title: Treatment for sleep apnea by continuous positive airway pressure improves levels of inflammatory markers - a meta-analysis.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is associated with coronary artery disease (CAD). Intermittent hypoxia associated with OSA increases sympathetic activity and may cause systemic inflammation, which may contribute to CAD in patients with OSA. Treatment with continuous positive airway pressure (CPAP) has been shown to change levels of inflammatory markers. We analyzed data from published studies by a systematic meta-analysis.
  
  
  OBJECTIVE
  To asses if treatment for sleep apnea by CPAP will affect levels of inflammatory markers.
  
  
  METHODS
  PubMed, Embase and Cochrane library.
  
  
  METHODS
  Study eligibility criteria full text English studies of adult, human subjects, addressing values of at least one of the inflammatory markers before and after CPAP treatment. We used the definition of OSA as an apnea-hypopnea index (AHI) of ≥ 5/h, reported values in mean and standard deviation or median with range.
  
  
  METHODS
  Adult, human.
  
  
  METHODS
  CPAP treatment for OSA.
  
  
  METHODS
  A total of 3835 studies were reviewed for inclusion, while 23 studies pooled for analysis. A total of 14 studies with 771 patients were pooled for C-reactive protein (CRP); 9 studies with 209 patients were pooled for tumor necrosis factor-alpha (TNF-α); and 8 studies with 165 patients were pooled for interleukin-6 (IL-6).
  THE FOLLOWING INFLAMMATORY MARKERS WERE CHOSEN: CRP, TNF-α, and IL-6.
  
  
  RESULTS
  C-reactive protein: Study level means ranged from 0.18 to 0.85 mg/dl before CPAP treatment and 0.10 to 0.72 mg/dl after CPAP treatment. Mean differences, at a study level, ranged from -0.05 to 0.50. The pooled mean difference was 0.14 [95% confidence interval 0.08 to 0.20, p < 0.00001]. There was heterogeneity in this endpoint (df = 13, p < 0.00001, I(2) = 95%). Tumor necrosis factor-α: Study level means ranged from 1.40 to 50.24 pg/ml before CPAP treatment and 1.80 to 28.63 pg/ml after CPAP treatment. Mean differences, at a study level, ranged from -1.23 to 21.61. The pooled mean difference was 1.14 [95% confidence interval 0.12 to 2.15, p = 0.03]. There was heterogeneity in this endpoint (df = 8, p < 0.00001, I2 = 89%). Interleukin-6: Study level means ranged from 1.2 to 131.66 pg/ml before CPAP treatment and 0.45 to 66.04 pg/ml after CPAP treatment. Mean differences, at a study level, ranged from -0.40 to 65.62. The pooled mean difference was 1.01 [95% confidence interval -0.00 to 2.03, p = 0.05]. There was heterogeneity in this endpoint (df = 7, p < 0.00001, I(2) = 95%).
  
  
  CONCLUSIONS
  Only published data. Studies pooled were mainly small, non-randomized trials.
  
  
  CONCLUSIONS
  Sleep apnea treatment with CPAP improves levels of inflammatory markers.
authors.affiliation: Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, IL, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Baessler
authors.affiliation: Pulmonary and Sleep Medicine, James A Lovell Federal Health Care Center, North Chicago, IL, USA ; James A. Lovell Federal Health Care Centre, 3001 Green Bay Road, North Chicago, IL, 60064, USA.
authors.forename: Rashid
authors.initials: R
authors.lastname: Nadeem
authors.affiliation: Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, IL, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Harvey
authors.affiliation: Pulmonary and Sleep Medicine, James A Lovell Federal Health Care Center, North Chicago, IL, USA.
authors.forename: Essam
authors.initials: E
authors.lastname: Madbouly
authors.affiliation: Bahria University medical and dental college, Karachi, Pakistan.
authors.forename: Amna
authors.initials: A
authors.lastname: Younus
authors.affiliation: McMaster University, Ontario, Canada.
authors.forename: Hassan
authors.initials: H
authors.lastname: Sajid
authors.affiliation: University of Karachi, Karachi, Pakistan.
authors.forename: Jawed
authors.initials: J
authors.lastname: Naseem
authors.affiliation: Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, IL, USA.
authors.forename: Asma
authors.initials: A
authors.lastname: Asif
authors.affiliation: Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, IL, USA.
authors.forename: Hasnain
authors.initials: H
authors.lastname: Bawaadam
keywords: AHI (apnea-hypopnea index); BMI (body mass index); CPAP (continuous positive airway pressure); CRP (C-reactive protein); IL-6 (interleukin-6); ODI (oxygen desaturation index); OSA (obstructive sleep apnea); TNF-α (tumor necrosis factor-alpha)