Abstract 16427: Does Elevated Myeloperoxidase Retard the Protective Association of HDL-C With Coronary Calcium and Cardiovascular Disease Risk?
Background: Myeloperoxidase (MPO), a leukocyte derived enzyme, may be an inflammatory mediator of atherosclerosis. MPO may promote dysfunctional high-density lipoprotein (HDL). We examined whether increased MPO levels unfavorably alters the relation of HDL-C with atherosclerosis and cardiovascular disease (CVD).
Methods: We examined 2047 adults (54% male, mean age 59 yrs) without known CVD. MPO was measured by immunoassay. Coronary artery calcium (CAC), a measure of subclinical atherosclerosis, was measured by computed tomography. CAC scores were divided into low (≤100) and high (>100). Subjects were divided according to baseline median HDL-C (52mg/dl) and median log normalized MPO (5.5 pmol/L). Cox and logistic regression, adjusted for age, sex, and risk factors, were performed examining HDL-C and log-MPO with 3.8-year incident CVD (myocardial infarction, cardiac death, stroke, or revascularization >90 days) and CAC>100, respectively.
Results: Subjects with high log-MPO (≥ 5.5 pmol/L) were more likely (p<0.02 to p <0.001) to be females with high BMI, blood pressure, and triglycerides (TG) and those with low HDL-C more likely (p<0.01) to be non-white, male, diabetic, hypertensive, and with higher BMI and TG. CVD incidence per thousand person years was highest in the low HDL-C and high log MPO (9.2) and lowest in those with high HDL-C and low MPO (3.4) (Figure). Those with low HDL-C/high log-MPO were more likely to have CAC>100 (adjusted odds ratio: 1.5, 95% CI: 1.1-2.1, p <0.02) compared to high HDL-C/low log-MPO (reference). CVD events were more likely with low HDL-C and high log MPO (unadjusted hazard ratio [HR]: 2.7, 95% CI:1.2-6.5, p= 0.02) compared to the reference, but this was attenuated and not significant after adjusting for risk factors.
Conclusions: Our study suggests that high MPO when accompanied by low HDL-C may identify those with increased CAC and CVD event risk, supporting a potential proinflammatory effect of MPO on HDL-C.
Author Disclosures: K. Malhotra: None. D.S. Berman: None. M.L. Kashyap: None. N.D. Wong: Honoraria; Modest; Sanofi, Esperion. Research Grant; Significant; Amgen, Gilead, Regeneron, Bristol Myers Squibb. Consultant/Advisory Board; Significant; Re-Engineering Healthcare.
- © 2014 by American Heart Association, Inc.