Participants with APOE ε4 (+) and high seizure frequency had an even higher risk of CI (OR = 7.95, 95% CI [1.88, 33.67], P = 0.005). After adjusting for age, gender, educational level, duration of epilepsy, seizure type, hypertension, diabetes, and dyslipidemia, those with APOE ε4 (-) and high seizure frequency showed a threefold risk of CI (OR = 3.34, 95% CI [0.99, 11.25], P = 0.051), while those with APOE ε4 (+) and high frequency demonstrated the highest risk of CI (OR = 10.53, 95% CI [1.75, 63.47], P = 0.010) (Fig. 2 and Table 2). Here, APOE is linked to diabetes mellitus.