Physiological parameters of infants and children with Prader-Willi syndrome were examined in order to clarify whether there were indicators of disturbed respiratory control mechanisms in the pre-obesity stage of the syndrome. From January 1993 to March 1995 in eight patients with Prader-Willi syndrome (five boys, three girls, aged 6 weeks-12.5 years), polysomnography was performed and compared with 28 children matched for gestational age, sex, birth weight and age at sleep study. The recordings included thoracic and abdominal breathing movements, nasal airflow, tcPO2, tcPCO2, oxygen saturation, EEG, EOG and ECG. Respiratory responses to hypercapnia during quiet sleep were obtained from five Prader-Willi patients and ten peers. The Prader-Willi group showed an increased number of apnoeas per hour of sleep, a decreased nadir of oxygen saturation, increased maximum of the instantaneous heart rate and decreased respiratory responses to hypercapnia during quiet sleep.
Conclusion: These findings indicate a primary disturbance of central respiratory control in patients with Prader-Willi syndrome which may be worsened by the development of obesity.