Comparing exercise determinants between Black and White older adults with heart failure.

BACKGROUND: Heart Failure is a leading cause of mortality among older adults. Engaging in regular exercise at moderate-to-vigorous intensity has been shown to improve survival rates. Theory-informed methodologies have been recommended to promote exercise, but limited application of theoretical framework has been conducted for understanding racial disparities among older adults with heart failure. This study aimed to use the Health Belief Model to compare exercise behavior determinants between Black and White older adults diagnosed with heart failure. METHODS: The HF-ACTION Trial is a multi-site study designed to promote exercise among individuals with heart failure that randomized participants to an experimental (three months of group exercise sessions followed by home-based training) or control arm. The present study used structural equation modeling to test the change in Health Belief Model constructs and exercise behavior across 12 months among older adults. RESULTS: Participants (n = 671) were older adults, 72.28 (SD = 5.41) years old, (Black: n = 230; White, n = 441) diagnosed with heart failure and reduced ejection fraction. The model found perceived benefits, self-efficacy, perceived threats, and perceived barriers to predict exercise behavior among Black and White older adults. However, among these constructs, only perceived benefits and self-efficacy were facilitated via intervention for both races. Additionally, the intervention was effective for addressing perceived barriers to exercise only among White participants. Finally, the intervention did not result in a change of perceived threats for both races. CONCLUSIONS: Among health belief model constructs, perceived threats and barriers were not facilitated for both races in the experimental arm, and the intervention did not resolve barriers among Black older adults. Racial differences need to be considered when designing interventions for clinical populations as future studies are warranted to address barriers to exercise among Black older adults with heart failure.

Resting-state MRI functional connectivity as a neural correlate of multidomain lifestyle adherence in older adults at risk for Alzheimer's disease.

Prior research has demonstrated the importance of a healthy lifestyle to protect brain health and diminish dementia risk in later life. While a multidomain lifestyle provides an ecological perspective to voluntary engagement, its association with brain health is still under-investigated. Therefore, understanding the neural mechanisms underlying multidomain lifestyle engagement, particularly in older adults at risk for Alzheimer's disease (AD), gives valuable insights into providing lifestyle advice and intervention for those in need. The current study included 139 healthy older adults with familial risk for AD from the Prevent-AD longitudinal aging cohort. Self-reported exercise engagement, cognitive activity engagement, healthy diet adherence, and social activity engagement were included to examine potential phenotypes of an individual's lifestyle adherence. Two adherence profiles were discovered using data-driven clustering methodology [i.e., Adherence to healthy lifestyle (AL) group and Non-adherence to healthy lifestyle group]. Resting-state functional connectivity matrices and grey matter brain features obtained from magnetic resonance imaging were used to classify the two groups using a support vector machine (SVM). The SVM classifier was 75% accurate in separating groups. The features that show consistently high importance to the classification model were functional connectivity mainly between nodes located in different prior-defined functional networks. Most nodes were located in the default mode network, dorsal attention network, and visual network. Our results provide preliminary evidence of neurobiological characteristics underlying multidomain healthy lifestyle choices.

The Daily Activity Study of Health (DASH): A pilot randomized controlled trial to enhance physical activity in sedentary older adults.

Sedentary behavior increases the risk for multiple chronic diseases, early mortality, and accelerated cognitive decline in older adults. Interventions to reduce sedentary behavior among older adults are needed to improve health outcomes and reduce the burden on healthcare systems. We designed a randomized controlled trial that uses a self-affirmation manipulation and gain-framed health messaging to effectively reduce sedentary behavior in older adults. This message-based intervention lasts 6 weeks, recruiting 80 healthy but sedentary older adults from the community, between the ages of 60 and 95 years. Participants are randomly assigned to one of two groups: 1) an intervention group, which receives self-affirmation followed by gain-framed health messages daily or 2) a control group, which receives daily loss-framed health messages only. Objective physical activity engagement is measured by accelerometers. Accelerometers are deployed a week before, during, and the last week of intervention to examine potential changes in sedentary time and physical activity engagement. Participants undertake structural and functional (resting and task-based) MRI scans, neuropsychological tests, computerized behavioral measures, and neurobehavioral inventories at baseline and after the intervention. A 3-month follow-up assesses the long-term maintenance of any engendered behaviors from the intervention period. This study will assess the effectiveness of a novel behavioral intervention at reducing sedentarism in older adults and examine the neurobehavioral mechanisms underlying any such changes.

A Cross-Sectional Study on the Impact of Arterial Stiffness on the Corpus Callosum, a Key White Matter Tract Implicated in Alzheimer's Disease.

BACKGROUND: Vascular risk factors such as arterial stiffness play an important role in the etiology of Alzheimer's disease (AD), presumably due to the emergence of white matter lesions. However, the impact of arterial stiffness to white matter structure involved in the etiology of AD, including the corpus callosum remains poorly understood. OBJECTIVE: The aims of the study are to better understand the relationship between arterial stiffness, white matter microstructure, and perfusion of the corpus callosum in older adults. METHODS: Arterial stiffness was estimated using the gold standard measure of carotid-femoral pulse wave velocity (cfPWV). Cognitive performance was evaluated with the Trail Making Test part B-A. Neurite orientation dispersion and density imaging was used to obtain microstructural information such as neurite density and extracellular water diffusion. The cerebral blood flow was estimated using arterial spin labelling. RESULTS: cfPWV better predicts the microstructural integrity of the corpus callosum when compared with other index of vascular aging (the augmentation index, the systolic blood pressure, and the pulse pressure). In particular, significant associations were found between the cfPWV, an alteration of the extracellular water diffusion, and a neuronal density increase in the body of the corpus callosum which was also correlated with the performance in cognitive flexibility. CONCLUSION: Our results suggest that arterial stiffness is associated with an alteration of brain integrity which impacts cognitive function in older adults.