Importance of initial nutritional status in refeeding syndrome in children with anorexia nervosa

Refeeding syndrome (RS) is defined as fluid and electrolyte shifts as a result of aggressive nutritional rehabilitation and these electrolyte imbalance can result in several cardiac complications. We aimed to evaluate the incidences of RS and hypercholesterolemia in children with anorexia nervosa (AN) and related factors for that. We retrospectively evaluated the medical records of 51 patients aged 10-18 years diagnosed with AN between January 2015 and May 2020. RS and hypercholesterolemia were seen in 21 (41.2%) and 39 (76.5%) of patients, respectively. Patients with RS had an older mean age (16.3 vs. 13.7 years, p = .021), lower body mass index (BMI) percentile on admission (0.1 vs. 1.6^th, p = .023), and a higher degree of weight loss (16.5 vs. 12.7 kg, p = .005) than those without RS. Age (odds ratio [OR], 3.49; 95% confidence interval [CI], 0.913-8.790; p = .021), initial BMI percentile (OR, 0.55; 95% CI, 0.286-1.853; p = .036), and BMI z-score (OR, 0.56; 95% CI, 0.256-1.987; p = .045) were predictors of RS. For identifying occurrence of RS, the area under the curve for BMI was 0.679 and the optimal BMI cutoff value and was 11.8 kg/m². RS and hypercholesterolemia were frequently observed in patients with AN, and low BMI percentile and older age were significantly associated with RS. Therefore, serum phosphate levels should be monitored more frequently in patients with severe malnutrition.