The involvement of the adrenergic system in feeding and eating disorders. A systematic review.

BACKGROUND: Adrenergic dysregulation has been proposed as a possible underlying mechanism in feeding and eating disorders (FED). This review aims to synthesise the current evidence on the role of adrenergic dysregulation in the pathogenesis and management of FED. METHODS: A systematic review was conducted in MEDLINE, Cochrane Library, and Clinicaltrials.gov. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was adopted. Preclinical, clinical, and pharmacological studies assessing the adrenergic system in FED were included. RESULTS: Thirty-one out of 1415 recognised studies were included. Preclinically, studies on adrenaline's anorectic impact, receptor subtypes, and effects on hepatic function in rats show that catecholamine anorexia is primarily alpha-adrenergic, whereas beta-adrenergic anorexia can be obtained only after puberty, implying an impact of sexual hormones. Clinically, catecholamine levels may be higher in FED patients than in healthy controls (HC). Individuals with anorexia nervosa (AN) may show higher epinephrine-induced platelet aggregability response than HC. Pharmacological trials suggest that the alpha-2-adrenergic medication clonidine may not lower AN symptoms, but agents regulating the adrenaline-noradrenaline neurotransmission (bupropion, reboxetine, duloxetine, sibutramine) have been found to improve binge eating symptoms. CONCLUSION: Adrenergic dysregulation may be involved in the pathophysiology of FED. More research is needed to comprehend underlying mechanisms and treatment implications.