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Effect of CPAP therapy on kidney function in patients with obstructive sleep apnoea and chronic kidney disease: a protocol for a randomised controlled clinical trial
  1. Alex N Rimke1,
  2. Sofia B Ahmed1,
  3. Tanvir C Turin1,
  4. Sachin R Pendharkar1,
  5. Jill K Raneri1,
  6. Emma J Lynch1,
  7. Patrick J Hanly2,3
  1. 1University of Calgary, Calgary, Canada
  2. 2Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
  3. 3Sleep Centre, Foothills Medical Centre, Calgary, Alberta, Canada
  1. Correspondence to Dr Patrick J Hanly; phanly{at}


Introduction Obstructive sleep apnoea (OSA) is common in patients with chronic kidney disease (CKD) and may contribute to the progression of kidney disease either through direct effects of hypoxia on the kidney or indirectly through hypoxaemia-induced oxidative stress, endothelial dysfunction, inflammation, activation of the renin–angiotensin and sympathetic nervous systems, and hypertension. Treatment of OSA with continuous positive airway pressure (CPAP) improves many of these physiological abnormalities in patients with normal renal function, though to date there are no trials evaluating the effect of OSA treatment on kidney function in patients with CKD. The purpose of this study is to test the feasibility and efficacy of CPAP therapy in CKD patients with OSA.

Methods and analysis The study is a randomised, controlled, non-blinded, parallel clinical trial in which patients with established CKD are screened for OSA. Patients with OSA are randomised to either conventional medical therapy (control group) or medical therapy and CPAP (CPAP group) and followed for 1 year. The primary outcome is the change in estimated glomerular filtration rate. Secondary outcomes are the change in the urinary albumin/creatinine ratio, the Epworth Sleepiness Scale , Pittsburgh Sleep Quality Index and Kidney Disease Quality of Life questionnaire.

Ethics and dissemination Ethics approval has been obtained from the Conjoint Health Research Ethics Board (ID: REB15-0055). Results from this study will be disseminated through presentations at scientific conferences and publication in peer-reviewed journals.

Trial registration number NCT02420184; Pre-results.

  • kidney
  • sleep
  • apnea
  • cpap

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  • Contributors PJH, SBA, TCT and SRP contributed to the study concept and design. TCT provided statistical expertise and analysis. JKR, EJL and ANR contributed to patient recruitment and data acquisition. ANR and PJH wrote the initial draft of the manuscript and all authors have reviewed, revised and approved the final version.

  • Funding This work was supported by Philips Respironics who provided financial support for ANR and respiratory equipment (CPAP units) for the study. Financial support for JKR was provided by the Cumming School of Medicine Sleep Research Program.

  • Disclaimer This is an investigator-initiated study and the sponsors have no role in the design or execution of the study, or in the dissemination of the results.

  • Competing interests None declared.

  • Ethics approval The study was reviewed by the Conjoint Health Research Ethics Board at the University of Calgary to ensure that its content and procedures were compliant with research standards and regulations (ID: REB15-0055).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Obtained.

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