Low-Density Lipoprotein Cholesterol Gymnastics: Exploring the Advantages and Limitations of the Friedewald, Martin-Hopkins, and Sampson Equations for Personalized Lipid Management.
Level 4 - case-series / case-control
Cross-sectional method comparison study evaluating estimation formulas against direct measurement.
PubMed 39338254 · doi:10.3390/jpm14091000
What was done
Directly measured low-density lipoprotein cholesterol (dLDL-C) and standard lipid profiles were assessed in a cohort of 222 individuals. LDL-C was also estimated using the Friedewald, Martin-Hopkins, and Sampson equations. Researchers analyzed percentage differences (%Delta) between estimated and measured LDL-C relative to dLDL-C, high-density lipoprotein cholesterol (HDL-C), and triglyceride levels, including a subgroup analysis of 30 individuals with extreme discrepancies.
What was found
The percentage difference (%Delta) compared to measured LDL-C was significantly lower (p < 0.0001) for the Martin-Hopkins (-8.8 ± 9.8%) and Sampson (-9.5 ± 9.2%) equations than the Friedewald equation (-12.2 ± 9.2%). All equations showed increasing underestimation of LDL-C as dLDL-C concentrations decreased. For the Martin-Hopkins equation, %Delta correlated positively with dLDL-C (≤130 mg/dL) and triglycerides, and negatively with HDL-C. In the 30 individuals with extreme %Delta values, severe underestimation occurred when low LDL-C, low triglycerides, and high HDL-C coincided.
Why it matters
While Martin-Hopkins and Sampson equations outperform Friedewald, clinicians must recognize that all three formulas underestimate LDL-C at low levels or when low triglycerides coincide with high HDL-C, highlighting when direct measurement is required.
Limits
The sample size is relatively small (n = 222), and the abstract does not describe cohort demographics, comorbidities, fasting status, or medication use. Clinical outcomes and cardiovascular risk misclassification rates were not evaluated.
Cited by
- supports Standard clinical lipid panels calculate LDL cholesterol via a mathematical formula rather than directly measuring it.