title: Effect of continuous positive airway pressure on hemoglobin A(1c) in patients with obstructive sleep apnea: a systematic review and meta-analysis.
abstract: BACKGROUND
  There is little conclusive data regarding the effect of continuous positive airway pressure (CPAP) on glycated hemoglobin (HbA(1c)). An earlier meta-analysis included two randomized controlled trials (RCTs) and found no significant effect of CPAP on HbA(1c). The meta-analysis presented here was conducted to include all relevant observational studies and RCTs on the effect of CPAP on HbA(1c).
  
  
  METHODS
  We searched the PubMed database for all studies published prior to March 2012 for trials of the effect of CPAP on HbA(1c). Data from observational studies and RCTs that met the inclusion criteria were extracted for pre- and post-treatment HbA(1c).
  
  
  RESULTS
  A total of nine studies that included 151 subjects met the inclusion criteria. The duration of the studies ranged from 41 days to 6 months. The mean net change in the HbA(1c) was -0.06 % [95 % CI: -0.24, 0.12] (p = 0.5). Five of the nine studies, with a total of 112 subjects, comprised patients with diabetes mellitus (DM) type 2. The mean net change in HbA(1c) for the subjects with DM type 2 was 0.08 % [95 % CI: -0.26, 0.42] (p = 0.65). The mean net change in HbA(1c) for subjects with DM type 2 in studies that were at least 3 months in duration was 0.16 % [95 % CI: -0.26, 0.58] (p = 0.45).
  
  
  CONCLUSIONS
  This meta-analysis found that CPAP does not reduce HbA(1c) levels when used in the short term.
authors: School of Medicine, University of South Carolina, Columbia, SC, USA. Imran.Iftikhar@uscmed.sc.edu
authors: Imran H
authors: IH
authors: Iftikhar
authors: Robert P
authors: RP
authors: Blankfield
mesh_terms: D045422:Continuous Positive Airway Pressure; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000628:therapy
chemical_list: D006442:Glycated Hemoglobin