Body mass index cut-off point associated with refeeding hypophosphatemia in adults with eating disorders

Objective Refeeding hypophosphatemia (RH) is a life-threatening complication in underweight patients with eating disorders (EDs). Although a lower body mass index (BMI) has been reported as a risk factor for RH, the exact BMI cut-off point is not known. Herein, we aimed to identify the optimal BMI cut-off point for RH in adults with EDs. Method The medical charts of Japanese inpatients with EDs at our hospital between April 1, 2012 and March 31, 2017 were retrospectively reviewed. The optimal BMI cut-off point for RH was determined via receiver operating characteristic analysis. Logistic regression analysis was subsequently performed to assess the association between RH and the BMI cut-off point after adjusting for the propensity score, which was based on known risk factors for RH. Results The optimal BMI cut-off point was identified as 12.6 kg/m(2). A BMI lower than the cut-off point significantly correlated with the occurrence of RH after adjusting for the propensity score. Discussion The optimal BMI cut-off point for the occurrence of RH was 12.6 kg/m(2) in adults with EDs. The findings of the present study may facilitate clinical decision making and early identification of patients who require prophylactic treatment for RH.