THURSDAY, Jan. 12 (HealthDay News) -- For cognitively normal carriers of APOE ε4, a sedentary lifestyle is associated with an increased risk of amyloid deposition, according to a study published online Jan. 9 in the Archives of Neurology.
Denise Head, Ph.D., from Washington University in St. Louis, and colleagues investigated whether physical activity moderates the correlation between APOE genotype and amyloid deposition in 201 cognitively normal adults (aged 45 to 88 years). APOE ε4 genotyping data were collected, and exercise levels were determined via a questionnaire. Cerebrospinal fluid (CSF) samples were collected from 165 participants, and 163 individuals underwent amyloid imaging with carbon 11-labeled Pittsburgh Compound B ([11C]PiB).
The researchers found that, compared with noncarriers, APOE ε4 carriers had evidence of significantly higher [11C]PiB binding and significantly lower levels of Aβ42 in the CSF. An interaction between APOE status and exercise engagement was seen with [11C]PiB binding; a more sedentary lifestyle was associated with significantly increased [11C]PiB binding for APOE ε4 carriers, but not noncarriers (P = 0.013 and 0.20, respectively). The associations remained significant after adjusting for confounding variables.
"These results suggest that cognitively normal sedentary APOE ε4-positive individuals may be at augmented risk for cerebral amyloid deposition," the authors write.
Two of the authors disclosed financial relationships with pharmaceutical, biotechnology, and medical device companies.