Biomarkers.

Background: Osteoarthritis (OA) is a degenerative disorder of bone aging and risk factor for cognitive decline. Bone morphogenetic proteins (BMPs) are growth factor proteins that regulate skeletal and neural development, and circulating BMPs may mediate molecular cross-talk between bone and brain. The present study examined plasma BMP levels in relation to OA and neurobehavioral outcomes in cognitively unimpaired (CU) older adults.

Public Health.

Background: Modifiable risk factors are important for prevention of age-related cognitive decline. Prior research has linked both physical activity (PA) and sleep with better memory outcomes. To better understand their potential synergistic effects, we examined independent and interactive effects of actigraphy-based PA and total sleep time on cognitive functioning in cognitively unimpaired older adults.

Biomarkers.

Background: Physical activity (PA) is associated with increased release of brain derived neurotrophic factor (BDNF), a mechanism that may underlie protective effects of PA on cognitive and brain aging. The Met allele of the BDNF Val66Met single-nucleotide polymorphism reduces activity-dependent BDNF release and is associated with increased phosphorylated tau (p-tau181) in dementia populations. We sought to determine whether BDNF Val66Met influences the effects of PA on plasma p-tau181 and cognition in older adults without dementia.

Developing Topics.

Background: Suboptimal cardiovascular health poses a significant risk for dementia, yet biological links between cardiovascular health and brain function are poorly understood. We examined how plasma markers of astrocytic activation (GFAP), neuronal axon breakdown (NfL), and Alzheimer's disease (AD) pathology (pTau181) relate to several behavioral and risk indicators of systemic cardiovascular health in older adults along the AD continuum.

Method: 209 older adults (59% female; 88% clinically normal; 15% amyloid PET+) completed 30-day FitbitTM Flex2 monitoring (average daily steps), blood pressure (BP) and heart rate quantification, and plasma assayed for GFAP, NfL, and pTau181 (Quanterix Simoa).

Dementia Care Research and Psychosocial Factors.

Background: Social health factors have been robustly associated with better cognitive health in older adults; however, less is known about how social network size affects the relationship between in-vivo biomarkers of Alzheimer's disease (AD) pathology and brain aging outcomes. We examined the independent and interactive relationships between plasma pTau181 and social network size on memory function and medial temporal lobe (MTL) volume in older adults.

Method: Participants were 58 community-dwelling older adults (mean age = 75.