Apolipoprotein E Genotype Contributes to Motor Progression in Parkinson's Disease

BACKGROUND Emerging evidence indicates that the apolipoprotein E (APOE) e4 exacerbates α-synuclein pathology. OBJECTIVE To determine whether APOE e4 contributes to motor progression in early Parkinson's disease (PD). METHODS Longitudinal data were obtained from 384 patients with PD divided into APOE e4 carriers (n = 85) and noncarriers (n = 299) in the Parkinson's Progression Marker Initiative. Participants underwent yearly motor assessments over a mean follow-up period of 78.9 months. Repeated measures and linear mixed models were used to test the effects of APOE e4. RESULTS The motor progression was significantly more rapid in patients with PD carrying APOE e4 than in noncarriers (β = 0.283, P = 0.026, 95% confidence interval: 0.033-0.532). Through subgroup analysis, we found that the effect of APOE e4 was significant only in patients with high amyloid β burden (β = 0.761, P