Non-HDL Study Exposes Basic Lipid Panel Error Rates

Patients evaluated with the basic lipid panel may have significant errors in risk classification, especially when relying on low-density lipoprotein cholesterol (LDLc).

Differences between LDLc and non-high density lipoprotein cholesterol (NHDLc) levels are greatest when accurate measurement is most critical as in high-risk patients with low LDLc targets and high triglycerides.

Scientists at the Johns Hopkins Ciccarone Center (Baltimore, MD, USA) examined lipid profiles in more than 1.3 million adults from the Very Large Database of Lipids (VLDL) dataset from 2009 to 2011. This is a massive collection of blood lipid samples measured with vertical density gradient ultracentrifugation by the Vertical Auto Profile (VAP) Lipid Panel (Atherotech; Birmingham, AL, USA).

The collaborating scientists from Johns Hopkins and Atherotech showed that a significant percentage of patients were reclassified by NHDLc and moved into to a higher treatment category compared with LDLc. For patients with estimated LDLc levels below 70 mg/dL and triglycerides between 150 and 199 mg/dL, 22% had NHDLc levels at or above 100 mg/dL, and 50% had NHDLc levels above the 93 mg/dL level.

Triglycerides were directly measured using the Abbott ARCHITECT C-8000 system (Abbott Laboratories; Abbott Park, IL, USA). Several limitations, including inaccuracy with elevated triglycerides as low as 150mg/dL , make LDLc a less accurate marker of cardiovascular risk than secondary measures such as NHDLc, which has targets set at about 30 mg/dL above LDLc targets with no specific studies establishing validity.

Michael Cobble, MD, Atherotech’s Chief Medical Officer, said, “Non-HDL cholesterol targets probably need to be lowered to bring them more in line with LDLc targets. However, from a clinical perspective, the variation and underestimation of risk that occurs with estimated LDLc in high-risk patients is unacceptable. A direct measure of LDLc along with non-HDLc components, as provided by the VAP Lipid Panel, is more accurate, in fasting or non-fasting patients." The study was published on September 18, 2013, in the Journal of the American College of Cardiology.

Related Links:
Johns Hopkins Ciccarone Center
Atherotech
Abbott Laboratories