Abstract:
There are over half a million Canadians living with dementia, the leading cause being Alzheimer’s disease (AD). Amyloid and tau are the pathological hallmarks of AD. They start to accumulate between one and two decades before memory impairment. We know that the apolipoprotein (APOE) 4 allele, the main genetic risk factor for AD, influences amyloid and tau accumulation. It is unclear if other factors, such as lifestyle factors (e.g. education and cognitive activity) or personality traits (e.g. optimism and neuroticism), can also modify amyloid and tau accumulation and/or if these factors can buffer the deleterious effect of APOE4 on AD pathology accumulation. Lifestyle and personality traits are of interest because they are modifiable (particularly lifestyle) and, therefore, could be prime targets for prevention efforts. The first objective of this proposal is to determine the lifestyle factors and personality traits that are associated with amyloid and tau burden in cognitively normal older adults at risk of developing AD dementia. The second objective is to determine if some lifestyle/personality factors can counteract the negative effects of APOE4 on AD pathology accumulation. Finally, we want to test if the lifestyle/personality factors can delay the clinical onset of the disease by buffering the negative impact of AD pathology on cognition. Finally, we will test if the factors influencing AD pathology differ between men and women, since we know that women are at increased risk of developing AD dementia. This work will be done in collaboration with the PREVENT-AD, a cohort of almost 400 cognitively normal or very mildly impaired older adults who have a parental history of AD-like dementia. It will focus on 120 individuals that did a brain scan to quantify amyloid and tau in vivo. This multidisciplinary study will give insights about new, sex-specific prevention strategies.