Peptide YY3–36 concentration in acute- and long-term recovered anorexia nervosa

Purpose The gut–brain axis could be a possible key factor in the pathophysiology of anorexia nervosa. The neuropeptide peptide YY3–36, secreted by endocrine L cells of the gastrointestinal tract, is a known regulator of appetite and food intake. The objective of this study was to investigate peptide YY3–36 plasma concentrations at different stages of anorexia nervosa in a combined cross-sectional and longitudinal design to differentiate between effects of acute undernutrition and more enduring characteristics. Methods We measured fasting plasma peptide YY3–36 concentrations in young patients with acute anorexia nervosa (n = 47) and long-term recovered patients (n = 35) cross-sectionally in comparison to healthy control participants (n = 58), and longitudinally over the course of inpatient treatment. Physical activity was controlled as it may modulate peptide YY secretion. Results There was no group difference in peptide YY3–36 concentration among young acutely underweight anorexia nervosa patients, long-term recovered anorexia nervosa patients, and healthy control participants. Longitudinally, there was no change in peptide YY3–36 concentration after short-term weight rehabilitation. For acute anorexia nervosa patients at admission to treatment, there was a negative correlation between peptide YY3–36 concentration and body mass index. Conclusions The current study provides additional evidence for a normal basal PYY3–36 concentration in AN. Future studies should study multiple appetite-regulating peptides and their complex interplay and also use research designs including a food challenge.