TABLE 3.
Demographic and clinical characteristics of patients in the study, stratified by RSW status and presence of hyponatremia. Data are presented as median (IQR) or frequency (%). Comparisons between groups were performed using the Kruskal–Wallis test (continuous variables) or Chi-square test (categorical variables).
| Demographic, Clinical and Biochemical Variables | Patients with RSW (n = 6) | Patients with hyponatremia (n = 17) | Patients without hypoNa (n = 16) | P-value |
|---|---|---|---|---|
| Demographic | ||||
| Sex, M | 83% | 77% | 56% | |
| Age, years | 68 (62–88) | 70 (60–77) | 72 (64–84) | 0.413 |
| Clinical | ||||
| Height, cm | 170 (168–175) | 170 (165–175) | 165 (150–170) | 0.543 |
| Weight, kg | 70 (70–100) | 75 (70–82) | 78 (64–90) | 0.083 |
| BMI, kg/m^2 | 29.4 (22.9–35.8) | 27.7 (22.9–30.1) | 28.3 (25.4–31.1) | 0.956 |
| PAS, mmHg | 120 (110–130) | 130 (120–145) | 120 (110–133) | 0.717 |
| PAD, mmHg | 70 (70–85) | 75 (70–85) | 70 (60–73) | 0.141 |
| 24 h urine output, mL | 3,550 (2,200–5,475) | 2,400 (1,250–4,050) | 2,400 (1,469–3950) | 0.355 |
| Hypertension | 2/6 | 15/17 | 8/16 | 0.381 |
| Diabetes | 0/6 | 8/17 | 6/16 | 0.010† |
| Ischemic heart disease | 1/6 | 6/17 | 6/16 | 0.127 |
| Heart failure | 0/6 | 2/17 | 5/16 | 0.809 |
| Cerebrovascular disease | 2/6 | 2/17 | 0/16 | 0.274 |
| COPD | 0/6 | 2/17 | 4/16 | 0.077 |
| Atrial fibrillation | 1/6 | 1/17 | 4/16 | 0.506 |
| Kidney failure | 0/6 | 7/17 | 5/16 | 0.285 |
| Chronic liver disease | 1/6 | 1/17 | 1/16 | 0.211 |
| Osteoporosis | 0/6 | 1/17 | 1/16 | 0.539 |
| Cancer disease | 1/6 | 3/17 | 3/16 | 1.000 |
| Diuretics | 0/6 | 11/17 | 9/16 | 0.020 |
| Hyponatremia | 6/6 | 17/17 | 0/16 | <0.001† |
| Intracranial pathology | 3/6 | 3/17 | 0/16 | 0.016 |
| Biochemical | ||||
| ProANP, nM | 4.9 (1.0–10.3) | 9.8 (4.2–13.2) | 9.7 (4.9–11.3) | 0.266 |
| Urodilatin at 6 a.m., ng/mL | 7.04 (3.16–7.55) | 0.15 (0.01–1.83) | 0.09 (0.01–1.30) | 0.007† |
| Urodilatin at 2 p.m., ng/mL | 5.37 (2.69–5.87) | 0.77 (0.07–2.06) | 0.37 (0.01–2.77) | 0.140 |
| Mean urodilatin, ng/mL | 5.46 (3.76–6.86) | 0.57 (0.05–1.60) | 0.27 (0.03–2.27) | 0.003† |
| Ht | 0.34 (0.25–0.40) | 0.31 (0.25–0.35) | 0.32 (0.29–0.35) | 0.484 |
| Uric acid (S), mg/dL | 4.9 (3.8–5.7) | 5.9 (4.3–8.3) | 7.4 (6.1–9.2) | 0.141 |
| Creatinine (S), mg/dL | 0.81 (0.67–1.16) | 0.94 (0.66–2.69) | 1.31 (0.84–1.83) | 0.434 |
| Uric acid (U) | 32.0 (23.8–63.3) | 16.0 (9.5–27.5) | 15.0 (7.3–26.8) | 0.037† |
| Creatinine (U) | 46.2 (30.4–60.5) | 33.0 (22.3–57.9) | 39.8 (24.3–60.6) | 0.795 |
| Na (S), mM | 132 (128–134) | 129 (124–133) | 142 (139–144) | <0.001† |
| Na (U), mM | 101 (75–126) | 81 (42–102) | 101 (66–112) | 0.218 |
| Glucose (S), mg/dL | 91 (88–98) | 90 (76–130) | 117 (88–145) | 0.205 |
| BUN (S), mg/dL | 42 (19–77) | 45 (21–145) | 68 (31–97) | 0.696 |
| K (S), mM | 4.15 (3.88–4.56) | 4.40 (3.83–4.77) | 3.74 (3.42–4.09) | 0.037† |
| GFR | 91 (62–97) | 79 (26–93) | 46 (31–80) | 0.150 |
| Albumin (S), g/dL | 33 (30–35) | 33 (22–37) | 34 (29–35) | 0.993 |
| AST, U/L | 24 (9–28) | 39 (15–85) | 24 (18–32) | 0.452 |
| ALT, U/L | 14 (6–22) | 41 (10–72) | 21 (9–28) | 0.237 |
| Total bilirubin | 0.68 (0.41–1.20) | 0.60 (0.40–2.12) | 0.50 (0.30–0.98) | 0.656 |
| TSH | 0.77 (0.60–1.73) | 1.29 (0.70–2.17) | 1.72 (1.31–3.31) | 0.192 |
| Cortisol | 14.3 (2.3–17.2) | 13.4 (8.6–18.9) | 11.3 (8.0–18.2) | 0.799 |
BMI, body mass index; Ht, hematocrit; BUN, blood urea nitrogen; S, serum; U, urinary; GFR, glomerular filtration rate; AST, aspartate aminotransferase; ALT, alanine aminotransferase; TSH, thyroid stimulating hormone; COPD, chronic obstructive pulmonary disease; † Statistically significant at p < 0.05.