide(mg/day) | 46.8±61.6 | 48.7±63.5 | 52.4±66.1 | 39.4±54.4 | 0.192 |
Values for categorical variables are given as number (percentage); values for continuous variables are given as mean ± standard deviation or median [interquartile range].
*Laboratory and dialysis-specific parameters are given as time-averaged values. GFR, glomerular filtration rate; nPCR, normalized protein catabolic rate; ACE, angiotensin converting enzyme; ARB, angiotensin receptor blocker.