Markers of Triglyceride-rich Lipoprotein Remnant Metabolism in Visceral Obesity

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 48; no. 2; pp. 278 - 283
• Main Authors: Chan, Dick C, Watts, Gerald F, Barrett, P. Hugh, Mamo, John C.L, Redgrave, Trevor G
• Format: Journal Article
• Language: English
• Published: England Am Assoc Clin Chem 01.02.2002
• Subjects: Apolipoprotein B-48; Apolipoprotein C-III; Apolipoproteins - blood; Apolipoproteins B - blood; Apolipoproteins C - blood; Biomarkers - blood; Cholesterol - blood; Humans; Lipoproteins - blood; Male; Obesity - blood; Triglycerides - blood
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/48.2.278

Triglyceride-rich lipoprotein remnants are atherogenic, and this may be particularly important in visceral obesity. We investigated remnant metabolism in obese men by measuring remnant-like particle-cholesterol (RLP-C), apolipoprotein (apo) B-48, apoC-III, and the clearance of a labeled remnant-like emulsion. Fasting RLP-C, apoB-48, and apoC-III concentrations were measured in 48 viscerally obese men and 10 lean controls. RLP-C was determined by immunoseparation assay, apoB-48 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and enhanced chemiluminescence, and apoC-III by immunoturbidimetric assay. The catabolism of chylomicron remnants was measured by intravenous injection of a remnant-like emulsion containing cholesteryl [(13)C]oleate, with isotopic enrichment of (13)CO(2) in breath determined by isotope-ratio mass spectrometry and a multicompartmental model to estimate fractional catabolic rate (FCR) of the emulsion. Compared with controls, obese men had significantly increased plasma concentrations of RLP-C, apoB-48, and apoC-III (P <0.001 for all). Plasma total apoB-100, non-HDL-cholesterol, LDL-cholesterol, triglycerides, and insulin resistance (HOMA score) were also significantly higher in the obese group (P <0.001 for all). Obese men had a significantly lower FCR of the remnant-like emulsion compared with controls (P = 0.020). Viscerally obese individuals have insulin resistance and increased plasma concentrations of triglyceride-rich lipoprotein remnants, which may be attributable to decreased catabolism of these particles.