Apolipoprotein E Alleles and Motor Signs in Older Adults with Alzheimer’s Dementia

We investigated associations between <i>apolipoprotein E</i> (<i>APOE</i>) alleles and motor manifestations in Alzheimer's dementia (AD) capitalizing on National Alzheimer's Coordinating Center data: the baseline evaluations of older adults (≥60 years) with a diagnosis of AD were analyzed. Those with a concomitant diagnosis Parkinson's disease or other parkinsonian syndrome, and those treated with anti-parkinsonian agents were excluded. Three <i>APOE</i> groups were formed: <i>APOE2</i> (<i>APOE2</i> carriers), <i>APOE3</i> (<i>APOE3/APOE3</i>) and <i>APOE4</i> (<i>APOE4/APOE4, APOE4/APOE3</i>). UPDRS-III was used to assess the presence or absence of motor signs in 9 domains. Adjusted binary logistic models featuring the three <i>APOE</i> groups as exposures and motor domains as outcomes were estimated. There were 389 individuals in the <i>APOE2</i>, 1799 in the <i>APOE3</i> and 2791 in the <i>APOE4</i> groups. Compared to the <i>APOE2</i> group, individuals in the APOE4 group had lower odds of having at least one motor sign [0.64 (0.50-0.82)]. Among motor signs, rigidity [0.53 (0.34-0.81)], bradykinesia [0.56 (0.40-0.77)], impaired chair rise [0.54 (0.37-0.78)] and impaired posture-gait [0.54 (0.36, 0.81)] exhibited significant associations. Exploratory analyses featuring <i>APOE</i> genotypes suggested dose-response relationships for both <i>APOE2</i> and <i>APOE4</i>. In conclusion, <i>APOE2</i> confers a risk towards motor (mainly parkinsonian) signs in AD. <i>APOE4</i> may have a protective effect.