Medical comorbidities and ethnicity impact plasma Alzheimer's disease biomarkers: Important considerations for clinical trials and practice
Sid E. O’Bryant, Melissa Petersen, James Hall, Leigh Johnson, for the HABS‐HD Study Team
Abstract
Abstract Introduction Despite the clinical implementation, there remain significant gaps in our knowledge regarding the impact of race/ethnicity or common medical comorbidity on plasma Alzheimer's disease (AD) biomarkers. Methods Plasma biomarkers of amyloid beta (Aβ) 40, Aβ 42 , total tau, and neurofilament light chain (NfL) were measured across cognitively normal Mexican Americans ( n = 445) and non‐Hispanic Whites ( n = 520). Results Dyslipidemia was associated with elevated Aβ 40 ( P = .01) and Aβ 42 ( P = .001) while hypertension was associated with elevated Aβ 40 ( P = .003), Aβ 42 ( P < .001), and total tau ( P = .002) levels. Diabetes was associated with higher Aβ 40 ( P < .001), Aβ 42 ( P < .001), total tau ( P < .001), and NfL ( P < .001) levels. Chronic kidney disease (CKD) was associated with elevations in Aβ 40 ( P < .001), Aβ 42 ( P < .001), total tau ( P < .001), and NfL ( P < .001) levels. Mexican Americans had significantly lower Aβ 40 ( P < .001) and higher total tau ( P = .005) levels. Discussion Plasma AD biomarkers vary significantly in association with common medical comorbidities as well as ethnicity. These findings are important for those using these biomarkers in clinical practice and clinical trials.