A scoping review of circulating peptides assessments in anorexia nervosa: Uncovering diversity and nuanced findings

Understanding biological mechanisms underlying anorexia nervosa (AN) is necessary to develop care strategies. Despite many articles dedicated to peptides assessment in AN, there is no systematic review. A scoping review of circulating peptides published in relation to AN, comparing their results with those of controls, was conducted. Embase and PubMed databases were search from 1966 to 2022 (PROSPERO CRD42022323716). All original English articles, assessing peptides in AN (except classical markers) were analyzed. 1151 studies for 207 peptides, in 486 published articles were selected, and evidences/trends in AN were compared to controls. Fifteen clusters of function gathering peptides covering physiopathological aspects of AN were identified. This scoping review revealed a large variety of circulating peptides explored in AN. Some peptides presented with convincing results and helped understanding pathophysiologic aspects. Other peptides presented with nuanced results, partly due to insufficient number of studies, multiple assay techniques, inadequate sampling time, and lack of phenotyping. Conversion from bench-to-bed remains difficult and may explain why peptides evaluations did not currently lead to specific international recommendations or tailored therapeutic/preventive strategies. Peptide evaluation in anorexia nervosa could explore secretion profiles, and test it in well-phenotyped patients with AN, to conclude for potential clinical use, and finally design therapeutic tests.