title: Does CPAP treatment in mild obstructive sleep apnea affect blood pressure?
abstract: OBJECTIVE
  Obstructive sleep apnea (OSA) is associated with significant cardiovascular (CV) morbidity. Continuous positive airway pressure (CPAP) is the standard treatment for moderate to severe OSA, resulting in a reduction in CV morbidity. No studies have compared CV outcomes between CPAP and no CPAP in mild OSA (5>or=AHI<15).
  
  
  METHODS
  Retrospective cohort study of subjects (age>or=18) with mild OSA diagnosed between 2004 and 2006. Subjects with a history of hypertension, angina, stroke and smoking were excluded. Subjects were stratified into two groups: CPAP (n=93) or no CPAP (n=162). The mean blood pressures (MBP) were compared 2 years after the diagnosis of OSA was established.
  
  
  RESULTS
  Unmatched for covariates (age, sex, BMI, neck circumference, AHI, arousal index and family h/o CV disorders), subjects with mild OSA on CPAP had a 1.97 point reduction, and no CPAP resulted in a 9.61 point elevation (p<0.0001) in MBP. With propensity score matching for covariates, the mean difference in MBP was -1.97 (95% CI: -14.03, -9.92; p<0.0001) with a sensitivity analysis of 2.646.
  
  
  CONCLUSIONS
  This study shows an elevation of the MBP in mild OSA patients who were not treated with CPAP. CPAP treatment in mild OSA patients decreased the MBP over a 2-year period.
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand. drboy48@yahoo.com
authors: Nattapong
authors: N
authors: Jaimchariyatam
authors: Carlos L
authors: CL
authors: Rodriguez
authors: Kumar
authors: K
authors: Budur
mesh_terms: D000328:Adult; D000367:Age Factors; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D012044:Regression Analysis; D012189:Retrospective Studies; D012737:Sex Factors; D012890:Sleep / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000628:therapy*