1. ¹Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
2. ²Department of Psychosomatic Medicine and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
3. ³Klinik am Korso, Hospital for Eating Disorders, Bad Oeynhausen, Germany

Correspondence: Dr H Frieling, Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany. Tel: +49 9131 853 4262; Fax: +49 9131 853 4105; E-mail: helge.frieling@uk-erlangen.de

⁴These authors contributed equally to this work

Received 17 August 2007; Revised 19 November 2007; Accepted 25 November 2007; Published online 2 January 2008.

Abstract

Disturbances of volume-regulating mechanisms have already been implicated in the pathophysiology of eating disorders like anorexia or bulimia nervosa with the peptide hormones vasopressin and atrial natriuretic peptide (ANP) being of special interest. Aim of the present study was to investigate, whether the expression of the corresponding genes was altered and if so, if these changes could be explained by epigenetic mechanisms such as DNA methylation. We analyzed blood samples of 46 women suffering from anorexia (n=22) or bulimia nervosa (n=24) as well as of 30 healthy controls. Peripheral mRNA expression and DNA methylation of the vasopressin and the ANP precursor genes were assessed using real-time PCR. We found significantly lower levels of ANP mRNA in patients with eating disorders. This downregulation was accompanied by a hypermethylation of the ANP gene promoter in the bulimic subgroup. We did not find differences regarding expression or methylation of the vasopressin gene. ANP mRNA expression was inversely associated with impaired impulse regulation. We conclude that epigenetic mechanisms may contribute to the known alterations of ANP homeostasis in women with eating disorders.