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CC BY-NC-ND 4.0 · J Lab Physicians 2021; 13(02): 129-133
DOI: 10.1055/s-0041-1729131
Original Article

Which LDL Value Should Clinicians Look at?

Harshad Malve
1   Department of Pharmacology, Vedanta Institute of Medical Sciences, Sasvand, Dhundalwadi, Dahanu, Maharashtra, India
,
Amit Asalkar
2   Hormo-Care and Consultant Endocrinologist, Aster Aadhar Hospital, Kolhapur, Maharashtra, India
› Author Affiliations Funding Support None.
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Abstract

Objectives LDL cholesterol is routinely estimated by the Friedewald formula to guide the treatment of dyslipidemia. However, Friedewald equation has certain limitations, especially with high triglyceride levels. Direct methods are available for LDL estimation but have received relatively little scrutiny in the Indian setting. This study was aimed at comparing the calculative and direct methods of LDL estimation in Indian hyperlipidemic patients.

Materials and Methods In this observational study, data from 380 consecutive lipid profiles of patients visiting a tertiary care hospital in Mumbai were analyzed retrospectively. CHOD PAP method was used to estimate total cholesterol. Enzymatic colorimetric method was used to estimate triglycerides. Enzyme selective protection method was used to estimate HDL. Direct LDL was estimated by homogenous enzymatic colorimetric assay and very low-density lipoprotein was calculated, whereas Friedewald’s formula was used to derive calculated LDL.

Results Total cholesterol values correlated positively with the LDL values measured by both methods. However, a statistically significant difference was noted between the correlation coefficients of both the methods. Triglyceride values correlated weakly with the LDL levels measured by both the methods. A weak negative correlation was observed with LDL by the calculated method, whereas a weak positive correlation existed between TG and LDL by the direct method. The difference between the correlation coefficients was statistically significant.

Conclusion Both direct and calculated methods of LDL estimation have their limitations. A robust study with a larger sample size is needed to further investigate whether the differences in the different LDL estimation methods can translate to “clinical relevance” in the Indian setting.

Keywords

hyperlipidemia - direct LDL estimation - Friedewald’s formula - LDL cholesterol


Publication History

Article published online:
26 May 2021

© 2021. The Indian Association of Laboratory Physicians. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

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  • References

  • 1 Gordon T, Kannel WB, Castelli WP, Dawber TR. Lipoproteins, cardiovascular disease, and death. The Framingham study. Arch Intern Med 1981; 141 (09) 1128-1131
    CrossrefPubMedGoogle Scholar
  • 2 Grundy SM. Role of low-density lipoproteins in atherogenesis and development of coronary heart disease. Clin Chem 1995; 41 (01) 139-146
    CrossrefPubMedGoogle Scholar
  • 3 Kannel WB, Nekton JD, Wentworth D. et al. Overall and coronary heart disease mortality rates in relation to major risk factors in 325,348 men screened for the MRFIT. Multiple risk factor intervention trial. Am Heart J 1986; 112 (04) 825-836
    CrossrefPubMedGoogle Scholar
  • 4 The lipid research clinics coronary primary prevention trial results. II. The relationship of reduction in incidence of coronary heart disease to cholesterol lowering. JAMA 1984; 251 (03) 365-374
    CrossrefPubMedGoogle Scholar
  • 5 Scandinavian Simvastatin Survival Study Group. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet 1994; 344 (8934) 1383-1389
    PubMedGoogle Scholar
  • 6 Sacks FM, Pfeffer MA, Moye LA. et al. The effect of pravastatin on coronary events after myocardial infarction in patients with average cholesterol levels. Cholesterol and recurrent events trial investigators. N Engl J Med 1996; 335 (14) 1001-1009
    CrossrefPubMedGoogle Scholar
  • 7 Delport R. The value of accurate analytics in the management of cardiovascular disease. Cardiovasc J S Afr 2006; 17 (01) 3-5
    PubMedGoogle Scholar
  • 8 Cathcart S, Dominiczak MH. The measurement of lipoprotein subfractions in plasma using a tabletop ultracentrifuge. Ann Clin Biochem 1990; 27 (Pt 5) 459-464
    CrossrefPubMedGoogle Scholar
  • 9 DeLong DM, DeLong ER, Wood PD, Lippel K, Rifkind BM. A comparison of methods for the estimation of plasma low- and very low-density lipoprotein cholesterol. The Lipid Research Clinics Prevalence Study. JAMA 1986; 256 (17) 2372-2377
    CrossrefPubMedGoogle Scholar
  • 10 Bachorik PS, Ross JW. The National Cholesterol Education Program Working Group on Lipoprotein Measurement. National Cholesterol Education Program recommendations for measurement of low-density lipoprotein cholesterol: executive summary. Clin Chem 1995; 41 (10) 1414-1420
    CrossrefPubMedGoogle Scholar
  • 11 Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem 1972; 18 (06) 499-502
    CrossrefPubMedGoogle Scholar
  • 12 Amayo AA, Kirera S. Comparison of calculated and direct low density lipoprotein cholesterol determinations in a routine laboratory. East Afr Med J 2004; 81 (03) 154-158
    CrossrefPubMedGoogle Scholar
  • 13 Rifai N, Warnick GR, McNamara JR. Belcher JD, Grinstead GF, Frantz ID Jr. Measurement of low-density-lipoprotein cholesterol in serum: a status report. Clin Chem 1992; 38 (01) 150-160
    CrossrefPubMedGoogle Scholar
  • 14 McNamara JR, Cohn JS, Wilson PW, Schaefer EJ. Calculated values for low-density lipoprotein cholesterol in the assessment of lipid abnormalities and coronary disease risk. Clin Chem 1990; 36 (01) 36-42
    CrossrefPubMedGoogle Scholar
  • 15 Matas C, Cabré M, La Ville A. et al. Limitations of the Friedewald formula for estimating low-density lipoprotein cholesterol in alcoholics with liver disease. Clin Chem 1994; 40 (03) 404-406
    CrossrefPubMedGoogle Scholar
  • 16 Maitra A, Hirany SV, Jialal I. Comparison of two assays for measuring LDL cholesterol. Clin Chem 1997; 43 (6 Pt 1) 1040-1047
    CrossrefPubMedGoogle Scholar
  • 17 Esteban-Salán M, Guimón-Bardesi A, de La Viuda-Unzueta JM, Azcarate-Ania MN, Pascual-Usandizaga P, Amoroto-Del-Río E. Analytical and clinical evaluation of two homogeneous assays for LDL-cholesterol in hyperlipidemic patients. Clin Chem 2000; 46 (8 Pt 1) 1121-1131
    CrossrefPubMedGoogle Scholar
  • 18 Harris N, Neufeld EJ, Newburger JW. et al. Analytical performance and clinical utility of a direct LDL-cholesterol assay in a hyperlipidemic pediatric population. Clin Chem 1996; 42 (08) 1182-1188
    CrossrefPubMedGoogle Scholar
  • 19 Schectman G, Patsches M, Sasse EA. Variability in cholesterol measurements: comparison of calculated and direct LDL cholesterol determinations. Clin Chem 1996; 42 (05) 732-737
    CrossrefPubMedGoogle Scholar
  • 20 Krause BR, Schork NJ, Kieft KA, Smith MP, Maciejko JJ. High correlation but lack of agreement between direct high-performance gel chromatography analysis and conventional indirect methods for determining lipoprotein cholesterol. Clin Chem 1996; 42 (12) 1996-2001
    CrossrefPubMedGoogle Scholar
  • 21 Allain CC, Poon LS, Chan CS, Richmond W, Fu PC. Enzymatic determination of total serum cholesterol. Clin Chem 1974; 20 (04) 470-475
    CrossrefPubMedGoogle Scholar
  • 22 Trinder P. Triglyceride estimation by GPO-PAP method. Ann Clin Chem 1969; 6: 24-27
    Google Scholar
  • 23 Belcher JD, McNamara JR, Grinstead GF. et al. Measurement of low-density lipoprotein cholesterol concentration. In: Rifai N, Warnick GR, eds. Methods for Clinical Laboratory Measurements of Lipid and Lipoprotein Risk Factors. Washington, DC:. AACC Press 1991; 75-86
    Google Scholar
  • 24 Nauck M, Warnick GR, Rifai N. Methods for measurement of LDL-cholesterol: a critical assessment of direct measurement by homogeneous assays versus calculation. Clin Chem 2002; 48 (02) 236-254
    CrossrefPubMedGoogle Scholar
  • 25 Miller WG, Myers GL, Sakurabayashi I. et al. Seven direct methods for measuring HDL and LDL cholesterol compared with ultracentrifugation reference measurement procedures. Clin Chem 2010; 56 (06) 977-986
    CrossrefPubMedGoogle Scholar
  • 26 Warade JP, Dahake H, Kavitha R. Comparison between direct estimation of LDL and Friedewald’s formula. IAIM 2016; 3 (02) 10-17
    Google Scholar
  • 27 Sahu S, Chawla R, Uppal B. Comparison of two methods of estimation of low density lipoprotein cholesterol, the direct versus Friedewald estimation. Indian J Clin Biochem 2005; 20 (02) 54-61
    CrossrefPubMedGoogle Scholar
  • 28 Kannan S, Mahadevan S, Ramji B, Jayapaul M, Kumaravel V. LDL-cholesterol: Friedewald calculated versus direct measurement-study from a large Indian laboratory database. Indian J Endocrinol Metab 2014; 18 (04) 502-504
    CrossrefPubMedGoogle Scholar
  • 29 Malve H. Comparison of direct versus Friedewald estimation of low density lipoprotein cholesterol in Indian patients: cost-effectiveness concerns?. Indian J Endocrinol Metab 2015; 19 (03) 436
    CrossrefPubMedGoogle Scholar
  • 30 Unruh L, Rice T, Rosenau PV, Barnes AJ. The 2013 cholesterol guideline controversy: would better evidence prevent pharmaceuticalization?. Health Policy 2016; 120 (07) 797-808
    CrossrefPubMedGoogle Scholar
  • 31 Palmer MK, Barter PJ, Lundman P, Nicholls SJ, Toth PP, Karlson BW. Comparing a novel equation for calculating low-density lipoprotein cholesterol with the Friedewald equation: a VOYAGER analysis. Clin Biochem 2019; 64: 24-29
    CrossrefPubMedGoogle Scholar
  • 32 Martin SS, Giugliano RP, Murphy SA. et al. Comparison of low-density lipoprotein cholesterol assessment by Martin/Hopkins estimation, Friedewald estimation, and preparative ultracentrifugation: insights from the Fourier trial. JAMA Cardiol 2018; 3 (08) 749-753
    CrossrefPubMedGoogle Scholar
  • 33 Krishnaveni P, Gowda VM. Assessing the validity of Friedewald’s formula and Anandraja’s formula for serum LDL-cholesterol calculation. J Clin Diagn Res 2015; 9 (12) BC01-BC04
    Google Scholar