Affiliations: [a] Department of Psychology, The Ohio State University, Columbus, OH, USA
| [b] Chronic Brain Injury Initiative, The Ohio State University, Columbus, OH, USA
Correspondence:
[*]
Correspondence to: Sarah Prieto, Department of Psychology, The Ohio State University, Columbus, OH, USA. Tel.: +1 614 292 3300; E-mail: [email protected].
Note: [1
] Data used in preparation of this article were obtained from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database (http://adni.loni.usc.edu). As such, the investigators within the ADNI contributed to the design and implementation of ADNI and/or provided data but did not participate in analysis or writing of this report. A complete listing of ADNI investigators can be found at: http://adni.loni.usc.edu/wp-content/uploads/how_to_apply/ADNI_Acknowledgement_List.pdf
Abstract: Background:A complex set of interactions between biological, genetic, and environmental factors likely underlies the development of Alzheimer’s disease (AD). Identifying which of these factors is most associated with AD is important for early diagnosis and treatment. Objective:We sought to examine genetic risk and structural brain volume on episodic memory in a sample of older adults ranging from cognitively normal to those diagnosed with AD. Methods:686 adults (55–91 years old) completed a 3T MRI scan, baseline cognitive assessments, and biospecimen collection through the Alzheimer’s Disease Neuroimaging Initiative. Hierarchical linear regression analyses examined main and interaction effects of medial temporal lobe (MTL) volume and polygenic hazard score (PHS), indicating genetic risk for AD, on a validated episodic memory composite score. Results:Genetic risk moderated the relationship between MTL volume and memory, such that individuals with high PHS and lower hippocampal and entorhinal volume had lower memory composite scores [ΔF (1,677) = 4.057, p = 0.044, ΔR2 = 0.002]. Further analyses showed this effect was driven by the left hippocampus [ΔF(1,677) = 5.256, p = 0.022, ΔR2 = 0.003] and right entorhinal cortex [ΔF (1,677) = 6.078, p = 0.014, ΔR2 = 0.003]. Conclusions:Among those with high genetic risk for AD, lower volume was associated with poorer memory. Results suggest that the interaction between AD genetic risk and MTL volume increases the likelihood for memory impairment among older adults. Results from this study suggest that genetic risk and brain volume should be considered key factors in tracking cognitive decline.
