Measuring very low density lipoprotein-triglyceride kinetics in man in vivo: how different the various methods really are

  title={Measuring very low density lipoprotein-triglyceride kinetics in man in vivo: how different the various methods really are},
  author={Faidon Magkos and Labros S. Sidossis},
  journal={Current Opinion in Clinical Nutrition and Metabolic Care},
  • F. Magkos, L. Sidossis
  • Published 1 September 2004
  • Biology
  • Current Opinion in Clinical Nutrition and Metabolic Care
Purpose of reviewThe purpose of this article is to briefly outline the methods that are currently available for the determination of very low density lipoprotein-triglyceride (VLDL-TG) kinetics in man in vivo. Recent findingsA number of novel methodologies have been developed over the years for quantifying VLDL-TG production, clearance, and turnover rates. Besides the splanchnic arteriovenous balance technique, tracer methods with radioactive and, more recently, stable isotopes have been widely… 
Measuring VLDL-triglyceride turnover in humans using ex vivo-prepared VLDL tracer Published, JLR Papers in Press, October 18, 2005.
A method using unique, ex vivo labeling of the fatty acid moiety of VLDL-TG followed by intravenous bolus infusion in the same person finds that plasma disappearance of ex vivo-labeled VLDl-TG was comparable to that of in vivo- labels and turnover rates can be safely estimated from the log linear decay of V LDL- TG specific activity.
VLDL-TG kinetics: a dual isotope study for quantifying VLDL-TG pool size, production rates, and fractional oxidation in humans.
The data demonstrate that VLDL-TG Ra measured by a biexponential fit to a bolus decay curve correlates well with V LDL- TG Ra measure by a primed continuous infusion, and therefore that a "second" peripheral VLDl-TG compartment with rapid exchange of TG exists.
Reproducibility of stable isotope-labeled tracer measures of VLDL-triglyceride and VLDL-apolipoprotein B-100 kinetics Published, JLR Papers in Press, February 26, 2007.
There were no systematic differences in plasma FFA, V LDL-TG, and VLDL-apoB-100 concentrations and kinetics between the two studies, and physiologically meaningful differences in mean values can be obtained with a sample size of 6–10 subjects for paired studies and 12–20 subjects per group for cross-sectional studies.
Stable isotope-labeled tracers for the investigation of fatty acid and triglyceride metabolism in humans in vivo
This article focuses on the use of stable isotope-labeled tracers for the quantitative evaluation of major pathways of fatty acid and triglyceride metabolism in humans in vivo.
Energy expenditure, insulin, and VLDL-triglyceride production in humans Published, JLR Papers in Press, July 18, 2006.
VLDL kinetics are similar in men and women and that REE and plasma insulin are significant independent predictors of VLDL-TG production, and it is suggested that REe plays a greater role in V LDL- TG production than previously anticipated.
Impact of body composition on very-low-density lipoprotein-triglycerides kinetics.
It is found that elevated VLDL-TG production without concomitant increased clearance via oxidation and adipose tissue redeposition contributes to hypertriglyceridemia in UBO women.
Determinants of VLDL-triglycerides production
Regulation of hepatic VLDL-TG production involves interplay between systemic FFA delivery, hormonal, and nutritional factors that act in concert with hepatic fatty acid handling to regulate short-term and long-term V LDL- TG production.
Basal and Insulin Mediated VLDL-Triglyceride Kinetics in Type 2 Diabetic Men
Ex vivo-labeled VLDL-TG tracers, blood and breath samples, fat biopsies, indirect calorimetry, and body composition measures were applied and it was found that greater basal abdominal VLDl-TG storage may help explain the accumulation of upper-body fat in insulin-resistant individuals.
Increased VLDL-Triglyceride Secretion Precedes Impaired Control of Endogenous Glucose Production in Obese, Normoglycemic Men
Basal VLDL-TG secretion rates are increased in normoglycemic but insulin-resistant, obese men, resulting in hypertriglyceridemia.


Use of stable isotopically labeled tracers to measure very low density lipoprotein-triglyceride turnover.
It is concluded that accounting for tracer recycling, particularly the contribution of hepatic glycerolipid pools, is essential to accurately measure VLDL-TG kinetics, and that bolus injection of stable isotopically labeled glycerl or palmitate tracers in conjunction with compartmental modeling analysis offers a reliable approach for measuring VLDl- TG kinetics.
The metabolic heterogeneity of human very low density lipoprotein triglyceride.
Quantification of triglyceride transport in blood plasma: a critical analysis.
Direct measurement of net splanchnic secretion of triglyceride fatty acids in very low density lipoproteins (VLDL) provides the must unambiguous information, but precision is low and methods to label VLDL-triglycerides in vitro deserve more study.
Kinetic model for production and metabolism of very low density lipoprotein triglycerides. Evidence for a slow production pathway and results for normolipidemic subjects.
The results of these studies strongly support the interpretation that the late, slow component of the VLDL-TG activity curve is predominantly due to the slowly turning-over precursor compartment in the conversion pathway and is not due either to a slow compartment in a labeled precursor, plasma free glycerol, or to an exchange of plasma VLDl-TG with an extravascular compartment.
Model development to describe the heterogeneous kinetics of apolipoprotein B and triglyceride in hypertriglyceridemic subjects.
The inclusion in the model of the rapidly turning over pool of triglyceride-rich particles, identified in the heparin-unbound fraction, suggests that values for triglyceride production in man have been underestimated.
Role of very low density lipoproteins in the energy metabolism of the rat.
The direct oxidation of fatty acids in VLDL played an important role in the energy metabolism of the rats, accounting for a percentage of the total CO2 production that was equal to the amount that arose from the oxidation of plasma FFA.
The quest for accurate determination of very low density lipoprotein triacylglycerol secretion rates.
  • L. Sidossis
  • Biology, Computer Science
    Current opinion in clinical nutrition and metabolic care
  • 2002
An elegant overview of the latest methodology for assessing lipid metabolism in vivo is presented and its apparent role as an independent risk factor in the development of coronary artery disease is investigated.
Transport of very low density lipoprotein triglycerides in varying degrees of obesity and hypertriglyceridemia.
The data showed a poor correlation between transport rates determined by multicompartment analysis and single-exponential analysis used previously by other investigators, and suggests that both overproduction of VLDL-TG and insufficient enhancement of clearance contributed to the development of hypertriglyceridemia.
Sex Difference in the Kinetics of Triglyceride Metabolism in Normal and Hypertriglyceridaemic Human Subjects
The sex difference in TG kinetics which Nikkila and Kekki originally note in normals can now be extended to includehypertriglyceridaemic subjects, and in general, overproduction, and not underutilization, is the initiating event in most cases of hypertrigiyceridaemia.