Biomarkers.

Background: Magnetic resonance elastography (MRE) is an MRI technique that uses mild, externally applied vibrations to quantify the mechanical properties of tissues in vivo. MRE measures, such as stiffness, have been shown to be sensitive to changes in brain health with aging and neurodegeneration. Here we used MRE to characterize differences in brain mechanical properties between individuals with amnestic mild cognitive impairment (aMCI) and cognitively unimpaired subjects (CU).

Public Health.

Background: Reducing risk of dementia requires a person to have accessible information about health and risk factors, person-centered health goals, and self-efficacy. Here, we test the feasibility of a new risk reduction program called Brain Wellness Information, Support, and Empowerment (Brain-WISE). Its unique features are that it (1) is aligned with a theoretical model of behavior change, (2) is relatively brief (six 90-min sessions), (3) is conducted with groups of people who have pre-existing community; (4) includes individual and group activities and person-centered health goals; and (5) is conducted with speech-language therapists.

Public Health.

Background: To create de novo infrastructure for ADRD research, The Delaware (DE) Center for Cognitive Aging Research (DECCAR) began a telehealth-based mild cognitive impairment (MCI) registry. The registry included a dynamic recruitment plan and remote intake procedures to classify community-dwelling adults as having MCI from probable Alzheimer's Disease. The main goal of the registry was to match participants to DECCAR-supported research studies.

Developing Topics.

Background: Aging is the primary risk factor for Alzheimer's disease (AD) which is the most common cause of dementia. The risk factors for AD emerge during midlife and are similar to cardiometabolic diseases. Midlife cardiometabolic changes are worsened by poor lifestyle habits, such as consuming a Western Diet (WD), which is partially characterized by high added sugar intake (i.

Alzheimer's Imaging Consortium.

Background: Magnetic resonance elastography (MRE) is an MRI technique that uses mild, externally applied vibrations to quantify the mechanical properties of tissues in vivo. MRE measures, such as stiffness, have been shown to be sensitive to changes in brain health with aging and neurodegeneration. Here we used MRE to characterize differences in brain mechanical properties between individuals with amnestic mild cognitive impairment (aMCI) and cognitively unimpaired subjects (CU).

Comparing single- and multi-post labeling delays for the measurements of resting cerebral and hippocampal blood flow for cerebrovascular testing in midlife adults.

Objectives: To assess the reliability and validity of measuring resting cerebral blood flow (CBF) and hippocampal CBF using a single-post-labeling delay (PLD) and a multi-PLD pseudo-continuous arterial spin labeling (pCASL) protocol for cerebrovascular reactivity (CVR) testing.

Methods: 25 healthy, midlife adults (57 ± 4 years old) were imaged in a Siemens Prisma 3T magnetic resonance imaging (MRI) scanner. Resting CBF and hippocampal CBF were assessed using two pCASL protocols, our modified single-PLD protocol (pCASL-MOD) to accommodate the needs for CVR testing and the multi-PLD Human Connectome Project (HCP) Lifespan protocol to serve as the reference control (pCASL-HCP).

Nicotinamide riboside for peripheral artery disease: the NICE randomized clinical trial.

People with lower extremity peripheral artery disease (PAD) have increased oxidative stress, impaired mitochondrial activity, and poor walking performance. NAD+ reduces oxidative stress and is an essential cofactor for mitochondrial respiration. Oral nicotinamide riboside (NR) increases bioavailability of NAD+ in humans.

CD8 T-cell metabolism is related to cerebrovascular reactivity in middle-aged adults.

Cerebrovascular reactivity (CVR) decreases with advancing age, contributing to increased risk of cognitive impairment; however, the mechanisms underlying the age-related decrease in CVR are incompletely understood. Age-related changes to T cells, such as impaired mitochondrial respiration, increased inflammation, likely contribute to peripheral and cerebrovascular dysfunction in animals. However, whether T-cell mitochondrial respiration is related to cerebrovascular function in humans is not known.

Effect of acute handgrip and aerobic exercise on wasted pressure effort and arterial wave reflections in healthy aging.

Aging increases arterial stiffness and wave reflections that augment left ventricular wasted pressure effort (WPE). A single bout of exercise may be effective at acutely reducing WPE via reductions in arterial wave reflections. In young adults (YA) acute aerobic exercise decreases, whereas handgrip increases, wave reflections.

Vascular determinants of hippocampal viscoelastic properties in healthy adults across the lifespan.

Arterial stiffness and cerebrovascular pulsatility are non-traditional risk factors of Alzheimer's disease. However, there is a gap in understanding the earliest mechanisms that link these vascular determinants to brain aging. Changes to mechanical tissue properties of the hippocampus (HC), a brain structure essential for memory encoding, may reflect the impact of vascular dysfunction on brain aging.

Dietary Supplementation With NAD+-Boosting Compounds in Humans: Current Knowledge and Future Directions.

Advancing age and many disease states are associated with declines in nicotinamide adenine dinucleotide (NAD+) levels. Preclinical studies suggest that boosting NAD+ abundance with precursor compounds, such as nicotinamide riboside or nicotinamide mononucleotide, has profound effects on physiological function in models of aging and disease. Translation of these compounds for oral supplementation in humans has been increasingly studied within the last 10 years; however, the clinical evidence that raising NAD+ concentrations can improve physiological function is unclear.

Hippocampal subfield viscoelasticity in amnestic mild cognitive impairment evaluated with MR elastography.

Hippocampal subfields (HCsf) are brain regions important for memory function that are vulnerable to decline with amnestic mild cognitive impairment (aMCI), which is often a preclinical stage of Alzheimer's disease. Studies in aMCI patients often assess HCsf tissue integrity using measures of volume, which has little specificity to microstructure and pathology. We use magnetic resonance elastography (MRE) to examine the viscoelastic mechanical properties of HCsf tissue, which is related to structural integrity, and sensitively detect differences in older adults with aMCI compared to an age-matched control group.

Nutraceuticals in the Prevention and Therapeutic Treatment of Cardiovascular and Cerebrovascular Disease.

Purpose: This review overviews and highlights arterial stiffening as a key physiological process and target for the prevention and/or lowering of cardio- and cerebrovascular disease (collectively CVD) risk.

Methods: We identified nutraceutical approaches from randomized controlled trials and discussed the associated mechanisms by which these compounds lower age-related arterial stiffness. Age-related CVD are the leading cause of mortality in modernized societies.

Structure-Function Dissociations of Human Hippocampal Subfield Stiffness and Memory Performance.

Aging and neurodegenerative diseases lead to decline in thinking and memory ability. The subfields of the hippocampus (HCsf) play important roles in memory formation and recall. Imaging techniques sensitive to the underlying HCsf tissue microstructure can reveal unique structure-function associations and their vulnerability in aging and disease.

Nicotinamide Riboside Supplementation for Treating Elevated Systolic Blood Pressure and Arterial Stiffness in Midlife and Older Adults.

Background: Aging is the primary risk factor for cardiovascular diseases, the leading cause of death worldwide. Age-related increases in systolic blood pressure (SBP) link advancing age to cardiovascular disease risk. A key mechanism mediating the increase in SBP with aging is stiffening of the large elastic arteries, which occurs due to increases in oxidative stress, inflammation, and vascular smooth muscle tone.

Ten days of high dietary sodium does not impair cerebral blood flow regulation in healthy adults.

High dietary sodium impairs cerebral blood flow regulation in rodents and is associated with increased stroke risk in humans. However, the effects of multiple days of high dietary sodium on cerebral blood flow regulation in humans is unknown. Therefore, the purpose of this study was to determine whether ten days of high dietary sodium impairs cerebral blood flow regulation.

Effect of Aging on the Viscoelastic Properties of Hippocampal Subfields Assessed with High-Resolution MR Elastography.

Age-related memory impairments have been linked to differences in structural brain parameters, including the integrity of the hippocampus (HC) and its distinct hippocampal subfields (HCsf). Imaging methods sensitive to the underlying tissue microstructure are valuable in characterizing age-related HCsf structural changes that may relate to cognitive function. Magnetic resonance elastography (MRE) is a noninvasive MRI technique that can quantify tissue viscoelasticity and may provide additional information about aging effects on HCsf health.

Blood lipid markers are associated with hippocampal viscoelastic properties and memory in humans.

Age-related memory loss shares similar risk factors as cardiometabolic diseases including elevated serum triglycerides (TGs) and low-density lipoprotein cholesterol (LDL-C) and reduced high-density lipoprotein cholesterol (HDL-C). The mechanisms linking these aberrant blood lipids to memory loss are not completely understood but may be partially mediated by reduced integrity of the hippocampus (HC), the primary brain structure for encoding and recalling memories. In this study, we tested the hypothesis that blood lipid markers are independently associated with memory performance and HC viscoelasticity-a noninvasive measure of brain tissue microstructural integrity assessed by high-resolution magnetic resonance elastography (MRE).

A high salt meal does not impair cerebrovascular reactivity in healthy young adults.

A high sodium (Na ) meal impairs peripheral vascular function. In rodents, chronic high dietary Na impairs cerebral vascular function, and in humans, habitual high dietary Na is associated with increased stroke risk. However, the effects of acute high dietary Na on the cerebral vasculature in humans are unknown.

Cardiometabolic risk factors are associated with immune cell mitochondrial respiration in humans.

Modifiable cardiometabolic risk factors induce the release of proinflammatory cytokines and reactive oxygen species from circulating peripheral blood mononuclear cells (PBMCs), resulting in increased cardiovascular disease risk and compromised immune health. These changes may be driven by metabolic reprogramming of PBMCs, resulting in reduced mitochondrial respiration; however, this has not been fully tested. We aimed to determine the independent associations between cardiometabolic risk factors including BMI, blood pressure, fasting glucose, and plasma lipids with mitochondrial respiration in PBMCs isolated from generally healthy individuals ( = 21) across the adult lifespan (12 men/9 women; age, 56 ± 21 yr; age range, 22-78 yr; body mass index, 27.

High Salt Intake Augments Blood Pressure Responses During Submaximal Aerobic Exercise.

Background High sodium (Na) intake is a widespread cardiovascular disease risk factor. High Na intake impairs endothelial function and exaggerates sympathetic reflexes, which may augment exercising blood pressure (BP) responses. Therefore, this study examined the influence of high dietary Na on BP responses during submaximal aerobic exercise.