Fasting plasma ghrelin levels in subtypes of anorexia nervosa

Ghrelin has a role in regulating eating behavior and energy metabolism in the central nervous system, and has been reported to play an important role in the pathophysiology of anorexia nervosa (AN). The aim of the present study was to compare fasting plasma ghrelin levels in different subtypes of untreated AN patients. The subjects included 39 female AN patients and 11 female controls. The patients were then divided into two subtypes as follows: 19 AN patients with restricting (AN-R) and 20 AN patients with binge-eating/purging (AN-BP) form of the illness. Blood samples from subjects after an overnight fast were used to analyze plasma ghrelin concentrations. Plasma ghrelin concentrations in both AN-R and AN-BP were negatively correlated with body mass index (BMI). The mean plasma ghrelin levels in both AN-R and AN-BP were significantly higher than that in controls. The mean ghrelin level in AN-BP was significantly higher than that in AN-R. However, mean BMI and serum potassium in both groups were not significantly different. These results suggest that both BMI and the presence of binge-eating/purging may have some influence on fasting plasma ghrelin levels in patients with AN.