Bidirectional associations between functional gastrointestinal disorders and epilepsy and the mediating role of mental health: A population-based study.

BACKGROUND

This study aimed to investigate the epidemiological and causal associations between functional gastrointestinal disorders (FGIDs) and epilepsy, with a focus on the mediating role of mental health.

METHODS

Based on the UK Biobank, Cox proportional hazard models were used to estimate the risk of incident epilepsy among participants with FGIDs and the risk of FGIDs among those with epilepsy. Mediation analysis quantified the contribution of mental health to these associations. The bidirectional causal relationships between these disorders were evaluated through Mendelian randomization (MR) analysis.

RESULTS

We identified significant bidirectional clinical risks between FGIDs and epilepsy among over 250,000 participants from the UK Biobank. Participants with FGIDs had a higher risk of epilepsy (hazard ratio [HR], 1.77; 95% confidence interval [CI], 1.51-2.09). Conversely, epilepsy was associated with a higher risk of FGIDs (HR 1.57, 95% CI 1.35-1.81). Mediation analyses indicated that mental health was associated with 2-6% of these bidirectional associations. MR analyses suggested a genetic link between other functional intestinal disorders and focal epilepsy with hippocampal sclerosis (odds ratio [OR] 1.62, 95% CI 1.09-2.41), but no consistent evidence for epilepsy-to-FGIDs causality.

CONCLUSION

This large-scale bidirectional cohort study highlights robust bidirectional links between FGIDs and epilepsy, with mental health modestly associated with these links. Clinically, integrated strategies targeting the gut-brain axis may incorporate psychological well-being alongside other contributory factors to optimize prevention and management.