ApoB Protein Testing More Accurately Predicts Heart Disease Risk than Testing for Cholesterol Alone

By LabMedica International staff writers
Posted on 07 Mar 2023

Image: ApoB may be a more accurate risk predictor of atherosclerotic cardiovascular disease (Photo courtesy of Intermountain Health)

As part of the annual physical exam, individuals are typically tested for their levels of HDL (the good) and LDL (the bad) cholesterol to assess their risk for heart disease. However, recent research has raised questions about the accuracy of these standard tests in predicting heart disease risk. Instead, emerging data suggest that testing for levels of Apolipoprotein B-100 (ApoB), a protein responsible for transporting fat molecules including LDL cholesterol - notoriously known as the "bad cholesterol" - throughout the body, may be a more precise indicator of atherosclerotic cardiovascular disease.

In a new study presented at the 2023 American College of Cardiology annual Scientific Sessions in New Orleans, researchers from Intermountain Health (Salt Lake City, UT, USA) found that ApoB testing can help identify patients who may continue to face a higher risk for a cardiovascular event, despite their normal LDL cholesterol levels. ApoB testing remains fairly uncommon, but is on the rise. ApoB levels measure atherogeneic particle numbers, and several studies suggest that particle numbers are superior than cholesterol levels as risk predictors of disease. The better assessment of particle numbers could make ApoB better at evaluating risk, particularly for patients having normal LDL cholesterol levels, including those with metabolic syndrome, like diabetes or prediabetes or low HDL and high triglyceride levels.

The researchers conducted a retrospective study by analyzing electronic health records of patients from 2010 to February 2022. The study revealed that the number of Apo B tests administered increased from 29 cases in 2010 to 131 in 2021. Additionally, the team observed a positive correlation between ApoB and LDL cholesterol levels, though the ApoB/LDL cholesterol ratio rose as LDL cholesterol decreased. This indicated a high number of atherogenic small, dense LDL particles characterized by smaller amounts of LDL cholesterol per particle. However, the researchers do not expect ApoB to replace standard HDL and LDL testing soon, as it is costlier and not yet firmly established in the healthcare system. Nevertheless, clinicians should increasingly consider ApoB testing a valuable tool for refining cardiovascular risk, particularly in specific patient groups.

“Testing for ApoB doesn’t tell you how much cholesterol a patient has, but instead it measures the number of particles that carry it,” said Jeffrey L. Anderson, Intermountain Health cardiologist and principal investigator of the study. “While it’s still not a commonly ordered test, we found that it’s both being used more often, and it could lead to a more accurate way to test for lipoprotein-related risk than how we do it now,”

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