Endocrine Abstracts

Appetite regulating hormones in constitutionally lean and anorexia nervosa subjects

B Galusca¹, N Germain¹, CW le Roux², D Frere¹, MA Ghatei², SR Bloom² & B Estour¹

¹CHU, Saint Etienne, France; ²Metabolic Medicine, Imperial College, London, United Kingdom.

Energy balance is controlled by the arcuate nucleus through integration of peripheral hormonal signals such as leptin, ghrelin, peptide YY (PYY) and glucagon like peptide 1 (GLP-1). The commonest reason for young women in the developed world to be underweight is restrictive anorexia nervosa (AN). Constitutionally thinness (CT) has been described in young women who satisfies the WHO definition for moderate to severe underweight (BMI 13–16.9 kg/m²). CT women have no psychological or hormonal features of anorexia nervosa which includes normal menstruation, normal thyroid function, normal cardiac function and normal insulin sensitivity. We hypothesized that appetite regulating hormones in CT subjects would be comparable with a normal weight control group. In this study, we measured ghrelin, PYY, GLP-1 and leptin in three groups of young women (normal weight (n=7), CT (n=10) and AN (n=12)). Samples were collected every four hours for a period of 24 hours. Standardized meals were served at 08:15, 12:15 and 19:00. The area under the curve for the PYY circadian cycle reached significantly higher levels in CT compared to controls and AN subjects. GLP-1 was significantly higher in subjects with AN compared to CT, while ghrelin was significantly higher in AN compared to controls and CT subjects. CT subject had the lowest ghrelin levels. The area under the curve for the leptin was significantly lower in the AN group. We conclude that the physiology of constitutional thinness is different to the pathophysiology of anorexia nervosa, since the appetite regulating hormones show significant differences. The variant of anorexia nervosa without amenorrhea recently proposed should only be considered aftermx excluding the diagnosis of constitutional thinness.

Endocrine Abstracts (2006) 11 P592