title: Effect of nCPAP therapy on heart rate in patients with obstructive sleep apnoea-hypopnoea.
abstract: BACKGROUND
  Elevated heart rate (HR) is a risk factor for cardiovascular disease. The effects of obstructive sleep apnoea-hypopnoea syndrome (OSAHS) on HR are controversial.
  
  
  OBJECTIVE
  To investigate the effect of nasal continuous positive airway pressure (nCPAP) therapy on HR in OSAHS patients.
  
  
  METHODS
  Sixty-two OSAHS patients underwent 24-h electrocardiographic recording, both before and 3 or 4 days after instigation of nCPAP.
  
  
  RESULTS
  After nCPAP was started, HR significantly decreased (mean +/- SD 71.8 +/- 10.6 vs. 67.5 +/- 9.4 bpm, p < 0.0001), both in the daytime (0600-2200 h, 76.3 +/- 12.2 vs. 72.2 +/- 10.2 bpm, p < 0.0001) and at night-time (2200-0600 h, 64.5 +/- 9.1 vs. 60.0 +/- 8.9 bpm, p < 0.0001). HR was significantly reduced in both periods in the 44 patients with hypertension and/or diabetes mellitus, but only during the night-time in the 18 with neither condition. Before nCPAP treatment, HR was positively correlated with percentage time of arterial O2 saturation <90% during sleep (p = 0.008) and with the apnoea-hypopnoea index during sleep (p = 0.003). In 15 patients undergoing HR for 2 days before starting nCPAP, the mean HRs for the two periods were similar (p = 0.95).
  
  
  CONCLUSIONS
  nCPAP therapy appears to decrease HR in OSAHS patients, and may thereby reduce their risk of cardiovascular disease.
authors.affiliation: Department of Respiratory Medicine, Kyoto University Hospital of Medicine, 54 Shogoin Kawahara-cho, Sakyo-Ku, 606-8507 Kyoto, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sumi
authors.forename: K
authors.initials: K
authors.lastname: Chin
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Matsumoto
authors.forename: A
authors.initials: A
authors.lastname: Niimi
authors.forename: M
authors.initials: M
authors.lastname: Mishima
mesh_terms: D052242:Adiponectin / Q000097:blood; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D002940:Circadian Rhythm; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000503:physiopathology* / Q000628:therapy*
chemical_list: D052242:Adiponectin; D015415:Biomarkers