Limits...
Education and Genetic Risk Modulate Hippocampal Structure in Alzheimer ’ s Disease

View Article: PubMed Central - PubMed

ABSTRACT

Genetic and environmental protective factors and risks modulate brain structure and function in neurodegenerative diseases and their preclinical stages. We wanted to investigate whether the years of formal education, a proxy measure for cognitive reserve, would influence hippocampal structure in Alzheimer’s disease patients, and whether apolipoprotein Eε4 (APOE4) carrier status and a first-degree family history of the disease would change a possible association. Fifty-eight Alzheimer’s disease patients underwent 3T magnetic resonance imaging. We applied a cortical unfolding approach to investigate individual subregions of the medial temporal lobe. Among patients homozygous for the APOE4 genotype or carrying both APOE4 and family history risks, lower education was associated with a thinner cortex in multiple medial temporal regions, including the hippocampus. Our data suggest that the years of formal education and genetic risks interact in their influence on hippocampal structure in Alzheimer’s disease patients.

No MeSH data available.


Related in: MedlinePlus

Correlation of education and cortical thickness. The figure illustrates the association of the years of education and cortical thickness across medial temporal subregions (legend see Figure 1). Patients homozygous for the APOE4 allele or APOE4 carriers with a first-degree family history of Alzheimer’s disease showed a positive correlation of education and thickness in all regions except CA1. Patients with an intermediate risk profile (APOE4 heterozygosis or family history risk) showed this correlation only in PHC with trends for other regions, such as the ERC. Patients in the low risk group (no APOE4 allele and no family history) did not show an association between education and thickness.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5036951&req=5

F2-ad-7-5-553: Correlation of education and cortical thickness. The figure illustrates the association of the years of education and cortical thickness across medial temporal subregions (legend see Figure 1). Patients homozygous for the APOE4 allele or APOE4 carriers with a first-degree family history of Alzheimer’s disease showed a positive correlation of education and thickness in all regions except CA1. Patients with an intermediate risk profile (APOE4 heterozygosis or family history risk) showed this correlation only in PHC with trends for other regions, such as the ERC. Patients in the low risk group (no APOE4 allele and no family history) did not show an association between education and thickness.

Mentions: Mean cortical thickness (averaged across all subregions) did not significantly differ between higher and lower educated patients (higher educated: 2,28 mm ± 0.12 mm, lower educated: 2,20 mm ± 0.17 mm). The mixed general linear models did not show main effects for education status and risk factor status, but revealed an interaction between both factors (F=3.97, df=2,46, p=0.026). Main effects for age and gender were not significant. Post hoc analyses (Figure 2) showed no correlation between the years of education and cortical thickness in all medial temporal lobe subregions among Alzheimer’s disease patients carrying no genetic risk factors. In patients carrying either the APOE4 allele or having a first-degree family history of Alzheimer’s disease, years of education and cortical thickness were positively correlated in the parahippocampal cortex (Pearson’s r=0.45, p=0.045), and across all medial temporal subregions combined (r=0.48, p=0.031). The entorhinal cortex failed to reach significance (r=0.44, p=0.053). Among patients homozygous for the APOE4 allele or carrying both APOE4 and family history risk factors, years of education and cortical thickness were positively correlated in the hippocampus CA23DG region (r=0.63, p=0.004), subiculum (r=0.47, p=0.044), entorhinal cortex (r=0.58, p=0.01), perirhinal cortex (r=0.73, p<0.001), parahippocampal cortex (r=0.72, p=0.001), fusiform gyrus (r=0.61, p=0.006), and across all subregions combined (r=0.77, p<0.001).


Education and Genetic Risk Modulate Hippocampal Structure in Alzheimer ’ s Disease
Correlation of education and cortical thickness. The figure illustrates the association of the years of education and cortical thickness across medial temporal subregions (legend see Figure 1). Patients homozygous for the APOE4 allele or APOE4 carriers with a first-degree family history of Alzheimer’s disease showed a positive correlation of education and thickness in all regions except CA1. Patients with an intermediate risk profile (APOE4 heterozygosis or family history risk) showed this correlation only in PHC with trends for other regions, such as the ERC. Patients in the low risk group (no APOE4 allele and no family history) did not show an association between education and thickness.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036951&req=5

F2-ad-7-5-553: Correlation of education and cortical thickness. The figure illustrates the association of the years of education and cortical thickness across medial temporal subregions (legend see Figure 1). Patients homozygous for the APOE4 allele or APOE4 carriers with a first-degree family history of Alzheimer’s disease showed a positive correlation of education and thickness in all regions except CA1. Patients with an intermediate risk profile (APOE4 heterozygosis or family history risk) showed this correlation only in PHC with trends for other regions, such as the ERC. Patients in the low risk group (no APOE4 allele and no family history) did not show an association between education and thickness.
Mentions: Mean cortical thickness (averaged across all subregions) did not significantly differ between higher and lower educated patients (higher educated: 2,28 mm ± 0.12 mm, lower educated: 2,20 mm ± 0.17 mm). The mixed general linear models did not show main effects for education status and risk factor status, but revealed an interaction between both factors (F=3.97, df=2,46, p=0.026). Main effects for age and gender were not significant. Post hoc analyses (Figure 2) showed no correlation between the years of education and cortical thickness in all medial temporal lobe subregions among Alzheimer’s disease patients carrying no genetic risk factors. In patients carrying either the APOE4 allele or having a first-degree family history of Alzheimer’s disease, years of education and cortical thickness were positively correlated in the parahippocampal cortex (Pearson’s r=0.45, p=0.045), and across all medial temporal subregions combined (r=0.48, p=0.031). The entorhinal cortex failed to reach significance (r=0.44, p=0.053). Among patients homozygous for the APOE4 allele or carrying both APOE4 and family history risk factors, years of education and cortical thickness were positively correlated in the hippocampus CA23DG region (r=0.63, p=0.004), subiculum (r=0.47, p=0.044), entorhinal cortex (r=0.58, p=0.01), perirhinal cortex (r=0.73, p<0.001), parahippocampal cortex (r=0.72, p=0.001), fusiform gyrus (r=0.61, p=0.006), and across all subregions combined (r=0.77, p<0.001).

View Article: PubMed Central - PubMed

ABSTRACT

Genetic and environmental protective factors and risks modulate brain structure and function in neurodegenerative diseases and their preclinical stages. We wanted to investigate whether the years of formal education, a proxy measure for cognitive reserve, would influence hippocampal structure in Alzheimer&rsquo;s disease patients, and whether apolipoprotein E&epsilon;4 (APOE4) carrier status and a first-degree family history of the disease would change a possible association. Fifty-eight Alzheimer&rsquo;s disease patients underwent 3T magnetic resonance imaging. We applied a cortical unfolding approach to investigate individual subregions of the medial temporal lobe. Among patients homozygous for the APOE4 genotype or carrying both APOE4 and family history risks, lower education was associated with a thinner cortex in multiple medial temporal regions, including the hippocampus. Our data suggest that the years of formal education and genetic risks interact in their influence on hippocampal structure in Alzheimer&rsquo;s disease patients.

No MeSH data available.


Related in: MedlinePlus