OSAS does not seem to be more prevalent in adolescents with PCOS. Concerning the respiratory variables, adolescents with PCOS do not seem to differ from healthy controls; however, there seem to be differences concerning sleep architecture.

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.

SUMMARY  Polygraphic recordings in the awake state and during sleep were performed in two girls with Rett syndrome, aged 9 y and 17 y, in order to characterize the clinically manifest breathing disorder of these patients. Primary hyperventilation was detected, leading to hypocapnia and compensatory apnoea. Hypoxaemia occurred as the consequence of prolonged apnoea. In the younger patient these disturbances were observed only in the awake state, whereas in the older patient they were found in the awake state and during sleep.

Insulin resistance and hyperandrogenemia do not seem to have a significant impact on RPV in obese adolescents with PCOS. Differences in sleep architecture found between patients with PCOS and controls, however, are possibly influenced by insulin resistance and/or serum androgens.

This is the first study concerning age-related values of plasma level and redox status of CoQ10 in apparently healthy children. Decreased CoQ10 values could be involved in various pathological conditions affecting childhood. Therefore, the application of age-adjusted reference values may provide more specific criteria to define threshold values for CoQ10 deficiency in plasma.