Assessing High-Density Lipoprotein: Shifting Focus from Quantity to Quality in Cardiovascular Disease Risk Assessment

Abstract

High-density lipoprotein cholesterol (HDL) has long been regarded as a protective factor against cardiovascular disease (CVD). However, recent research challenges this notion, suggesting that HDL functionality rather than its quantity may be a more accurate predictor of CVD risk. While epidemiological studies have traditionally found that higher HDL levels are associated with reduced CVD risk, intervention trials aiming to elevate HDL levels have yielded inconsistent results. Moreover, observational studies have reported that unusually high HDL levels are associated with increased mortality rates. These discrepancies underscore the complexity of the role of HDL in CVD. Reverse cholesterol transport, facilitated by HDL, plays a crucial role in preventing atherosclerosis by removing cholesterol from peripheral tissues. Additionally, HDL exhibits anti-inflammatory properties by inhibiting endothelial adhesion molecules and suppressing pro-inflammatory cytokines. Recent studies have highlighted the importance of HDL particle number, size, and functionality in assessing CVD risk. For instance, increased HDL particle number and larger particle size have been associated with reduced CVD risk, independent of HDL cholesterol levels. Furthermore, HDL’s cholesterol efflux capacity has emerged as a promising biomarker for predicting CVD risk, with higher efflux capacity correlating with lower CVD incidence and mortality. This article reviews the latest findings regarding the role of HDL in CVD risk assessment, emphasizing the need to focus on HDL quantity and HDL quality.