Zinc levels in severe eating disorders

Severe eating and feeding disorders including Anorexia Nervosa of both restricting (AN-R) and binge-purge (AN-BP) subtypes and Avoidant Restrictive Food Intake Disorder (ARFID) lead to multiple macronutrient and micronutrient deficiencies, including zinc, in the setting of inadequate dietary intake. We investigated whether zinc levels correlated with severe malnutrition, with particular subtypes of eating disorders (EDs), and the effect of the refeeding process.

This prospective study included 92 adult patients with severe AN or ARFID hospitalized in a medical stabilization unit. Denver Health staff were recruited as controls. Blood samples were drawn within four days of admission and 72 h of discharge. All inferential analyses were performed using general linear models.

Admission zinc levels were statistically significantly lower in cases compared to controls. Admission zinc levels were significantly higher for patients with AN-R than patients with AN-BP. Zinc levels decreased significantly during treatment in cases, compared to controls. ED diagnoses and percent ideal body weight (%IBW) did not appear to predict changes in zinc levels during admission.

Given zinc's pervasive roles in metabolism throughout the body as well as common symptoms of deficiency including impaired taste and smell, decreased appetite, and depression, zinc levels could be relevant to the high relapse rate in severe ED. The observed decrease in zinc, which was larger in cases than controls, during refeeding suggests the possibility of a "refeeding hypozincemia" which may present a new therapeutic target. These characteristics make zinc an intriguing focus of future study that could impact the recidivism rate in severe ED.

Evidence obtained from well-designed cohort or case-control analytic studies.