# U-shaped association between serum uric acid at admission and post-stroke epilepsy in patients with ischemic stroke: a cohort study

## TL;DR

This study found that both very low and very high levels of serum uric acid at hospital admission are linked to a higher risk of developing epilepsy after an ischemic stroke.

## Contribution

The study reveals a U-shaped relationship between serum uric acid levels and post-stroke epilepsy risk, suggesting an optimal intermediate range.

## Key findings

- Low and high serum uric acid levels are associated with increased post-stroke epilepsy risk.
- An intermediate range of serum uric acid (~305.3–373.9 μmol/L) is linked to lower epilepsy risk.
- The association shows a nonlinear pattern with an inflection point around 335 μmol/L.

## Abstract

The relationship between serum uric acid (SUA) and post-stroke epilepsy (PSE) remains uncertain. We investigated the association between serum uric acid at admission and PSE after acute ischemic stroke.

A retrospective cohort study was conducted on 21,459 ischemic stroke patients. Serum uric acid at admission was measured as part of routine laboratory testing and analyzed in quartiles (Q1-Q4). Logistic regression models with restricted cubic splines (RCS) were used to investigate the potential nonlinearity of the association between serum uric acid (SUA) levels and the risk of post-stroke epilepsy (PSE), with adjustments for demographic, clinical, and laboratory variables. Propensity score matching (PSM) was additionally employed to address potential confounding.

A U-shaped association was observed. Compared with the mid-range (Q2–Q3: ~305.3–373.9 μmol/L), both low (Q1) and high (Q4) SUA were associated with higher PSE risk (adjusted OR 2.32, 95% CI 1.79–2.99; and 1.60, 95% CI 1.26–2.02). RCS identified an inflection point around 335 μmol/L: below this level, higher SUA related to lower PSE risk, whereas above it, higher SUA related to higher risk. Findings were robust in propensity score–based and sensitivity analyses.

SUA shows a U-shaped association with PSE after ischemic stroke. SUA levels within an intermediate range were associated with a lower risk of PSE. This observation is hypothesis-generating and requires confirmation in prospective studies to evaluate potential causal relationships.