محور روده - قفسه در کودکان مبتلا به بی اشتهایی عصبی

Entero-insular axis plays an important role in generating satiety signal. Thus disturbances in this axis may influence the course of anorexia nervosa. The aim of the study was analysis of the function of the hormonal part of the entero-insular axis in girls with anorexia nervosa. Thirteen girls with anorexia nervosa and in 10 healthy girls were studied. Each girl was subjected to oral glucose tolerance test and standard meal test. Blood was collected before stimulation and within 15, 30, 60, and 120 min thereafter. The concentrations of all peptides were determined by radioimmunoassay commercial kits. Fasted and postprandial levels of these peptides as well as integrated outputs were measured. Fasting insulin concentration was significantly higher in the group of girls with anorexia nervosa than in the control group (p<0.03). What more in girls with anorexia the integrated output of insulin was significantly lower in oral glucose tolerance test than after the meal (p<0.001). Also the integrated output of glucagon in both tests was higher in the group of girls with anorexia than in the control group. The mean output of pancreatic polypeptide and cholecystokinin in anorexia group was significantly higher (p<0.001 in both cases) than that in the control group but only after the test meal. The integrated outputs of gastric inhibitory peptide in both tests were significantly higher in anorectic girls than those in the control group (oral glucose tolerance test, p<0.02; meal test, p<0.001), However, mean values of the integrated output of glucagon-like peptide 1 in both tests were significantly higher in the control group than in the girls with anorexia (p<0.001 in each case). Highly significant correlation was found between glucose concentration and the concentrations of insulin, cholecystokinin, and gastric inhibitory peptide in both tests and for the both groups. In the anorectic girls, significant correlation between insulin concentration and the concentration of gastric inhibitory peptide was found after both stimulation tests and between insulin and cholecystokinin after oral glucose only. Conclusion: the disturbed secretion of the hormones of entero-insular axis after the meal in anorectic girls may have negative influence on the course of anorexia nervosa. This disease has no effect on the incretin function of cholecystokinin, gastric inhibitory peptide and glucagon-like peptide 1.

Initially, the term entero-insular axis was defined as a group of signals originating from the intestine that can stimulate, inhibit or modulate insulin secretion (Creutzfeldt, 1979 and Unger and Eisentraut, 1969). Currently, it has been accepted that entero-insular axis represents the interaction of signals from the gastrointestinal tract with the whole endocrine part of the pancreas. The endocrine cells of the intestine secrete, among others, such peptides endowed with incretin activity as glucagon-like peptide 1 (GLP-1), gastric inhibitory peptide (GIP), and cholecystokinin (CCK). Besides incretin hormones, also neural connections, as well as direct or indirect actions of food constituents and their metabolites, participate in signals sent from the intestine to the pancreas (Flatt, 1996). In addition to insulin, also glucagon, somatostatin and pancreatic peptide are the effectors of these signals (Creutzfeldt and Ebert, 1988). Anorexia nervosa has become recently an important epidemiological problem. It is known that hormones, and especially neuropeptides and gastrointestinal peptides play an essential role in pathogenesis of this disease (Gwirtsman et al., 1989). Entero-insular axis, as a functionally isolated system including both pancreatic and intestinal hormones, plays an important role in generating satiety signal. It can be speculated that any disturbance appearing within entero-insular axis may thus influence the course of anorexia nervosa. Therefore, we decided to investigate the possible changes within hormonal part of the entero-insular axis in girls with anorexia nervosa.

The observed disturbances of the secretion of the hormones of entero-insular axis after the meal in children with anorexia nervosa may aggravate the course of this disease. The function of CCK, GIP and GLP-1 as incretin factors is not disturbed in children with anorexia nervosa. The action of these hormones is most evident after oral administration of glucose.