Usefulness of novel Martin/Hopkins and Sampson equations over Friedewald equation in cardiology outpatients: A CVSCORE‐TR substudy

2021 ◽  
Author(s):  
Lale Dinç Asarcıklı ◽  
Mehmet Kış ◽  
Tolga Sinan Güvenç ◽  
Veysel Tosun ◽  
Burak Acar ◽  
...  
Keyword(s):  
Friedewald Equation

scholarly journals Variability in cholesterol measurements: comparison of calculated and direct LDL cholesterol determinations

1996 ◽  
Vol 42 (5) ◽  
pp. 732-737 ◽  
Author(s):  
G Schectman ◽  
M Patsches ◽  
E A Sasse
Keyword(s):  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Low Density Lipoprotein Cholesterol ◽  
Lipid Disorder ◽  
Total Variability ◽  
Friedewald Equation ◽  
C Value ◽  
Hypercholesterolemic Subjects

Abstract Calculated low-density lipoprotein cholesterol (LDL-C) concentrations determined from the Friedewald equation have a large intraindividual CV, in part because the calculation incorporates the variability of cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglyceride measurements. We studied whether a new assay that measures LDL-C directly will reduce this variability and reduce the need for averaging serial specimens. Four blood samples were obtained 1 week apart from 35 mildly hypercholesterolemic subjects and analyzed for total cholesterol, triglycerides, and HDL-C. LDL-C was calculated by the Friedewald equation, and was also measured directly with a commercially available direct LDL-C assay. The intraindividual CV for the direct and calculated LDL-C assays were similar [CV of direct LDL-C assay (mean +/- SE): 6.8 +/- 0.5% vs calculated LDL-C: 7.3 +/- 0.6%; difference 0.44%, 95% confidence interval: -0.7-1.5%]. For both assays, at least two blood tests were required from each subject to reduce total variability of LDL-C to less than or equal to 5%. We conclude that the direct LDL-C assay did not reduce the variability in LDL-C compared with the conventional LDL-C calculation. However, it may have a specific role in lipid disorder evaluation and (or) monitoring when triglycerides are increased or the LDL-C value alone is needed.

P5332Magic mirror on the wall, can we reach our LDL-C goal? Comparison of calculated LDL-C and direct measured LDL-C levels in atherogenic dyslipidemia condition

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
I Reiber ◽  
L Mark ◽  
G Y Paragh
Keyword(s):  
Routine Clinical Practice ◽  
Atherogenic Dyslipidemia ◽  
Additional Risk ◽  
Mean Values ◽  
Lipid Status ◽  
Remnant Cholesterol ◽  
Friedewald Equation ◽  
Expensive Process ◽  
Homogeneous Assays ◽  
High Triglyceride

Abstract Background LDL-C represents the primary lipoprotein target for reducing cardiovascular risk. LDL-C can either be calculated or measured directly. Friedewald equation has certain limitations especially with high triglyceride and low LDL-C levels. Although a number of automated direct LDL-C assays are commercially available, non of them is considered to be equivalent to the “gold standard” of direct LDL-C, beta quantitation, a complex and expensive process that is unavailable in routine clinical practice. In atherogenic dyslipidemia condition (ADC) (triglycerides≥2.3 mmol/L and HDL-C<1.0 mmol/L) non-HDL-C and remnant cholesterol are proven additional risk factors. Purpose We compared one of the direct homogeneous assays with the widely used Friedewald's and the new Martin/Hopkins methods of estimation of LDL-C to see the differences in average LDL-C, remnant cholesterol and non-HDL-C levels and in availability of less than 1.8 mmol/L of LDL-C in atherogenic dyslipidemia condition. Methods We investigated 14 906 lipid profiles from fasting blood samples of Hungarian individuals with triglycerides <4.5 mmol/L. Total cholesterol (TC), HDL-C, triglycerides (TG) and direct LDL-C (D-LDL-C) were measured directly by the enzimatic assays. We also estimated calculated LDL-C by the Friedewald's formula (F-LDL-C) and by using the new Martin/Hopkins estimation (MH-LDL-C). We have now prepared first a variant of Martin/Hopkins table in mmol/L, in which the modified adjustable factors of 2.2 are included. We determined also non-HDL-C and remnant cholesterol (RC) as a difference of non-HDL-C and F-LDL-C (F-RC), MH-LDL-C (MH-RC), D-LDL-C (D-RC). Results In the investigated population 19.25% was F-LDL-C, 15.48% MH-LDL-C and 7.92% D-LDL-C below 1.8 mmol/L. ADC occurred at 8.12%. For ADC, when F-LDL-C<1.8 mmol/L (A), mean values for F-LDL-C, MH-LDL-C, D-LDL-C and non-HDL-C were 1.23±0.4; 1.65±0.39; 2.06±0.4 and 2.46±0.5 mmol/L respectively. These mean levels were 1.01±0.36; 1.4±0.3; 1.83±0.3 and 2.15±0.34 mmol/L for MH-LDL-C<1.8 mmol/L (B). For D-LDL-C<1.8 mmol/L (C), mean values were 0.79±0.35; 1.13±0.26; 1.54±0.19 and 1.83±0.25 mmol/L respectively. The average RC values (in mmol/L) for A were F-RC: 1.23±0.36; MH-RC: 0.81±0.18; D-RC: 0.4±0.17, for B 1.14±0.33; 0.74±0.14; 0.32±0.13, and for C 1.04±0.27; 0.70±0.1; 0.29±0.12 respectively. Conclusions The Friedewald equation tends to underestimate and the homogeneous enzimatic direct LDL-C assays to overestimate the LDL-C levels compared to the new, accurate, calculated LDL-C values in atherogenic dyslipidemia condition. Based on the data presented in our investigation we should like to propose that more realistic vasculo-protective lipid status can be attained if we calculate LDL-C using the Martin/Hopkins estimation.

scholarly journals Comparison of a New Method for the Direct and Simultaneous Assessment of LDL- and HDL-Cholesterol with Ultracentrifugation and Established Methods

2000 ◽  
Vol 46 (4) ◽  
pp. 493-505 ◽  
Author(s):  
Pascale Benlian ◽  
Christophe Cansier ◽  
Geneviève Hennache ◽  
Oumayma Khallouf ◽  
Pascale Bayer ◽  
...  
Keyword(s):  
Cholesterol Oxidase ◽  
Total Error ◽  
Hdl Cholesterol ◽  
New Method ◽  
Friedewald Equation ◽  
Reliable Quantification ◽  
Serum Storage ◽  
Oxidase Reaction ◽  
Routine Assessment ◽  
Simultaneous Assessment

Abstract Background: Automated electrophoresis combined with enzymatic cholesterol staining might improve routine assessment of LDL- and HDL-cholesterol (LDLC and HDLC), as an alternative to the Friedewald equation and precipitation. A new method (Hydrasys; SEBIA) that adapts the cholesterol esterase/cholesterol oxidase reaction within urea-free gels was evaluated. Methods: Fresh sera from 725 subjects (512 dyslipidemics) were analyzed by electrophoresis, in parallel with sequential ultracentrifugation, β-quantification, calculation, and precipitation. Results: Electrophoresis was linear up to 4 g/L cholesterol, with a detection limit of 0.042 g/L cholesterol/band. Within-run, between-run, between-batch, and between-operator imprecision (CVs) were 1.6%, 2.0%, 1.5%, and 2.7% for LDLC, and 3.9%, 4.3%, 5.5%, and 4.9% for HDLC, and remained unchanged up to 6.3 g/L plasma triglycerides (TGs). Precision decreased with very low HDLC (&lt;0.25 g/L). Serum storage for 3–7 days at +4 or −80 °C did not interfere significantly with the assay. Agreement with β-quantification was stable for LDLC up to 5.07 g/L (r = 0.94), even at TG concentrations &gt;4 g/L (r = 0.91). Bias (2.88% ± 12%) and total error (7.84%) were unchanged at TG concentrations up to 18.5 g/L. Electrophoresis predicted National Cholesterol Education Program cut-points with &lt;0.04 g/L error, exactly and appropriately classified 79% and 96% of the subjects, and divided by 2.4 (all subjects) and 5.8 (TGs &gt;1.5 g/L) the percentage of subjects underestimated by calculation. One-half of the patients with TGs &gt;4 g/L had LDLC &gt;1.30 g/L. For HDLC, correlation was better with precipitation (r = 0.87) than ultracentrifugation (r = 0.76). Error (−0.10% ± 26%) increased when HDLC decreased (&lt;0.35 g/L). Direct assessment of the LDLC/HDLC ratio detected 45% more high-risk subjects than the calculation/precipitation combination. Conclusions: Electrophoresis provides reliable quantification of LDLC, improving precision, accuracy, and concordance over calculation, particularly with increasing plasma TGs. Implementation of methods to detect low cholesterol concentrations could extend the applications for HDLC assessment.

Sign in / Sign up

Export Citation Format

Share Document