Does aggressive refeeding in hospitalized adolescents with anorexia nervosa result in increased hypophosphatemia?

Concerns about refeeding syndrome have led to relatively conservative nutritional rehabilitation in malnourished inpatients with anorexia nervosa (AN), which delays weight gain. Compared to other programs, we aggressively refed hospitalized adolescents. We sought to determine the incidence of hypophosphatemia (HP) in 12-18-year-old inpatients in order to inform nutritional guidelines in this group.

A 1-year retrospective chart review was undertaken of 46 admissions (29 adolescents) with AN admitted to the adolescent ward of a tertiary children's hospital. Data collected over the initial 2 weeks included number of past admissions, nutritional intake, weight, height, body mass index, and weight change at 2 weeks. Serum phosphorus levels and oral phosphate supplementation was recorded.

The mean (SD) age was 15.7 years (1.4). The mean (SD) ideal body weight was 72.9% (9.1). Sixty-one percent of admissions were commenced on 1,900 kcal (8,000 kJ), and 28% on 2,200 kcal (9,300 kJ). Four patients were deemed at high risk of refeeding syndrome; of these patients, three were commenced on rehydration therapy and one on 1,400 kcal (6,000 kJ). All patients were graded up to 2,700 kcal (11,400 kJ) with further increments of 300 kcal (1,260 kJ) as required. Thirty-seven percent developed mild HP; no patient developed moderate or severe HP. Percent ideal body weight at admission was significantly associated with the subsequent development of HP (p = .007).

These data support more aggressive approaches to nutritional rehabilitation for hospitalized adolescents with AN compared to current recommendations and practice.