APOE and dementia: After adjusting for age, gender, education, and APOE ε4 genotype, individuals in the α-synuclein-H group were found to have an increased risk of cognitive progression to dementia compared to those in the lower group, as indicated by the Cox proportional hazards model (HR = 1.670, 95% CI: 1.142 to 2.440, p = 0.008, Fig. 2G).