Abstract P338: Carotid Extra Media Thickness: An Indicator of Fat, Arterial Stiffness, Inflammation or Thickness?
Introduction: Epicardial fat is an emerging risk factor for cardiovascular (CV) disease. The importance of perivascular fat as a CV risk factor, which can be measured by ultrasound as Extra Medial Thickness (EMT), is less well described.
Hypothesis: We hypothesized that EMT would be related to obesity and EMT may influence carotid stiffness.
Methods: EMT defines the interface between the distal common carotid near wall to the jugular vein intima and includes arterial adventitia, interstitial tissue, perivascular fat, and vein intima. Mean of the maximum for right and left carotid EMT was measured at follow-up (5.9 years) with ultrasound (GE Vivid 7, Bothell, Wash.) in 112 subjects (34% male, 68% Non-Caucasian, mean age 22.9 ∓ 3.6 years) in a group of lean (L), obese (O), and T2DM (T) youth from a longitudinal study of CV Risk Factors. Anthropometrics, BP, fasting labs, and vascular measures for CIMT and arterial stiffness (Beta stiffness and Peterson’s elastic modulus) were obtained at baseline and follow-up. Variance stabilizing transformations were performed as appropriate. ANOVA was performed to compare means between the 3 study groups. ANCOVA was used to further delineate determinants of EMT. CV risk factors were regressed on EMT and other covariates in general linear models.
Results: Mean EMT was lower in L (0.86±.28) compared to the O (0.98±.24) and T (1.00±.28) subjects, p<0.05. Age and BMIz at baseline and change in glucose were determinants of EMT, while differences between study groups were no longer significant. EMT predicted higher CRP, but, significance was lost after adjustment for follow-up BMIz. EMT predicted higher Beta and Peterson’s which persisted after adjustment for BMI, glucose, and CRP.
Conclusion: Adiposity and poor glucose control may lead to increased perivascular fat. Thicker EMT may lead to increased carotid stiffness, a risk factor for CV events. Public health measures to reduce obesity and glycemic-related arterial changes are needed to prevent future heart attack and stroke.
Author Disclosures: C.E. McCoy: None. P.R. Khoury: None. Z. Gao: None. T.R. Kimball: B. Research Grant; Modest; R01 HL105591. L.M. Dolan: B. Research Grant; Modest; R01 HL105591. E.M. Urbina: B. Research Grant; Significant; R01 HL105591.
- © 2014 by American Heart Association, Inc.