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The Martin/Hopkins method of low-density lipoprotein (LDL) cholesterol assessment is more accurate that the usual calculation method, according to an analysis of the FOURIER trial.

Among FOURIER participants with stable cardiovascular disease, the median Martin/Hopkins LDL cholesterol level was 2 mg/dL below the reference standard of preparative ultracentrifugation -- a statistically similar result, whereas the Friedewald method underestimated LDL cholesterol by 4 mg/dL (P<0.001).

The Martin/Hopkins method correlated significantly better with preparative ultracentrifugation than did the Friedewald, according to a group led by Seth Martin, MD, MHS, of Johns Hopkins University School of Medicine in Baltimore, reporting online in .

While 22.9% of Martin/Hopkins LDL cholesterol values were at least 5 mg/dL different from reference and 2.6% were off by more than 10 mg/dL, these proportions were 40.1% and 13.3% with Friedewald estimation, respectively (P<0.001 for each).

The Martin/Hopkins method "uses the same standard lipid measurements of total and HDL [high-density lipoprotein] cholesterol and triglycerides as the Friedewald equation does, but it uses a personalized rather than fixed conversion factor in calculating LDL cholesterol levels," Martin and colleagues noted.

The Friedewald formula has been used to calculate LDL cholesterol for more than 40 years, Neil Stone, MD, of Northwestern University Feinberg School of Medicine in Chicago, pointed out in an invited commentary.

Now, "just as it's timely to consider nonfasting lipid measurements in routine clinical assessment, it may also be timely to consider the clinical advantages of the Martin/Hopkins method for LDL-C determination compared with that derived from the Friedewald equation," he said.

"With doubts about LDL cholesterol accuracy, the clinician-patient discussion about the potential for net benefit by adding a nonstatin treatment is hampered," Stone added.

The difference between methods was more pronounced when triglyceride levels exceeded 150 mg/dL.

For this analysis, Martin's group relied on FOURIER patients who had multiple LDL cholesterol values from Martin/Hopkins, Friedewald, and ultracentrifugation assessment (n=12,742).

"But not everything that matters depends on measurement," Stone concluded. "Clinical judgment and shared decision making as suggested in recent guidelines are still required to put treatment decisions based on LDL cholesterol measurements in the appropriate perspective for the individual patient."