Sleep apnea is characterized by pauses in breathing during sleep. There are three forms: central, obstructive, and complex, or mixed sleep apnea. Central sleep apnea, a manifestation of respiratory instability in many clinical conditions and with a variety of causes, is the result of a temporary cessation of breathing in which the inhibitory influences favoring the instability predominate over excitatory influences favoring stable breathing. In contrast to central sleep apnea, according to the published data from previous studies, an association exists between obstructive sleep apnea and various comorbidities, especially chronic obstructive pulmonary disease. This article examines retrospectively the possible association of central sleep apnea with special sleep-related symptoms and various co-morbidities. Data of all patients with different types of central sleep apnea were collected from our hospital charts within the Department of Pneumology, HELIOS Clinic, University of Witten/Herdecke, Wuppertal, Germany, within the study period of January 1, 2011 to September 19, 2014. After clinical examination, all patients underwent polysomnography in our sleep laboratory. We identified a total of 60 (3.5 %) patients with central sleep apnea from 1722 patients with assumed sleep disordered breathing of the mean age of 68.2 ± 13.7 years (44 males - 73.3 %, 95 % CI 0.6-0.9 and 16 females - 26.7 %, 95 % CI 0.2-0.4). Typical symptoms of sleep-disordered breathing were not observed. A relation to co-morbidities was not found. Central sleep apnea was often diagnosed in the elderly. A direct association between central sleep apnea and symptoms of sleep-disordered breathing and various co-morbidities was not detected. This is in direct contrast to the obstructive sleep apnea syndrome.
Keywords: Central sleep apnea; Comorbidities; Obstructive sleep apnea; Polysomnography; Sleepiness; Symptoms.