Increased suppression of serum ghrelin concentration by hyperinsulinemia in women with anorexia nervosa

Context: Ghrelin is a peptide secreted mainly by the stomach, which has the ability to stimulate appetite and food intake. Serum ghrelin concentration decreases rapidly after a meal, probably because of the concurrent increase in serum insulin. Anorexia nervosa (AN) is an eating disorder, which is characterized by high serum ghrelin concentration; however, the regulation of circulating ghrelin by insulin in this disorder remains unclear. Objective: To estimate serum ghrelin concentration in the fasting state and after hyperinsulinemia in women with AN. Design and participants: We examined 19 women with AN, 26 lean healthy women, and 25 women who were overweight or obese. Serum ghrelin concentration was measured in the fasting state and after euglycemic hyperinsulinemic clamp. Results: Insulin sensitivity was similar in AN and normal-weight women, and was markedly decreased in the obese subjects. In the fasting state, serum ghrelin was higher in AN group than in other groups (normal-weight, P=0.017; obese, P=0.0001) and in normal-weight women than in obese women (P=0.044). Hyperinsulinemia resulted in a marked decrease in serum ghrelin in AN (P<0.0001) and normal-weight women (P=0.002). The fall in serum ghrelin was higher in AN group than in other groups (normal-weight, P=0.0008; obese, P=0.0001), and was related to insulin sensitivity (r=0.24, P<0.05). In multiple regression analysis, only fasting serum ghrelin and the presence of AN were independent predictors of this fall. Conclusions: Women with AN have an increased suppression of serum ghrelin by hyperinsulinemia. This phenomenon might lead to an increased and more rapid feeling of satiety in AN.