title: Sleep-related groaning: prevalence and characteristics in a cohort of patients with suspected obstructive sleep apnea.
abstract: CONCLUSIONS
  Nocturnal groaning has the same prevalence in patients referred for diagnosis of sleep-disordered breathing as among other populations referred for sleep studies. The respiratory tracings in these patients have a distinct appearance that is possible to recognize with a polygraphic recording and thereby prevent the pattern from being misdiagnosed as central apneas.
  
  
  OBJECTIVE
  The aim of this study was first to estimate the prevalence of groaning in patients referred for diagnosis of sleep-related breathing disorders. Second, we wanted to describe the respiratory pattern in order to distinguish the patients from patients with sleep apnea.
  
  
  METHODS
  This was a prospective study in 1004 patients, performed in the Sleep Unit in our ENT Department, during a 12 month period.
  
  
  RESULTS
  Four patients were diagnosed with video polysomnography, and the diagnosis of nocturnal groaning was confirmed. The prevalence of groaning in our sleep laboratory was 0.4%. All the patients had a mild form of sleep-related disturbance, and all groaning episodes occurred during REM sleep. The groaning events appeared in clusters. The length of each groan varied between 4 and 38 s. The number of events in a period varied between 2 and 11, and the length of each groaning period ranged between 11 and 168 s.
authors.affiliation: Sleep Unit, Department of Otorhinolaryngology/Head and Neck surgery, Lovisenberg Diakonale Hospital, Oslo, Norway. brov@lds.no
authors.forename: Britt
authors.initials: B
authors.lastname: Overland
authors.forename: Harriet
authors.initials: H
authors.lastname: Akre
authors.forename: Hanne
authors.initials: H
authors.lastname: Berdal
authors.forename: Olav
authors.initials: O
authors.lastname: Skatvedt
mesh_terms: D000328:Adult; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D010699:Phonation / Q000502:physiology; D017286:Polysomnography; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D020921:Sleep Arousal Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D012895:Sleep, REM / Q000502:physiology*; D014831:Voice / Q000502:physiology*