title: Sleep apnea, hypertension, and the effects of continuous positive airway pressure.
abstract: BACKGROUND
  Sleep apnea is being studied as a risk factor for hypertension. This observational chart review was conducted to determine the long-term effects of continuous positive airway pressure (CPAP) treatment on blood pressure (BP) in a sample of sleep apnea patients from urban and rural populations.
  
  
  METHODS
  This study was conducted using data from 180 clinical charts from 1995 to 2002. Patients were identified as hypertensive or normotensive by their initial BP values before they were diagnosed with sleep apnea and were also reviewed after the use of CPAP.
  
  
  RESULTS
  Of the patients diagnosed with sleep apnea, 32% were found to have hypertension (mean systolic BP: 164.4 +/- 20.3 mmHg; mean diastolic BP: 96.9 +/- 5.3 mmHg). The average use of CPAP was 12.1 +/- 22.4 months. The hypertensive group showed a significant reduction in BP with CPAP use: systolic BP dropped by an average of 11.2 mmHg (P < .001) and diastolic BP dropped by an average of 5.9 mmHg (P < .001).
  
  
  CONCLUSIONS
  Our results confirm that frequency of hypertension is increased among sleep apnea patients. The long-term use of CPAP in hypertensive patients with sleep apnea is associated with a significant decrease in BP to levels that considerably decrease cardiovascular risk.
authors.affiliation: Sleep Research Laboratory, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada. sdhillon@sciborg.uwaterloo.ca
authors.forename: Sukhjeet
authors.initials: S
authors.lastname: Dhillon
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Chung
authors.forename: Terence
authors.initials: T
authors.lastname: Fargher
authors.forename: Nada
authors.initials: N
authors.lastname: Huterer
authors.forename: Colin M
authors.initials: CM
authors.lastname: Shapiro
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D012119:Respiration; D012189:Retrospective Studies; D012891:Sleep Apnea Syndromes / Q000503:physiopathology / Q000628:therapy*