Plasma lipoproteins and fatty acid composition after "minipill"

Fatty acid composition of lipoprotein lipids in hepatobiliary diseases

Liver damage and alterations in the exocrine function of the gland lead to a profound alteration of the plasma lipoprotein profile. To determine whether hepatic disease results in changes in the lipoprotein fatty acid composition, i.e. to determine whether liver function influences the homeostasis of complex lipids in plasma, we studied the fatty acid profile of lipids from VLDL, LDL and HDL, as well as from total plasma, in thirty-one patients of both sexes with hepatobiliary pathology (compensated liver cirrhosis, uncompensated liver cirrhosis, primary biliary cirrhosis, other intrahepatic cholestasis, and acute viral hepatitis). We also studied a group of healthy adults as controls. We present the lipoprotein profile and the fatty acid composition (myristic C14, palmitic C16, palmitoleic C16: 1, stearic C18, oleic C18: 1, linoleic C18: 2, eicosatrienoic C20: 3 omega 6 and arachidonic C20: 4) of lipoprotein and total plasma triacylglycerols, cholesteryl esters and phospholipids. The main observation of this study is that, despite the profound changes in the lipoprotein profile and the lower abundance of polyunsaturated fatty acids in complex lipids, the composition of all triacylglycerols, cholesteryl esters and phospholipids is very similar for the corresponding lipoproteins of patients with hepatobiliary disease and of control subjects. This indicates that in the controls as in the studied patients, the exchange of lipids between plasmatic lipoproteins is very rapid and demonstrates the possible importance of the extrahepatic synthesis of cholesteryl ester transfer protein.

Oral contraceptives, lipids and cardiovascular disease

Evidence for the involvement of changes in lipid metabolism and oral contraceptive use in the development of cardiovascular disease is briefly reviewed with particular reference to the main object of the article, to assess the effect of different oral contraceptive formulations on serum lipid levels. The preferred formulations should contain a low dose of ethynyloestradiol and should not increase serum levels of cholesterol and LDL-C or reduce those of HDL-C. Such formulations appear to be the triphasic one containing ethynyloestradiol and levonorgestrel and the ethynyloestradiol-desogestrel combination, which appears to be unique in that it may actually increase HDL-C. However other determinants in addition to effects on lipid metabolism will be important in deciding the choice of an oral contraceptive. Any changes which do occur in serum lipid concentrations with OC use appear within the first three months and do not appear to be progressive with continued use after this time.