Abstract
In patients with coronary artery disease (CAD), further increasing the level of high-density lipoprotein (HDL) cholesterol (HDL-C) as an add-on to statins cannot reduce cardiovascular risk. And it has been reported that HDL functional metric—cholesterol efflux capacity (CEC) may be a better predictor of CAD risk than HDL-C. CEC measurement is time-consuming and not applicable in clinical settings. Thus, it is meaningful to explore an easily acquired index for evaluating CEC. Thirty-six CAD patients and sixty-one non-CAD controls were enrolled in this cross-sectional study. All CAD patients had acute coronary syndrome (ACS). CEC was measured using a [3H] cholesterol loading Raw 264.7 cell model with apolipoprotein B-depleted plasma (a surrogate for HDL). Proton nuclear magnetic resonance (NMR) spectroscopy was used to assess HDL components and subclass distribution. CEC was significantly impaired in CAD patients (11.9 ± 2.3%) compared to controls (13.0 ± 2.2%, p = 0.022). In control group, CEC was positively correlated with enzymatically measured HDL-C levels (r = 0.358, p = 0.006) or with NMR-determined HDL-C levels (NMR-HDL-C, r = 0.416, p = 0.001). However, in CAD group, there was no significant correlation between CEC and HDL-C (r = 0.216, p = 0.206) or NMR-HDL-C (r = 0.065, p = 0.708). Instead, we found that the level of high-sensitivity C-reactive protein (hsCRP) was inversely associated with CEC (r = − 0.351, p = 0.036). Multiple regression analysis showed that the hsCRP level was associated with CEC after adjusting other cardiovascular risk factors and HDL-C, although the association would not reach significance if adjusting for multiple testing. NMR spectroscopy showed that HDL particles shifted to larger ones in patients with high hsCRP levels, and this phenomenon was accompanied by decreased CEC. In patients with CAD, the level of HDL-C cannot reflect HDL function. The impaired correlation between HDL-C and CEC is possibly due to an inflammation-induced HDL subclass remodeling. These hypothesis-generating data suggest that hsCRP levels, a marker of acute inflammation, may associate with HDL dysfunction in ACS subjects. Due to the design limited to be correlative in nature, not permitting causal inference and a larger, strictly designed study is still needed.
Highlights
In patients with coronary artery disease (CAD), further increasing the level of high-density lipoprotein (HDL) cholesterol (HDL-C) as an add-on to statins cannot reduce cardiovascular risk
Concentrations of total cholesterol (TC), HDL-C, and lowdensity lipoprotein cholesterol (LDL-C) were lower, but serum high-sensitivity C-reactive protein (hsCRP) was significantly higher in CAD patients than in the non-CAD controls (1.76 [0.88–4.05] vs. 0.91 [0.32–1.87], p = 0.004)
Subsequent attempts for drug therapies that aim to raise HDL-C levels with niacin[3] or cholesteryl ester transfer protein (CETP) inhibitor[2] have both been in vain
Summary
In patients with coronary artery disease (CAD), further increasing the level of high-density lipoprotein (HDL) cholesterol (HDL-C) as an add-on to statins cannot reduce cardiovascular risk. Abbreviations HDL High-density lipoprotein HDL-C High density lipoprotein cholesterol CETP Cholesteryl ester transfer protein RCT Reverse cholesterol transport CEC Cholesterol efflux capacity CAD Coronary artery disease hsCRP High-sensitivity C-reactive protein hsTnT High-sensitivity Troponin T MI Myocardial infarction HIV Human immunodeficiency virus NMR Nuclear magnetic resonance. A recent epidemiological study has revealed that extremely high HDL-C levels are associated with increased CAD mortality[6] These results highlight the potential limitations of using HDL-C levels, a static mass-based parameter, to assess the risk of CAD, and call for investigations on more robust HDL functional markers for evaluating cardiovascular risks. Cholesterol efflux capacity (CEC), a metric reflecting the ability of HDL as a cellular cholesterol acceptor, has been demonstrated to be inversely associated with subclinical atherosclerosis[8,9], the incidence of cardiovascular events[10,11,12], and prognosis of CAD13,14, and is considered a reliable CAD m arker[10]
Published Version (Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have