What is HDL3 Cholesterol?
HDL comprises of several subclass particles, which differ in their sizes, densities and components. These HDL subclasses are considered to play different roles in the progression and regression of arteriosclerosis. HDL3 Cholesterol is a smaller and more dense subfraction of the HDL particle.
What is the clinical significance of HDL3 Cholesterol?
HDL is the scavenger of cholesterol within arterial walls and if HDL3 Cholesterol is in too low numbers the ability to remove this cholesterol is reduced. Therefore it is widely accepted that there is an inverse correlation between HDL3 Cholesterol and CVD risk, as demonstrated in a number of recent key publications:
HDL3 subclass may be primarily responsible for the inverse association of HDL-C and CV disease. (Albers et. al, 2016)¹
The aims of this secondary analysis were to examine the levels of cholesterol in high density lipoprotein (HDL) subclasses (HDL2-C and HDL3-C), small dense low density lipoprotein (sdLDL-C), and LDL triglyceride (LDL-TG) at baseline, as well as the relationship between these levels and CV outcomes. Analyses were performed on 3094 study participants who were already on statin therapy prior to enrollment in the trial.
The results of this secondary analysis of the AIM-HIGH Study indicate that levels of HDL3-C, but not other lipoprotein fractions, are predictive of CV events, suggesting that the HDL3 subclass may be primarily responsible for the inverse association of HDL-C and CV disease.
In secondary prevention, increased risk for long-term hard clinical events is associated with low HDL3-C, but not HDL2-C or HDL-C, highlighting the potential value of subclassifying HDL-C. (Martin et. al, 2015)²
We collaboratively analysed data from two, complementary prospective cohorts: the TRIUMPH study of 2465 acute myocardial infarction patients, and the IHCS study of 2414 patients who underwent coronary angiography.
In secondary prevention, increased risk for long-term hard clinical events is associated with low HDL3-C, but not HDL2-C or HDL-C, highlighting the potential value of subclassifying HDL-C.
Smaller, denser HDL3-C levels are primarily responsible for the inverse association between HDL-C and incident CHD in this diverse group of primary prevention subjects. (Joshi et. al, 2016)³
We aimed to clarify the associations of high-density lipoprotein cholesterol (HDL-C) subclasses with incident coronary heart disease (CHD) in two large primary prevention cohorts.
We measured cholesterol at baseline from the two major HDL subfractions (larger, more buoyant HDL2 and smaller, denser HDL3) in 4114 (mean age 53.8 years; 64% female) African American participants from the Jackson Heart Study and 818 (mean age 57.3 years, 52% female) predominantly Caucasian participants from the Framingham Offspring Cohort Study.
Smaller, denser HDL3-C levels are primarily responsible for the inverse association between HDL-C and incident CHD in this diverse group of primary prevention subjects. These findings have important implications ranging from considerations of HDL biology to interpretations of clinical trials utilizing HDL-C therapeutics.
Testing HDL3-C enables a more complete cardiac risk profile
Standard tests for cholesterol, HDL, LDL and triglyceride levels only detect approximately 20% of all coronary artery disease patients. The other 80% can only be identified by differentiating subgroups, and carrying out more detailed lipid testing.
Several clinical studies indicate that measuring these HDL subclasses better reflects primary and secondary CHD risk than measurement of total HDL, making it a significant independent biomarker for better risk profiling when used together with other risk markers.
Randox HDL3 assay
Randox HDL3 Cholesterol is an automated assay for the quantitative determination of HDL3 cholesterol in human serum or plasma.
Conventional methods for the determination of HDL2 and HDL3 in plasma involve ultracentrifugation and gradient gel electrophoresis. These methods are, however, unsuitable for routine analysis of large numbers of samples, since they require complicated, time-consuming techniques. The Randox HDL3-C is a fully automated homogeneous assay for the quantification of HDL3-C.
Other features of the Randox test include:
- Liquid ready-to-use
- Available on most automated biochemistry analysers
- Open vial stability of 28 days when stored at +2 to +8°C
- Dedicated controls and calibrators available
- Measuring range of 4 – 60mg/dl
- Demonstrates a strong correlation with the conventional Ultracentrifugation Method
- Allows for quantification of HDL2-C by the subtraction of HDL3-C from total HDL-C
- The HDL3 assay measures Total HDL3
Randox offers the complete cardiac risk profile
As clinical studies have shown, traditional biomarkers for lipids only give a limited overview of a person’s lipid profile and as a result their risk of cardiovascular events.
With primary and secondary cardiovascular issues on the rise globally, the need to encourage more extensive lipid profiling is on the increase
The Randox HDL3 assay can be added to biochemistry test menus, to help truly identify the risk of disease and as such provide the necessary tools for clinicians to prevent and reduce the risks.
Refer to our cardiology page for full details.