Markers of triglyceride-rich lipoprotein remnant metabolism in visceral obesity.
BACKGROUND
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.


METHODS
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.


RESULTS
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).


CONCLUSIONS
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.
Chan
Dick C
DC
Department of Medicine, University of Western Australia, Royal Perth Hospital, GPO Box X2213, Perth, WA 6847 Australia.
Watts
Gerald F
GF
Barrett
P Hugh
PH
Mamo
John C L
JC
Redgrave
Trevor G
TG
D053283:Apolipoprotein B-48; D053305:Apolipoprotein C-III; D001053:Apolipoproteins / Q000097:blood; D001055:Apolipoproteins B / Q000097:blood; D001056:Apolipoproteins C / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002784:Cholesterol / Q000097:blood*; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D009765:Obesity / Q000097:blood*; D014280:Triglycerides / Q000097:blood*
D053283:Apolipoprotein B-48; D053305:Apolipoprotein C-III; D001053:Apolipoproteins; D001055:Apolipoproteins B; D001056:Apolipoproteins C; D015415:Biomarkers; D008074:Lipoproteins; D014280:Triglycerides; C112017:remnant-like particle cholesterol; D002784:Cholesterol