Time-dependent risk of sleep disorders in patients with epilepsy: a nationwide cohort study

Sleep disturbances are common yet underrecognized comorbidities in epilepsy, adversely affecting seizure control and quality of life. This study aimed to evaluate the long-term risk and risk factors of sleep disorders among patients with newly diagnosed epilepsy using a nationwide cohort with 10 years of follow-up.

Data were obtained from the Korean National Health Insurance Service (2002-2013). Newly diagnosed patients with epilepsy (ICD-10 codes G40-G41; n = 2,414) were matched by age and sex to controls (n = 24,140) without a prior history of sleep disorders (ICD-10 codes F51, G47). The primary outcome was the incidence of newly diagnosed sleep disorders. Incidence rates (IRs), incidence rate ratios (IRRs), and adjusted hazard ratios (aHRs) were calculated using multivariable and time-stratified Cox regression models.

During follow-up, 15.0% of patients with epilepsy and 8.1% of controls developed sleep disorders, corresponding to IRs of 41.1 and 20.1 per 1,000 person-years (IRR = 2.05, 95% CI = 1.83-2.29). The risk was highest within the first two years after epilepsy diagnosis (aHR = 2.48, 95% CI = 1.93-3.11) and declined thereafter. Younger patients (< 60 years), men, and former smokers exhibited higher risks.

Patients with epilepsy were associated with an increased risk of developing sleep disorders, particularly in the early post-diagnosis period and among younger male patients and former smokers. These findings emphasize the need for early screening and management. Future studies incorporating medication profiles and diverse populations may further clarify these associations.