Endothelial Function and White Matter Hyperintensities in Older Adults With Cardiovascular Disease

Abstract

Background and Purpose-The presence of white matter hyperintensities on brain MRI is common among elderly individuals. Previous research suggests that cardiovascular risk factors are associated with increased white matter hyperintensities. Examining the role of direct physiological measures of vascular function will help to clarify the vascular mechanisms related to white matter hyperintensities. The aim of the present study was to examine the association between endothelial-dependent and endothelial-independent vasodilatation and white matter hyperintensity volume. Methods-Twenty-five older adults with a range of cardiovascular diseases underwent brain MRI and completed assessments of blood vessel integrity using endothelial-dependent and independent flow-mediated dilation of the brachial artery. A semi-automated pixel-based method was used to quantify total brain volume and white matter hyperintensity volume, with white matter hyperintensity volume corrected for total brain volume. The association between measures of flow-mediated dilation and log-transformed white matter hyperintensities was examined. Results-Correlation analysis revealed that endothelial-dependent vasodilatation was significantly and inversely associated with white matter hyperintensity volume. In contrast, endothelial-independent vasodilatation was not associated with white matter hyperintensities. Neither endothelial-dependent nor endothelial-independent vasodilatation was associated with total brain volume. Conclusions-These data provide preliminary evidence that the integrity of the vascular endothelium is associated with white matter hyperintensities in older adults with cardiovascular disease. Impaired vascular function may be one mechanism that contributes to the development of white matter hyperintensities in the brain. Additional longitudinal research combining measures of vessel function, neuroimaging and cognition will be helpful in clarifying this potential mechanism. (Stroke. 2007;38:308-312.)

Vascular health and cognitive function in older adults with cardiovascular disease

“…Our work also extends upon previous analyses from our own laboratory 20 , i.e., broadening upon our assessments between endothelial-mediated brachial responses and MRI-based brain imaging 20 . In that prior investigation, we demonstrated brachial flow-mediated responses correlated to white matter hyperintensities in brains of older adults with cardiovascular disease 20 .…”

“…The dependent cognitive indices were organized as composites of tests, with groups oriented to 1. attention-executive function; 2. language; 3. visual integration; 4. learning/memory; and 5. global cognitive functioning. 20 , we hypothesized that the attention-executive performance would be the cognitive domain most affected by vascular properties. Nonetheless, regression analyses were also conducted to assess the relationship between vascular performance and other cognitive domains, insuring that we would underscore the relationship of vascular performance on attention-executive capacities, and also discern any unanticipated relationships between vascular performance and other cognitive domains.…”

Albuminuria and Cognitive Decline in People with Diabetes and Normal Renal Function

“…For example, with impaired renal function, nitric oxide inhibitor levels increase. Nitric oxide regulates the microcirculation and the blood-brain barrier, which are implicated in brain white matter disease (28). Alternatively, complications associated with albuminuria, such as anemia, acidosis, hyperparathyroidism, and hypertension, can affect cognitive function (29).…”

Functional MR Imaging Evidence of Altered Functional Activation in Metabolic Syndrome

“…Support is provided by a growing body of literature documenting that peripheral cardiovascular dysfunction is related to poor cerebrovascular health and diminished cognitive function in older patients with cardiovascular disease. [43][44][45][51][52][53][54][55] Due to the multifaceted nature of MetS, further research is necessary to explore the contributions of frank vascular disease to the observed cognitive taskϪrelated BOLD response changes in midlife. Further exploration of other potential mechanisms such as alterations in cerebral glucose metabolism and inflammation will also be valuable.…”