Improvement in Sleep Apnea during Nocturnal Peritoneal Dialysis Is Associated with Reduced Airway Congestion and Better Uremic Clearance

Abstract

Background and objectives: Among peritoneal dialysis (PD) patients, nocturnal PD (NPD) is known to improve sleep apnea compared with continuous ambulatory peritoneal dialysis (CAPD), but the contributing factors are unclear.Design, setting, participants, and measurements: Thirty-eight incident ESRD patients underwent overnight polysomnography (PSG) during NPD and CAPD. Bioelectrical impedance analysis, magnetic resonance imaging of the upper airway, and urea kinetics (Kt/V) during sleep were measured on both occasions.Results: The prevalence of severe sleep apnea (apnea-hypopnea index, AHI > 15/h) was 21.1% during NPD, and 42.1% during CAPD. Mean AHI increased from 9.6 ؎ 2.7/h during NPD to 21.5 ؎ 4.2/h during CAPD. Both obstructive and central apnea worsened after conversion to CAPD. NPD achieved greater reductions in total body water, hydration fraction, and net ultrafiltration than CAPD during sleep. Overnight peritoneal Kt/V and creatinine clearance were lower after conversion. Both peritoneal Kt/V and peritoneal creatinine clearance correlated with AHI, as did their changes after conversion. Volumetric magnetic resonance imaging revealed reduced pharyngeal volumes and cross-sectional area, and tongue enlargement after conversion.Conclusions: Improvement in sleep apnea during NPD versus CAPD is associated with better fluid and uremic clearance and reduced upper airway congestion during sleep.

Sleep-Disordered Breathing and Excessive Daytime Sleepiness in Chronic Kidney Disease and Hemodialysis

“…In addition, the severity of SDB did not vary between dialysis and off-dialysis evenings or morning and afternoon/evening dialysis shifts, in concordance with previous reports (20,23,35). Observations that nocturnal HD (36) and nocturnal peritoneal dialysis (37,38) significantly improve sleep apnea suggest that factors originating from the deterioration of renal function, rather than from dialysis per se or from comorbidities, may partially explain the increased prevalence of SDB in all stages of CKD. In both patient groups, it is important to investigate the extent to which fluid retention may lead to airway edema, nocturnal hypoxemia, and the observed severity and obstructive patterns of SDB (39,40).…”

Association of Nocturnal Hypoxemia with Progression of CKD

“…Our results have an important clinical implication. Kidney failure and nephrotic proteinuria have been reported to cause obstructive sleep apnea, mainly because of airway edema resulting from fluid overload and low osmolality (42)(43)(44). In turn, this study has shown the possible adverse effects of NH on kidney function in patients with CKD.…”

Sleep Apnea Is Associated with Cardiovascular Risk Factors among Kidney Transplant Patients

“…Mallamaci et al (13) reported the association between respiratory disturbance index and BMI in Tx patients, which is in accordance with our findings. Finally, extracellular water may increase in at least some of the Tx patients (26,27), which may also be associated with increased risk for OSA (28). Male gender (29), older age (4), several anthropometric parameters (30)(31)(32), and also somatic comorbidity (5) are associated with OSA in the general population.…”