[Chemoreflexsensitivity is reduced in obstructive sleep apnea and might be modulated by the autonomic system]. / Eingeschränkte Chemoreflexsensitivität als Ausdruck einer erhöhten adrenergen Aktivierung bei obstruktiver Schlafapnoe.

BACKGROUND: Chemoreflexes are important mechanisms for regulating ventilatory and cardiovascular function, which are supposed to be influenced in obstructive sleep apnea (OSA). PATIENTS AND METHODS: For determination of chemoreflexsensitivity (CHRS) the ratio of the RR-interval shift in the surface ECG during 5 min inhalation of oxygen via a nose mask was formed in 15 patients with suspected OSA. Noradrenaline plasma concentrations were measured and were correlated to CHRS. RESULTS: Patients with OSA showed a reduced CHRS. CHRS was correlated to the severity of sleep apnea (respiratory disturbance index [RDI]; r = -0.622; p = 0.013), and to minimal nocturnal oxygen saturation (r = 0.594; p = 0.032). Reduced CHRS was associated with higher noradrenaline concentrations (r = -0.542; p = 0.037). CONCLUSION: CHRS is reduced in patients with OSA and correlates with the severity of OSA. Further on, CHRS might be modulated by the autonomic system. Therefore, the determination of CHRS enables to estimate sympathetic activation in these patients.