Clinical outcomes in patients hospitalized with hyponatremia in the Northern territory of australia: A Retrospective, longitudinal Data-Linkage study.

purposeHyponatremia is a common electrolyte disorder in hospitalized patients, associated with various adverse outcomes. This study aimed to evaluate the prevalence, associated clinical characteristics, and outcomes of hyponatremia among a large cohort of hospitalized Australian patients.

methodsA retrospective cohort study involving 33,383 hospitalized patients with serum sodium concentrations categorized as normal (135–145 mmol/L), mild hyponatremia (130–134 mmol/L), moderate hyponatremia (125–129 mmol/L), and profound hyponatremia (< 125 mmol/L). The follow-up period extended up to 10 years. The Cox proportional hazards model was used to analyze time-to-death outcomes.

resultsThe overall prevalence of hyponatremia was 25.5%, with mild, moderate, and profound cases accounting for 22.0%, 2.5%, and 1.0%, respectively. First Nations Australians had a higher incidence of hyponatremia compared to non-First Nation patients (33.6% vs. 21.8%, p < 0.001). Patients with all levels of hyponatremia were older and had lower albumin and eGFR levels. All levels of hyponatremia were associated with longer hospital stays (p < 0.001). Mortality rates were notably higher among patients with hyponatremia compared to normonatremia, with hazard ratios (HRs) of 1.73 (95%CI 1.57–1.91, p < 0.001), 2.24 (95%CI 1.91, 2.64, p < 0.001), and 1.99 (95%CI 1.58, 2.51, p < 0.001) for mild, moderate, and profound hyponatremia, respectively.

conclusionsHyponatremia was highly prevalent in hospitalized patients and was associated with increased morbidity and mortality. Early recognition and targeted management strategies, especially in high-risk populations such as the elderly and First Nations Australians should be implemented.