A standard enteral formula versus an iso-caloric lower carbohydrate/high fat enteral formula in the hospital management of adolescent and young adults admitted with anorexia nervosa: a randomised controlled trial.

BACKGROUND: The nutritional rehabilitation of malnourished patients hospitalised with anorexia nervosa is essential. The provision of adequate nutrition must occur, while simultaneously, minimising the risk of refeeding complications, such as electrolyte, metabolic, and organ dysfunction. The aim of this study was to compare the efficacy and safety of an iso-caloric lower carbohydrate/high fat enteral formula (28% carbohydrate, 56% fat) against a standard enteral formula (54% carbohydrate, 29% fat). METHODS: Patients (aged 15-25 years) hospitalised with anorexia nervosa were recruited into this double blinded randomised controlled trial. An interim analysis was completed at midpoint, when 24 participants, mean age 17.5 years (± 1.1), had been randomly allocated to lower carbohydrate/high fat (n = 14) or standard (n = 10) feeds. RESULTS: At baseline, there was no significant difference in degree of malnutrition, medical instability, history of purging or serum phosphate levels between the two treatment arms. A significantly lower rate of hypophosphatemia developed in patients who received the lower carbohydrate/high fat formula compared to standard formula (5/14 vs 9/10, p = 0.013). The serum phosphate level decreased in both feeds, however it decreased to a larger extent in the standard feed compared to the lower carbohydrate/high fat feed (standard feed 1.11 ± 0.13 mmol/L at baseline vs 0.88 ± 0.12 mmol/L at week 1; lower carbohydrate/high fat feed 1.18 ± 0.19 mmol/L at baseline vs 1.06 ± 0.15 mmol/L at week 1). Overall, serum phosphate levels were significantly higher in the lower carbohydrate/high fat feed compared with standard feed treatment arm at Week 1 (1.06 ± 0.15 mmol/L vs 0.88 ± 0.12 mmol/L, p < 0.001). There was no significant difference in weight gain, number of days to reach medical stability, incidence of hypoglycaemia, or hospital length of stay. CONCLUSIONS: The results of this study indicate that enteral nutrition provided to hospitalised malnourished young people with anorexia nervosa using a lower carbohydrate/high fat formula (28% carbohydrate, 56% fat) seems to provide protection from hypophosphatemia in the first week compared to when using a standard enteral formula. Further research may be required to confirm this finding in other malnourished populations. TRIAL REGISTRATION: ANZCTR, ACTRN12617000342314. Registered 3 March 2017, http://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12617000342314.

Patients hospitalised with anorexia nervosa require nutrition support as part of their treatment, whilst refeeding complications are prevented. Of particular concern, is the reintroduction of carbohydrate to malnourished patients, which has been proposed to cause a surge in insulin levels and disturbance in electrolytes, particularly a decrease in blood phosphate levels. This double-blinded randomised controlled trial measured the occurrence of low phosphate blood levels and other refeeding complications, in adolescent and young adult patients hospitalised with anorexia nervosa. These patients were provided either a lower carbohydrate/high fat feed (28% carbohydrate, 56% fat) or a standard enteral feed (54% carbohydrate, 29% fat). Fewer patients in the lower carbohydrate/high fat feed group (5/14) than standard feed group (9/10) developed a low phosphate level. There was no significant difference in weight gain, number of days to reach medical stability, occurrence of hypoglycaemia, or hospital length of stay.

Study protocol for a randomised controlled trial investigating two different refeeding formulations to improve safety and efficacy of hospital management of adolescent and young adults admitted with anorexia nervosa.

INTRODUCTION: Providing effective nutritional rehabilitation to patients hospitalised with anorexia nervosa (AN) is challenging, partly due to conservative recommendations that advocate feeding patients at low energy intakes. An 'underfeeding syndrome' can develop when patients are not provided with adequate nutrition during treatment, whereby malnourished patients fail to restore weight in a timely matter, and even lose weight. Of particular concern, the reintroduction of carbohydrate in a starved patient can increase the risk of developing electrolyte, metabolic and organ dysfunction. The proposed trial assesses the efficacy and safety of a lower carbohydrate enteral formula (28% carbohydrate) against a standard enteral formula (54% carbohydrate), in adolescent and young adult patients (aged 15-25 years), hospitalised with AN. METHODS AND ANALYSIS: The study employs a double-blind randomised controlled trial design. At admission to hospital, malnourished adolescent and young adults with AN will be randomly allocated to commence feeding on a standard enteral feeding formula (1.5 kcal/mL, 54% carbohydrate) or a lower carbohydrate isocaloric enteral feeding formula (1.5 kcal/mL, 28% carbohydrate). Assessments of nutritional intake, weight and biochemistry (phosphate, magnesium, potassium) will be conducted at baseline and during the first 3 weeks of hospital admission. The primary outcome measure will be incidence of hypophosphatemia. Secondary outcomes include weight gain, oedema, other electrolyte distortion, length of hospital admission, admission to the Intensive Care Unit (ICU) and number of days to reach medical stability, using defined parameters. ETHICS AND DISSEMINATION: The protocol was approved by the Western Sydney Local Health District Human Research Ethics Committee and institutional research governance approvals were granted. Written informed consent will be sought prior to study enrolment. Study findings will be widely disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12617000342314); Pre-results.

An audit of the changes in thiamine levels during higher caloric nutritional rehabilitation of adolescent patients hospitalised with a restrictive eating disorder.

BACKGROUND: Routine supplementation of thiamine in patients with restrictive eating disorders prior to initiation of nutritional rehabilitation, is an example of a clinical guideline based on expert opinion rather than evidence-based recommendations. This study investigates whether adolescents hospitalised with a restrictive eating disorder commenced on a higher caloric refeeding regimen, present with or develop thiamine deficiency during their admission. METHODS: An eighteen month retrospective audit of 119 consecutive admissions for nutritional rehabilitation was conducted on patients admitted with an eating disorder in a large tertiary teaching hospital in Western Sydney. Data from paper-based and electronic medical records were collected. Baseline and weekly blood thiamine levels were documented, as well as patient demographic information including admission weight, age, length of stay, percentage median body mass index, weight change throughout admission and caloric prescription. RESULTS: Sixty admissions met inclusion criteria, mean age 17.2 years (SD 1.2); 88% female; BMI 16.8 kg/m2 (SD 1.8) on admission. A linear mixed effects model identified that median thiamine levels increased by 9.2 nmol/L per week (p < 0.001). No patient developed thiamine deficiency during their admission, one patient was admitted with thiamine levels below the normal range at 62 nmol (normal range 67 - 200 nmol/L) which resolved by the second week of admission. In 15 out of 60 patients (25%), thiamine levels were observed to rise above the upper limit. CONCLUSIONS: Nutritional management of 60 malnourished adolescents hospitalised with an eating disorder was conducted safely with the provision of only 10 mg thiamine in a multivitamin daily, and no additional thiamine supplementation. The high caloric refeeding protocol, inclusive of a daily multivitamin, provided adequate thiamine to prevent thiamine deficiency. Further research should examine thiamine requirements in an exclusive severely malnourished population to assess the need for thiamine replacement in the most vulnerable group.

Higher Caloric Refeeding Is Safe in Hospitalised Adolescent Patients with Restrictive Eating Disorders.

Introduction. This study examines weight gain and assesses complications associated with refeeding hospitalised adolescents with restrictive eating disorders (EDs) prescribed initial calories above current recommendations. Methods. Patients admitted to an adolescent ED structured "rapid refeeding" program for >48 hours and receiving ≥2400 kcal/day were included in a 3-year retrospective chart review. Results. The mean (SD) age of the 162 adolescents was 16.7 years (0.9), admission % median BMI was 80.1% (10.2), and discharge % median BMI was 93.1% (7.0). The mean (SD) starting caloric intake was 2611.7 kcal/day (261.5) equating to 58.4 kcal/kg (10.2). Most patients (92.6%) were treated with nasogastric tube feeding. The mean (SD) length of stay was 3.6 weeks (1.9), and average weekly weight gain was 2.1 kg (0.8). No patients developed cardiac signs of RFS or delirium; complications included 4% peripheral oedema, 1% hypophosphatemia (<0.75 mmol/L), 7% hypomagnesaemia (<0.70 mmol/L), and 2% hypokalaemia (<3.2 mmol/L). Caloric prescription on admission was associated with developing oedema (95% CI 1.001 to 1.047; p = 0.039). No statistical significance was found between electrolytes and calories provided during refeeding. Conclusion. A rapid refeeding protocol with the inclusion of phosphate supplementation can safely achieve rapid weight restoration without increased complications associated with refeeding syndrome.