The effect of CPAP therapy on kidney function in CKD patients with OSA

Date
2020-01-28
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Abstract
Introduction: Chronic kidney disease (CKD) is a prevalent disorder with significant consequences on patients’ health outcomes and substantial costs to the healthcare system. Obstructive sleep apnea (OSA) is present in ~40% of CKD patients and may contribute to worsening kidney function. A pilot study to investigate the effects of continuous positive airway pressure (CPAP) on kidney function in patients with CKD and OSA was performed to determine potential effects on health outcomes and feasibility of a larger study. Methods: The study was a randomized, controlled, non-blinded, parallel clinical trial in which CKD patients were screened for OSA. Although a convenience sample of 60 patients with stage 3 and 4 CKD and OSA was planned, recruitment was stopped after 57 patients due to budgetary constraints. Patients were randomized to receive usual medical treatment for CKD or usual treatment and CPAP for 12 months. Home sleep apnea tests were performed at baseline and 12 months and CPAP adherence was monitored throughout the study. Recruiting trends were recorded from July 2015 to July 2018. Estimated glomerular filtration rate (eGFR) and albumin:creatinine ratio (ACR) were recorded every three months for 12 months. Results: 57 patients were randomized from the 1665 patients eligible for the study; however, follow-up data at 12 months was obtained in 51 patients. Recruitment failure occurred primarily due to insufficient recruiters (461 patients) and refused consent (645 patients). While there were no significant differences in eGFR and ACR over 12 months between the two groups, a trend for improvement in eGFR and ACR in patients considered at low risk of progression to end-stage kidney disease occurred. Conclusions: Recruitment of CKD patients with OSA for a clinical trial was challenging, but several strategies may improve enrolment in future studies. Although primary analysis did not show treatment of OSA in patients with stage 3 and 4 CKD improved eGFR and ACR, there was a trend for CPAP to improve these outcomes in patients with a low risk of CKD progression. This pilot randomized controlled trial provides preliminary data to determine if a larger clinical trial is merited and its future design.
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Keywords
Chronic kidney Disease, CKD, Obstructive Sleep Apnea, OSA, Continuous positive airway pressure, CPAP, estimated glomerular filtration rate, eGFR, albumin:creatinine ratio, ACR
Citation
Rimke, A. (2020). The effect of CPAP therapy on kidney function in CKD patients with OSA (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.