Serum total tau, neurofilament light, and glial fibrillary acidic protein are associated with mortality in a population study

Abstract

AbstractBackgroundTotal tau (t‐tau), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP) are neuronal cytoskeletal biomarkers that may indicate greater risk of poor outcomes in age‐related conditions, including mortality. Health disparities experienced by some racial minority subgroups may influence biomarker expression and effects on longevity. We aimed to examine (a) associations of serum t‐tau, NfL, and GFAP with overall and cardiovascular mortality and (b) differences in associations by racial background.MethodsData came from 1327 older participants from the Chicago Health and Aging Project (CHAP), a longitudinal population‐based study. Cox proportional hazards regression models were used to examine associations between concentrations of serum t‐tau, NfL, and GFAP biomarker(s) and mortality (overall/cardiovascular mortality based on age at death). Interaction terms were used to examine differences between African‐American and European‐American participants. Models were adjusted for age, sex, education, the APOE‐ε4 allele, body mass index, chronic health conditions, and cognitive and physical functioning.ResultsModels showed that fivefold higher concentrations of t‐tau (HR = 1.46, 95% CI: 1.27, 1.68), NfL (HR = 2.13, 95% CI: 1.76, 2.58), and GFAP (HR = 1.43, 95% CI: 1.08, 1.90) were separately associated with increased risk of overall mortality, with higher risk in African Americans in t‐tau or NfL. In models with all biomarkers, NfL (HR = 2.17, 95% CI: 1.65, 2.85) was associated with risk of overall mortality, with racial differences in t‐tau. Higher concentrations of t‐tau (HR = 1.32, 95% CI: 1.02, 1.70), NfL (HR = 1.95, 95% CI: 1.40, 2.72), and GFAP (HR = 1.87, 95% CI: 1.18, 2.98) were separately associated with risk of cardiovascular mortality, with racial differences in t‐tau, NfL, or GFAP. In combined models, NfL (HR = 1.73, 95% CI: 1.08, 2.78) was associated with cardiovascular mortality.ConclusionsSerum t‐tau, NfL, and GFAP may be early indicators for mortality outcomes among older adults, with racial differences among associations.