[Incidence of obstructive sleep apnea syndrome in combination with chronic obstructive respiratory tract disease].

Polysomnographic measurements were performed in 210 indoor patients (age mean = 49.7 +/- 8.9 years, Broca mean = 126.0 +/- 20.7% FEV1%p mean = 79.9 +/- 23.9) of a pneumological rehabilitation centre who had a suspicious history or clinical symptoms of obstructive sleep apnoea. 72 had neither an airway obstruction nor a pathological apnoea index. 58 patients only suffered from airway obstruction and 42 had only a pathological apnoea index. In 38 patients, a pathological apnoea index and also airway obstructions were seen. For the last three groups we calculated the mean of the SaO2-values for an 8 hour night time period with and without n-CPAP-therapy. In both groups with only one disease a typical pattern of the SaO2-values during sleep could be demonstrated. The patients with overlap syndrome (SAS + COB) showed a superposition of both single disease SaO2-time courses even with much lower initial SaO2-values. During n-CPAP-therapy in all groups a reduction of the variations of SaO2 induced by sleep pattern and circadian rhythm are evident.