Table 1 Characteristics of 262 CRS patients with and without hyponatremia at hospital admission
| Â | CRS patients with hyponatremiaa | CRS patients without hyponatremiaa | |||||||
|---|---|---|---|---|---|---|---|---|---|
% n | n | mean ± SD | nb | % n | n | mean ± SD | nb | p value | |
Patient characteristics | |||||||||
 Men (n) | 36.7 | 33 |  | 90 | 52.3 | 90 |  | 172 | 0.019 |
 Women (n) | 63.3 | 57 |  | 90 | 47.7 | 82 |  | 172 | |
 Age (years) |  | 90 | 74.0 ± 13.0 | 90 |  |  | 73.8 ± 13.0 | 172 | 0.768 |
 Body mass index (kg/m2) |  | 41 | 30.2 ± 8.1 | 90 |  | 98 | 30.3 ± 7.3 | 172 | 0.709 |
 Hypovolemia | 41.1 | 37 |  | 90 | 16.3 | 28 |  | 172 | < 0.0001 |
 Diarrhea (n) | 17.8 | 16 |  | 90 | 5.2 | 9 |  | 172 | 0.002 |
 Classes of oral diuretics per patient (n) |  | 88 | 1.6 ± 1.0 | 90 |  | 161 | 1.3 ± 0.7 | 172 | 0.003 |
 Torasemide (mg/d) |  | 68 | 23.1 ± 49.0 | 90 |  | 57 | 19.2 ± 28.0 | 172 | 0.612 |
 Furosemide (mg/d) |  | 70 | 34.4 ± 135.8 | 90 |  | 62 | 1.9 ± 7.9 | 172 | 0.003 |
 Hydrochlorothiazide (mg/d) |  | 71 | 7.7 ± 11.5 | 90 |  | 57 | 2.2 ± 6.3 | 172 | 0.002 |
 Xipamide (mg/d) |  | 67 | 4.3 ± 16.4 | 90 |  | 62 | 0.8 ± 3.3 | 172 | 0.159 |
 Spironolactone (mg/d) |  | 69 | 13.8 ± 38.2 | 90 |  | 63 | 5.0 ± 17.9 | 172 | 0.109 |
 Eplerenone (mg/d) |  | 70 | 1.1 ± 5.1 | 90 |  | 63 | 1.4 ± 5.6 | 172 | 0.707 |
Laboratory parameters | |||||||||
 Na (serum, mmol/L) |  | 90 | 129.6 ± 5.1 | 90 |  | 172 | 139.4 ± 3.0 | 172 | < 0.0001 |
 Na at discharge (serum, mmol/L) |  | 23 | 136.5 ± 4.3 | 75 |  | 16 | 139.0 ± 3.9 | 136 | < 0.0001 |
 Na (urine, mmol/L) |  | 37 | 68.2 ± 34.5 | 90 |  | 76 | 78.3 ± 30.0 | 172 | 0.113 |
 Na (collecting urine, mmol/24 h) |  | 31 | 191.0 ± 163.8 | 90 |  | 63 | 185.5 ± 109.2 | 172 | 0.477 |
 Urea (serum, mmol/L) |  | 87 | 26.3 ± 14.6 | 90 |  | 160 | 22.4 ± 16.1 | 172 | 0.006 |
 Cystatin C (serum, mg/mL) |  | 25 | 2.7 ± 1.0 | 90 |  | 46 | 2.7 ± 1.1 | 172 | 0.827 |
 Creatinine prior to hospitalization (serum, μmol/L) |  | 53 | 148.8 ± 61.3 | 90 |  | 96 | 171.1 ± 107.0 | 172 | 0.251 |
 Creatinine (serum, μmol/L) |  | 90 | 300.7 ± 205.8 | 90 |  | 172 | 285.5 ± 256.1 | 172 | 0.147 |
 Osmolality, calculated (serum, mosm/kg) |  | 52 | 295.6 ± 22.2 | 90 |  | 93 | 308.4 ± 18.9 | 172 | 0.0002 |
 C-reactive protein (serum, mg/L) |  | 89 | 57.8 ± 75.0 | 90 |  | 172 | 54.5 ± 80.4 | 172 | 0.308 |
 Procalcitonine (serum, pg/mL) |  | 24 | 1.7 ± 2.6 | 90 |  | 38 | 1.0 ± 1.9 | 172 | 0.680 |
Renal and cardiac parameters | |||||||||
 Acute kidney injury | 71.1 | 64 |  | 90 | 45.9 | 79 |  | 172 |  |
  AKIN 1 | 48.4 | 31 |  | 64 | 31.6 | 25 |  | 79 |  |
  AKIN 2 | 11.0 | 7 |  | 64 | 15.2 | 12 |  | 79 |  |
  AKIN 3 | 40.6 | 26 |  | 64 | 53.2 | 42 |  | 79 |  |
 Chronic kidney disease | 28.9 | 26 |  | 90 | 54.1 | 93 |  | 172 |  |
  KDIGO 1–3 | 42.3 | 11 |  | 26 | 52.6 | 49 |  | 93 |  |
  KDIGO 4 | 19.2 | 5 |  | 26 | 23.7 | 22 |  | 93 |  |
  KDIGO 5 | 38.5 | 10 |  | 26 | 23.7 | 22 |  | 93 |  |
 Estimated glomerular filtration rate, if steady state (mL/min/1.73 m2) |  | 26 | 27.9 ± 19.8 | 90 |  | 93 | 31.7 ± 20.1 | 172 | 0.403 |
 arteriovenous fistula, preexisting (n) | 5.5 | 5 |  | 90 | 14.5 | 25 |  | 172 | 0.017 |
 Left ventricular ejection fraction (%) |  | 56 | 48.5 ± 12.7 | 90 |  | 102 | 44.4 ± 13.4 | 172 | 0.046 |
 Brain natriuretic peptide (serum, pg/mL) |  | 56 | 1321.0 ± 1851.0 | 90 |  | 117 | 1319.0 ± 1725.0 | 172 | 0.940 |
Diabetes-related parameters | |||||||||
 Diabetes mellitus (n) | 66.7 | 60 |  | 90 | 65.7 | 113 |  | 172 | 0.892 |
  - insulin- dependent (n) | 65.0 | 39 |  | 60 | 66.4 | 75 |  | 113 | 0.973 |
  - oral antidiabetics (n) | 8.3 | 5 |  | 60 | 11.5 | 13 |  | 113 | 0.608 |
  - diet alone (n) | 26.7 | 16 |  | 60 | 22.1 | 25 |  | 113 | 0.574 |
 Glucose on admission, non-fasting (capillary blood, mmol/L) |  | 51 | 9.6 ± 6.6 | 90 |  | 96 | 7.7 ± 3.5 | 172 | 0.063 |
 Glucose, fasting (capillary blood, mmol/L) |  | 15 | 7.5 ± 2.6 | 90 |  | 27 | 6.7 ± 1.7 | 172 | 0.209 |
 HbA1c (%) |  | 28 | 7.6 ± 2.6 | 90 |  | 47 | 6.6 ± 0.8 | 172 | 0.235 |
 Hypoglycemia (symptomatic) on admission (n) | 8.9 | 8 |  | 90 | 4.6 | 8 |  | 172 | 0.184 |
Outcome parameters | |||||||||
 Hospitalization (days) |  |  | 16.5 ± 11.0 | 76 |  | 159 | 18.5 ± 16.5 | 172 | 0.905 |
 new-onset hemodialysis (in hospital, n) | 36.7 | 33 |  | 90 | 31.4 | 54 |  | 172 | 0.409 |
 chronic dialysisc (n) | 19.6 | 10 |  | 51 | 27.0 | 27 |  | 103 | 0.104 |
 Death in hospital (n) | 15.6 | 14 |  | 90 | 7.6 | 13 |  | 172 | 0.054 |
 One-year mortality (n) | 43.3 | 39 |  | 90 | 40.1 | 69 |  | 172 | 0.692 |