Responses of growth hormone and cortisol to intravenous glucose loading test in patients with anorexia nervosa

Abstract

The hypothalamic satiety and hunger centers appear to be affected by changes in circulating blood glucose concentrations. The response of the centers, in turn, is reflected by alterations in growth hormone (GH) and cortisol levels. There are no studies attempting to relate blood glucose and GH and cortisol changes in patients with anorexia nervosa (AN) during an intravenous glucose tolerance test (IVGTT). In the present inquiry, IVGTT (10g) were performed on AN patients to characterize the satiety and hunger centers' responses to changes in glucose and insulin levels as reflected by GH and cortisol levels. Study participants were 15 female AN patients and eight healthy female volunteers. No significant differences in blood glucose levels were observed between the two groups. However, immunoreactive insulin (IRI) levels in AN patients were significantly lower than those in the control group. Although GH and cortisol concentrations were significantly suppressed after the infusion in the control group, the AN patients' GH levels paradoxically increased, and cortisol levels did not change. Moreover, a negative correlation was observed between ΔGH and ΔIRI in all individuals in this study ( r = −.61, P < .01). In conclusion, abnormal GH and cortisol responses to a 10-g IVGTT were found in patients with AN. ΔGH levels correlated negatively with ΔIRI levels. These data suggest that hypothalamic satiety and hunger centers in AN respond abnormally to change in blood glucose levels.