title: Metabolic syndrome amplifies the age-associated increases in vascular thickness and stiffness.
abstract: OBJECTIVE
  We sought to evaluate whether the clustering of multiple components of the metabolic syndrome (MS) has a greater impact on these vascular parameters than individual components of MS.
  
  
  BACKGROUND
  Intima-media thickness (IMT) and vascular stiffness have been shown to be independent predictors of adverse cardiovascular events. The MS is defined as the clustering of three or more of the cardiovascular risk factors of dysglycemia, hypertension, dyslipidemia, and obesity.
  
  
  METHODS
  Carotid IMT and stiffness were derived via B-mode ultrasonography in 471 participants from the Baltimore Longitudinal Study on Aging, who were without clinical cardiovascular disease and not receiving antihypertensive therapy.
  
  
  RESULTS
  The MS conferred a disproportionate increase in carotid IMT (+16%, p < 0.0001) and stiffness (+32%, p < 0.0001), compared with control subjects. Multiple regression models, which included age, gender, smoking, low-density lipoprotein, as well as each individual component of MS as continuous variables, showed that MS was an independent determinant of both IMT (p = 0.002) and stiffness (p = 0.012). The MS was associated with a greater prevalence of subjects whose values were in the highest quartiles of IMT, stiffness, or both.
  
  
  CONCLUSIONS
  Even after taking into account each individual component of MS, the clustering of at least three of these components is independently associated with increased IMT and stiffness. This suggests that the components of MS interact to synergistically impact vascular thickness and stiffness. Future studies should examine whether the excess cardiovascular risk associated with MS is partly mediated through the amplified alterations in these vascular properties.
authors.affiliation: Laboratory of Cardiovascular Science, Laboratory of Clinical Investigation, Gerontology Research Center, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224-6825, USA. Scuteria@grc.nia.nih.gov
authors.forename: Angelo
authors.initials: A
authors.lastname: Scuteri
authors.forename: Samer S
authors.initials: SS
authors.lastname: Najjar
authors.forename: Denis C
authors.initials: DC
authors.lastname: Muller
authors.forename: Reubin
authors.initials: R
authors.lastname: Andres
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Hougaku
authors.forename: E Jeffrey
authors.initials: EJ
authors.lastname: Metter
authors.forename: Edward G
authors.initials: EG
authors.lastname: Lakatta
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography