Multiple vascular risk factors raise risk of late-onset epilepsy

Modifiable vascular risk factors and a history of stroke are associated with an increased risk of late-onset epilepsy, according to a meta-analysis.

Researchers used individual participant data from six cohorts: the Atherosclerosis Risk in Communities Study (ARIC), the Cardiovascular Health Study (CHS), the Multi-Ethnic Study of Atherosclerosis (MESA), the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS), the Washington Heights/Inwood Columbia Aging Project (WHICAP), and the Northern Manhattan Study (NOMAS).

Data on sociodemographic characteristics and vascular risk factors assessed by self-report, examinations, laboratory measures, and medication use were collected. The primary outcome was incident late-onset epilepsy.

The meta-analysis included 42,257 participants (mean age 71.4 years, 56 percent female). Over a mean follow-up of 9.3 years, 1,500 participants (3.5 percent) received a diagnosis of late-onset epilepsy, yielding an incidence rate of 3.8 per 1,000 person-years.

The risk of late-onset epilepsy was positively associated with current smoking (hazard ratio [HR], 1.39, 95 percent confidence interval [CI], 1.18–1.64), hypertension (HR, 1.17, 95 percent CI, 1.04–1.31), diabetes (HR, 1.42, 95 percent CI, 1.25–1.62), chronic kidney disease (HR, 1.29, 95 percent CI, 1.13–1.48), history of stroke (HR, 1.99, 95 percent CI, 1.63–2.43), and apolipoprotein E ε4 allele (1 ε4 allele: HR, 1.22, 95 percent CI, 1.07–1.39; 2 ε4 alleles: HR, 1.84, 95 percent CI, 1.36–2.50).

The observed associations were consistent across age, sex, and race and ethnicity subgroups.

The findings support the hypothesis that late-onset epilepsy may reflect underlying vascular burden in the brain, the researchers said.