Hyponatremia in Acute Stroke: A Comparative Study of Ischemic and Hemorrhagic Stroke Subtypes.

BACKGROUND

Hyponatremia, an often underappreciated electrolyte imbalance in acute stroke, may exacerbate cerebral edema and negatively impact clinical outcomes. Although both ischemic and hemorrhagic strokes can be affected, there is a paucity of studies comparing the prevalence and severity of hyponatremia between these subtypes, particularly in resource-limited settings.

OBJECTIVE

This study aims to ascertain the prevalence and severity of hyponatremia in patients with ischemic and hemorrhagic strokes and to compare subtype-specific differences in clinical and biochemical profiles.

METHODS

This descriptive cross-sectional study involved 158 consecutive adult patients who presented with radiologically confirmed acute stroke within 24 hours of onset at a tertiary care hospital in Pakistan between December 2023 and March 2024. Patients were categorized into ischemic or hemorrhagic stroke subtypes based on computed tomography (CT)/magnetic resonance imaging (MRI) findings. Hyponatremia was considered a serum sodium concentration < 135 mmol/L, confirmed on two separate occasions 12 hours apart. Demographic, clinical, and biochemical data were collected. Statistical analyses included chi-square tests, t-tests, and multivariable logistic regression to adjust for confounders, with statistical significance set at p < 0.05.

RESULTS

Hyponatremia was observed in 33% of patients, with a significantly higher prevalence in hemorrhagic stroke compared to ischemic stroke. Patients with hemorrhagic stroke had 5.2 times greater odds of hyponatremia. The distribution of hyponatremia severity was similar across stroke subtypes. Serum sodium levels were significantly lower in the hemorrhagic group. No significant associations were found between hyponatremia and age or sex.

CONCLUSION

Hyponatremia is significantly more prevalent in hemorrhagic stroke than in ischemic stroke, which indicates that close monitoring and early intervention are needed in these patients. Despite the similar severity distributions, the elevated risk in hemorrhagic stroke highlights the need for subtype-specific strategies in electrolyte management during acute stroke care.