Abnormal clearance of postprandial Sf 100-400 plasma lipoproteins in insulin-dependent diabetes mellitus.
Studies were carried out in three normolipidemic non-obese men with insulin-dependent diabetes mellitus (IDDM) and three normal men, to assess whether the clearance of postprandial Sf 100-400 lipoproteins is decreased in IDDM. Sf greater than 100 lipoproteins isolated from plasma 4.5 h after fat ingestion were labeled with 125I and injected into the same subject intravenously. ApoB radioactivity was measured over time in Sf greater than 400, Sf 100-400, and Sf 20-100 lipoproteins isolated from plasma and analyzed using a kinetic model that included both fast and slow delipidation cascades, where lipolysis and uptake of particles by the liver and other tissues were represented. Fractional catabolic rates of Sf 100-400 lipoproteins (min-1) were decreased in diabetic versus control subjects: fast = 0.170 +/- 0.126 versus 0.680 +/- 0.242 (mean +/- SD) (P less than 0.05, two-tailed) and slow = 0.011 +/- 0.006 versus 0.031 +/- 0.015 (P less than 0.05, one-tailed). Kinetic analysis showed that the data were consistent with decreased uptake by the tissues for the fast cascade (diabetic, 0.084 +/- 0.082, vs. control, 0.617 +/- 0.328, P less than 0.05, one-tailed). A similar trend was observed for the slow cascade. There were no significant differences between the two groups in the intraplasma lipolysis rates of Sf 100-400 particles. Analysis of the composition of the injected particles showed that they were total cholesterol (TC)- versus triglyceride (TG)-enriched (P less than 0.001, log-ratio analysis of composition) in IDDM subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
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Georgopoulos
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Phair
D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004041:Dietary Fats / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D008074:Lipoproteins / Q000097:blood / Q000302:isolation & purification / Q000493:pharmacokinetics*; D008297:Male; D008657:Metabolic Clearance Rate; D008958:Models, Molecular; D014280:Triglycerides / Q000097:blood*
D004041:Dietary Fats; D008074:Lipoproteins; D014280:Triglycerides