Owing to a higher genetic risk for AD attributable to APOE ε4 in individuals who are 60 to 80 years old [55–57] and an existing study that hypothesized protective association of KL-VSHET+ status to be strongest in APOE ε4 carriers who are 60 to 80 years old [6], the a priori focus of the current study was also at this particular age range. Here, APOE is linked to Alzheimer disease.