Table 1.
Demographic and clinical characteristics, laboratory values, and comorbidities in hospitalized patients with COVID-19 with and without hyponatremia on admission.
| Serum sodium | Serum sodium | p-Values | |
|---|---|---|---|
| ≤135 mEq/L | >135 mEq/L | ||
| n = 366 | n =433 | ||
| Demographic characteristics | |||
| Age, years | 59.25 (48.53–66.60) | 53.96 (41.68–65.37) | <0.01 |
| Men | 244 (66.7%) | 242 (55.9%) | <0.01 |
| Presenting symptoms and vital signs | |||
| Anosmia | 41 (11.3%) | 68 (15.9%) | 0.06 |
| Arthralgia | 16 (4.4%) | 17 (4.0%) | 0.75 |
| Headaches | 83 (23.0%) | 85 (19.9%) | 0.29 |
| Coma | 1 (0.3%) | 3 (0.7%) | 0.63 |
| Confusion | 9 (2.5%) | 12 (2.8%) | 0.78 |
| Seizures | 4 (1.1%) | 3 (0.7%) | 0.71 |
| Diarrhea | 50 (13.9%) | 47 (11.0%) | 0.23 |
| Dysgeusia | 42 (11.6%) | 48 (11.2%) | 0.86 |
| Dyspnea | 216 (59.8%) | 240 (56.2%) | 0.30 |
| Abdominal pain | 22 (6.1%) | 15 (3.5%) | 0.09 |
| Chest pain | 37 (10.2%) | 43 (10.1%) | 0.93 |
| Conjunctivitis | 1 (0.3%) | 4 (0.9%) | 0.38 |
| General discomfort | 122 (33.8%) | 129 (30.2%) | 0.28 |
| Myalgia | 75 (20.8%) | 89 (20.9%) | 0.97 |
| Odynophagia | 93 (25.8%) | 125 (29.3%) | 0.27 |
| Cough | 240 (66.5%) | 282 (66.0%) | 0.90 |
| Vomit | 34 (9.4%) | 30 (7.0%) | 0.22 |
| Fever 37°5–37°9 | 5 (1.4%) | 20 (4.7%) | <0.01 |
| Fever >38° | 244 (67.6%) | 261 (61.1%) | 0.06 |
| Pneumonia (radiological-clinical) | 18 (5.0%) | 9 (2.1%) | 0.03 |
| Oxygen saturation (%) | 93 (89–96) | 94 (90–97) | <0.01 |
| Laboratory values | |||
| Serum Sodium (mEq/L) | 133 (131.7–134.2) | 138 (137–140) | <0.01 |
| Category of hyponatremia | |||
| Serum sodium (mEq/L) 131–135 | 310 (84.7%) | N/A | |
| Serum sodium (mEq/L) 126–130 | 45 (12.3%) | N/A | |
| Serum sodium (mEq/L) <126 | 11 (3.0%) | N/A | |
| Serum glucose (g/L) | 1.17 (1.04–1.45) | 1.28 (1.05–1.78) | <0.01 |
| Blood leukocytes/mm3 | 7,850 (5,700–10,725) | 7,250 (5,600–9,900) | 0.26 |
| Blood platelets/1,000 mm3 | 207 (159.75–265.25) | 209.50 (168–268) | 0.39 |
| Comorbidities | |||
| Hypertension | 150 (41.2%) | 128 (29.8%) | <0.01 |
| Diabetes mellitus | 89 (24.5%) | 102 (23.7%) | 0.81 |
| Obesity | 49 (13.5%) | 74 (17.2%) | 0.15 |
| Morbid obesity | 2 (0.5%) | 11 (2.6%) | 0.03 |
| Asthma | 13 (3.6%) | 35 (8.1%) | <0.01 |
| Chronic obstructive pulmonary disease | 7 (1.9%) | 14 (3.3%) | 0.24 |
| Previous pneumonia | 7 (1.9%) | 11 (2.6%) | 0.55 |
| Former smoker | 38 (10.4%) | 44 (10.2%) | 0.92 |
| Current smoker | 13 (3.6%) | 25 (5.8%) | 0.14 |
| Non-dialysis chronic kidney disease | 20 (5.5%) | 10 (2.3%) | 0.02 |
| Receiving maintenance dialysis | 16 (4.4%) | 12 (2.8%) | 0.22 |
| Congestive heart failure | 22 (6.0%) | 22 (5.1%) | 0.57 |
| Chronic liver disease | 6 (1.6%) | 1 (0.2%) | 0.03 |
| Cancer | 33 (9.1%) | 18 (4.2%) | <0.01 |
| Other immunodeficiency disorder | 18 (4.9%) | 21 (4.9%) | 0.97 |
| HIV | 4 (1.1%) | 7 (1.6%) | 0.52 |
| Pulmonary TB | 9 (2.5%) | 7 (1.6%) | 0.40 |
| Chronic neurological diseases | 28 (7.7%) | 36 (8.4%) | 0.73 |
| Pregnancy | 3 (0.8%) | 6 (0.8%) | 0.45 |
| Acute kidney injury (AKI) | 22 (6%) | 23 (5.3%) | 0.67 |
| Charlson comorbidity index (CCI) | 2 (1–4) | 2 (0–3) | <0.01 |
| Risk factors associated with hyponatremia | |||
| Antihypertensive drugs | 63 (17.2%) | 61 (14.1%) | 0.22 |
| Antiepileptic drugs, antidepressant use, and others | 10 (2.7%) | 17 (3.9%) | 0.35 |
| Thiazides | 0 (0%) | 4 (0.9%) | 0.13 |
| Hypothyroidism | 24 (6.6%) | 18 (4.2%) | 0.17 |
Age, oxygen saturation, Laboratory values, and CCI: Median (IQR); presenting symptoms, vital signs, and comorbidities: N (%).