The plasma biomarkers MR-proANP (r = 0.25 and r = 0.42), cystatin C (r = 0.23 and r = 0.36), and MR-proADM (r = 0.26 and r = 0.55) were significantly correlated to age at baseline in both participants with incident isolated AD and incident isolated AAA, respectively, whereas lipoprotein-associated phospholipase A2 (activity) (r = 0.059) and lipoprotein-associated phospholipase A2 (mass) (r = 0.09) levels were significantly correlated to age at baseline only in those with incident isolated AD. This evidence concerns the gene NPPA and Alzheimer disease.