Utility of Discrepancies Between Friedewald and Martin Equations in Predicting Pathogenic Variants of Familial Hypercholesterolemia in Children

BACKGROUND: The Friedewald equation, commonly used to calculate low-density lipoprotein cholesterol (LDL-C), occasionally yields inaccurate estimations for very-low-density lipoprotein cholesterol, suggesting the need for an alternative method such as the Martin equation. In this study, we aimed to evaluate the discrepancies between the Friedewald and Martin equations, particularly in the context of pathogenic variants associated with familial hypercholesterolemia (FH). METHODS AND RESULTS: =11.348, P<0.001). Even in 37 children with LDL-C <180 mg/dL, discrepancies between the equations were still associated with the presence of pathogenic FH variants (Fisher's exact test, P=0.028). CONCLUSIONS: Discrepancies in LDL-C levels measured by the Friedewald and Martin equations might serve as a useful predictive marker for identifying pathogenic variants of FH, especially in cases of LDL-C <180 mg/dL, which are often challenging to diagnose.