CONCORDANCE BETWEEN DIRECT MEASUREMENT OF LDL-C AND ESTIMATION BY THE EXTENDED MARTIN-HOPKINS EQUATION AT HIGH TRIGLYCERIDE

Abstract

Cardiovascular disease remains one of the leading causes of mortality worldwide, and LDL-C is a critical risk factor. Although direct measurement of LDL-C using homogeneous enzymatic assays provides high accuracy, it remains costly and time-consuming. The Friedewald equation, while widely applied, reduces accuracy in patients with elevated triglyceride, whereas the extended Martin-Hopkins (eMH) equation has been proposed to overcome this limitation. This cross-sectional study was conducted on 626 patients at Thong Nhat Hospital with TG levels ranging from 400-800 mg/dL. LDL-C concentrations were determined using a homogeneous enzymatic method and estimated using both the Friedewald and eMH equations. Accuracy was assessed by Pearson's/Spearman's correlation coefficient, mean absolute error (MAE), root mean square error (RMSE), and concordance rate for risk reclassification. The eMH equation demonstrated a higher correlation with direct measurement compared to Friedewald (0,74 > 0,70), lower MAE and RMSE values (20,6 mg/dL and 27,8 mg/dL vs 42,3 mg/dL and 52,2 mg/ dL), and a higher concordance rate (39% vs 29%). In conclusion, the eMH equation showed superior accuracy and concordance within the TG range of 400-800 mg/dL compared with the Friedewald equation. Nevertheless, further multicenter studies and comparisons with reference β-quantification methods are warranted before broad public implementation