[Metabolism of plasma cholesterol and lipoproteins after total resection of the small intestine in patients with parenteral nutrition. Effects of the amount of phospholipids infused].

The aim of this study was to investigate the plasma lipoprotein profile in 2 patients treated by parenteral nutrition for total small bowel resection over a 15 month period. According to the amount of infused phospholipids (6 g/d vs 3 g/d), infused during 4 non consecutive 6 month or 6 week periods, HDL-cholesterol, apolipoproteins AI and B plasma levels were 30 to 50% below normal values. During the higher phospholipid supply, cholesterolemia seemed normal; each phospholipid supply decrease was followed by a reduction of cholesterol, phospholipids and apolipoprotein B plasma levels of 40, 50 and 25%, respectively, while HDL-cholesterol and apolipoprotein AI plasma levels remained unchanged. Density gradient ultracentrifugation showed that plasma cholesterol changes were mainly due to cholesterol changes (as free cholesterol associated with phospholipids) located in the density range of 1.019-1.040, reflecting the presence of lipoprotein X-like particles, whose levels remained unchanged during each period. An apolipoprotein E, CII and CIII enrichment of plasma was observed and was more pronounced when patients received higher phospholipid infusion. These results show that, in patients without a small bowel, minor changes in phospholipids supply are responsible for serious alterations of the lipoprotein profile; formation of lipoprotein X-like particles could be favored by the low HDL levels in these patients.