Effect of systemic administration of isotretinoin on blood lipids and fatty acids in acne patients

Background. In many studies, an increase in total cholesterol and triglycerides with isotretinoin therapy have been shown and investigators have commented on potential cardiovascular risk. A low intake of linoleic acid, the main essential fatty acid in man, may act as an independent risk factor for coronary heart disease. In vitro etretin alters both the incorporation of extracellular fatty acids into cell membranes and the fatty acid composition of the cell membrane itself. It is, therefore, important to establish whether isotretinoin has any effect on the metabolism of polyunsaturated fatty acids. Methods. The effect of treatment with isotretinoin for 4 months on the metabolism of polyunsaturated fatty acids in patients with acne was assessed. Quantitative total cholesterol and triglycerides as well as plasma phospholipid, triglycerides, and cholesteryl ester fatty acids were measured in 12 patients and red cell phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol fatty acids were measured in 13 patients before and after isotretinoin therapy. Results. There was a significant increase in the concentrations of cholesterol (P < 0.02) and triglycerides (P < 0.04) during treatment. There was no significant difference in plasma phospholipids, triglycerides, and cholesterol esters, or in the red cell phosphatidylethanolamine, phosphatidylcholine, and phospharidylinositol during isotretinoin therapy. Conclusions. This study failed to demonstrate any effect of isotretinoin on the metabolism of polyunsaturated fatty acids. There was a significant increase in total cholesterol and triglyceride levels following isotretinoin therapy supporting the findings of many previous studies.