Stratifying by sex and AD status revealed a significant correlation between age at draw and ET-1 (r = 0.343, p = 0.038), but not for females with probable AD (r = 0.256, p = 0.115), males without probable AD (r = −0.117, p = 0.645), or males with probable AD (r = −0.263, p = 0.276). Here, EDN1 is linked to Alzheimer disease.