biostudies-literatureUnknown17Ofori E<h4>Introduction</h4>The apolipoprotein E (<i>APOE</i>) ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease (AD) and cardiovascular disease. This study aimed to investigate the interactive effects of <i>APOE</i> ε4 genotype and cardiovascular risk on the microstructure of the nucleus basalis of Meynert (NBM), a key cholinergic region affected early in AD, using advanced diffusion magnetic resonance imaging.<h4>Methods</h4>This cross-sectional study included 167 cognitively unimpaired older adults from the Arizona <i>APOE</i> Cohort. Participants were stratified by genotype: <i>APOE</i> ε4 non-carriers (<i>N</i> = 83), heterozygous carriers (<i>N</i> = 51), and homozygous carriers (<i>N</i> = 33). Cardiovascular risk was quantified using a composite score calcuFrontiers in aging neuroscience1597127https://www.ebi.ac.uk/biostudies/studies/S-EPMC12479503biostudies-literatureFree-water imaging of the nucleus basalis of Meynert in apolipoprotein E4 carriers.PMC12479503Chen KOfori EBraden BBSu YReiman EMCaselli RJfalseFree-water imaging of the nucleus basalis of Meynert in apolipoprotein E4 carriers.<h4>Introduction</h4>The apolipoprotein E (<i>APOE</i>) ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease (AD) and cardiovascular disease. This study aimed to investigate the interactive effects of <i>APOE</i> ε4 genotype and cardiovascular risk on the microstructure of the nucleus basalis of Meynert (NBM), a key cholinergic region affected early in AD, using advanced diffusion magnetic resonance imaging.<h4>Methods</h4>This cross-sectional study included 167 cognitively unimpaired older adults from the Arizona <i>APOE</i> Cohort. Participants were stratified by genotype: <i>APOE</i> ε4 non-carriers (<i>N</i> = 83), heterozygous carriers (<i>N</i> = 51), and homozygous carriers (<i>N</i> = 33). Cardiovascular risk was quantified using a composite score calcu2025-01-01T00:00:00Z20252026-06-04T00:10:45.369Z2026-05-03T03:12:37.811ZS-EPMC124795034103582610.3389/fnagi.2025.1597127