CC BY-NC-ND 4.0 · J Lab Physicians 2022; 14(04): 456-464
DOI: 10.1055/s-0042-1748628
Original Article

Comparative Study of Calculated LDL-Cholesterol Levels with the Direct Assay in Patients with Hypothyroidism

1   Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
1   Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
Ravindra Kumar G. Shukla
2   Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
Praveen Sharma
1   Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
› Author Affiliations
Funding None.


Background Hypothyroidism is one among the many factors that predisposes one to coronary artery disease. As low-density lipoprotein-cholesterol (LDL-C) is associated with cardiovascular risk, calculated LDL-C should have good accuracy with minimal bias. Hypothyroidism alters the lipid composition of lipoproteins by the secretion of triglyceride-rich lipoproteins, which affects the calculation of LDL-C. The present study aimed to compare 13 different formulae for the calculation of LDL-C including the newly derived Martin's formula by direct assay in patients of hypothyroidism.

Method In this analytical cross-sectional study, a total of 105 patients with laboratory evidence of hypothyroidism, from January to June 2019, were studied, and blood samples were subjected for lipid profile analysis at central biochemistry laboratory. Calculated LDL-C was assessed by different formulae.

Result We observed that calculated LDL-C by Friedewald's, Cordova's, Anandaraja's, Hattori's, and Chen's formulae has bias less than ± 5 compared with direct LDL-C, with Anandaraja's formula having the lowest bias (2.744) and Cordova's formula having lowest bias percentage (−1.077) among them. According to the Bland–Altman plots, the bias in Friedewald's and Anandraja's were equally distributed below and above the reference line of direct LDL-C.

Conclusion This is the first study comparing different formulae for LDL-C calculation in patients with hypothyroidism. Anandaraja's formula was as equally effective as Friedewald's formula when used as an alternative cost-effective tool to evaluate LDL-C in hypothyroid patients. The recently proposed Martin's formula for calculated LDL-C had a higher bias when compared with Friedewald's and Anandaraja's formulae in patients with hypothyroidism.

Publication History

Article published online:
01 June 2022

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  • References

  • 1 Bakker O, Hudig F, Meijssen S, Wiersinga WM. Effects of triiodothyronine and amiodarone on the promoter of the human LDL receptor gene. Biochem Biophys Res Commun 1998; 249 (02) 517-521
  • 2 Shin D-J, Osborne TF. Thyroid hormone regulation and cholesterol metabolism are connected through sterol regulatory element-binding protein-2 (SREBP-2). J Biol Chem 2003; 278 (36) 34114-34118
  • 3 Nikkilä EA, Kekki M. Plasma triglyceride metabolism in thyroid disease. J Clin Invest 1972; 51 (08) 2103-2114
  • 4 Abrams JJ, Grundy SM. Cholesterol metabolism in hypothyroidism and hyperthyroidism in man. J Lipid Res 1981; 22 (02) 323-338
  • 5 Fabbrini E, Magkos F, Patterson BW, Mittendorfer B, Klein S. Subclinical hypothyroidism and hyperthyroidism have opposite effects on hepatic very-low-density lipoprotein-triglyceride kinetics. J Clin Endocrinol Metab 2012; 97 (03) E414-E418
  • 6 Pesic MM, Radojkovic D, Antic S, Kocic R, Stankovic-Djordjevic D. Subclinical hypothyroidism: association with cardiovascular risk factors and components of metabolic syndrome. Biotechnol Biotechnol Equip 2015; 29 (01) 157-163
  • 7 Geng H, Zhang X, Wang C. et al. Even mildly elevated TSH is associated with an atherogenic lipid profile in postmenopausal women with subclinical hypothyroidism. Endocr Res 2015; 40 (01) 1-7
  • 8 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
  • 9 Hattori Y, Suzuki M, Tsushima M. et al. Development of approximate formula for LDL-chol, LDL-apo B and LDL-chol/LDL-apo B as indices of hyperapobetalipoproteinemia and small dense LDL. Atherosclerosis 1998; 138 (02) 289-299
  • 10 Anandaraja S, Narang R, Godeswar R, Laksmy R, Talwar KK. Low-density lipoprotein cholesterol estimation by a new formula in Indian population. Int J Cardiol 2005; 102 (01) 117-120
  • 11 Chen Y, Zhang X, Pan B. et al. A modified formula for calculating low-density lipoprotein cholesterol values. Lipids Health Dis 2010; 9: 52
  • 12 de Cordova CMM, de Cordova MM. A new accurate, simple formula for LDL-cholesterol estimation based on directly measured blood lipids from a large cohort. Ann Clin Biochem 2013; 50 (Pt 1): 13-19
  • 13 Teerakanchana T, Puavilai W, Suriyaprom K, Tungtrongchitr R. Comparative study of LDL-cholesterol levels in Thai patients by the direct method and using the Friedewald formula. Southeast Asian J Trop Med Public Health 2007; 38 (03) 519-527
  • 14 Ahmadi S-A, Boroumand M-A, Gohari-Moghaddam K, Tajik P, Dibaj S-M. The impact of low serum triglyceride on LDL-cholesterol estimation. Arch Iran Med 2008; 11 (03) 318-321
  • 15 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
  • 16 Rao A, Parker AH, el-Sheroni NA, Babelly MM. Calculation of low-density lipoprotein cholesterol with use of triglyceride/cholesterol ratios in lipoproteins compared with other calculation methods. Clin Chem 1988; 34 (12) 2532-2534
  • 17 Martin SS, Blaha MJ, Elshazly MB. et al. Comparison of a novel method vs the Friedewald equation for estimating low-density lipoprotein cholesterol levels from the standard lipid profile. JAMA 2013; 310 (19) 2061-2068
  • 18 Hata Y, Nakajima K. Application of Friedewald's LDL-cholesterol estimation formula to serum lipids in the Japanese population. Jpn Circ J 1986; 50 (12) 1191-1200
  • 19 Puavilai W, Laorugpongse D, Deerochanawong C, Muthapongthavorn N, Srilert P. The accuracy in using modified Friedewald equation to calculate LDL from non-fast triglyceride: a pilot study. J Med Assoc Thai 2009; 92 (02) 182-187
  • 20 Vujovic A, Kotur-Stevuljevic J, Spasic S. et al. Evaluation of different formulas for LDL-C calculation. Lipids Health Dis 2010; 9: 27
  • 21 Tremblay AJ, Morrissette H, Gagné J-M, Bergeron J, Gagné C, Couture P. Validation of the Friedewald formula for the determination of low-density lipoprotein cholesterol compared with beta-quantification in a large population. Clin Biochem 2004; 37 (09) 785-790
  • 22 Choukem S-P, Manases T, Nda-Mefoo J-P. et al. Validation of the Friedewald formula for the estimation of low density lipoprotein cholesterol in a sub-Saharan African population. Clin Biochem 2018; 53: 25-30
  • 23 Tsai C-H, Wu H-H, Weng S-J. Comparison of various formulae for estimating low-density lipoprotein cholesterol by a combination of ages and genders in Taiwanese adults. BMC Cardiovasc Disord 2014; 14: 113
  • 24 Rim JH, Lee Y-H, Lee MH. et al. Comparison and validation of 10 equations including a novel method for estimation of LDL-cholesterol in a 168,212 Asian population. Medicine (Baltimore) 2016; 95 (14) e3230
  • 25 Knopfholz J, Disserol CC, Pierin AJ. et al. Validation of the Friedewald formula in patients with metabolic syndrome. Cholesterol 2014; 2014: 261878
  • 26 Onyenekwu CP, Hoffmann M, Smit F, Matsha TE, Erasmus RT. Comparison of LDL-cholesterol estimate using the Friedewald formula and the newly proposed de Cordova formula with a directly measured LDL-cholesterol in a healthy South African population. Ann Clin Biochem 2014; 51 (Pt 6): 672-679
  • 27 Lee J, Jang S, Son H. Validation of the Martin method for estimating low-density lipoprotein cholesterol levels in Korean Adults: findings from the Korea National Health and Nutrition Examination Survey, 2009-2011. PLoS One 2016; 11 (01) e0148147
  • 28 Alpdemir M, Alpdemir MF. Comparison of Martin and Friedewald equation for estimated LDL-C in adults. Turk Kardiyol Dern Ars 2021; 49 (08) 619-626
  • 29 Fawwad A, Sabir R, Riaz M, Moin H, Basit A. Measured versus calculated LDL-cholesterol in subjects with type 2 diabetes. Pak J Med Sci 2016; 32 (04) 955-960
  • 30 Karkhaneh A, Bagherieh M, Sadeghi S, Kheirollahi A. Evaluation of eight formulas for LDL-C estimation in Iranian subjects with different metabolic health statuses. Lipids Health Dis 2019; 18 (01) 231
  • 31 Paz E, Hermida J, Bouzas L, Brenlla J, Tutor JC. LDL cholesterol estimation using the Anandaraja's and Friedewald's formulas in schizophrenic patients treated with antipsychotic drugs. Clin Biochem 2008; 41 (12) 1002-1007
  • 32 Lin QZ, Chen YQ, Guo LL. et al. Comparison of non-fasting LDL-C levels calculated by Friedewald formula with those directly measured in Chinese patients with coronary heart disease after a daily breakfast. Clin Chim Acta 2019; 495: 399-405
  • 33 Alamdari S, Amouzegar A, Tohidi M. et al. Hypothyroidism and lipid levels in a community based study (TTS). Int J Endocrinol Metab 2015; 14 (01) e22827
  • 34 Rizos CV, Elisaf MS, Liberopoulos EN. Effects of thyroid dysfunction on lipid profile. Open Cardiovasc Med J 2011; 5: 76-84
  • 35 Khatoon D, Ahmed A, Jabeen N, Rehman E. Hypothyroidism; as a cause of dyslipidemia in young predisposes to increased risk of cardiovascular disease. Prof Med J 2017; 24: 36-41
  • 36 Bachorik PS. Measurement of low density lipoprotein cholesterol. In: Rifai N, Warnick GR, Dominiczak MH. eds. Handbook of Lipoprotein Testing. Washington: AACC Press; 1997: 145-60
  • 37 Türkalp I, Cil Z, Ozkazanç D. Analytical performance of a direct assay for LDL-cholesterol: a comparative assessment versus Friedewald's formula. Anadolu Kardiyol Derg 2005; 5 (01) 13-17
  • 38 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
  • 39 Sakaue T, Hirano T, Yoshino G, Sakai K, Takeuchi H, Adachi M. Reactions of direct LDL-cholesterol assays with pure LDL fraction and IDL: comparison of three homogeneous methods. Clin Chim Acta 2000; 295 (1-2): 97-106
  • 40 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
  • 41 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
  • 42 Rubiés-Prat J, Reverter JL, Sentí M. et al. Calculated low-density lipoprotein cholesterol should not be used for management of lipoprotein abnormalities in patients with diabetes mellitus. Diabetes Care 1993; 16 (08) 1081-1086
  • 43 Gasko R. Low-density lipoprotein cholesterol estimation by the Anandaraja's formula—confirmation. Lipids Health Dis 2006; 5: 18
  • 44 Gupta S, Verma M, Singh K. Does LDL-C estimation using Anandaraja's formula give a better agreement with direct LDL-C estimation than the Friedewald's formula?. Indian J Clin Biochem 2012; 27 (02) 127-133
  • 45 Kamal AHM, Hossain M, Chowdhury S, Mahmud NU. A comparison of calculated with direct measurement of low density lipoprotein cholesterol level. JCMCTA 2009; 20: 19-23
  • 46 Kamezaki F, Sonoda S, Nakata S, Otsuji Y. A direct measurement for LDL-cholesterol increases hypercholesterolemia prevalence: comparison with Friedewald calculation. J UOEH 2010; 32 (03) 211-220
  • 47 Agrawal M, Spencer HJ, Faas FH. Method of LDL cholesterol measurement influences classification of LDL cholesterol treatment goals: clinical research study. J Investig Med 2010; 58 (08) 945-949
  • 48 Faas FH, Earleywine A, Smith G, Simmons DL. How should low-density lipoprotein cholesterol concentration be determined?. J Fam Pract 2002; 51 (11) 972-975
  • 49 Gazi IF, Elisaf M. LDL-cholesterol calculation formulas in patients with or without the metabolic syndrome. Int J Cardiol 2007; 119 (03) 414-415