Risk of epilepsy in type 1 diabetes mellitus: a population-based cohort study

Abstract

Aims/hypothesis: Type 1 diabetes mellitus is a major public health problem of increasing global concern, with potential neurological complications. A possible association exists between type 1 diabetes and subsequent epilepsy. This study evaluated the relationship between type 1 diabetes and epilepsy in Taiwan. Methods: Claims data from the Taiwan National Health Insurance Research Database were used to conduct retrospective cohort analyses. The study cohort contained 2568 patients with type 1 diabetes, each of whom was frequency-matched by sex, urbanisation of residence area and index year with ten patients without type 1 diabetes. Cox proportional hazard regression analysis was conducted to estimate the effects of type 1 diabetes on epilepsy risk. Results: In patients with type 1 diabetes, the risk of developing epilepsy was significantly higher than that in patients without type 1 diabetes (p < 0.0001 for logrank test). After adjustment for potential confounders, the type 1 diabetes cohort was 2.84 times as likely to develop epilepsy than the control cohort was (HR 2.84 [95% CI 2.11, 3.83]). Conclusions/interpretation: Patients with type 1 diabetes are at an increased risk of developing epilepsy. Metabolic abnormalities of type 1 diabetes, such as hyperglycaemia and hypoglycaemia, may have a damaging effect on the central nervous system and be associated with significant long-term neurological sequelae. The causative factors between type 1 diabetes and the increased risk of epilepsy require further investigation.