This blood test may predict heart disease better than LDL cholesterol, some doctors say

Heart disease remains the leading cause of death for both men and women in the United States. While “bad” or LDL cholesterol is a well-known risk factor routinely screened for during yearly physicals, emerging research suggests another blood marker, Apolipoprotein B (apoB), may offer a more comprehensive assessment of heart disease risk.

A Deeper Look at Heart Disease Risk

ApoB is a protein found on the surface of harmful lipoproteins, including LDL, that contribute to the buildup of plaque in arteries. Because each harmful particle contains one apoB molecule, testing for apoB essentially measures the total number of these potentially artery-clogging compounds. Cholesterol, a waxy substance vital for building cells and hormones, is packaged within these lipoproteins.

Did You Know? Less than 1% of adults in the U.S. Have been tested for apoB, despite its potential as a more accurate predictor of heart disease risk.

Currently, doctors primarily monitor LDL cholesterol levels to gauge a patient’s risk. Elevated LDL often prompts recommendations for lifestyle changes or medication. However, a normal LDL reading doesn’t always guarantee a clear bill of health. A mismatch between normal LDL and elevated apoB – termed “discordance” – can occur, particularly in individuals who are overweight, have diabetes, or high triglyceride levels.

The Role of ApoB Testing

While the American Heart Association doesn’t currently recommend routine apoB testing, except for those with high triglycerides, some cardiologists believe broader screening is warranted. Dr. Ann Marie Navar, a preventive cardiologist at UT Southwestern Medical Center in Dallas, routinely checks apoB in her patients and believes all adults should be screened. Dr. Samia Mora, director of the Center for Lipid Metabolomics at Brigham and Women’s Hospital, suggests at least one apoB test to confirm alignment with LDL results.

Expert Insight: The potential benefit of apoB testing lies in its ability to provide a more complete picture of a patient’s cardiovascular risk, particularly in cases where LDL levels may not fully reflect the number of harmful particles circulating in the bloodstream.

Dr. Thomas Dayspring, a renowned cholesterol expert, asserts that apoB is “by far the best metric” for cardiovascular risk assessment. An apoB test directly assesses the number of artery-clogging particles. Dr. Jeffrey Berger, a preventive cardiologist at NYU Langone, describes apoB as a way to assess “cholesterol burden.”

ApoB testing is gaining traction, even appearing in collaborations between health influencers and commercial testing companies, such as a recent partnership between Sweetgreen and Function Health. The test typically costs around $70 if not covered by insurance.

While there aren’t established target levels for apoB, values under 90 mg/dL are generally considered acceptable, with some experts suggesting even lower targets may be optimal. Dr. Michael Shapiro, chair of the American Heart Association Council on Lipidology, Lipoprotein, Metabolism & Thrombosis, finds the test most useful when evaluating patients already undergoing lipid-lowering therapy.

Frequently Asked Questions

What is the difference between LDL and apoB?

LDL cholesterol measures the amount of cholesterol carried by LDL particles, while apoB measures the number of LDL particles themselves.

Who currently receives apoB testing?

The American Heart Association’s guidelines do not recommend routine apoB testing, except for patients with high triglycerides. Some cardiologists, like Dr. Navar, routinely check apoB in all their patients.

What factors can cause a mismatch between LDL and apoB levels?

Factors such as being overweight, having diabetes, or high triglyceride levels can lead to a discordance between normal LDL levels and elevated apoB.

Given the potential for a more accurate risk assessment, will apoB testing become more commonplace in preventative cardiology?