“Furthermore, children with a greater deficit had more benefit from GH treatment,” Dr. Elbrich P. C. Siemensma, with Erasmus University Medical Center Rotterdam, and colleagues report.
The team previously showed that long-term continuous growth hormone therapy benefited children with Prader-Willi syndrome (PWS) in terms of mental and motor development.
The current study assessed the effect of growth hormone treatment on cognitive function in 50 children with genetically confirmed PWS between the ages of 3 and 14 years. The participants were randomized to GH therapy or a control group for 2 years, and then all the children were treated with GH and followed for 4 years.
During the 2-year randomized trial, all cognitive subtest scores and total IQ scores remained constant in the GH-treated group, but declined relative to baseline in the untreated arm, the investigators found. This decrease was statistically significant for skills involving vocabulary and recognition of similarities, but nonsignificant for total IQ.
After 4 years of open treatment with growth hormone in the whole group, mean scores for Similarities and Block design increased compared to baseline, while Vocabulary scores and total IQ scores remained similar to baseline, according to the report.
Dr. Siemensma and colleagues found that lower baseline scores correlated with greater increases in scores for Similarities and Block design. “The more children lag behind, the more they benefit from GH treatment,” they comment.
“Based on our results, we conclude that GH treatment in children with PWS is not merely an effective treatment for normalizing height and improving body composition, but it also has a beneficial effect on their cognitive functioning,” they state.
The study was initiated by the investigators and funded by an independent research grant from Pfizer Inc.