Ghrelin/obestatin ratio in two populations with low bodyweight: Constitutional thinness and anorexia nervosa Natacha Germain a , Bogdan Galusca a , Dominique Grouselle b , Delphine Frere c , Virginie Tolle b , Philippe Zizzari b , Franc ¸ois Lang d , Jacques Epelbaum b , Bruno Estour a, * a Service d’Endocrinologie de CHU Saint Etienne, France b UMR 894 INSERM, Faculte´ de Me ´decine, Universite´ Paris Descartes, IFR Broca-Sainte Anne, 75014 Paris, France c Laboratoire de Me ´decine Nucle´aire de CHU Saint Etienne, France d Service de Psychiatrie de CHU Saint Etienne, France Received 25 July 2008; received in revised form 1 September 2008; accepted 1 October 2008 Psychoneuroendocrinology (2009) 34, 413—419 KEYWORDS Obestatin; Acylated grelin; Constitutional thinness; Anorexia nervosa Summary Constitutional thinness (CT) and anorexia nervosa (AN) are two categories of severely underweight subjects. Some appetite-regulating hormones display opposite levels in AN and CT. While levels of ghrelin, an orexigenic hormone, fit with the normal food intake in CT, the lack of efficacy of increased ghrelin levels in AN is not clear. Obestatin is a recently described peptide derived from the preproghrelin gene, reported to inhibit appetite in contrast to ghrelin. The aim of this study was to determine whether the circadian profile of obestatin, total and acylated ghrelin levels is different in CT subjects when compared with AN patients. Six-points circadian profiles of plasma obestatin, acylated ghrelin, total ghrelin and other hormonal and nutritional parameters were evaluated in four groups of young women: 10 CT, 15 restricting-type AN, 7 restored from AN and 9 control subjects. Obestatin circadian levels were significantly higher in AN ( p < 0.0001) while no difference was found between CT and control subjects. Acylated and total ghrelin were found increased in AN. Acylated ghrelin/obestatin and total ghrelin/obestatin were found decreased in AN compared to CT or C subjects ( p < 0.05). The percentage of acylated ghrelin was found decreased in CT group ( p < 0.05). The decreased ghrelin/obestatin ratio found in AN might participate in the restraint in nutriment intake of these patients. In contrast, in CT a lower percentage of acylated over total ghrelin might be considered in the aetiology of this condition. # 2008 Elsevier Ltd. All rights reserved. * Corresponding author at: Endocrinology Department, CHU Saint Etienne, 42055 Saint Etienne, Cedex 2, France. Tel.: +33 4 77 12 77 27; fax: +33 4 77 12 04 93. E-mail address: bruno.estour@chu-st-etienne.fr (B. Estour). available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/psyneuen 0306-4530/$ — see front matter # 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.psyneuen.2008.10.001