Effect of nutritional rehabilitation on circulating ghrelin and growth hormone levels in patients with anorexia nervosa

Circulating ghrelin and growth hormone (GH) are up-regulated in anorexia nervosa (AN) as a consequence of prolonged starvation. The current study examines the effect of nutritional rehabilitation with improvement of eating behavior on ghrelin and GH levels in AN patients during the course of inpatient treatment. The subjects included 34 female AN patients and 9 age-matched female controls. Fasting blood samples were collected before, during and after treatment. For data analysis, AN subjects were divided into three subtypes. The first group included seven patients with emergent hospitalization (E-AN), who were accompanied by severe emaciation due to their inability for food intake for more than a month. The other two groups included 14 AN with restricting (AN-R) and 13 AN with binge-eating/purging (AN-BP) patients. There were significant correlations between ghrelin, GH and body mass index (BMI) before treatment in all subjects. However, ghrelin levels were not significantly correlated with BMI and GH although there was a relationship between GH and BMI after treatment. Before treatment, E-AN patients had the highest levels of ghrelin and GH with the lowest glucose levels and liver dysfunction. The AN-BP group had a higher level of ghrelin than the AN-R group. During treatment, comparing with the controls group only the AN-R group showed higher level of ghrelin. Contrarily, the ghrelin levels in the E-AN group, who showed improved glucose levels, and the AN-BP group, who stopped vomiting behavior due to our treatment, decreased ghrelin levels. After treatment, only the AN-BP group showed a higher ghrelin level as compared to the controls. Although GH levels of the three AN groups decreased gradually according to our treatment progress, it still showed the higher value than the control group at the end of the treatment because every AN patients could not reach to more than 80% of their ideal body weight at discharge. These findings suggest that (1) severe emaciation with abnormal fasting hypoglycemia in AN patients may cause very high levels of GH and ghrelin, (2) that GH levels in AN patients may relate to nutritional status and (3) that ghrelin may be influenced by not only nutritional status but also the eating behavior of the patients.