Severe obstructive sleep disorders in Prader-Willi syndrome patients in southern Italy

Sleep-related disordered breathing (SDB) is very common in paediatric patients affected by Prader-Willi Syndrome (PWS). However, data addressing SBD patterns and their management are lacking. The aim of the present study was to analyse SDB features in 14 PWS patients (age range, 8 months-17 years). Polygraphic registration (PG) during a 12-h nocturnal sleep was performed in all patients. Obstructive and central apnoea indices and oxygen saturation (SpO(2)) were recorded along with demographic and clinical data. Obstructive sleep apnoea (OSA) was diagnosed in 13/14 patients (92.9%); the mean obstructive apnoea-hypopnea index (OAHI) was 7.6 +/- 4.2 events/h with a mean central apnoea index (CAI) of 0.7 +/- 1.04 events/h. Time spent with SpO(2) < 90% was of 0.02% [range 0-23%], with a mean oxygen desaturation index of 12.1 +/- 6.9 events/h. No correlation was found between OAHI and body mass index (mean BMI 28 +/- 9.8 kg/m(2) and BMI z-score 2.7 +/- 1.7). Conclusion: OSA was the predominant sleep-related disorder in our PWS patients, not associated with age or obesity, and appeared more severe than previously reported. Further studies addressing the underlying mechanisms are necessary in larger study populations to better design the most appropriate clinical approach.