An article by Jennifer Miller, Ph D, and colleagues looked at the initiation of growth hormone therapy and sleep in PWS. In particular, it studied the changes in sleep in the 6 weeks following initiation of growth hormone therapy.
The article concluded that most patients had better sleep (less apnea), and this is consistent with longer term studies that show improvements in sleep quality.
However, about a third had worsening of sleep disturbances — generally associated with enlarged tonsils and upper respiratory infections. They recommended sleep studies at baseline and 6 weeks after initiating growth hormone therapy in patients with PWS.
A summary of the article by Dr. Miller was published with comments in Growth, Genetics, and Hormones, a free e-newsletter, primarily for endocrinologists (but anyone can sign up and receive it). The e-newsletter includes a review of recent articles of interest in the literature, with editorial comments about the implications of the studies.
An abstract of the original article can be found here: Miller J, Silverstein J, Shuster J, Driscoll DJ, Wagner M. Short-term effects of growth hormone on sleep abnormalities in Prader-Willi Syndrome. J Clin Endocrinol Metab. 2005; epub (10.1210/jc.2005-1279).