Sleep-related breathing disorders in patients with Prader-Willi syndrome depending on the period of growth hormone treatment.

Introduction: Sleep-related breathing disorders (SRBD) are commonly present in patients with Prader-Willi syndrome (PWS). Recombinant human growth hormone (rhGH) treatment is reported to improve breathing function in PWS, but the findings are not explicit.
Material and Methods: Screening polysomnography- polygraphy (PSG), assessing nasal respiratory flow, respiratory effort, and blood oxygen saturation, was used. Group 1 - before rhGH therapy (n = 11, mean age 3.0 years); PSG was repeated after the start of rhGH therapy in a mean time of 0.9 years in six patients (Group 1a). Group 2 - on rhGH treatment, for a mean time of four years (n = 17, mean age 8.8 years). Group 3 - without rhGH therapy due to severe obesity (n = 8, mean age 13.1 years).
Results: Group 1 - mean apnoea-hypopnoea index (AHI) was 10.2, oxygen desaturation index (ODI)- 36.3, Group 1a- AHI 12.0, ODI 60.9, Group 2-AHI 9.0, ODI 25.1, Group 3- AHI 8.2, ODI 22.0. ODI was significantly higher in Group 1a than in the other groups (p < 0.005), but not strictly related to SRBD. The results in Group 2 did not differ significantly from those of Group 1.
Conclusions: Our study proves the high frequency of SRBD among PWS patients, with worsening of ODI after short-term rhGH therapy.