APOE and hypertensive disorder: The simple mediation models revealed that the association between age and processing speed was mediated through the WMH-SGM network pattern (Effect = 0.115, SE = 0.043, 95% confidence intervals [CI] [0.035; 0.203], with a diminished, but still significant direct effect of age on processing speed performance after adjusting for total intracranial volume (TIV), sex, years of education, apolipoprotein E (APOE) ε4 carrier status, hypertension status, and the time interval between MRI scans and neuropsychological assessment (Table 1).