Abstract 17054: Sex-Related Differences in Atherosclerosis Burden and Composition Evaluated by Magnetic Resonance: A Complex Interaction Between Visceral Adiposity and Atherogenic Lipoproteins

Abstract

Introduction: Visceral adiposity increases the level of atherogenic lipoproteins and is linked to sex-related differences in cardiovascular risk. Hypothesis. Atherogenic lipoproteins could mediate the relationship between visceral fat and sex-related differences in atherosclerosis burden and composition, including the lipid-rich necrotic core (LRNC). Methods: This study included 294 women (39.4 ± 15.0 years) and 324 men (39.5 ± 13.8 years), matched for age and risk factors (hypertension, dyslipidemia, obesity, diabetes, smoking). Carotid atherosclerosis, visceral abdominal fat (VAT) and cardiac fat (CAT) were studied by magnetic resonance imaging. Results: For similar age and risk profile, women had less VAT ( p <0.001) and CAT ( p <0.001) than men. Carotid atherosclerosis prevalence ( p <0.001) and carotid wall volume ( p <0.001) were higher in men. Although LRNC prevalence was similar in women and men ( p =0.23), men had a greater LRNC volume ( p <0.001). An interaction was observed between waist-to-hip ratio (WHR) and sex on LRNC volume ( p =0.025). There was also an interaction between sex, VAT, and total cholesterol/high-density lipoprotein cholesterol ratio (TC/HDL-C) on LRNC volume ( p =0.012), beyond age and risk factors ( p =0.011). Only 8.6% of men and none of the women were classified at high risk (presence of LRNC) by the Framingham Risk Score while 35.4% of men and 14.0% of women were classified at high risk by the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) risk score (risk of advanced atherosclerosis). Elevated TC/HDL-C (≥3) and/or WHR (≥0.8 in women, ≥0.9 in men) were superior to the PDAY risk score, identifying 62.2% of women (Net Reclassification Improvement [NRI]=1.85, p <0.001) and 79.3% of men (NRI=0.26, p <0.001) with LRNC. Conclusions: Women had less visceral adiposity, carotid atherosclerosis burden and LRNC volume, independently of age and risk profile. Carotid LRNC volume varied with sex, VAT, and atherogenic lipoproteins. WHR and TC/HDL-C improved the identification of high-risk carotid atherosclerosis features in women as well as men. This evidence supports the clinical potential of the atherogenic lipoprotein profile and of adiposity distribution in atherosclerosis risk evaluation of both women and men.