Cis-MR analysis detected significant associations of higher plasma SAP values with increased risk of dementia outcomes: AD (35 274 cases, odds ratio (OR) 1.07, 95%CI 1.02; 1.11, p = 1.8 × 10−3), and LBD (2981 cases, OR 1.37, 95%CI 1.19; 1.59, p = 1.5 × 10−5) (figure 4; electronic supplementary material, table S10). This evidence concerns the gene APCS and dementia.