Endocrine Responses to Meals in Patients with AN

Prolonged malnutrition in people with anorexia nervosa (AN) has been associated with changes in endocrine function. Kimberly P. Kinzig, PhD, and colleagues at Johns Hopkins University, Baltimore, and Case Western Reserve University, Cleveland, recently reported that among a group of patients with AN some endocrine responses to a meal were state-related and improved as nutrition improved. However, other endocrine responses did not get better after short-term refeeding. The authors measured meal-induced endocrine responses in 13 AN patients at three points during hospitalization: before refeeding (mean body mass index, or BMI, was 16.7 kg/m2); after two weeks of refeeding (mean BMI: 18.0), and after weight restoration (mean BMI: 20.3). Thirteen control subjects (BMI: 19.0-24.9) were tested once. In the 2.5-hr test sessions, blood was drawn every 15 minutes before, during, and after all the subjects ate a 700-kcal test meal. Among AN patients, leptin levels were unchanged in the first two sessions but were significantly increased at the third session, after weight was restored. In comparision to controls, peak levels of insulin and glucose in response to the test meal were delayed among AN patients; however, response patterns at the third measurement were similar to those of controls. Pancreatic polypeptide (PP) levels were increased in patients with AN compared with the controls, regardless of weight status. The delay in insulin release and elevated PP levels did not correct with short-term feeding, and may have contributed to a high relapse rate in the AN patients, according to the authors. The study was presented last fall at the Eating Disorders Research Society Meeting in Toronto.