title: Endothelial function and white matter hyperintensities in older adults with cardiovascular disease.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Psychiatry and Human Behavior, Brown Medical School, Providence, RI 02903, USA. Karin_Hoth@Brown.edu
authors.forename: Karin F
authors.initials: KF
authors.lastname: Hoth
authors.forename: David F
authors.initials: DF
authors.lastname: Tate
authors.forename: Athena
authors.initials: A
authors.lastname: Poppas
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Forman
authors.forename: John
authors.initials: J
authors.lastname: Gunstad
authors.forename: David J
authors.initials: DJ
authors.lastname: Moser
authors.forename: Robert H
authors.initials: RH
authors.lastname: Paul
authors.forename: Angela L
authors.initials: AL
authors.lastname: Jefferson
authors.forename: Andreana P
authors.initials: AP
authors.lastname: Haley
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Cohen
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000000981:diagnostic imaging* / Q000502:physiology; D011859:Radiography; D014664:Vasodilation / Q000502:physiology