Discordance Between Standard Equations for Determination of LDL Cholesterol in Patients With Atherosclerosis.

Document Type


Publication Date


Publication Title

Journal of the American College of Cardiology


oregon; portland; cards; cards publication; Aged; Atherosclerosis; Biomarkers; Cholesterol, LDL; Female; Humans; Male; Retrospective Studies; Triglycerides


BACKGROUND: Accurate estimation of low-density lipoprotein cholesterol (LDL-C) is important for guiding cholesterol-lowering therapy. Different methods currently exist to estimate LDL-C.

OBJECTIVES: This study sought to assess discordance of estimated LDL-C using the Friedewald, Sampson, and Martin/Hopkins equations.

METHODS: Electronic health record data from patients with atherosclerotic cardiovascular disease and triglyceride (TG) levels of/dL between October 1, 2015, and June 30, 2019, were retrospectively analyzed. LDL-C was estimated using the Friedewald, Sampson, and Martin/Hopkins equations. Patients were categorized as concordant if LDL-C was/dL with each pairwise comparison of equations and as discordant if LDL-C was/dL for the index equation and ≥70 mg/dL for the comparator.

RESULTS: The study included 146,106 patients with atherosclerotic cardiovascular disease (mean age: 68 years; 56% male; 91% White). The Martin/Hopkins equation consistently estimated higher LDL-C values than the Friedewald and Sampson equations. Discordance rates were 15% for the Friedewald vs Martin/Hopkins comparison, 9% for the Friedewald vs Sampson comparison, and 7% for the Sampson vs Martin/Hopkins comparison. Discordance increased at lower LDL-C cutpoints and in those with elevated TG levels. Among patients with TG levels of ≥150 mg/dL, a >10 mg/dL difference in LDL-C was present in 67%, 27%, and 23% of patients when comparing the Friedewald vs Martin/Hopkins, Friedewald vs Sampson, and Sampson vs Martin/Hopkins equations, respectively.

CONCLUSIONS: Clinically meaningful differences in estimated LDL-C exist among equations, particularly at TG levels of ≥150 mg/dL and/or lower LDL-C levels. Reliance on the Friedewald and Sampson equations may result in the underestimation and undertreatment of LDL-C in those at increased risk.

Clinical Institute

Cardiovascular (Heart)