Short-term effect of rhGH treatment in children with Prader-Labhart-Willi sindrome on respiratory function: a polysomnographic and ENT endoscopic study

Background: Although significant improvement of respiratory function has been reported during rhGH treatment of Prader-Labhart-Willi Syndrome (PLWS), in the last five years several cases of sudden death during the first 6 months of GH therapy were reported in literature. Objectives and hypotheses: to establish if a short-term GH treatment causes obstructive apnea in PWLS patients with normal upper airways patency. Population and/or methods: 12 patients (6 boys , aged 3.9±1.9 years) were studied by one night polysomnography (PSG) monitoring (Grass 4.2) and ENT video endoscopic before and after six weeks of rhGH treatment (0.03mg/kg b.w./day). All patients underwent auxologic assessment including height, weight, BIA and plicometry, fasting blood glucose, insulin and IGF1 evaluation. The main PSG parameter considered was total apnea hypopnea index (AHI), resulting from two components: central apnea hypopnea index (CI) and obstructive apnea hypopnea index (OI). All patients were normal weight and free of severe or moderate upper airways obstruction (such as adenoid/tonsil hypertrophy, nasal obstruction with or without respiratory tract infection) when started GH treatment. Results: Statistically unsignificant changes of PSG indexes were observed after six weeks of GH therapy (see Table). We didn’t find any statistically significantly correlation between body fat, IGF1 and insulin and PSG changing during GH treatment. Video endoscopic ENT evaluation didn’t showed any significant increase of tonsillar and adenoid size after GH treatment. Precise conclusions: Our data confirm previous studies (Miller et al., JCEM, 2006; Festen et al. JCEM 2006) showing that GH treatment doesn’t cause obstructive apnea in PWLS patients with normal upper airways patency.