Clinical Profile, Etiological Spectrum, and Three-Month Outcomes of Hyponatremia in Hospitalized Geriatric Patients: A Prospective Longitudinal Observational Study

Abstract

Background: Hyponatremia is the most common electrolyte disorder among hospitalized older adults and is associated with increased morbidity, mortality, prolonged hospitalization, and poor clinical outcomes. Data on its clinical profile and outcomes in South Indian geriatric patients remain limited.

Objectives: To evaluate the clinical profile, etiological spectrum, and three-month outcomes of hyponatremia among hospitalized geriatric patients.

Materials and Methods: A prospective longitudinal observational study was conducted in the Department of General Medicine, PES Institute of Medical Sciences and Research, Kuppam, from March 2024 to September 2025. Fifty-seven patients aged ≥60 years with serum sodium <130 mEq/L were enrolled. Clinical features, etiological factors, laboratory findings, treatment, serial serum sodium levels, complications, and outcomes were recorded. Data were analyzed using IBM SPSS Statistics version 23.0. A p-value <0.05 was considered statistically significant.

Results: Acute hyponatremia (82.5%) and hypervolemic hyponatremia (57.9%) were the predominant presentations. Drug-induced hyponatremia (29.8%), infections (28.1%), and SIADH (28.1%) were the leading etiologies. Mean serum sodium increased significantly from 122.03 ± 6.37 mEq/L at admission to 136.24 ± 2.95 mEq/L at discharge and 139.95 ± 2.48 mEq/L at three months (p<0.001). Recovery was observed in 86.0% of patients at discharge and 96.5% at three months, with mortality in one patient (1.8%).

Conclusion: Hyponatremia in hospitalized geriatric patients was predominantly acute and hypervolemic, with drug-induced causes, infections, and SIADH accounting for most cases. Early etiological evaluation, medication review, and individualized management resulted in significant improvement in serum sodium concentrations and favorable three-month outcomes.