According to a recent Dutch study, early treatment with growth hormone – before the age of one year – was associated with better body composition and better cognitive function after eight years in children with Prader-Willi syndrome. (PWS).
The findings support further research supporting early treatment with growth hormone for children PWS.
The study, “Long-term growth hormone therapy for children with PWS: the earlier you start, the better the results?was published in the Journal of Clinical Medicine.
Growth hormone (GH) treatment is standard for children diagnosed with PWS as a way to normalize growth rates and body composition. The disorder is characterized by low levels of growth hormones and other hormones, and symptoms include weak muscles, slow growth, developmental delays, and learning difficulties.
Despite its approved use as standard treatment for children with PWS, the effects of long-term treatment with growth hormone have not been evaluated in comparison to untreated children of the same age.
Also, it is unclear whether starting treatment in the first year of life is more effective and consistently safe than starting it later in childhood.
To answer this, a team in the Netherlands conducted a prospective study whose primary objective was to assess the effects of long-term GH treatment on body composition and cognition in children with PWS versus to untreated children of the same age.
Additionally, the researchers compared the outcomes of children treated in the first year of life with those who started treatment between ages 2 and 5. The results were evaluated after eight years of daily treatment with 1 mg of GH per m2 of square meter.
The children were divided into three subgroups according to the age at which they started GH treatment: 27 children were in subgroup A (having started GH up to 1.05 years old, mean age 9 months), 28 children in subgroup B (who started GH between 1.05 and 2.27 years old), and 27 children in subgroup C (who started GH between 2.27 and 5 years old) . All 82 participants completed eight years of treatment.
Children in subgroup A had significantly lower weight-for-height standard deviation scores — a way to measure how much a certain parameter varies around the mean in a comparison group — and tended to be taller at first of the treatment. This group also had a significantly lower trunk to peripheral fat ratio.
The researchers first compared the results of children treated with GH against 22 children of the same age who did not receive the treatment and served as controls. The analysis showed that after eight years, the GH-treated children had significantly better body composition – as shown by significantly higher lean body mass – and were taller than the untreated children.
In addition, head circumference, a growth parameter, was significantly greater in GH-treated children. The children also scored higher on tests of cognitive functioning than the untreated children, although this difference was not statistically significant. The same was observed for the total IQ score, 70.4 versus 67.3.
The results showed that those who started GH in the first year of life (subgroup A) had a significantly lower average trunk/peripheral fat ratio than children who started GH later (subgroup A). group C). Children in subgroup A also had a significantly lower body fat percentage.
Additionally, lean body mass index — a measure of lean body mass that takes height into account — increased in subgroups A and C, but persisted longer in younger children. Height showed no significant difference between subgroups and was within the normal range.
After eight years, the mean total IQ score was significantly higher in subgroup A (score of 78.1) than in subgroup C (64.8). The children in subgroup A showed a significant improvement in their vocabulary test compared to the other children.
Regarding safety parameters, the subgroups showed no differences in fasting blood glucose, insulin, and triglyceride levels. Systolic blood pressure was within the normal range in all children.
Overall, “children who started GH in the first year of life had greater effects on body composition in the first years of treatment and had higher IQs after 8 years,” writes the researchers.
“These results support our hypothesis: the earlier the start of GH treatment, the better the results,” they concluded.