What’s new in cardiology testing?
Cardiovascular disease (CVD) is the leading cause of death worldwide (WHO, 2015), responsible for 17.5 million deaths per year worldwide. That’s a shocking 31% of all global deaths! This figure is set to increase to over 23.6 million by 2030, and with such startling statistics, it is important to stress the need for further risk assessment biomarkers to be taken into account in the assessment of CVD!
Traditional vs. novel biomarkers
Traditional and routinely run biomarkers include Total Cholesterol, HDL Cholesterol, LDL Cholesterol and Triglycerides, but with a growing body of research indicating that further risk assessment biomarkers need to be taken into account, it is important to stress the value of novel biomarkers.
Conventional tests for CVD risk assessment detect a mere 20% of all CVD patients; the other 80% can be identified by carrying out more detailed lipid testing. Novel biomarkers therefore enhance the chance of patient risk being identified. Novel biomarkers include HDL and LDL subclasses including HDL3 and sLDL, in addition to extended lipids Lipoprotein(a), and the Apolipoprotein’s. These tests are discussed below:
HDL and LDL subclasses
HDL3 is a sub-fraction of the HDL molecule, and enhances risk profiling of CVD due to its strong correlation with MI; elevated levels of HDL3 particles reflect abnormally increased triglyceride content of the HDL particle. This means that whilst a patient may have high levels of HDL, they may also have elevated levels of HDL3 which essentially renders the potentially potent protection factor of HDL as a cholesterol scavenger as almost useless.
Randox offers an automated HDL3 assay for the quantitative determination of HDL3 cholesterol in human serum or plasma. For more information please visit: http://www.randox.com/hdl3/
sLDL is a subtype of LDL Cholesterol. It is more atherogenic due to its small size which makes it more susceptible to oxidation, and enables it to more readily permeate the inner arterial walls, causing damage and destruction. As such, the measurement of sLDL is extremely valuable as a vital risk marker of MI; in fact, elevated levels of sLDL are associated with a three-fold increased risk of MI.
Randox offers an automated sLDL assay with a wide measuring range of 0.189-22.2 mmol/l; therefore it will comfortably detect levels outside of the healthy limit of 4.90 mmol/l, ensuring a worthy addition for true assessment of CVD risk. For more information please visit: http://www.randox.com/sldl-cholesterol/
Extended lipids profile – increasing the accuracy of patient profiling
Lp(a) offers an excellent addition to the lipids profile, and should be considered due to its role in the assessment of genetically inherited risks of CVD. As genetically determined, Lp(a) remains fairly constant and is unaffected by lifestyle changes and some treatments. Elevated levels are associated with premature development of atherosclerosis and CVD, and are independent of other lipids. Testing for elevated levels is recommended for patients with a family history of premature CVD or elevated Lp(a), and for patients who have developed CVD at a young age.
Randox Lp(a) offers superior methodology, as it contains a very high density of isoform-insensitive antibodies and detection reagent. There is a five point calibrator available which takes into account the heterogeneity of the Lp(a) molecule for each of the levels, which results in excellent commutability of the calibrator with patient samples. For more information please visit: http://www.randox.com/lipoprotein-a/
Apolipoprotein’s (Apo’s) have the role of transferring triglycerides, cholesterol and other fats to appropriate cells for metabolism. Measurement of these allows investigation into why abnormal lipid levels may be occurring. Tests include Apo A-I, Apo A-II, Apo B, Apo C-II, Apo C-III and Apo E.
Apo A-I is responsible for removing excess cholesterol from extra-hepatic tissues and has an inverse relationship to CVD; this test is used to find the cause of high lipid levels and detect if abnormal levels are due to a disorder causing Apo-A I deficiency.
Apo A-II is a major constituent of HDL Cholesterol and plays an important role in reverse cholesterol transport and lipid metabolism; the production of Apo A-II levels determine the distribution of Apo A-I in HDL (Apo A-I removes excess cholesterol), and therefore increased production of Apo A-II promotes atherosclerosis.
Apo B is the main protein in LDL cholesterol and is concerned with the uptake of cholesterol; elevated levels indicate increased risk of CVD even when total and LDL cholesterol levels are normal.
Apo A-I and Apo B are useful to assess patients with a personal or family history of high concentrations of lipids and/or heart diseases, for diagnosis of conditions causing elevated lipid levels, for monitoring the effectiveness of lipid lowering treatments, and, when used together they can determine Apo B/Apo A-I ratio as an alternative to total cholesterol/HDL cholesterol ratio when determining CVD risk.
Apo C-II and Apo C-III aid in the assessment of CVD as both are associated with hypertriglyceridemia (elevated triglyceride levels) in patients; a deficiency in Apo C-II can lead to hypertriglyceridemia, whereas elevated levels of Apo C-III are associated with both primary and secondary hypertriglyceridemia. In addition, Apo C-III is often reported higher in patients with type 2 diabetes, hyperbilirubinemia, kidney deficiency and decreased thyroid function.
Apo E is responsible for the transport of triglycerides to the liver and distribution of cholesterol between cells; deficiency can lead to premature atherosclerosis.
Therefore measurement of Lipoproteins and their counterparts, apolipoprotein’s, increase patient profiling to give a more accurate assessment of risk of CVD. For more information on Randox extended lipid profile, please visit http://www.randox.com/lipid-reagents/
For more information on Randox range of cardiology reagents please visit http://www.randox.com/cardiology-reagents