Is growth hormone treatment in children associated with weight gain?--longitudinal analysis of KIGS data.

OBJECTIVE: Growth hormone (GH) increases lean body mass and reduces fat mass. However, the long-term changes in weight status during growth hormone treatment, according to age and weight status at onset of treatment, have not previously been reported in large data sets.

METHODS: Changes in BMI-SDS between starting GH treatment and attaining near adult height (NAH) were analysed in 2643 children with idiopathic GH deficiency (IGHD), 281 children small for gestational age (SGA), 1661 girls with Turner syndrome (TS), and 142 children with Prader-Willi syndrome (PWS) in the KIGS database.

RESULTS: BMI-SDS increased significantly between onset of GH treatment and NAH (IGHD:+0·29, SGA:+0·69, TS:+0·48) except in PWS (-0·02). These increases were greater in children with younger age at onset of GH treatment (significant in all indications) and with lower doses of GH treatment (significant in IGHD & TS) in multiple linear regression analyses also including gender, duration of GH treatment, BMI-SDS and height-SDS at onset of treatment, and birth weight-SDS. Obese children at onset of GH treatment decreased their BMI-SDS, while underweight and normal weight children at onset of GH treatment increased their BMI-SDS independently of GH treatment indication.

CONCLUSIONS: Long-term GH treatment was associated with changes in weight status, which were beneficial for underweight and obese children independent of the indication for GH. However, the increase in BMI-SDS in normal weight children treated with GH needs to be investigated in future prospective longitudinal studies to analyse whether this represents an increase of fat mass, lean body mass or both.