Evidence for metabolic and endocrine abnormalities in subjects recovered from anorexia nervosa

Subjects with anorexia nervosa (AN) at low weight display metabolic, endocrine, and behavioral abnormalities. Whether these various differences are a consequence of the condition and persist after recovery is unclear. We tested the hypothesis that abnormalities in the insulin and leptin axes and in the desire to eat persisted in subjects who had recovered from AN in terms of body mass index (BMI) and menstrual function. Endocrine, metabolic, and psychological parameters were assessed by sampling under fasting conditions and serially in response to a standard meal. Subjects included 18 females recovered from AN and 18 female controls and measures included plasma insulin, leptin, glucose and beta-hydroxybutyrate (beta-HBA) concentrations together with desire to eat. Fasting glucose concentrations were normal in both groups, but fasting insulin concentrations were significantly lower and the fasting glucose/insulin ratio significantly higher in the recovered subjects. The glucose concentration was significantly higher at the end of the meal period in the recovered group. The peak increase of insulin during the meal was significantly less in the recovered group and in response to the meal, glucose/insulin ratios were significantly higher for the first 45 minutes indicating a delayed insulin response. Fasting beta-HBA concentrations were not significantly different between groups, but postmeal decreases were significant and larger in the recovered AN group. Fasting and meal-related leptin concentrations were not significantly different between the groups and in both groups were correlated with BMI. In controls, but not in recovered subjects, the reported desire to eat was correlated with plasma glucose and leptin concentrations. The insulin, glucose and beta-HBA data indicated the presence of insulin hypersensitivity in the recovered subjects. As the insulin response to the meal was blunted and apparently delayed, there may be a persistent alteration in pancreatic function as a long-term pathological consequence of the anorexia. Alternatively, these data indicate a possible trait marker for AN.