scholarly journals Direct Determination of Lipoprotein Particle Sizes and Concentrations by Ion Mobility Analysis

2008 ◽  
Vol 54 (8) ◽  
pp. 1307-1316 ◽  
Author(s):  
Michael P Caulfield ◽  
Shuguang Li ◽  
Gloria Lee ◽  
Patricia J Blanche ◽  
Wael A Salameh ◽  
...  
Keyword(s):  
Ion Mobility ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Direct Determination ◽  
Serum Samples ◽  
Lipoprotein Particles ◽  
Lipoprotein Subclasses ◽  
Scan Time ◽  
Coefficients Of Variation

Abstract Background: Current methods for measuring the concentrations of lipoprotein particles and their distributions in particle subpopulations are not standardized. We describe here and validate a new gas-phase differential electrophoretic macromolecular mobility-based method (ion mobility, or IM) for direct quantification of lipoprotein particles, from small, dense HDL to large, buoyant, very-low-density lipoprotein (VLDL). Methods: After an ultracentrifugation step to remove albumin, we determined the size and concentrations of lipoprotein particles in serum samples using IM. Scan time is 2 min and covers a particle range of 17.2–540.0 Å. After scanning, data are pooled by totaling the particle number across a predetermined size range that corresponds to particular lipoprotein subclasses. IM results were correlated with those of standard methods for cholesterol and apolipoprotein analysis. Results: Intra- and interassay coefficients of variation for LDL particle size were <1.0%. The intra- and interassay variation for LDL and HDL particle subfraction measurements was <20%. IM-measured non-HDL correlated well with apolipoprotein B (r = 0.92). Conclusions: The IM method provides accurate, reproducible, direct determination of size and concentration for a broad range of lipoprotein particles. Use of this methodology in studies of patients with cardiovascular disease and other pathologic states will permit testing of its clinical utility for risk assessment and management of these conditions.

Comparison of a direct enzymatic assay and polyacrylamide tube gel electrophoresis for measurement of small, dense low-density lipoprotein cholesterol

2015 ◽  
Vol 53 (1) ◽  
Author(s):  
Somlak Vanavanan ◽  
Pornpen Srisawasdi ◽  
Mana Rochanawutanon ◽  
Jirapa Kerdmongkol ◽  
Martin H. Kroll
Keyword(s):  
Gel Electrophoresis ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cardiovascular Prevention ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Lipoprotein Particles ◽  
Ldl Particles

AbstractSmall, dense low-density lipoprotein cholesterol (sdLDL-C) has been linked to the progression of cardiovascular disease. We compared two methods for determination of sdLDL-C, a direct enzymatic (ENZ) method and a polyacrylamide tube gel electrophoresis (PGE) assay, and investigated the associations of both sdLDL-C measurements with metabolic syndrome.We analyzed 242 patient sera for sdLDL and atherosclerosis-related markers. The PGE method separates the intermediate-density lipoprotein particles into three midbands (MID-A to MID-C) and the LDL particles into seven subfractions (LDL1 to LDL7); the sdLDL-PGE result is calculated as the sum of cholesterol concentrations from LDL3 to LDL7.The regression equation for sdLDL-C was [ENZThe ENZ assay for sdLDL-C correlated well with the PGE method. The ENZ method measures a broader range of atherogenic lipoprotein particles than PGE and has the potential to identify subjects with vascular risk, thus contributing in directing specific interventions for cardiovascular prevention.

scholarly journals Analytical performance and clinical utility of a direct LDL-cholesterol assay in a hyperlipidemic pediatric population

1996 ◽  
Vol 42 (8) ◽  
pp. 1182-1188 ◽  
Author(s):  
N Harris ◽  
E J Neufeld ◽  
J W Newburger ◽  
B Ticho ◽  
A Baker ◽  
...  
Keyword(s):  
Clinical Utility ◽  
Pediatric Patients ◽  
Ldl Cholesterol ◽  
Pediatric Population ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Direct Determination ◽  
Low Density Lipoprotein Cholesterol ◽  
The Mean

Abstract This study compares a new latex immunoseparation method for the direct determination of plasma low-density lipoprotein cholesterol (LDL-C) with the reference procedure for LDL-C (beta-quantification) in a pediatric hyperlipidemic population. The direct LDL-C assay has a mean bias of -98 mg/L in a fasting group (n = 96) of patients (mean triglycerides 1057 +/- 720 mg/L) and a bias of +177 mg/L in a nonfasting group (n = 42, mean triglycerides 4854 +/- 5457 mg/L). The mean total analytical error calculated from our data is 13.8%. The direct LDL-C assay and the commonly used Friedewald calculation respectively classified 81% and 84% of fasting patients correctly, according to the cutoffs of 1100 and 1300 mg/L for LDL-C set by the National Cholesterol Education Program for pediatric patients. Of combined fasting and nonfasting patients, 80% were correctly classified by the direct LDL-C assay. Therefore, despite several analytical shortcomings, the direct LDL-C assay may be useful in managing hyperlipidemic children without the need for a fasting specimen.

scholarly journals Development of Fatty Acid Reference Ranges and Relationship with Lipid Biomarkers in Middle-Aged Healthy Singaporean Men and Women

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 435
Author(s):  
Cody A. C. Lust ◽  
Xinyan Bi ◽  
Christiani Jeyakumar Henry ◽  
David W. L. Ma
Keyword(s):  
Disease Risk ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Multiple Regression Model ◽  
Dietary Fatty Acids ◽  
Lipid Biomarkers ◽  
Reference Ranges ◽  
Middle Aged ◽  
Serum Samples ◽  
Biologically Relevant

Dietary fatty acids (FA) are essential for overall human health, yet individual FA reference ranges have yet to be established. Developing individual FA reference ranges can provide context to reported concentrations and whether an individual displays deficient, or excess amounts of FA. Reference ranges of sixty-seven individual FA (μmol/L) were profiled and analyzed using gas chromatography with a flame ionization detector from serum samples collected from 476 middle-aged Singaporean males (BMI:23.3 ± 2.9) and females (BMI:21.8 ± 3.6). Measures of triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol (TC) (mmol/L) were also collected. The mean FA concentration seen in this cohort (11,458 ± 2478 was similar to that of overweight North American cohorts assessed in past studies. Ten biologically relevant FA were compared between sexes, with females exhibiting significantly higher concentrations in four FA (p < 0.05). A multiple regression model revealed the ten FA contributed significantly to nearly all lipid biomarkers (p < 0.05). A majority of participants who had FA concentrations in the ≥95th percentile also exhibited TG, HDL, LDL, and TC levels in the “high” risk classification of developing cardiovascular disease. Future studies profiling individual FA reference ranges in many unique, global cohorts are necessary to develop cut-off values of individual FA concentrations highly related to disease-risk.

scholarly journals Long-term fasting improves lipoprotein-associated atherogenic risk in humans

2021 ◽  
Author(s):  
Franziska Grundler ◽  
Dietmar Plonné ◽  
Robin Mesnage ◽  
Diethard Müller ◽  
Cesare R. Sirtori ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Apolipoprotein A1 ◽  
Health Concern ◽  
Low Density ◽  
Lipoprotein Subclasses ◽  
Ldl Particles ◽  
Increased Risk

Abstract Purpose Dyslipidemia is a major health concern associated with an increased risk of cardiovascular mortality. Long-term fasting (LF) has been shown to improve plasma lipid profile. We performed an in-depth investigation of lipoprotein composition. Methods This observational study included 40 volunteers (50% men, aged 32–65 years), who underwent a medically supervised fast of 14 days (250 kcal/day). Changes in lipid and lipoprotein levels, as well as in lipoprotein subclasses and particles, were measured by ultracentrifugation and nuclear magnetic resonance (NMR) at baseline, and after 7 and 14 fasting days. Results The largest changes were found after 14 fasting days. There were significant reductions in triglycerides (TG, − 0.35 ± 0.1 mmol/L), very low-density lipoprotein (VLDL)-TG (− 0.46 ± 0.08 mmol/L), VLDL-cholesterol (VLDL-C, − 0.16 ± 0.03 mmol/L) and low-density lipoprotein (LDL)-C (− 0.72 ± 0.14 mmol/L). Analysis of LDL subclasses showed a significant decrease in LDL1-C (− 0.16 ± 0.05 mmol/L), LDL2-C (− 0.30 ± 0.06 mmol/L) and LDL3-C (− 0.27 ± 0.05 mmol/L). NMR spectroscopy showed a significant reduction in large VLDL particles (− 5.18 ± 1.26 nmol/L), as well as large (− 244.13 ± 39.45 nmol/L) and small LDL particles (− 38.45 ± 44.04 nmol/L). A significant decrease in high-density lipoprotein (HDL)-C (− 0.16 ± 0.04 mmol/L) was observed. By contrast, the concentration in large HDL particles was significantly raised. Apolipoprotein A1 decreased significantly whereas apolipoprotein B, lipoprotein(a), fibrinogen and high-sensitivity C-reactive protein were unchanged. Conclusion Our results suggest that LF improves lipoprotein levels and lipoprotein subclasses and ameliorates the lipoprotein-associated atherogenic risk profile, suggesting a reduction in the cardiovascular risk linked to dyslipidemia. Trial Registration Study registration number: DRKS-ID: DRKS00010111 Date of registration: 03/06/2016 “retrospectively registered”.

scholarly journals Development of Capture Assays for Different Modifications of Human Low-Density Lipoprotein

2005 ◽  
Vol 12 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Gabriel Virella ◽  
M. Brooks Derrick ◽  
Virginia Pate ◽  
Charlyne Chassereau ◽  
Suzanne R. Thorpe ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Density ◽  
Modified Ldl ◽  
Capture Assay ◽  
Carboxymethyl Lysine

ABSTRACT Antibodies to malondialdehyde (MDA)-modified low-density lipoprotein (LDL), copper-oxidized LDL (oxLDL), N ε(carboxymethyl) lysine (CML)-modified LDL, and advanced glycosylation end product (AGE)-modified LDL were obtained by immunization of rabbits with in vitro-modified human LDL preparations. After absorption of apolipoprotein B (ApoB) antibodies, we obtained antibodies specific for each modified lipoprotein with unique patterns of reactivity. MDA-LDL antibodies reacted strongly with MDA-LDL and also with oxLDL. CML-LDL antibodies reacted strongly with CML-LDL and also AGE-LDL. oxLDL antibodies reacted with oxLDL but not with MDA-LDL, and AGE-LDL antibodies reacted with AGE-LDL but not with CML-LDL. Capture assays were set with each antiserum, and we tested their ability to capture ApoB-containing lipoproteins isolated from precipitated immune complexes (IC) and from the supernatants remaining after IC precipitation (free lipoproteins). All antibodies captured lipoproteins contained in IC more effectively than free lipoproteins. Analysis of lipoproteins in IC by gas chromatography-mass spectrometry showed that they contained MDA-LDL and CML-LDL in significantly higher concentrations than free lipoproteins. A significant correlation (r = 0.706, P < 0.019) was obtained between the MDA concentrations determined by chemical analysis and by the capture assay of lipoproteins present in IC. In conclusion, we have developed capture assays for different LDL modifications in human ApoB/E lipoprotein-rich fractions isolated from precipitated IC. This approach obviates the interference of IC in previously reported modified LDL assays and allows determination of the degree of modification of LDL with greater accuracy.

Sign in / Sign up

Export Citation Format

Share Document