Korean Circ J.  2016 Sep;46(5):688-698. 10.4070/kcj.2016.46.5.688.

Comparison of Formulas for Calculating Low-density Lipoprotein Cholesterol in General Population and High-risk Patients with Cardiovascular Disease

• Choi H
• Shim JS
• Lee MH
• Yoon YM
• Choi DP
• Kim HC

• KMID: 2389627
• DOI: http://doi.org/10.4070/kcj.2016.46.5.688

Abstract

BACKGROUND AND OBJECTIVES
Low-density lipoprotein cholesterol (LDL-C), an established cardiovascular risk factor, can be generally determined by calculation from total cholesterol, high-density lipoprotein cholesterol, and triglyceride concentrations. The aim of this study was to compare LDL-C estimations using various formulas with directly measured LDL-C in a community-based group and hospital-based group among the Korean population.
SUBJECTS AND METHODS
A total of 1498 participants were classified into four groups according to triglyceride concentrations as follows: <100, 100-199, 200-299, and ≥300 mg/dL. LDL-C was calculated using the Friedewald, Chen, Vujovic, Hattori, de Cordova, and Anandaraja formulas and directly measured using a homogenous enzymatic method. Pearson's correlation coefficients, intraclass correlation coefficients (ICC), Passing & Bablok regression, and Bland-Altman plots were used to evaluate the performance of six formulas.
RESULTS
The Friedewald formula had the highest accuracy (ICC=0.977; 95% confidence interval 0.974-0.979) of all the triglyceride ranges, while the Vujovic formula had the highest accuracy (ICC=0.876; 98.75% confidence interval 0.668-0.951) in people with triglycerides ≥300 mg/dL. The mean difference was the lowest for the Friedewald formula (0.5 mg/dL) and the percentage error was the lowest for the Vujovic formula (30.2%). However, underestimation of the LDL-C formulas increased with triglyceride concentrations.
CONCLUSION
The accuracy of the LDL-C formulas varied considerably with differences in triglyceride concentrations. The Friedewald formula outperformed other formulas for estimating LDL-C against a direct measurement and the Vujovic formula was suitable for hypertriglyceridemic samples; it could be used as an alternative cost-effective tool to measure LDL-C when the direct measurement cannot be afforded.

Keyword

Low-density lipoprotein cholesterol; Cholesterol; Triglyceride; Friedewald formula

MeSH Terms

Cardiovascular Diseases*
Cholesterol*
Humans
Lipoproteins*
Methods
Risk Factors
Triglycerides
Cholesterol
Lipoproteins
Triglycerides

Figure

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  Fig. 1 Flow chart of study participants. LDL-C: low-density lipoprotein cholesterol, TG: triglycerides.

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  Fig. 2 Bland-Altman plots of estimated formulas against directly-measured LDL-C. The mean difference represents the estimation of bias between the two observations and the percentage error represents the proportion between the magnitude of measurement and error in measurement. LDL-C: low-density lipoprotein cholesterol.

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  Fig. 3 Passing & Bablok regression of estimated formulas against directly-measured LDL-C. The dotted line represents the line of identity. No significant deviation from linearity. LDL-C: low-density lipoprotein cholesterol.

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