Perceived Stress is Associated with Alzheimer's Disease Cerebrospinal Fluid Biomarkers in African Americans with Mild Cognitive Impairment.

Background: African Americans (AA) have a higher Alzheimer's disease (AD) prevalence and report more perceived stress than White Americans. The biological basis of the stress-AD link is unclear. This study investigates the connection between stress and AD biomarkers in a biracial cohort. Objective: Establish biomarker evidence for the observed association between stress and AD, especially in AA. Methods: A cross-sectional study (n = 364, 41.8% AA) administering cognitive tests and the perceived stress scale (PSS) questionnaire. A subset (n = 309) provided cerebrospinal fluid for measurement of A beta(42), Tau, Ptau, Tau/A beta(42) (TAR), and Ptau/A beta(42) (PTAR). Multivariate linear regression, including factors that confound racial differences in AD, was performed. Results: Higher PSS scores were associated with higher Ptau (beta = 0.43, p = 0.01) and PTAR (beta = 0.005, p = 0.03) in AA with impaired cognition (mild cognitive impairment). Conclusion: Higher PSS scores were associated with Tau-related AD biomarker indices in AA/MCI, suggesting a potential biological connection for stress with AD and its racial disparity.