Growth hormone treatment of children with Prader‐Willi syndrome affects linear growth and body composition favourably

Abstract

We have compared the growth and the body composition in children with Prader‐Willi syndrome (PWS) with and without growth hormone treatment (recombinant GH 0.1 IU/kg/day) after a 1‐y period. Twenty‐nine prepubertal children with PWS, with mean body mass index (BMI) SDS of 2.2, and 10 (control) healthy obese children with mean BMI SDS of 5.6, underwent 24‐h frequent blood sampling. Both PWS and control obese children had low and similar GH levels (0.7 /ng/l ± 0.4 SD). Serum IGF‐I levels, however, were significantly lower in children with PWS (‐1.5 SDS ± 0.8 SD vs ‐0.2 SDS ±0.8 SD). The 29 PWS children were randomized into 2 groups of 15 and 14 subjects for GH treatment and no treatment, respectively. Height velocity increased from ‐1.9 SDS to + 6.0 SDS in the treated group (p < 0:001) and decreased from ‐0.1 SDS to ‐1.4 SDS in the control PWS group during the study year. BMI decreased significantly for the treated group (+3.0 SDS to + 2.0 SDS). Relative fat mass decreased significantly, while fat‐free mass increased (p < 0:001) for the treated group. No significant changes were noticed in body composition in the control PWS group. In conclusion, the low spontaneous 24‐h GH secretion, regardless of body weight, and the exceptional response to growth hormone treatment together with the finding of low IGF‐I levels suggest that growth hormone deficiency is a common feature of PWS, as a result of hypothalamic dysfunction. Treatment with growth hormone is beneficial for the majority of PWS children.