title: The effect of continuous positive airway pressure on cardiopulmonary coupling.
abstract: OBJECTIVE
  The aim of the study was to investigate cardiopulmonary coupling (CPC) as a tool for evaluating the efficacy of continuous positive airway pressure (CPAP) in the treatment of obstructive sleep apnea (OSA).
  
  
  METHODS
  The medical records of patients who had undergone either standard polysomnography (PSG-only group, n = 62) or split-night CPAP titration (CPAP titration group, n = 115) due to habitual snoring or sleep apnea were analyzed.
  
  
  RESULTS
  The apnea-hypopnea index, CPC variables, and sleep stage (%) during the first 2 h of the sleep study did not differ between the PSG-only and CPAP titration groups. A comparison of data collected over the first 2 h and that collected over the rest of the sleep study revealed that high-frequency coupling (HFC) increased, and low-frequency coupling (LFC) and elevated LFC (e-LFC) decreased only for the CPAP titration group, while they did not change for the PSG-only group. The proportions of N1 and N3 stages and arousal index decreased while the proportion of R stage increased for both groups. The proportion of N2 stage and mean O2saturation increased only for the CPAP titration group, while they did not change significantly for the PSG-only group. HFC increased while LFC and e-LFC decreased linearly as apnea-hypopnea index decreased for the CPAP titration group.
  
  
  CONCLUSIONS
  CPC effectively reflects the treatment effect of CPAP when compared with an electroencephalography-based sleep stage assessment.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Konkuk University, Seoul, South Korea.
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Otorhinolaryngology, Ajou University, School of Medicine, Woncheon-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-721, South Korea. entkhj@ajou.ac.kr.
authors.forename: Hyun Jun
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000465:Algorithms; D001143:Arousal / Q000502:physiology*; D045422:Continuous Positive Airway Pressure; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood*; D017286:Polysomnography / Q000379:methods*; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D012894:Sleep Stages / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D010100:Oxygen
keywords: Cardiopulmonary coupling; Continuous positive airway pressure; Obstructive sleep apnea; Titration