Effects of total cholesterol and triglyceride on the percentage difference between the low-density lipoprotein cholesterol concentration measured directly and calculated using the Friedewald formula

Author(s):  
Kyung Ran Jun ◽  
Hae-il Park ◽  
Sail Chun ◽  
Hyosoon Park ◽  
Won-Ki Min
Author(s):  
Agnieszka Ćwiklińska ◽  
Ewa Wieczorek ◽  
Anna Gliwińska ◽  
Marta Marcinkowska ◽  
Monika Czaplińska ◽  
...  

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.


1988 ◽  
Vol 34 (12) ◽  
pp. 2456-2459 ◽  
Author(s):  
J S Cohn ◽  
J R McNamara ◽  
E J Schaefer

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.


1985 ◽  
Vol 31 (10) ◽  
pp. 1729-1730 ◽  
Author(s):  
G E Hoffmann ◽  
R Hiefinger ◽  
L Weiss ◽  
W Poppe

Abstract Five methods for the quantification of low-density-lipoprotein cholesterol were compared: ultracentrifugation, electrophoresis, precipitation with polyvinyl sulfate or heparin, and an indirect calculation procedure (Friedewald formula). Excellent agreement of results was obtained with all procedures for 49 of 51 sera. Discrepancies were as much as 1.69 g/L for the remaining two cases, which contained appreciable amounts of "floating" beta-cholesterol as detected with a combination of ultracentrifugation and electrophoresis.


2020 ◽  
pp. 263246362097804
Author(s):  
Rejitha Jagesh ◽  
Mathew John ◽  
Manju Manoharan Nair Jalaja ◽  
Tittu Oommen ◽  
Deepa Gopinath

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.


2021 ◽  
Vol 23 (3) ◽  
pp. 411-416
Author(s):  
I. M. Bilai ◽  
M. I. Romanenko ◽  
D. H. Ivanchenko

Statin side effects are not a rare occurrence, in particular dyspeptic disorders, insomnia, headache, skin erythema, rash are often noted. All of this determines scientists to find new effective and low-toxic hypolipidemic agents. Various natural and synthetic xanthine derivatives have been recognized as therapeutically potential compounds and reported to control various diseases. Therefore, the study of new xanthine derivatives and their hypolipidemic effects, which would have a significant therapeutic effect with minimal side effects, is relevant. The aim of the study was to examine the effect of 7-β-hydroxy-γ-aryloxypropylxanthinyl-8-thioalkanic acid derivatives on lipidogram parameters in experimental laboratory rats. Materials and methods. The objects of the study were 7-β-hydroxy-γ-aryloxypropylxanthinyl-8-thioalkanic acid derivatives. The experiments were performed in white laboratory Wistar rats weighing 180–220 g. Experimental modeling of hyperlipidemia – tween model: intraperitoneal administration of tween-80 at a dose of 200 mg/100 g body weight. The test compounds were administered orally, simultaneously with tween, at a dose of 1/10 of LD50 (previously calculated by Prozorovsky express method) for 6 days. The following indicators of lipidogram were determined: total cholesterol (TC), high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol), triglycerides (TG) and atherogenic index of plasma: TC – HDL cholesterol / HDL cholesterol. The experiments were carried out with respect to Bioethical rules and norms. Results. The studies have shown data on the hypolipidemic activity of 7-β-hydroxy-γ-aryloxypropylxanthinyl-8-thioalkane acid derivatives. According to the conditional efficiency index Ʃ, which included the overall percentage of the following indicators – total cholesterol, low-density lipoprotein cholesterol and triglycerides, the leading compounds were 2439 (87.47 %), 6047 (82.30 %). The reference drug atorvastatin had a value of 82.98 %. Conclusions. The major compound was 2439 identified among all compared to the control group. The prospect of further research is a more detailed study on the ability of xanthine derivatives to exhibit hypolipidemic effects and to influence oxidative stress in various hyperlipidemic models.


1997 ◽  
Vol 92 (5) ◽  
pp. 473-479 ◽  
Author(s):  
Gregory D. Sloop ◽  
David W. Garber

1. Increased blood or plasma viscosity has been observed in almost all conditions associated with accelerated atherosclerosis. Cognizant of the enlarging body of evidence implicating increased viscosity in atherogenesis, we hypothesize that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity correlate with their association with risk of atherosclerosis. 2. Blood viscometry was performed on samples from 28 healthy, non-fasting adult volunteers using a capillary viscometer. Data were correlated with haematocrit, fibrinogen, serum viscosity, total cholesterol, high-density lipoprotein-cholesterol, triglycerides and calculated low-density lipoprotein-cholesterol. 3. Low-density lipoprotein-cholesterol was more strongly correlated with blood viscosity than was total cholesterol (r = 0.4149, P = 0.0281, compared with r = 0.2790, P = 0.1505). High-density lipoprotein-cholesterol levels were inversely associated with blood viscosity (r = −0.4018, P = 0.0341). 4. To confirm these effects, viscometry was performed on erythrocytes, suspended in saline, which had been incubated in plasma of various low-density lipoprotein/high-density lipoprotein ratios. Viscosity correlated directly with low-density lipoprotein/high-density lipoprotein ratio (n = 23, r = 0.8561, P < 0.01). 5. Low-density lipoprotein receptor occupancy data suggests that these effects on viscosity are mediated by erythrocyte aggregation. 6. These results demonstrate that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity in healthy subjects correlate with their association with risk of atherosclerosis. These effects on viscosity may play a role in atherogenesis by modulating the dwell or residence time of atherogenic particles in the vicinity of the endothelium.


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