Lipid metabolism in anorexia nervosa

BACKGROUND: Anorexia nervosa is a model of simple starvation accompanied by secondary hyperlipoproteinemia. Plasma fatty acid pattern influences levels of plasma lipids and lipoproteins. Level of plasma lathosterol represents a marker of cholesterol synthesis de novo; levels of plant sterols reflect resorption of exogenous cholesterol. The aim of the study was to evaluate fatty acids in plasma lipid classes and their relationships to plasma lipids, lipoproteins, lathosterol, campesterol and beta-sitosterol. METHODS AND RESULTS: We examined 16 women with anorexia nervosa and 25 matched controls. Main lipid classes were separated by thin-layer chromatography, fatty acids and non-cholesterol sterols were evaluated by capillary gas chromatography. Patients with anorexia nervosa revealed increased concentrations of total cholesterol, triglycerides, HDL-cholesterol, campesterol and beta-sitosterol; changes in plasma levels of lathosterol did not reach statistical significance. The most consistent finding in fatty acid composition was a decreased content of linoleic acid and raised content of palmitoleic acid in all lipid classes. CONCLUSIONS: Changes of plasma lipids and lipoproteins in anorexia nervosa result from complex mechanisms including increased synthesis of triglyceride-rich lipoproteins along with unchanged cholesterol synthesis rate. Hypercholesterolemia in anorexia nervosa may also result from increased resorption of exogenous cholesterol.