O1‐11‐06: Lower Prevalence of Abnormal CSF Alzheimer’s Biomarkers Among African Americans than Caucasians with Normal Cognition or Cognitive Impairment
Year: 2016
Type: article
Study design: Observational Study
Abstract: Epidemiological and genome-wise association studies suggest Alzheimer′s disease (AD) among African Americans to differ phenotypically from Caucasians: African Americans have AD dementia at greater prevalence, earlier onset, and slower progression than Caucasians, and certain genetic variants confer greater AD risks for African Americans than Caucasians. There has been little work on the AD biomarker profiles among African Americans. We conducted a comparative biomarker (clinical, CSF, and imaging) study among older African Americans and Caucasians to characterize their AD biomarker profiles according to cognition. We prospectively recruited 66 African Americans and 70 Caucasians with normal cognition, mild cognitive impairment (MCI), and mild AD dementia from the greater Atlanta area to undergo neuropsychological, genetic, CSF, and MRI analysis. Those with suspected vascular etiology for cognitive impairment were excluded. We measured CSF AD biomarkers (Aβ42, t-Tau, p-Tau181), endothelial markers (ICAM1, VCAM1), and neuronal injury marker NFL; hippocampal volumes; and total white matter hyperintensity area (WMH). 136 subjects were included (normal cognition=57, MCI=52, mild AD dementia=27) with an even racial distribution within each category (41-52% African Americans). The two races were similar in age (69.4 vs. 70.8 yr), education (16.2 vs. 16.4 yr), APOE ε4 status (51% vs. 47%), and CSF Aβ42 levels (302.3 vs. 294.6 pg/mL). Compared to Caucasians, African Americans had lower t-Tau (50.0 vs. 71.5 pg/mL, p<0.001), p-Tau181(29.9 vs. 42.1 pg/mL, p<0.001), and VCAM1 (31.2 vs. 41.0 ng/mL, p=0.008) levels; and were less likely to have CSF biomarker profiles consistent with AD (0% vs. 32% for normal cognition, p=0.002; 37% vs. 60%, p=0.040 for MCI/dementia). MRI measures of hippocampal volumes and WMH were similar between the two races. Compared to Caucasians, African Americans with clinically suspected AD syndromes were less likely to have CSF biomarkers in support of AD. This is in keeping with the finding that African Americans with normal cognition were less likely to have CSF biomarkers suggestive of AD (pre-symptomatic AD) than Caucasians with normal cognition. Results from association studies involving AD in African Americans need to be interpreted with caution.
Source: Alzheimer s & Dementia
Institution: Emory University
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2532948991