These include health factors such as cardiovascular disease, diabetes, and hypertension [27], genetic factors such as presence of the APOE e4 allele [29], lifestyle variables such as smoking [30] and education [31], behavioral traits such as cognitive ability [31,32], the personality trait of conscientiousness [33], and candidate biomarkers of age such as telomere length [34,35]. Here, APOE is linked to diabetes mellitus.