PPIA and Alzheimer disease: Spearman correlation analysis found that plasma sLRP1 levels were positively related to MoCA (r = 0.414, p = 0.040) scores in the AD groups, and plasma MMP9 levels and MoCA (r = −0.528, p = 0.014) scores showed a significant negative correlation in the SIVD groups; however, CyPA levels were not significantly correlated with cognitive scores (Table 3 and Supplementary Figure 2).