Loneliness and biomarkers of Alzheimer's disease, axonal damage, and astrogliosis: A coordinated analysis of two longitudinal cohorts.

Objectives: Loneliness is associated with an elevated risk of dementia. There is mixed evidence from imaging studies on whether loneliness is associated with neuropathology in dementia-free adults. This study tests whether loneliness is associated with plasma neurobiomarkers of amyloid (Aβ42/Aβ40), phosphorylated tau 181 (pTau181), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) and imaging measures of amyloid and tau.

Blood-Based Biomarkers and Risk of Onset of Mild Cognitive Impairment Over the Short and Long Term.

Background And Objectives: Blood-based biomarkers of amyloid and tau have been shown to predict Alzheimer disease (AD) dementia. Much less is known about their ability to predict risk of mild cognitive impairment (MCI), an earlier disease stage. This study examined whether levels of blood biomarkers of amyloid (Aβ/Aβ ratio), tau (p-tau), neurodegeneration (NfL), and glial activation and neuroinflammation (glial fibrillary acidic protein [GFAP], YKL40, soluble triggering receptor expressed on myeloid cells 2 [sTREM2]) collected when participants were cognitively normal are associated with the time to onset of MCI.

White matter free water mediates the associations between placental growth factor, white matter hyperintensities, and cognitive status.

Introduction: Placental growth factor (PlGF) may regulate cerebrovascular permeability. We hypothesized that white matter interstitial fluid accumulation, estimated via magnetic resonance imaging (MRI) free water (FW), would explain the associations between elevated PlGF, white matter hyperintensities (WMH), and cognitive impairment.

Methods: MarkVCID consortium participants ≥55 years old with plasma PlGF and brain MRI were included.

Sex differences in the trajectories of plasma biomarkers, brain atrophy, and cognitive decline relative to amyloid onset.

Introduction: The factors that influence the progression of Alzheimer's disease (AD) after individuals become amyloid-positive are poorly understood. This study examines how sex influences the longitudinal trajectories of plasma AD and neurodegenerative biomarkers in the years following a person's estimated onset of amyloid-β.

Methods: Linear mixed-effects modeling investigated overall and sex-specific longitudinal trajectories of plasma biomarkers, brain volumes, and cognition relative to the estimated age of amyloid onset in a cohort of 78 amyloid-positive Baltimore Longitudinal Study of Aging (BLSA) participants (n = 45 male; follow-up time: 6.

Preoperative Neurofilament Light Associated With Postoperative Delirium in Hip Fracture Repair Patients Without Dementia.

Background: Delirium commonly occurs in older adults following surgery; although its pathophysiology is not fully understood, underlying neurodegeneration is a risk factor.

Objective: Examine the association of preoperative levels of markers of neuronal damage, neurofilament light (NfL) and phosphorylated tau (p-tau), with postoperative delirium.

Methods: Preoperative cerebrospinal fluid (CSF) and plasma were obtained from 158 patients undergoing hip fracture repair and enrolled in the clinical trial "A STrategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients.