Validation of multiple equations for estimating low-density lipoprotein cholesterol levels in Korean adults

Rihwa Choi,Youngju Oh,Eun Hee Lee,Mi-Jung Park,Sung Ho Kim,Sang Gon Lee

doi:10.1186/s12944-021-01525-6

Abstract

BackgroundLimited data are available for validation of low-density lipoprotein cholesterol (LDL) calculation (LDLcal) in the adult Korean population. The aim of this study was to develop and validate a new equation for LDLcal and to compare it with previous such equations in a Korean population.MethodsA new equation for LDLcal was developed (LDLChoi). LDLChoi and 11 other previously published equations were applied and compared with directly measured LDL concentration (LDLdirect) in a development cohort (population 1), an independent validation cohort in the same laboratory (population 2), and the Korea National Health and Nutrition Examination Survey 2017 cohort (population 3).ResultsAmong the 12 equations, the newly-developed equation (LDLChoi = total cholesterol – 0.87 x high-density lipoprotein cholesterol – 0.13 x triglycerides) had the highest intraclass correlation coefficient (ICC) and the lowest mean systemic difference and median absolute percentage error in populations 1 and 2 but not in population 3. Subgroup analysis showed good agreement between LDLChoi and LDLdirect (ICC > 0.75) in population 2, whose LDLdirect < 70 mg/dL. For samples with high triglycerides (> 400 mg/dL), equation accuracy varied. Categorization concordance according to the National Cholesterol Education Program Adult Treatment Panel III criteria with the other 11 equations were less than 80%; that of LDLChoi was 87.6 and 87.4% in populations 1 and 2, respectively.ConclusionsAccuracy of 12 equations for LDLcal varied by cohort and subgroup based on LDLdirect and triglycerides. A laboratory-specific equation for LDLcal and/or LDLdirect may be needed for accurate evaluation of LDL status.

Highlights

Low-density lipoprotein cholesterol (LDL) is a wellknown risk factor and therapeutic target for atherosclerotic disease [1, 2]
In the United States, Martin et al suggested a new equation for LDL estimation (LDLMartin) using an adjustable factor for TG: very-low-density lipoprotein cholesterol (VLDL) ratio based on TG and non-high-density lipoprotein cholesterol (HDL) concentration stratification based on lipid profiles obtained from 1,350,908 subjects [4]
Data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2017, a nationwide cross-sectional study regularly conducted by the Division of Chronic Disease Surveillance, Korea Centers for Disease Control and Prevention of the Ministry of Health and Welfare, was independently analyzed to evaluate generalizability of the 11 previously suggested equations and the LDLChoi equation developed in this study

Summary

Introduction

Low-density lipoprotein cholesterol (LDL) is a wellknown risk factor and therapeutic target for atherosclerotic disease [1, 2]. In the United States, Martin et al suggested a new equation for LDL estimation (LDLMartin) using an adjustable factor for TG: very-low-density lipoprotein cholesterol (VLDL) ratio based on TG and non-HDL concentration (non-HDL = TC – HDL) stratification based on lipid profiles obtained from 1,350,908 subjects [4]. A recent study from the VOYAGER meta-analysis database aimed to investigate the difference in LDLcal when using the LDLMartin and LDLFriedewald equations reported that LDLMartin might not be suitable for patients with TG ≥ 400 mg/dL and can result in overestimation of LDLdirect [13]. The aim of this study was to develop and validate a new equation for LDLcal and to compare it with previous such equations in a Korean population

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