Even if their LDL cholesterol levels are under control, people with high levels of particular triglyceride-carrying apolipoproteins may still be two to three times more likely to develop coronary heart disease. This finding was made by researchers at King's College London and Oxford Public Health. Circulation Research publishes the findings. Apolipoprotein levels in blood are frequently used to identify people who are at risk for cardiovascular disease. Apolipoproteins transport lipids like cholesterol in our blood, and those with greater amounts of them are at an increased risk of cardiovascular disease. Doctors frequently prescribe a statin, an LDL-cholesterol reducing medication, to lower a patient's risk level. Some persons may still have a "residual" risk of getting cardiovascular disease despite having ideal levels of LDL-cholesterol as a result of taking statins. After adjusting for known risk variables and statin use, the researchers examined the relationships between 13 apolipoproteins and coronary heart disease in blood samples supplied to the PROCARDIS and Bruneck trials. Lp(a), LDL-C, HDL-C, and triglycerides were the four major apolipoprotein categories that were used to categorize the different types of lipids that each protein carried.
Key findings:
- ApoC1, ApoC3, and ApoE, which contain triglycerides, were linked to a two- to three-fold increased risk of coronary heart disease;
- A two-fold increased risk of coronary heart disease was independently linked to ApoB, which transports LDL cholesterol;
- ApoA4 and ApoM, which are related to HDL-cholesterol (often known as "good cholesterol"), were linked to a decreased risk of coronary heart disease;
Both the PROCARDIS and Bruneck studies found agreement between the 13 apolipoproteins investigated and coronary heart disease.
Lead author of the study and Oxford Population Health Professor of Epidemiology and Public Health Medicine Robert Clarke stated, "There is an unmet clinical need to understand why some people still have a residual risk of developing coronary heart disease, despite lowering blood levels of LDL-cholesterol and taking into account other known risk factors. The associations found in this study should spur further investigation into apolipoproteins, particularly those that carry triglycerides throughout the body, as this information may help us identify individuals still at risk for coronary heart disease and guide the development of personalized treatments to further lower their risk levels beyond statin therapy.