Search PubMed⌕ Search

Biomedical subjects

Martin Adiels

Publications and source records attributed to Martin Adiels.

4 recordsLinked to original sources

Diabetic dyslipidaemia.

PURPOSE OF REVIEW: Diabetic dyslipidaemia is a cluster of plasma lipid and lipoprotein abnormalities that are metabolically interrelated. The increase of large type 1 very low density lipoprotein particles in type 2 diabetes initiates a sequence of events that generates atherogenic remnants, small dense low-density lipoprotein and small dense high-density lipoprotein particles. Thus, it is of great importance to elucidate the mechanisms behind the overproduction of large very low density lipoprotein particles in diabetic dyslipidaemia. This review discusses the pathophysiology of very low density lipoprotein metabolism in type 2 diabetes and recent concepts of lipid management of diabetic dyslipidaemia. RECENT FINDINGS: Results indicate that triglyceride and apolipoprotein B production in types 1 and 2 very low density lipoprotein are significantly correlated, suggesting a coupling of the two processes governing the metabolism of these lipoprotein subpopulations. Insulin resistance, hyperglycaemia, and liver fat were associated with excess hepatic production of type 1 but not type 2 very low density lipoprotein particles. These data provide support for the independent regulation of types 1 and 2 very low density lipoprotein apolipoprotein B production. SUMMARY: Recent data suggest that the assembly of very low density lipoprotein is fundamentally altered in type 2 diabetes, explaining the overproduction of large type 1 very low density lipoprotein as well as the inability of insulin to suppress production of type 1 very low density lipoprotein in type 2 diabetes. Future discoveries hopefully will delineate the regulatory steps to allow more targeted treatment of diabetic dyslipidaemia.

Animals↗

Overproduction of VLDL1 driven by hyperglycemia is a dominant feature of diabetic dyslipidemia.

OBJECTIVE: We sought to compare the synthesis and metabolism of VLDL1 and VLDL2 in patients with type 2 diabetes mellitus (DM2) and nondiabetic subjects. METHODS AND RESULTS: We used a novel multicompartmental model to simultaneously determine the kinetics of apolipoprotein (apo) B and triglyceride (TG) in VLDL1 and VLDL2 after a bolus injection of [2H3]leucine and [2H5]glycerol and to follow the catabolism and transfer of the lipoprotein particles. Our results show that the overproduction of VLDL particles in DM2 is explained by enhanced secretion of VLDL1 apoB and TG. Direct production of VLDL2 apoB and TG was not influenced by diabetes per se. The production rates of VLDL1 apoB and TG were closely related, as were the corresponding pool sizes. VLDL1 and VLDL2 compositions did not differ in subjects with DM2 and controls, and the TG to apoB ratio of newly synthesized particles was very similar in the 2 groups. Plasma glucose, insulin, and free fatty acids together explained 55% of the variation in VLDL1 TG production rate. CONCLUSIONS: Insulin resistance and DM2 are associated with excess hepatic production of VLDL1 particles similar in size and composition to those in nondiabetic subjects. We propose that hyperglycemia is the driving force that aggravates overproduction of VLDL1 in DM2.

Adult↗

A new combined multicompartmental model for apolipoprotein B-100 and triglyceride metabolism in VLDL subfractions.

The use of stable isotopes in conjunction with compartmental modeling analysis has greatly facilitated studies of the metabolism of the apolipoprotein B (apoB)-containing lipoproteins in humans. The aim of this study was to develop a multicompartment model that allows us to simultaneously determine the kinetics of apoB and triglyceride (TG) in VLDL(1) and VLDL(2) after a bolus injection of [(2)H(3)]leucine and [(2)H(5)]glycerol and to follow the catabolism and transfer of the lipoprotein particles. Here, we describe the model and present the results of its application in a fasting steady-state situation in 17 subjects with lipid values representative of a Western population. Analysis of the correlations showed that plasma TG was determined by the VLDL(1) and VLDL(2) apoB and TG fractional catabolic rate. Furthermore, the model showed a linear correlation between VLDL(1) TG and apoB production. A novel observation was that VLDL TG entered the circulation within 21 min after its synthesis, whereas VLDL apoB entered the circulation after 33 min. These observations are consistent with a sequential assembly model of VLDL and suggest that the TG is added to a primordial apoB-containing particle in the liver.

Apolipoprotein B-100↗