The effect of twelve months rhGH treatment on upper airways of non severely obese children with Prader-Willi syndrome.

In a previous study we showed in 16 non-severely obese and obstructive apnoea free children with Prader-Willi Syndrome that a six weeks rhGH treatment does not significantly affect airways patency. We report here the auxological and polisomnographic results of twelve among the above children who attained 12 month of rhGH treatment.Patients and Methods: Twelve children (9 boys, aged from 1.6 to 7.7 median 2.25 yrs) with genetically confirmed Prader-Willi syndrome were studied before and after 6 weeks and 12 months of rhGH treatment. In each of the three evaluations the patients were studied by anthropometry, one night 16 channels polysomnography and ENT examination of upper airways by flexible fibreoptic endoscope. The polysomnographic parameters considered were respiratory disturbance index (RDI), obstructive apnea index (OAI) and minimal SaO2. The Katz criteria were used for polysomnography evaluation. Tonsils hypertrophy was scored from 0 to +4 according to the Brodsky criteria and adenoid hypertrophy was classified as Wang criteria. SDS BMI was calculated according to CDC standards. Non parametric Friedman test and Fisher's exact test were used for statistical analysis.Results: The main results are reported in the table. In particular we found a statistically significant reduction of RDI after 12 months of rhGH treatment and any reduction of upper airways patency in all but in one patient who required adenotonsillectomy. SDS BMI showed a slight, statistically unsignificant increase.Conclusions: The significant reduction of RDI is in agreement with previous studies showing improvement of respiratory function during GH treatment of Prader-Willi children. The important adenoids and tonsils hypertrophy observed in one of our patients during medium-term GH treatment, does not prove a GH dependency of lymphatic tissue hypetrophy, however points out the importance of a close ENT follow-up in these patients.