Five methods for determining low-density lipoprotein cholesterol compared.

1984 ◽  
Vol 30 (11) ◽  
pp. 1797-1800 ◽  
Author(s):  
P N Demacker ◽  
A G Hijmans ◽  
B J Brenninkmeijer ◽  
A P Jansen ◽  
A van 't Laar
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density Lipoproteins ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Very Low Density Lipoproteins ◽  
Serum Triglycerides ◽  
Type Iii ◽  
Friedewald Formula

Abstract We evaluated three precipitation methods for determination of low-density lipoprotein cholesterol in serum and an indirect method involving the Friedewald formula (Clin Chem 18: 499-502, 1972) by comparison with results by ultracentrifugation. The results of all methods for 83 sera, including 59 hyperlipidemic type IIA, IIB, and IV sera agreed very well, at least for concentrations of serum triglycerides below 8 mmol/L. The accuracy of the Friedewald formula was confirmed in 285 other sera, including 66 sera with triglycerides content between 4.52 and 8.0 mmol/L. For type III sera, the precipitation methods produced similar values to those obtained with the Friedewald formula, all being much higher than the ultracentrifugation values. Density-gradient ultracentrifugation showed that the very-low-density lipoprotein remnants in type III sera almost completely coprecipitated with the low-density lipoproteins. The precipitation methods are not only accurate but also very precise (CV less than 5%); they can therefore be used in clinical laboratories to measure atherogenic low-density lipoproteins plus the remnants of very-low-density lipoproteins. However, when serum triglycerides and high-density lipoprotein cholesterol also are determined, the Friedewald formula is a reliable alternative.

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.

Abstract 405: Utility of Very Low-density Lipoprotein Cholesterol to Total Triglyceride Ratio (VLDL-C/TG) and Non-VLDL TG to Quantify Remnant Lipoprotein Cholesterol (RLP-C): The Very Large Database of Lipids Study 7C

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Aditya D Hendrani ◽  
Renato Quispe ◽  
Seth S Martin ◽  
Krishnaji R Kulkarni ◽  
Peter P Toth ◽  
...  
Keyword(s):  
Diagnostic Criteria ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Type Iii ◽  
Very Large Database ◽  
Relationship Of

Background: RLP-C is comprised of atherogenic triglyceride- (TG-) rich lipoproteins, commonly defined as the sum of intermediate-density lipoprotein cholesterol (IDL-C) and very low-density lipoprotein cholesterol remnants (VLDL 3 -C). In clinical practice, the VLDL-C/TG ratio is used to diagnose type III dyslipidemia, a primary lipoprotein disorder characterized by high levels of RLP-C. Methods: Serum lipids of 556,307 U.S. adults with TG ≥130 mg/dL were analyzed by ultracentrifugation (VAP, Atherotech, Birmingham, AL). We estimated TG content in VLDL (VLDL-TG) as the product of VLDL-C and validated variable TG/VLDL-C factors. Non-VLDL-TG was then calculated as total TG minus VLDL-TG, for which negative values represented the presence of RLP-C. We examined the relationship of non-VLDL-TG to 1000 quantiles of VLDL-C/TG ratio. We defined a VLDL-C/TG ratio cutpoint for presence of RLP-C based on the quantile at which median non-VLDL-TG≤0. Results: We found median non-VLDL-TG≤0 at VLDL-C/TG = 0.18 (Figure) . There were 174,907 adults who did not meet diagnostic criteria for type III dyslipidemia (VLDL-C/TG 0.18 to <0.30), whose levels of RLP-C and non-VLDL-TG levels were 37 (31-46) and -20 (-40 to -8) mg/dL, respectively. A total of 1,550 adults met classical diagnostic criteria for type III dyslipidemia (VLDL-C/TG ≥0.3), whose plasma levels of RLP-C and non-VLDL-TG levels were 80 (67-101) and -187 (-290 to -129) mg/dL, respectively. Conclusion: A threshold of VLDL-C/TG ≥0.18 correlates with the accumulation of RLP-C in plasma. If validated in future studies, these findings will improve identification of individuals who are at greater risk for atherosclerotic disease.

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.

scholarly journals Rutin ameliorates carbon tetrachloride (CCl4)-induced hepatorenal toxicity and hypogonadism in male rats

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7011 ◽  
Author(s):  
Hany Elsawy ◽  
Gehan M. Badr ◽  
Azza Sedky ◽  
Basem M. Abdallah ◽  
Abdullah M. Alzahrani ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Sperm Quality ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serum Testosterone ◽  
Lipoprotein Cholesterol ◽  
Male Rats ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Serum Triglycerides

Rutin, a food derived-polyphenolic bioflavonoid, has been acknowledged for several health benefits. This study aims to explore the ameliorative effects of rutin against carbon tetrachloride (CCl4) toxicity in male rats. Adult male rats were given either CCl4 (30% in olive oil, 3 ml/kg b.w. intraperitoneally) alone or in combination with rutin (70 mg/kg intragastrically) twice a week for 4 weeks. Our data showed that rutin mitigated CCl4 hepatorenal damage, as indicated by diagnostic markers (i.e., transaminases, alkaline phosphatase, total bilirubin, total protein, albumin, urea, uric acid and creatinine), and histopathological findings. In addition, CCl4 induced profound elevation of free radical generation and oxidative stress, as evidenced by increasing lipid peroxidation and reducing catalase, superoxide dismutase and glutathione peroxidase activities in liver, kidney and testicular tissues; these effects were suppressed by coexposure with rutin. Moreover, the increase in the levels of serum triglycerides, cholesterol, low-density lipoprotein cholesterol, and very-low-density lipoprotein cholesterol induced by CCl4 was effectively counteracted by rutin. The decrease in the level of high-density lipoprotein cholesterol in the CCl4 group was also counteracted by rutin treatment. Interestingly, the decreased levels of hormonal mediators associated with sperm production, including serum testosterone, luteinizing hormone and follicle-stimulating hormone, and the impaired sperm quality induced by CCl4 were reversed by rutin. Data from the current study clearly demonstrated that rutin supplementation could at least partly overcome CCl4-induced hepatotoxicity, nephrotoxicity and reproductive toxicity by antioxidant and antidyslipidemic effects.

Effect of serum lipoprotein(a) on estimation of low-density lipoprotein cholesterol by the Friedewald formula

1994 ◽  
Vol 40 (4) ◽  
pp. 571-573 ◽  
Author(s):  
K M Li ◽  
D E Wilcken ◽  
N P Dudman
Keyword(s):  
Serum Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Total Serum ◽  
Total Serum Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Lipoprotein A ◽  
Friedewald Formula

Abstract The calculation of serum low-density lipoprotein cholesterol (LDL-C) by the Friedewald formula does not account for the cholesterol associated with lipoprotein(a) [Lp(a)]. To quantify the contribution of Lp(a) cholesterol to total serum cholesterol, we measured concentrations of serum Lp(a) by an ELISA and concentrations of other serum lipids and lipoproteins by standard assays in 23 normolipemic women, ages 50-60 years. In measuring serum high-density lipoprotein we found that polyethylene glycol 6000 precipitated &gt; 99.8% of all Lp(a). When serum Lp(a) concentrations were &lt; or = 300 mg/L, 301-600 mg/L, and &gt; 600 mg/L, the uncorrected serum LDL-C was overestimated, respectively, by a mean of 4.1% (n = 7), 8.5% (n = 8), and 21.4% (n = 8). Serum Lp(a) concentrations were positively correlated with percentage overestimation (P &lt; 0.001), but were not correlated with either corrected or uncorrected serum LDL-C. We conclude that the Friedewald formula should be modified to take into account the contribution of Lp(a) cholesterol to total serum cholesterol.

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