Clinical and Laboratory Predictors of Disease Severity and Length of Stay in Patients with Hyponatremia.

Abstract

Background: Hyponatremia is one of the most common electrolyte abnormalities in hospitalized patients and is associated with increased mortality.

Aims: The study aimed to determine the prevalence of hyponatremia, risk factors and aetiology in elderly people.

Subjects and methods: A cross-sectional study was conducted in hospital settings between March 2023 and November 2024 in 69 male and female participants with hyponatremia. Patients' blood samples were tested for predicted factors (creatinine, blood sugar and hypervolemia). Statistical analysis was performed and P < 0.05 was considered statistically significant.

Results: The mean age of the participants was 66.10 years, with 36 (52.2%) male and 33 (47.8%) female patients, while the mean age of severe hyponatremia patients was 59.5 years ( P = 0.04). Hyponatremic patients displayed a depressed serum sodium level (117.35 mEq/L), creatinine level of 0.94 mg/dL and blood sugar level of 140.29 mg/dL. Mean hospital stay duration was 5.96 days, 37 (47.8%) patients had mild hyponatremia, 24 (34.8%) patients had moderate hyponatremia and 8 (17.4%) patients had severe hyponatremia. Patients with severe hyponatremia had significantly higher blood sugar levels, 174.25 mg/dL ( P < 0.001), with no significant correlation with creatinine. A significant association was observed between aetiology and severity of hyponatremia, particularly for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cardiac causes. Severe hyponatremia (β =0.08, P = 0.83), serum creatinine (β =0.68, P = 0.58) and cirrhosis (β = -0.04, P = 0.73) were not significantly associated with length of hospital stay.

Conclusion: Aetiological factors, especially the SIADH and cardiac causes, demonstrated a significant association with hyponatremia severity. Multivariable logistic regression did not identify any independent predictors of severe hyponatremia.