Biology subjects

Gayda, M.

Publications and source records attributed to Gayda, M..

4 recordsLinked to original sources

bioRxiv2026

Regional distribution of white matter hyperintensity burden in coronary artery disease and links with coronary revascularization procedure

IntroductionCoronary artery disease (CAD) increases the risk of cerebrovascular events, yet early brain injury in this population remains poorly characterized. White matter hyperintensities (WMHs), a biomarker of cerebrovascular lesions, are prevalent in CAD and are linked to risk of stroke. Beyond total burden, spatial distribution of WMHs carries pathological significance and is critical for understanding CAD-related injury. While clinical outcomes including coronary revascularization procedure and myocardial infarction influence CAD prognosis, their impact on WMH burden remains unclear. MethodsThis study investigated regional WMH burden in CAD and its relationship with clinical characteristics. 82 adults over 50 years participated, including 44 individuals with CAD and 38 controls. WMHs were segmented from fluid attenuated inversion recovery and T1-weighted MRI and categorized as total, periventricular, deep, and superficial regions. History of myocardial infarction and coronary revascularization (coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI)), was obtained from medical files. ResultsIndividuals with CAD exhibited higher total, periventricular, and deep WMH volumes than controls. Participants who underwent CABG had higher superficial WMH volumes than those with PCI, suggesting greater disease severity influences WMH burden. ConclusionCAD is characterized by a distinct pattern of cerebrovascular vulnerability, with revascularization procedures influencing WMH burden

neuroscience↗

bioRxiv2025

Greater cardiorespiratory fitness is associated with higher cerebral blood flow and lower oxygen extraction fraction in healthy older adults

Aerobic exercise training promotes cardiovascular, brain and cognitive health. Regular exercise is associated with higher cardiorespiratory fitness, commonly assessed by peak oxygen uptake (VO2peak) during maximal effort testing. Higher cardiorespiratory fitness has been linked to preserved brain health, particularly higher grey matter volume and perfusion. The brain relies heavily on oxidative metabolism, yet the relationship between cardiorespiratory fitness and brain oxidative metabolism remains underexplored. This study investigated the association between VO2peak and two key cerebral metabolic parameters: the cerebral metabolic rate of oxygen consumption (CMRO2) and oxygen extraction fraction (OEF), which represents the balance between cerebral blood flow (CBF) and CMRO2. Thirty-seven healthy adults aged [≥]50 underwent maximal cardiopulmonary exercise testing for VO2peak assessment. Neuroimaging included dual calibrated functional MRI (dc-fMRI) and quantitative susceptibility mapping (QSM). Higher VO2peak correlated positively with higher CBF across whole-brain grey matter but showed no relationship with CMRO2. Conversely, higher VO2peak negatively correlated with lower OEF from both dc-fMRI and QSM. These findings suggest that greater cardiorespiratory fitness enhances cerebral perfusion without changing resting metabolic rate in healthy older adults, resulting in a reduced oxygen extraction. These results are consistent with exercise yielding improved vascular- metabolic coupling, which would reduce the likelihood of transient hypoxic episodes.

biophysics↗

bioRxiv2025

Preservation of cerebral vascular and metabolic health with greater cardiorespiratory fitness in coronary artery disease

BackgroundCoronary artery disease (CAD) is the leading cause of cardiovascular-related death globally. Beyond its cardiac consequences, CAD significantly impacts brain health, causing grey matter atrophy, reduced cerebral blood flow (CBF), impaired cerebrovascular reactivity (CVR), and cognitive decline. Recent evidence also highlights altered cerebral metabolism in CAD, characterized by reduced cerebral metabolic rate of oxygen consumption (CMRO2) and increased oxygen extraction fraction (OEF). Notably, impaired cardiorespiratory fitness, as measured by reduced peak oxygen uptake (VO2peak), is a hallmark of CAD progression and a strong prognostic marker of cardiovascular and neurological outcomes. Although VO2peak is associated with brain structural integrity and cognitive function, its relationship to cerebral vascular and metabolic function in CAD patients remains poorly understood. MethodsThirty-seven healthy individuals (age=65.35 {+/-} 8.31) and thirty-five patients with CAD (age=66.42 {+/-} 9.29) participated in this study. The objective was to determine whether higher cardiorespiratory fitness is associated with markers of cerebral health known to be impaired in CAD, in order to assess the potential of exercise as a strategy to mitigate CAD-related brain alterations. Cerebral vascular and metabolic biomarkers, including CBF, CVR, CMRO2, and OEF, were quantified using calibrated functional magnetic resonance imaging (MRI). Participants also completed a maximal cardiopulmonary exercise test on a bicycle ergometer to determine peak oxygen uptake (VO2peak). ResultsAcross all participants, VO2peak was positively associated with CBF ({beta}=0.32, p=0.02), and CVR ({beta}=0.002, p=0.04), in grey matter, confirming a link between aerobic fitness and vascular health across the cardiovascular health spectrum. However, metabolic markers exhibited group-specific patterns. Specifically, in CAD patients, VO2peak was positively associated with CMRO2 ({beta} = 0.08, p = 0.02), suggesting that reduced CMRO2 in CAD may be partially preserved by greater cardiorespiratory fitness. In contrast, a negative association between VO2peak and OEF was observed exclusively in healthy controls ({beta} = -3.6, p = 0.02), consistent with adaptations in healthy aging being primarily driven by improved CBF without changes in CMRO2. ConclusionThis study shows that higher cardiorespiratory fitness is associated with improved cerebral vascular and metabolic function, with distinct patterns observed between healthy individuals and those with CAD. In patients with CAD, greater fitness appears to preserve cerebral oxygen metabolism, while in healthy individuals, fitness is primarily linked to enhanced perfusion. These findings support the role of aerobic exercise as a promising strategy to counteract CAD-related brain alterations, emphasizing the importance of targeting cardiorespiratory fitness in both prevention and rehabilitation settings.

biophysics↗

bioRxiv2025

The Impact of Coronary Artery Disease on Brain Vascular and Metabolic Health: Links to Cognitive Function

BackgroundCoronary artery disease (CAD) is the leading cause of mortality worldwide and is associated with an increased incidence of cognitive decline, however the pathological mechanisms linking CAD to brain and cognitive health remain unclear. Prior research has identified regional deficits in cerebral blood flow (CBF) and cerebrovascular reactivity (CVR), a measure of vascular reserve, in patients with CAD. However, the impact of these cerebrovascular deficits on cognition has not been explored, nor has the effect of CAD on cerebral metabolic health. This study aims to fill these gaps by investigating how CAD influences cerebral vascular and metabolic health, and how these alterations relate to cognitive function across multiple domains. MethodsQuantitative magnetic resonance imaging (MRI) was employed to measure a comprehensive profile of cerebral vascular and metabolic health, including CBF, CVR, cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF). Cognition was assessed using a validated neuropsychological battery from which composite scores were extracted, reflecting executive functions, working memory, processing speed, and verbal episodic memory. ResultsA total of 35 patients with CAD and 37 healthy controls were included in the final analysis. Patients with CAD demonstrated widespread impairments in both cerebral vascular and metabolic health, characterized by lower CBF, CVR, and CMRO2, and increased OEF, indicative of insufficient oxygen delivery. Notably, lower CVR was associated with poorer executive function, suggesting a specific role of vascular reserve for preserving executive functions. Furthermore, higher OEF was associated with poorer working memory, showing the importance of preserved oxygen consumption for maintaining cognitive function. ConclusionThis study reveals that CAD is associated with impaired cerebral vascular and metabolic health, providing a pathological basis for cognitive decline. Specifically, reduced CVR and elevated OEF emerged as sensitive biomarkers linking impaired brain health and cognition. These markers hold promise for guiding future interventions aimed at preserving cognitive health in patients with CAD. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LICoronary artery disease is associated with an increased incidence of cognitive decline but the biological mechanisms underlying these changes in cognition are unclear. C_LIO_LIThis is the first study to comprehensively demonstrate profound and widespread deficits in both cerebral vascular and oxidative metabolic health in patients with coronary artery disease. C_LIO_LICerebrovascular reactivity and oxygen extraction fraction may be sensitive biomarkers of early cognitive decline in coronary artery disease. C_LI What Are the Clinical Implications?O_LIThe widespread impairments in cerebral vascular and metabolic health suggest that coronary artery disease has profound consequences on the brain. C_LIO_LIPoor vascular reserve and an imbalance between oxygen delivery and usage may be crucial determinants of cognitive health. These results highlight the limitations of traditional biomarkers in understanding the brains vulnerability and the need for these novel and quantitative biomarkers of cerebral physiological health. C_LIO_LIThese findings suggest that cerebral vascular and metabolic deficits exist even in the absence of overt cognitive decline in coronary artery disease, emphasizing the need for early detection and preventative strategies. C_LI

biophysics↗