Literature Review
TORONTO—Modifiable risk factors predict memory resilience in aging adults with genetic risk for Alzheimer’s disease, according to data presented at the Alzheimer’s Association International Conference. Several factors predict memory resilience in both sexes. A greater number of sex-specific factors apply to females than to males, however. The predictive factors are similar, regardless of whether risk results from APOE or CLU.
Kirstie McDermott, graduate student at the University of Alberta in Edmonton, Canada, and colleagues sought to determine whether longitudinal memory trajectories suggest a distinct phenotype of memory resilience, which they defined as high memory performance despite genetic risk for Alzheimer’s disease. The researchers also looked for predictors of memory resilience.
Ms. McDermott and colleagues followed 642 cognitively normal adults between ages 53 and 95 who were participating in the Victoria Longitudinal Study. Maximum follow-up was nine years. Carriers of the APOE ε4 allele or the CLU CC genotype were considered to be at genetic risk for Alzheimer’s disease. The investigators tested 22 predictors of resilience from five nongenetic risk domains (ie, demographic, functional, health, mobility, and lifestyle). They stratified their analyses by sex to compare the effect of these predictors in males and females.
Memory was stable in 67.6% of females and in 52.8% of males. Growth mixture modeling enabled the investigators to identify two similar classes of longitudinal memory trajectories among males and females. Random forest analysis identified younger age, higher education, stronger grip, and more everyday novel cognitive activity (such as playing bridge or filing taxes) as important predictors of memory resilience for both sexes.
For females, living with another person; being married; lower pulse pressure; higher peak expiratory flow; better subjective health rating; faster walking and turning time; more social visits with family, friends, and neighbors; and volunteering more often predicted memory resilience. The only predictor of memory resilience specific to males was a low number of depressive symptoms. The predictors were similar for both genotypes of Alzheimer’s disease risk.
“The more we know about both common and gender-specific factors that may protect against Alzheimer’s risk, the better we can create tailored and appropriate interventions that promote functional maintenance and delay cognitive decline,” said Ms. McDermott.
—Erik Greb