Drug for Prader-Willi may worsen sleep apnea

NEW YORK (Reuters Health) - Short-term administration of growth hormone (GH) improves sleep abnormalities in most patients with a rare genetic disease called Prader-Willi Syndrome (PWS), according to a study. However, a subset of patients may experience a worsening of sleep disturbances.

PWS has a range of features including poor muscle tone, short stature, learning disabilities, and chronic hunger and overeating that can lead to obesity. Another feature that may be present is sleep apnea, a condition in which breathing repeatedly stops during sleep.

GH was approved for PWS in 2000. However, deaths in individuals with PWS soon after beginning GH treatment prompted concern that GH may worsen sleep apnea.

Dr. Jennifer Miller and colleagues from the University of Florida College of Medicine in Gainesville examined the effects of GH therapy on sleep apnea in 25 patients with genetically confirmed PWS who underwent overnight sleep studies at baseline and 6 weeks after starting GH.

GH treatment lessened the frequency and severity of sleep apnea events in most patients, they report in the Journal of Clinical Endocrinology and Metabolism.

However, in six patients, these episodes worsened.

Four of the latter patients had concurrent upper respiratory tract infections. All four had enlarged tonsils on evaluation. Tonsillectomy and adenoidectomy improved symptoms of obstructive sleep apnea in these patients.

Because it is not possible to predict which patients will do worse on GH, patients "should have sleep studies before and after starting GH, the researchers advise, "and should be monitored for sleep apnea with upper respiratory infections."

SOURCE: Journal of Clinical Endocrinology and Metabolism, February 2006.