Dietary Energy Intake, Body Composition and Resting Energy Expenditure in Prepubertal Children with Prader-Willi Syndrome before and during Growth Hormone Treatment: A Randomized Controlled Trial

Background/Aims: Dietary management is a difficult but key aspect of care in children with Prader-Willi syndrome (PWS). We therefore investigated the effect of growth hormone (GH) treatment on reported energy intake in children with PWS, in relation with body composition, resting energy expenditure (REE) and hormone levels. Methods: In a randomized controlled GH trial including 47 children with PWS, we assessed 5-day dietary records and dual-energy X-ray absorptiometry for body composition. REE was calculated by Müller's equation, based on fat mass, fat free mass and gender. Results: Baseline energy intake of children with PWS was lower than normal daily energy requirements (p < 0.001), and decreased with age to 50% in prepubertal children. Energy intake in infants [m/f: 11/8; median (interquartile range [IQR]) age 2.7 years (1.5-3.2)] increased after 1 year of GH treatment (p = 0.008); this tended to be higher in the GH group than in the untreated group (p = 0.07). In prepubertal children [m/f: 14/14; median (IQR) age 6.8 years (5.1-8.1)], the increase in energy intake was higher in the GH group, but this was not different compared to the untreated group. REE was not different between the GH group and the untreated group. Increase in energy intake during 2 years of GH treatment was correlated with lower fat percentage standard deviation scores (p = 0.037) and higher adiponectin levels (p = 0.007). Conclusion: Our study demonstrates that parents of children with PWS are very well capable of restricting energy intake up to 50% compared to daily energy requirements for age- and sex-matched healthy children. GH treatment was associated with a slight increase in energy intake, but also improved body composition and adiponectin levels, which suggests a protective effect of GH treatment.