title: Comparison between insulin resistance indices and carotid and femoral atherosclerosis: a cross-sectional population study.
abstract: OBJECTIVE
  The aim of this study was to investigate the association between commonly used insulin resistance (IR) indices and the presence and extent of carotid and femoral atherosclerosis in a general population setting.
  
  
  METHODS
  Cross-sectional analysis of 762 volunteers from the ongoing epidemiological Cyprus Study (46.6% male; mean age=60.5±10.2). 1) Carotid intima-media thickness (IMTcc), 2) carotid and femoral atherosclerotic plaque presence, 3) total plaque area in the carotid/femoral bifurcations (sum of the largest plaques in each carotid/femoral bifurcation-SPAcar/fem), and 4) total plaque area in both carotid and femoral bifurcations (sum of the areas of the largest plaques present in each of the four bifurcations-SPA) were measured using ultrasound at baseline. The HOMA-IR, QUICKI and McAuley indices as well as fasting insulin levels were estimated and their quartiles were used in linear and logistic regression analysis.
  
  
  RESULTS
  All IR indices studied were strongly associated with IMTcc (P<0.01for all) even after adjustment for age and sex and exclusion of diabetic subjects. However, when looking at plaque presence and size (i.e.area) only the HOMA-IR and especially the McAuley Index were associated with both carotid plaque presence (ORadj=1.17; 95%CI=1.01 to 1.36; P=0.03 and ORadj=0.86; 95%CI=0.74 to 0.99; P=0.04 respectively) and area (ORadj=0.10; 95%CI=0.008 to 0.20; P=0.03 and ORadj=-0.11; 95%CI=-0.20 to -0.009; P=0.03 respectively), after adjustment. The McAuley Index remained a significant predictor of both carotid plaque presence and area even after exclusion of diabetic subjects (P=0.04).
  
  
  CONCLUSIONS
  Our results show that while all indices were associated with carotid IMT, supporting a strong role for IR in intimal-medial thickening, only the HOMA-IR and especially the McAuley Index were associated with both carotid plaque presence and area, after adjustment. This highlights the importance of including triglyceride levels in estimating the risk for atherosclerotic plaque in the carotids as well as the possible differences in determinants for atherosclerosis between arterial sites.
authors: Cyprus International Institute for Environmental and Public Health, in association with Harvard T. H. Chan School of Public Health, Cyprus University of Technology, Limassol, Cyprus - andrie.panayiotou@cut.ac.cy.
authors: A G
authors: AG
authors: Panayiotou
authors: P
authors: P
authors: Kouis
authors: M
authors: M
authors: Griffin
authors: A N
authors: AN
authors: Nicolaides
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000175:diagnosis*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D059168:Carotid Intima-Media Thickness; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003535:Cyprus; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging*; D006801:Humans; D007333:Insulin Resistance; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging*; D012307:Risk Factors