title: Continuous positive airway pressure as treatment for systemic hypertension in people with obstructive sleep apnoea: randomised controlled trial.
abstract: OBJECTIVE
  To assess the effect of continuous positive airway pressure (CPAP) on 24 hour ambulatory blood pressure monitoring values in a large number of patients with untreated systemic hypertension of new onset and obstructive sleep apnoea.
  
  
  METHODS
  Multicentre, double blind, randomised, placebo controlled trial.
  
  
  METHODS
  Eleven general hospitals in Spain between 2004 and 2007.
  
  
  METHODS
  340 patients recently diagnosed as having systemic hypertension by a general practitioner (systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or both) and an apnoea-hypopnoea index per hour of sleep of >15 events/hour.
  
  
  METHODS
  Patients were assigned to CPAP (n=169) or sham CPAP (n=171) for three months. Main outcome measurements Net changes in the different 24 hour ambulatory blood pressure monitoring values from baseline to three months of optimal or sham CPAP.
  
  
  RESULTS
  277 (81%) of the 340 patients randomised were men; the patients had a mean age of 52.4 (SD 10.5) years, a body mass index of 31.9 (5.7), an Epworth sleepiness scale score of 10.1 (4.3), an apnoea-hypopnoea index of 43.5 (24.5). No differences between groups were seen at baseline. Compared with placebo and analysed by intention to treat, the mean 24 hour ambulatory blood pressure of the CPAP group decreased by 1.5 (95% confidence interval: 0.4 to 2.7) mm Hg (P=0.01). The mean 24 hour ambulatory blood pressure monitoring measures decreased by 2.1 mm Hg (0.4 to 3.7) mm Hg (P=0.01) for systolic pressure and 1.3 (0.2 to 2.3) mm Hg (P=0.02) for diastolic blood pressure. Mean nocturnal blood pressure decreased by 2.1 (0.5 to 3.6) mm Hg (P=0.01).
  
  
  CONCLUSIONS
  CPAP produced a statistically significant reduction in blood pressure in patients with systemic hypertension and obstructive sleep apnoea. This reduction is small and did not achieve the 3 mm Hg drop in mean 24 hour ambulatory blood pressure that the trial was powered to detect. Consequently, these results may have uncertain clinical relevance. However, taking into account the prevalence of hypertension and the likelihood of comorbidities, the decrease in blood pressure, although minimal, may be beneficial.
  
  
  BACKGROUND
  Clinical trials NCT00202527.
authors.affiliation: Sleep Unit, Hospital Universitario Txagorritxu, Facultad de Medicina, Universidad del País Vasco, Vitoria 01009, Spain. joaquin.durancantolla@gmail.com
authors.forename: Joaquín
authors.initials: J
authors.lastname: Durán-Cantolla
authors.forename: Felipe
authors.initials: F
authors.lastname: Aizpuru
authors.forename: Jose María
authors.initials: JM
authors.lastname: Montserrat
authors.forename: Eugeni
authors.initials: E
authors.lastname: Ballester
authors.forename: Joaquín
authors.initials: J
authors.lastname: Terán-Santos
authors.forename: Jose Ignacio
authors.initials: JI
authors.lastname: Aguirregomoscorta
authors.forename: Mónica
authors.initials: M
authors.lastname: Gonzalez
authors.forename: Patricia
authors.initials: P
authors.lastname: Lloberes
authors.forename: Juan Fernando
authors.initials: JF
authors.lastname: Masa
authors.forename: Mónica
authors.initials: M
authors.lastname: De La Peña
authors.forename: Santiago
authors.initials: S
authors.lastname: Carrizo
authors.forename: Mercedes
authors.initials: M
authors.lastname: Mayos
authors.forename: Ferrán
authors.initials: F
authors.lastname: Barbé
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D055815:Young Adult