APOE4 has been associated with greater cortical amyloid deposition. In this study, researchers examined whether physical exercise moderated the association between APOE genotype and amyloid deposition in cognitively normal adults.
Long term physical activity patterns over the last decade were assessed by questionnaire for 201 cognitively normal subjects. Participants were classified as either low or high exercisers based on exercise guidelines of the American Heart Association. Amyloid imaging was done with carbon 11-labeled Pittsburgh Compound B (PiB) positron emission tomography.
APOE4 carriers had higher brain PiB binding and lower cerebrospinal fluid (CSF) amyloid-beta 42 levels than did noncarriers. Higher PiB binding and lower CSF Aβ42 levels were also observed in more sedentary individuals. A more sedentary lifestyle was significantly associated with higher PiB binding for APOE4 carriers but not for noncarriers. All findings remained significant after controlling for age; sex; educational level; body mass index; the presence or history of hypertension, diabetes mellitus, heart problems, or depression; and the interval between assessments. The authors suggest that cognitively normal sedentary APOE4-positive individuals may be at augmented risk for cerebral amyloid deposition.
Head D, Bugg JM, Goate AM, Fagan AM, Mintun MA, Benzinger T, Holtzman DM, Morris JC: Exercise Engagement as a Moderator of the Effects of APOE Genotype on Amyloid Deposition. Arch Neurol. 69(5): 636-643 (2012).