Mediation analysis indicated that FW had a significant indirect effect (β = −0.0010, 95 % CI: −0.0034, −0.0001), accounting for 13.89 % of the relationship between IHD and ADNI-EF slope after adjusting for age, sex, education, right handedness, APOE ε4, hypertension, diabetes mellitus, hyperlipidemia, smoking, atrial fibrillation, and heart failure (Fig. 3). This evidence concerns the gene APOE and heart failure.