Abstract 9867: Associations of Urinary Isoprostane Levels with Prevalence and Progression of Coronary Artery Calcification and Carotid Plaque in the Multi-Ethnic Study of Atherosclerosis (mesa)

Abstract

Introduction: Urinary isoprostanes reflect oxidative stress, which is implicated in the pathogenesis of atherosclerotic cardiovascular disease (ASCVD). Coronary artery calcium (CAC) & carotid plaque are markers of subclinical atherosclerosis and prognostic of ASCVD risk. We examined if the urinary isoprostane iPF2α-III and its metabolite iPF2α-III-M were associated with CAC & carotid plaque. Hypothesis: Higher urinary isoprostanes are associated with a greater prevalence, incidence, burden, and progression of CAC & carotid plaque. Methods: 1097 MESA participants free of ASCVD had urinary isoprostanes measured at baseline. All participants underwent cardiac CT at baseline; 1083 underwent repeat CT ~10 yrs later. CAC was measured by Agatston scoring. All participants had carotid ultrasound (US) at baseline; 837 underwent repeat carotid US ~10 yrs later. Carotid plaque score (CPS) was defined as the number of carotid segments containing plaque. Isoprostane levels were divided into tertiles. Relative risk regression and linear mixed effect models determined prevalence/incidence and burden/progression respectively of CAC & CPS. Results: Mean age of participants at baseline was 62.2 (8.3) yrs; 49% were women. There was no association of isoprostanes with CAC at baseline. There was a positive, but not statistically significant association, comparing the highest vs lowest tertiles of iPF2α-III-M and CAC progression over 10 yrs (Fig 1a). There was a statistically significant association comparing the highest vs lowest tertiles of isoprostanes with prevalence and burden of carotid plaque at baseline, but not with CPS incidence/progression (Fig 1b). Conclusions: In this multiethnic cohort, urinary isoprostanes were weakly but positively associated with carotid plaque burden and prevalence in cross sectional analysis and also showed a non-significant trend toward CAC progression, suggesting this measure of oxidative stress may be associated with ASCVD.