title: Clustering of metabolic syndrome risk factors and arterial stiffness in young adults: the Northern Ireland Young Hearts Project.
abstract: OBJECTIVE
  This study aimed to investigate whether the clustering of the risk factors of the metabolic syndrome (MetS) is associated with stiffness of central and peripheral arterial segments; whether these associations are similar in men and women; and whether insulin resistance and low-grade inflammation mediate any such associations.
  
  
  BACKGROUND
  Increased arterial stiffness may explain, at least in part, the increased cardiovascular and diabetes risk associated with the MetS. However, the mechanisms linking the MetS to an increased arterial stiffness are incompletely understood, and gender differences may exist.
  
  
  METHODS
  Cross-sectional analyses of data on 313 young men and women (mean age 23 years) from the Northern Ireland Young Hearts Project. Subjects were categorized according to the number of traits of the MetS; in addition a continuous MetS score was calculated. Arterial stiffness was assessed by measuring pulse wave velocity (PWV) in three arterial segments using a non-invasive optical method.
  
  
  RESULTS
  The prevalence of the MetS was similar for men (10.6%) and women (10.5%). After adjustment for potential confounders and other cardiovascular risk factors, PWV of the three arterial segments investigated increased with increasing traits of the MetS in women only. Women with the MetS, as compared to those without risk factors of the syndrome, had greater PWV of the aorto-iliac (+14.0%, P = 0.016), the aorto-radial (+13.2%, P = 0.010) and aorto-dorsalis pedis (+11.8%, P = 0.011) segments. A great deal (up to 75%) of the association between the MetS and aortic-iliac PWV was mediated by heart rate, inflammation markers [C-reactive protein (CRP) and fibrinogen] and insulin resistance [homeostatic model assessment-insulin resistance (HOMA-IR)], whereas these variables did not explain much of the association between the MetS and PWV of the peripheral segments.
  
  
  CONCLUSIONS
  Young women with the MetS show increased stiffness of peripheral and central arteries, a mechanism that may explain their increased cardiovascular risk. Low-grade inflammation, insulin resistance and sympathetic activation explain much of the adverse impact of the MetS on central, but not peripheral, arterial stiffness.
authors.affiliation: Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA), Maastricht, The Netherlands. i.ferreira@epid.unimaas.nl
authors.forename: Isabel
authors.initials: I
authors.lastname: Ferreira
authors.forename: Colin A
authors.initials: CA
authors.lastname: Boreham
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Twisk
authors.forename: Alison M
authors.initials: AM
authors.lastname: Gallagher
authors.forename: Ian S
authors.initials: IS
authors.lastname: Young
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Murray
authors.forename: Coen D A
authors.initials: CD
authors.lastname: Stehouwer
mesh_terms: D000328:Adult; D001158:Arteries / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000378:metabolism; D003430:Cross-Sectional Studies; D004548:Elasticity; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D024821:Metabolic Syndrome / Q000378:metabolism / Q000503:physiopathology*; D011674:Pulse; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D005340:Fibrinogen; D002097:C-Reactive Protein