Metabolism of an artificial emulsion resembling chylomicrons in patients with multiple myeloma

Multiple myeloma, as other neoplastic diseases, is accompanied by alteratio ns in lipid metabolism. The metabolism of chylomicrons is unexplored in thi s condition, dispite the importance of these lipoproteins for the energy bo dy supply. Chylomicron metabolism in the bloodstream consists of lipolysis by lipoprotein lipase and uptake of remnants by the liver. Triglyceride-ric h emulsions can mimic chylomicron metabolism in man and are a useful tool t o evaluate this metabolic pathway. A double-labeled chylomicron-resembling emulsion was injected into 20 patients with multiple myeloma and 30 normoli pidemic healthy subjects. The plasma kinetic curves of the emulsion H-3-tri glyceride and C-14-cholesteryl ester were determined in plasma samples coll ected over 60 minutes. The fractional clearance rate (FCR) of triglycerides in multiple myeloma was not changed compared to controls. However, FCR of cholesteryl esters was smaller in multiple myeloma (0.025 +/- 0.003 and 0.0 61 +/- 0.010 min(-1), respectively). These results indicate that chylomicro n lipolysis is not affected in multiple myeloma, whereas remnant removal is diminished. (C) 1999 Elsevier Science Ltd. All rights reserved.