title: Effects of nocturnal continuous positive airway pressure therapy in patients with resistant hypertension and obstructive sleep apnea.
abstract: OBJECTIVE
  To examine the long-term effects of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) in patients with obstructive sleep apnea and resistant hypertension.
  
  
  METHODS
  Study subjects were 98 patients with obstructive sleep apnea syndrome and hypertension who had 3 or more documented daytime BP measurements taken within 3 months of enrollment and every 3 months after CPAP initiation for 1 year. Resistant hypertension was defined as daytime BP of at least 140 mm Hg systolic or 90 mm Hg diastolic, despite the use of 3 or more antihypertensive medications. Patients in the resistant hypertension group (n = 42) were compared with subjects with controlled hypertension (n = 56).
  
  
  RESULTS
  Mean difference in mean arterial pressure was -5.6 (95% confidence interval [CI] -2.0 to -8.7 mm Hg; p = 0.03) in the resistant group and -0.8 mm Hg (95% CI -2.9 to 3.3 mm Hg; p = 0.53) in patients with controlled BP at the end of follow up period. CPAP permitted de-escalation of antihypertensive treatment in 71% of subjects with resistant hypertension but did not significantly alter the antihypertensive regimen in the controlled group. Multivariate regression analysis showed that baseline BP (odds ratio 5.4, 95% CI 2.3 to 8.9; p = 0.01) and diuretic therapy (odds ratio = 3.2, 95% CI 1.8 to 6.1; p = 0.02), but not apnea-hypopnea index or hours of CPAP use, were independently associated with a decrease in mean arterial pressure after 12 months of CPAP therapy.
  
  
  CONCLUSIONS
  In this observational study, CPAP was associated with different effects on blood pressure control in hypertensive patients with sleep apnea. A beneficial response to CPAP therapy was found mainly in subjects with the most severe hypertensive disease.
authors.affiliation: University of Oklahoma Health Sciences Center, Pulmonary and Critical Care Medicine, 920 Stanton L Young Blvd, WP 1310, Oklahoma City, OK 73104, USA. tarek-dernaika@ouhsc.edu
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Dernaika
authors.forename: Gary T
authors.initials: GT
authors.lastname: Kinasewitz
authors.forename: Maroun M
authors.initials: MM
authors.lastname: Tawk
mesh_terms: D000959:Antihypertensive Agents / Q000494:pharmacology; D015897:Comorbidity; D045422:Continuous Positive Airway Pressure; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology / Q000628:therapy*
chemical_list: D000959:Antihypertensive Agents