Abstract
Anorexia nervosa (AN) is a complex psychiatric disorder with a high morbidity and mortality, characteristic with a food intake restriction (restricting type) and/ or other weight-regulatory behaviours such as self-induced vomiting, misuse of laxatives and diuretics or excessive exercise (purging type). The disorder has a prevalence of around 0.2 - 0.8 % among young women and women/men ratio is about 10:1.
The most common onset of AN is in early to mid-adolescence. AN represents a patophysiological model of simple starvation with endocrinal, metabolic, hematologic, musculoskeletal and nutritional abnormalities.
In patients with AN, dyslipidemia with elevated total cholesterol, HDL-C and triglycerides is present in more than 50 %. Some studies have proved a deficiency in polyunsaturated fatty acids (LC-PUFA) of the n-3 and n-6 family in patients with AN, with compensatory changes in non-essential fatty acids (FA).
There have been no sign of essential fatty acids deficiency. There have been found elevated levels of short chain saturated, short-chain monounsaturated, branched chain and odd-chain fatty acids in plasma phospholipids in patients with AN.
In our previous study, we have proved elevated levels of plant sterols (campesterol and P-sitosteroI), which have been used as a surrogate marker of exogenous cholesterol intake. Lathosterol (as a marker of de-novo cholesterol synthesis) level have been unchanged.
Patients with AN had increased levels of plasma total cholesterol, triglycerides and HDL-cholesterol. We have found significant differences between AN group and control group in FA profiles in cholesterol esters and phosphatidylcholine.
An increased activity of A9 desaturase and a decreased activity of A5 desaturase have been observed in cholesterol esters of AN group. There is a supposition, that proinflammatory cytokines, eicosanoids and oxylipins (docosanoids) can be involved in AN development.
A novel AN susceptibility gene, Epoxide Hydrolase 2 (EPHX2), influences AN risk through in vivo interaction with dietary LC-PUFA. There have been found significantly higher activity of soluble Epoxide Hydrolase in AN patients, with higher levels of proinflammatory oxylipins derived from a-linolenic acid, docosahexaenoic acid, arachidonic acid, linoleic acid.
A role of bile acids in metabolic changes in patients with AN is an actual subject of our research. Nestel (1973) describes a decreased secretion of bile acids in AN patients.
Bile acids, which had been considered as compounds, necessary for lipid digestion and absorption, are now considered as important metabolic modulators with significant endocrine and metabolic effects. Anorexia nervosa is a complex disorder with extensive changes in lipid metabolism, including dyslipidemia, changes in fatty acids profiles or changes in conversion of LC-PUFA to proinflammatory and anti-inflammatory eikosanoids.
A role of bile acids in metabolic pathways is a subject of our further research.