Sleep Apnea and the Kidney

Abstract

Purpose of Review There are some uncertainties about the interactions between obstructive sleep apnea (OSA) and chronic kidney disease (CKD). We critically reviewed recent studies on this topic with a focus on experimental and clinical evidence of bidirectional influences between OSA and CKD, as well as the effects of treatment of either disease. Recent Findings Experimental intermittent hypoxia endangers the kidneys, possibly through activation of inflammatory pathways and increased blood pressure. In humans, severe OSA can independently decrease kidney function. Treatment of OSA by CPAP tends to blunt kidney function decline over time, although its effect may vary. OSA may increase cardiovascular complications and mortality in patients with end-stage renal disease (ESRD), while it seems of little harm after renal transplantation. Excessive fluid removal may explain some of the improvements in OSA severity in ESRD and after transplantation. Summary Severe OSA and CKD do interact negatively, mainly through hypoxia and fluid retention. The moderate mutually interactive benefits that treatment of each disease exerts on the other one warrant further studies to improve patient management.

The Burden of Comorbidities in Obstructive Sleep Apnea and the Pathophysiologic Mechanisms and Effects of CPAP

“…End-stage renal failure affects 57% of patients with OSAS [ 80 , 81 ]. Hypoxia, fluid retention, and rennin-angiotensin system activation are the key elements of the interconnection between OSAS and kidney failure, aggravating both conditions [ 82 , 83 ]. Nevertheless, not only can OSAS lead to kidney failure installation, but there is an inverse variant of this relation [ 84 ].…”

Prevalence and Burden of Comorbidities in Obstructive Sleep Apnea Syndrome

“…End-stage renal failure affects 57% of patients with OSAS [77,78]. Hypoxia, fluid retention, rennin-angiotensin system activation are the key elements of the OSAS and kidney failure interconnection, aggravating of both conditions [79,80]. Nevertheless, not only OSAS can lead to kidney failure installation -there is an inverse variant [81].…”

Is kidney a new organ target in patients with obstructive sleep apnea? Research priorities in a rapidly evolving field

“…The first reports dated back to 1985 when Millman et al found that patients with endstage renal disease (ESRD) showed a high risk for OSA [12]. Since then, a growing body of evidence has been gathered about the association between OSA and CKD from various epidemiological points of view (OSA in CKD, CKD in OSA, OSA in ESRD), and with different study designs (case series, cross-sectional, cohort studies and randomized controlled trials -RCTs), as well as studies on the effects of OSA on renal function in animal models [7,13,14]. Nevertheless, there is significant heterogeneity of the existing studies in terms of outcomes, which often leads to contradictory results.…”