scholarly journals Is it time to abandon Friedewald formula? New equations for LDL-C calculation

2021 ◽  
Vol 49 (8) ◽  
pp. 615-618
Author(s):  
Özcan Başaran ◽  
Keyword(s):  
Friedewald Formula

scholarly journals Impact of Adoption of Directly Measured Low-Density Lipoprotein-Cholesterol (LDL-C) on Targets of Lipid Control and Its Comparison With Friedewald Formula-Calculated LDL Cholesterol in People With Type-2 Diabetes Mellitus

2020 ◽  
pp. 263246362097804
Author(s):  
Rejitha Jagesh ◽  
Mathew John ◽  
Manju Manoharan Nair Jalaja ◽  
Tittu Oommen ◽  
Deepa Gopinath
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Atherosclerotic Cardiovascular Disease ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Friedewald Formula

Objectives: The accurate and precise measurement of low-density lipoprotein-cholesterol (LDL-C) is important in the assessment of atherosclerotic cardiovascular disease risk (ASCVD) in people with diabetes mellitus. This study aimed at comparing directly measured LDL-C with Friedewald formula (FF)-calculated LDL-C (c-LDL-C) in people with type-2 diabetes. Methods: Fasting lipid profiles of 1905 people with type-2 diabetes, whose LDL-C was estimated by direct LDL assay, were chosen for the study. In the same group, LDL-C was calculated with FF. Correlation and agreement between these methods were analyzed at various strata of triglycerides (TGs). The possibility of misclassifying people at various levels of LDL-C targets proposed in literature was calculated. Results: The mean LDL-C levels were lower in the c-LDL-C group across various TG strata. A significant correlation was found between c-LDL-C and direct LDL-C for all the study samples ( r = 0.948, P < .001) and across all TG strata. Analysis of agreement showed a positive bias for direct LDL-C which increased at higher strata of TGs. c-LDL-C underestimated ASCVD by misclassifying people at various LDL-C target levels. Conclusion: There is a difference between direct LDL-C and c-LDL-C values in people with diabetes and this may result in misclassifying ASCVD especially at lower levels of LDL-C and higher levels of TGs.

Non-HDL-C/TG ratio indicates significant underestimation of calculated low-density lipoprotein cholesterol (LDL-C) better than TG level: a study on the reliability of mathematical formulas used for LDL-C estimation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Agnieszka Ćwiklińska ◽  
Ewa Wieczorek ◽  
Anna Gliwińska ◽  
Marta Marcinkowska ◽  
Monika Czaplińska ◽  
...  
Keyword(s):  
Total Error ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Percentage Difference ◽  
Mathematical Formulas ◽  
Friedewald Formula ◽  
Significant Underestimation

Abstract Objectives Low-density lipoprotein cholesterol (LDL-C) is the main laboratory parameter used for the management of cardiovascular disease. The aim of this study was to compare measured LDL-C with LDL-C as calculated by the Friedewald, Martin/Hopkins, Vujovic, and Sampson formulas with regard to triglyceride (TG), LDL-C and non-high-density lipoprotein cholesterol (non-HDL-C)/TG ratio. Methods The 1,209 calculated LDL-C results were compared with LDL-C measured using ultracentrifugation-precipitation (first study) and direct (second study) methods. The Passing-Bablok regression was applied to compare the methods. The percentage difference between calculated and measured LDL-C (total error) and the number of results exceeding the total error goal of 12% were established. Results There was good correlation between the measurement and calculation methods (r 0.962–0.985). The median total error ranged from −2.7%/+1.4% (first/second study) for Vujovic formula to −6.7%/−4.3% for Friedewald formula. The numbers of underestimated results exceeding the total error goal of 12% were 67 (Vujovic), 134 (Martin/Hopkins), 157 (Samspon), and 239 (Friedewald). Less than 7% of those results were obtained for samples with TG >4.5 mmol/L. From 57% (Martin/Hopkins) to 81% (Vujovic) of underestimated results were obtained for samples with a non-HDL-C/TG ratio of <2.4. Conclusions The Martin/Hopkins, Vujovic and Sampson formulas appear to be more accurate than the Friedewald formula. To minimize the number of significantly underestimated LDL-C results, we propose the implementation of risk categories according to non-HDL-C/TG ratio and suggest that for samples with a non-HDL-C/TG ratio of <1.2, the LDL-C level should not be calculated but measured independently from TG level.

scholarly journals PENETUAN FORMULA UNTUK MENETAPKAN ESTIMASI KOLESTEROL-LDL

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Gilang Nugraha ◽  
Soebagijoh Poegoeh Edijanto
Keyword(s):  
Correlation Coefficient ◽  
Ldl Cholesterol ◽  
Clinical Pathology ◽  
Statistical Test ◽  
Validation Methods ◽  
Clinical Laboratories ◽  
Friedewald Formula

Abstract: Measurement LDL-Cholesterol (LDL-C) can be performed by estimating LDL-C (cLDL-C) inthe blood. In addition to the first proposed Friedewald formula, several new formulas that promise betterexamination in determining LDL-C levels, proposed by Anandaraja, Puavilai, Chen, Vujovic, deCordova and Dansethakul. The subjects of the study were patients who performed routine lipid profileexamination in Institution of Clinical Pathology of Gedung Pusat Diagnostik Terpadu RSUD Dr.Soetomo Surabaya who performs 10 to 12 hours of fasting with TG less than 400 mg / dL. The sampleconsisted of 41 men and 48 women with an average age of 52 years. The statistical test on each cLDLC gave the Friedewald -1.32% bias value; Anandaraja -3,92%; Puavilai 4.26%, Chen -2.19%; Vujovic-23.65%; de Cordova -0.91% and Dansethakul 4.45%. The correlation coefficient on Friedewald0.9509; Anandaraja 0.9013; Puavilai 0.9576, Chen 0.9585; Vujovic 0.8745; de Cordova 0.9300 andDansethakul 0.9505. The proposed cLDL-C formula Chen et al promises in determining the LDL-Cestimate and the Vujovic formula gives a poor result in this study. Validation methods should be appliedto each of the cLDL formulas if they are to be applied to clinical laboratories.

scholarly journals Reagent-free, Simultaneous Determination of Serum Cholesterol in HDL and LDL by Infrared Spectroscopy

2002 ◽  
Vol 48 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Kan-Zhi Liu ◽  
R Anthony Shaw ◽  
Angela Man ◽  
Thomas C Dembinski ◽  
Henry H Mantsch
Keyword(s):  
Ir Spectroscopy ◽  
Ldl Cholesterol ◽  
Clinical Laboratory ◽  
Hdl Cholesterol ◽  
Serum Samples ◽  
Clinical Method ◽  
Predicted Values ◽  
Friedewald Formula ◽  
Spectral Ranges

Abstract Background: The purpose of this study was to assess the feasibility of infrared (IR) spectroscopy for the simultaneous quantification of serum LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) concentrations. Methods: Serum samples (n = 90) were obtained. Duplicate aliquots (5 μL) of the serum specimens were dried onto IR-transparent barium fluoride substrates, and transmission IR spectra were measured for the dry films. In parallel, the HDL-C and LDL-C concentrations were determined separately for each specimen by standard methods (the Friedewald formula for LDL-C and an automated homogeneous HDL-C assay). The proposed IR method was then developed with a partial least-squares (PLS) regression analysis to quantitatively correlate IR spectral features with the clinical analytical results for 60 randomly chosen specimens. The resulting quantification methods were then validated with the remaining 30 specimens. The PLS model for LDL-C used two spectral ranges (1700–1800 and 2800–3000 cm−1) and eight PLS factors, whereas the PLS model for HDL-C used three spectral ranges (800–1500, 1700–1800, and 2800–3500 cm−1) with six factors. Results: For the 60 specimens used to train the IR-based method, the SE between IR-predicted values and the clinical laboratory assays was 0.22 mmol/L for LDL-C and 0.15 mmol/L for HDL-C (r = 0.98 for LDL-C; r = 0.91 for HDL-C). The corresponding SEs for the test spectra were 0.34 mmol/L (r = 0.96) and 0.26 mmol/L (r = 0.82) for LDL-C and HDL-C, respectively. The precision for the IR-based assays was estimated by the SD of duplicate measurements to be 0.11 mmol/L (LDL-C) and 0.09 mmol/L (HDL-C). Conclusions: IR spectroscopy has the potential to become the clinical method of choice for quick and simultaneous determinations of LDL-C and HDL-C.

scholarly journals Analytical and Clinical Evaluation of Two Homogeneous Assays for LDL-Cholesterol in Hyperlipidemic Patients

2000 ◽  
Vol 46 (8) ◽  
pp. 1121-1131 ◽  
Author(s):  
Margarita Esteban-Salán ◽  
Amada Guimón-Bardesi ◽  
Jesús María de la Viuda-Unzueta ◽  
María Nerea Azcarate-Ania ◽  
Pilar Pascual-Usandizaga ◽  
...  
Keyword(s):  
Ldl Cholesterol ◽  
Treatment Guidelines ◽  
Clinical Performance ◽  
Total Error ◽  
Direct Methods ◽  
Lipid Lowering ◽  
Serum Samples ◽  
Wide Range ◽  
Friedewald Formula ◽  
Homogeneous Assays

Abstract Background: LDL-cholesterol (LDL-C) concentrations are the primary basis for treatment guidelines established for hyperlipidemic patients. LDL-C concentrations are commonly monitored by means of the Friedewald formula, which provides a relative estimation of LDL-C concentration when the triglyceride concentration is &lt;2000 mg/L and there are no abnormal lipids. The Friedewald formula has several limitations and may not meet the current total error requirement of &lt;12% in LDL-C measurements. Methods: We evaluated the analytical and clinical performance of two direct methods (Roche and Wako) by analyzing 313 fresh serum samples obtained from dyslipidemic patients in a lipid clinic and comparing them with modified β-quantification. Results: Both homogeneous assays displayed excellent precision (CV &lt;2%). The Roche method showed a mean total error of 7.72%, and the Wako method showed a mean total error of 4.46% over a wide range of LDL-C concentrations. The Roche method correlated highly with the modified β-quantification assay (r = 0.929; y = 1.052x − 168 mg/L; n = 166) and showed a bias of −4.5% as a result of the assigned standard value. The Wako method also correlated highly with β-quantification (r = 0.966; y = 0.9125x + 104.8 mg/L; n = 145) without significant bias. The Roche method correctly classified 97% of patients with triglycerides &lt;2000 mg/L, 75% of patients with type IIb hyperlipemia (HPL), and 84% of patients with type IV HPL based on the cutpoints of 1300 and 1600 mg/L, compared with 98%, 78.4%, and 89%, respectively, for the Wako method. In dysbetalipoproteinemic patients, both methods have a 30% mean positive bias compared with β-quantification. Conclusions: Both direct methods can be a useful alternative when ultracentrifugation is not available for the diagnosis and control of lipid-lowering medication for patients with mixed HPL, but not for patients with type III hyperlipidemia.

Plasma lipoprotein(a) and the Friedewald formula.

1989 ◽  
Vol 35 (10) ◽  
pp. 2156-2157 ◽  
Author(s):  
D T Kurschinski ◽  
D A Dennen ◽  
M Garcia ◽  
A M Scanu
Keyword(s):  
Plasma Lipoprotein ◽  
Lipoprotein A ◽  
Friedewald Formula

Lipoprotein cholesterol concentrations in the plasma of human subjects as measured in the fed and fasted states.

1988 ◽  
Vol 34 (12) ◽  
pp. 2456-2459 ◽  
Author(s):  
J S Cohn ◽  
J R McNamara ◽  
E J Schaefer
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Plasma Triglyceride ◽  
Lipoprotein Cholesterol ◽  
Cholesterol Concentration ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Plasma Triglyceride Concentration ◽  
Triglyceride Concentration ◽  
Friedewald Formula

Abstract Lipoprotein cholesterol concentrations in plasma are routinely estimated by using the Friedewald formula, whereby very-low-density lipoprotein cholesterol (VLDL-C) is estimated to be one-fifth the plasma triglyceride concentration. Ordinarily, this formula is applied only to plasma sampled from patients in the fasted state. To determine whether lipoprotein cholesterol measurements are altered substantially in plasma sampled from nonfasting subjects, we obtained postprandial blood samples from 22 healthy subjects (nine men, 13 women, ages 22-79 years) fed a fat-rich meal (1 g fat per kilogram body wt.). The plasma triglyceride concentration increased postprandially in all subjects (233 +/- 16% of baseline at 3 h). The mean cholesterol concentration in plasma was essentially unchanged. High-density lipoprotein cholesterol (HDL-C) was significantly decreased (94 +/- 2% at 3 h, P less than 0.001). VLDL-C and low-density lipoprotein cholesterol (LDL-C), estimated by the Friedewald formula, were compared with measurements obtained by modified Lipid Research Clinics (LRC) methodology. As measured by either method, VLDL-C increased and LDL-C decreased significantly after the fat-rich meal. These postprandial changes were significantly greater (P less than 0.01) when estimated by the Friedewald formula than by LRC methodology. We conclude that (a) lipoprotein cholesterol concentrations measured in the fed subject differ significantly from those measured in the fasted subject, and (b) plasma must be obtained after at least a 12-h fast if an individual's risk of coronary heart disease is to be accurately assessed.

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