Chronic stress, social support, and Alzheimer's blood-based biomarkers in the HABS-HD study

High levels of chronic stress and low social support have been associated with worse cognition among older adults, but the underlying mechanisms remain unclear.

We included 2117 older adults (mean age 65.5 years) enrolled in the Health and Aging Brain Study - Health Disparities (HABS-HD). Linear regression models evaluated the associations between social support or chronic stress and Alzheimer's-related blood-based biomarkers (BBMs), including amyloid beta (Aβ) 42/40 ratio, neurofilament light chain (NfL), phosphorylated tau (p-tau)181, and total tau (t-tau). Interactions between chronic stress or social support and gender or race/ethnicity in relation to BBMs were assessed.

Higher chronic stress was associated with higher levels of t-tau. Higher social support was associated with lower levels of NfL. Neither gender nor race/ethnicity modified the associations between chronic stress or social support and BBM levels.

Chronic stress and social support are associated with BBMs of neurodegeneration.

Higher chronic stress was associated with higher levels of plasma total tau. Higher social support was associated with lower levels of plasma neurofilament light chain. Neither gender nor race/ethnicity modified the associations between chronic stress or social support and levels of blood-based biomarkers. Chronic stress and social support affect pathways related to neurodegeneration.