Comparison of Formulas for Low-Density Lipoprotein (LDL) Calculation for Predicting the Risk of Metabolic Syndrome
Abstract
Background: The correlation between serum cholesterol level and the risk of developing atherosclerosis and metabolic syndrome has been well established in previous studies. Serum low-density lipoprotein (LDL-C) measurement is conducted using different methods which are generally divided into two groups, namely direct and indirect. Using indirect methods or calculations such as the Friedewald or Iranian formula for measuring LDL, particularly in developing countries, is quite common. The present study has stepped in to compare the robustness of the extant formulas in prognosticating and determining the incidence of metabolic syndrome. Materials and Methods: In this cross-sectional study, the target population was the community of Fasa cohort study. According to the views of the statistical advisor, 9530 people were included in the study and clinical laboratory examinations were done for each person. Their serum LDL level was measured using the existing formulas. Then, the results of the serum LDL level that was computed with different formulas, were compared with both the status of metabolic syndrome and laboratory tests of individuals. Results: The Iranian formula has the highest area under curve, the sensitivity of 0.73, and specificity of 0.77, higher positive and negative predictive values among other formulas. In Friedewald formula, for example, sensitivity and specificity equal 0.28 and 0.80, respectively. After further analysis, two new models proposed for predicting metabolic syndrome. The results revealed that these two models even outperform the Iranian formula. Conclusion: The Iranian formula for plasma LDL calculation has higher precision and application for predicting and measuring the metabolic syndrome in the Iranian population due to its considerable features. It is required to develop a new formula for each population and even for each sex, if possible. [GMJ.2020;9:e1607]References
Gordon T, Castelli WP, Hjortland MC, Kannel WB, Dawber TR. High density lipoprotein as a protective factor against coronary heart disease: the Framingham Study. Am J Med. 1977;62(5):707-14.
https://doi.org/10.1016/0002-9343(77)90874-9
Anandaraja S, Narang R, Godeswar R, Laksmy R, Talwar K. Low-density lipoprotein cholesterol estimation by a new formula in Indian population. Int J Cardiol. 2005;102(1):117-20.
https://doi.org/10.1016/j.ijcard.2004.05.009
PMid:15939107
Expert Panel on Detection E. Executive summary of the third report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III). Jama. 2001;285(19):2486.
https://doi.org/10.1001/jama.285.19.2486
PMid:11368702
Group SSSS. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet. 1994;344(8934):1383-9.
https://doi.org/10.1016/S0140-6736(94)90566-5
Group L-TIwPiIDS. Prevention of cardiovascular events and death with pravastatin in patients with coronary heart disease and a broad range of initial cholesterol levels. N Engl J Med. 1998;339(19):1349-57.
https://doi.org/10.1056/NEJM199811053391902
PMid:9841303
Vujovic A, Kotur-Stevuljevic J, Spasic S, Bujisic N, Martinovic J, Vujovic M et al. Evaluation of different formulas for LDL-C calculation. Lipids Health Dis. 2010;9(1):27.
https://doi.org/10.1186/1476-511X-9-27
PMid:20219094 PMCid:PMC2847568
Bairaktari ET, Seferiadis KI, Elisaf MS. Evaluation of methods for the measurement of low-density lipoprotein cholesterol. J Cardiovasc Pharmacol Ther. 2005;10(1):45-54.
https://doi.org/10.1177/107424840501000106
PMid:15821838
Mahmood SS, Levy D, Vasan RS, Wang TJ. The Framingham Heart Study and the epidemiology of cardiovascular disease: a historical perspective. lancet. 2014;383(9921):999-1008.
https://doi.org/10.1016/S0140-6736(13)61752-3
AHMADI SA, Boroumand M-A, GOUHARI MK, Tajik P, Dibaj S-M. The impact of low serum triglyceride on LDL-cholesterol estimation. Arch Iran Med. 2008 May;11(3):318-21.
Chen Y, Zhang X, Pan B, Jin X, Yao H, Chen B et al. A modified formula for calculating low-density lipoprotein cholesterol values. Lipids Health Dis. 2010;9(1):52.
https://doi.org/10.1186/1476-511X-9-52
PMid:20487572 PMCid:PMC2890624
Farjam M, Bahrami H, Bahramali E, Jamshidi J, Askari A, Zakeri H et al. A cohort study protocol to analyze the predisposing factors to common chronic non-communicable diseases in rural areas: Fasa Cohort Study. BMC Public Health. 2016;16(1):1090.
https://doi.org/10.1186/s12889-016-3760-z
PMid:27756262 PMCid:PMC5069851
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(6):499-502.
https://doi.org/10.1093/clinchem/18.6.499
PMid:4337382
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(1):13-9.
https://doi.org/10.1258/acb.2012.011259
PMid:23108766
Zimmet P, Alberti KGM, Kaufman F, Tajima N, Silink M, Arslanian S et al. The metabolic syndrome in children and adolescents-an IDF consensus report. Pediatr Diabetes. 2007;8(5):299-306.
https://doi.org/10.1111/j.1399-5448.2007.00271.x
PMid:17850473
Oliveira MJA, van Deventer HE, Bachmann LM, Warnick GR, Nakajima K, Nakamura M et al. Evaluation of four different equations for calculating LDL-C with eight different direct HDL-C assays. Clinica Chimica Acta. 2013;423:135-40..
https://doi.org/10.1016/j.cca.2013.04.009
PMid:23628525 PMCid:PMC4159084
Mora S, Rifai N, Buring JE, Ridker PM. Comparison of LDL Cholesterol Concentrations by Friedewald Calculation and Direct Measurement in Relation to Cardiovascular Events in 27 331 Women. Clin Chem. 2009;55(5):888.
https://doi.org/10.1373/clinchem.2008.117929
PMid:19395440 PMCid:PMC2692888
Schectman G, Patsches M, Sasse EA. Variability in cholesterol measurements: comparison of calculated and direct LDL cholesterol determinations. Clin Chem. 1996;42(5):732.
https://doi.org/10.1093/clinchem/42.5.732
PMid:8653899

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