Abstract INTRODUCTION Physical activity is associated with greater myelin content in older individuals with cerebral small vessel disease (CSVD), a condition marked by demyelination. However, potential mechanisms underlying this relationship remain understudied. METHODS We assessed cross‐sectionally whether serum high‐density lipoprotein (HDL), low‐density lipoprotein, and triglycerides moderated the association between physical activity and in vivo myelin in older individuals with CSVD and mild cognitive impairme…

Abstract INTRODUCTION Arterial stiffness (carotid‐femoral pulse wave velocity [cfPWV]) and plasma neurofilament light (NfL), markers of vascular and neuroaxonal aging, are linked to cognitive decline. Whether higher cfPWV amplifies the NfL–cognition relationship remains unclear. METHODS Cognitively unimpaired older adults ( N = 570) were assessed using composite cognitive scores from confirmatory factor analysis. cfPWV was dichotomized at the median. Plasma NfL was quantified on a Single Moleculte Array‐High Defin…

Abstract INTRODUCTION The 24‐hour activity cycle (24‐HAC) includes physical activity (PA), sedentary behavior (SB), and sleep. The 24‐HAC composition and brain health relationship in adults with mild cognitive impairment (MCI) remains underexplored. We examined associations between 24‐HAC composition and gray matter (GM) volume. METHODS Cross‐sectional study in 110 adults with MCI. Actigraphy assessed 24‐HAC behaviors. FreeSurfer quantified GM. Compositional linear regressions and isotemporal substitution determin…

Abstract INTRODUCTION Age‐related cognitive decline occurs, in part, due to diminishing white matter integrity. Higher cardiorespiratory fitness (CRF) is associated with better cognitive performance, but the neurobiological mechanisms underlying this association remain uncertain. Previous magnetic resonance imaging (MRI) studies have suggested that CRF‐related changes in white matter microstructure might prevent or slow age‐related cognitive decline, but have been limited by small sample sizes and methodological l…

Introduction Disruptions in estrogen exposure (i.e., surgically induced menopause) have been linked to poorer cognitive aging and dementia risk. Hormone therapy use (e.g., birth control, menopausal hormone therapy) has shown mixed associations with cognitive performance, possibly due to limited cognitive test batteries. To address previous inconsistencies, we investigated baseline data from Investigating Gains in Neurocognition in an Intervention Trial of Exercise (IGNITE). We hypothesized that (1) oophorectomy pr…