The basic lipid panel, relied upon for more than 85% of adult cholesterol testing each year, could be leaving millions at risk due to errors in estimation of LDL cholesterol levels according to a study published in the Journal of the American College of Cardiology.
The study compared the accuracy of calculated LDL cholesterol measurement in the traditional basic lipid panel (standard cholesterol test) to directly measured LDL cholesterol in the VAP Lipid Panel from Atherotech Diagnostics Lab, Birmingham, Ala.
The research, which involved more than 1.3 million U.S. adults, represents the largest study of its kind to date and could significantly impact patient care and clinical practice guidelines in the years ahead, according to the company.
Senior Investigator Steven R. Jones, MD, of the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, said LDL cholesterol is routinely estimated by the 1970s-era Friedewald equation in order to guide treatment and lower heart disease risk. However, rigorous comparison with direct LDL cholesterol measurement has received little attention, especially at levels below 70 mg/dl, which is often the target in high-risk patients, including those with conditions such as diabetes or coronary heart disease.
“It’s the first time we’ve compared LDL cholesterol measurements using the Friedewald calculation to the density gradient ultracentrifugation method, which directly measures LDL cholesterol, the primary target of therapy in cholesterol testing for heart disease risk assessment,” Jones says. “What’s important in this study is that Friedewald and direct LDL cholesterol are most different, with Friedewald LDL generally lower than direct LDL, when accuracy is most crucial in patients with LDL cholesterol levels in the high-risk treatment target range and elevated triglycerides.”
From 2009 to 2011, researchers examined consecutive lipid profiles in 1,310,440 patients from the Very Large Database of Lipids (VLDL) dataset who underwent vertical density gradient ultracentrifugation of cholesterol by the Vertical Auto Profile (VAP Lipid Panel). Results showed the basic lipid panel underestimated risk in 23% to 59% of patients with Friedewald estimated LDL cholesterol levels below 70 md/dl and triglycerides above 150, which could result in under treatment of high-risk patients.
The study, titled “Friedewald Estimated versus Directly Measured Low-Density Lipoprotein Cholesterol and Treatment Implications” is the product of academic-industry collaboration between investigators at Johns Hopkins University and Atherotech Diagnostics Lab.