Cognitive Functioning of Unaffected First-degree Relatives of Individuals With Late-onset Alzheimer's Disease: A Systematic Literature Review and Meta-analysis

AbstractFirst-degree relatives of individuals with late-onset Alzheimer's disease (LOAD) are at increased risk for developing dementia, yet the associations between family history of LOAD and cognitive dysfunction remain unclear. In this quantitative review, we provide the first meta-analysis on the cognitive profile of unaffected first-degree blood relatives of LOAD-affected individuals compared to controls without a family history of LOAD. A systematic literature search was conducted in PsycINFO, PubMed /MEDLINE, and Scopus. We fitted a three-level structural equation modeling meta-analysis to control for non-independent effect sizes. Heterogeneity and risk of publication bias were also investigated. Thirty-four studies enabled us to estimate 218 effect sizes across several cognitive domains. Overall, first-degree relatives (n = 4,086, mean age = 57.40,SD = 4.71) showed significantly inferior cognitive performance (Hedges’g = -0.16; 95% CI, -0.25 to -0.08;p <  .001) compared to controls (n = 2,388, mean age = 58.43,SD = 5.69). Specifically, controls outperformed first-degree relatives in language, visuospatial and verbal long-term memory, executive functions, verbal short-term memory, and verbal IQ. Among the first-degree relatives, APOE É›4 carriership was associated with more significant dysfunction in cog nition (g = -0.24; 95% CI, -0.38 to -0.11;p <  .001) compared to non-carriers (g = -0.14; 95% CI, -0.28 to -0.01;pâ€...
Source: Neuropsychology Review - Category: Neuroscience Source Type: research