title: Ghrelin/obestatin ratio in two populations with low bodyweight: constitutional thinness and anorexia nervosa.
abstract: 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.
authors.affiliation: Service d'Endocrinologie de CHU Saint Etienne, France.
authors.forename: Natacha
authors.initials: N
authors.lastname: Germain
authors.forename: Bogdan
authors.initials: B
authors.lastname: Galusca
authors.forename: Dominique
authors.initials: D
authors.lastname: Grouselle
authors.forename: Delphine
authors.initials: D
authors.lastname: Frere
authors.forename: Virginie
authors.initials: V
authors.lastname: Tolle
authors.forename: Philippe
authors.initials: P
authors.lastname: Zizzari
authors.forename: François
authors.initials: F
authors.lastname: Lang
authors.forename: Jacques
authors.initials: J
authors.lastname: Epelbaum
authors.forename: Bruno
authors.initials: B
authors.lastname: Estour
mesh_terms: D000856:Anorexia Nervosa / Q000097:blood*; D015992:Body Mass Index; D001835:Body Weight; D002940:Circadian Rhythm; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D013851:Thinness / Q000097:blood*; D055815:Young Adult
chemical_list: D054439:Ghrelin