Obstructive Sleep Apnea Increases Sudden Cardiac Death in Incident Hemodialysis Patients

Sleep apnea and sudden death in the non-cardiac population: A systematic review

INTRODUCTION

Obstructive sleep apnea (OSA) is one of the main risk factors for cardiovascular diseases and is associated with both morbidity and mortality. OSA has also been linked to arrhythmias and sudden death.

OBJECTIVE

To assess whether OSA increases the risk of sudden death in the non-cardiac population.

METHODS

This is a systematic review of the literature. The descriptors "sudden death" and "sleep apnea" and "tachyarrhythmias" and "sleep apnea" were searched in the PubMed/Medline and SciELO databases.

RESULTS

Thirteen articles that addressed the relationship between OSA and the development of tachyarrhythmias and/or sudden death with prevalence data, electrocardiographic findings, and a relationship with other comorbidities were selected. The airway obstruction observed in OSA triggers several systemic repercussions, e.g., changes in intrathoracic pressure, intermittent hypoxia, activation of the sympathetic nervous system and chemoreceptors, and release of catecholamines. These mechanisms would be implicated in the appearance of arrhythmogenic factors, which could result in sudden death.

CONCLUSION

There was a cause-effect relationship between OSA and cardiac arrhythmias. In view of the pathophysiology of OSA and its arrhythmogenic role, studies have shown a higher risk of sudden death in individuals who previously had heart disease. On the other hand, there is little evidence about the occurrence of sudden death in individuals with OSA and no heart disease, and OSA is not a risk factor for sudden death in this population.

Sleep-Disordered Breathing Destabilizes Ventricular Repolarization

Rationale

Sleep-disordered breathing (SDB) increases the risk of cardiac arrhythmias and sudden cardiac death.

Objectives

To characterize the associations between SDB, intermittent hypoxemia, and the beat-to-beat QT variability index (QTVI), a measure of ventricular repolarization lability associated with a higher risk for cardiac arrhythmias, sudden cardiac death, and mortality.

Methods

Three distinct cohorts were used for the current study. The first cohort, used for cross-sectional analysis, was a matched sample of 122 participants with and without severe SDB. The second cohort, used for longitudinal analysis, consisted of a matched sample of 52 participants with and without incident SDB. The cross-sectional and longitudinal cohorts were selected from the Sleep Heart Health Study participants. The third cohort comprised 19 healthy adults exposed to acute intermittent hypoxia and ambient air on two separate days. Electrocardiographic measures were calculated from one-lead electrocardiograms.

Results

Compared to those without SDB, participants with severe SDB had greater QTVI (-1.19 in participants with severe SDB vs. -1.43 in participants without SDB, P = 0.027), heart rate (68.34 vs. 64.92 beats/minute; P = 0.028), and hypoxemia burden during sleep as assessed by the total sleep time with oxygen saturation less than 90% (TST90; 11.39% vs. 1.32%, P < 0.001). TST90, but not the frequency of arousals, was a predictor of QTVI. QTVI during sleep was predictive of all-cause mortality. With incident SDB, mean QTVI increased from -1.23 to -0.86 over 5 years (P = 0.017). Finally, exposing healthy adults to acute intermittent hypoxia for four hours progressively increased QTVI (from -1.85 at baseline to -1.64 after four hours of intermittent hypoxia; P = 0.016).

Conclusions

Prevalent and incident SDB are associated with ventricular repolarization instability, which predisposes to ventricular arrhythmias and sudden cardiac death. Intermittent hypoxemia destabilizes ventricular repolarization and may contribute to increased mortality in SDB.

Association of the combination of obstructive sleep apnea risk and sleep duration with ideal cardiovascular health metrics in patients undergoing hemodialysis

BACKGROUND

The purpose of this study was to explore the separate and combined associations of obstructive sleep apnea (OSA) risk and sleep duration with ideal cardiovascular health metrics in hemodialysis (HD) patients.

METHODS

470 HD participants (average: 59.48 ± 12.89 y, 281 men) were included in this study. Sleep duration was measured as self-reported average sleep time during the previous month. The OSA risk was assessed using the STOP-BANG questionnaire. Participants were divided into three groups based on the number of ideal cardiovascular health (CVH) metrics: 0-2,3-4, and 5-7. Ordinal logistic regression was conducted to model the associations of CVH metrics with sleep duration, OSA risk, and their combined effects by adjusting for specific covariates.

RESULTS

After adjusting for covariates, short sleep duration (< 7 h) (OR = 0.53; 95% CI [ 0.30, 0.92]) and OSA risk (OR = 0.58; 95% CI [0.32, 0.83]) were negatively associated with better CVH (ideal vs. intermediate; intermediate vs. poor), respectively. For HD patients with both short sleep duration and OSA risk, the odds of ideal CVH metrics were reduced by 72% (odds ratio 0.28 [95% CI 0.13, 0.60]).

CONCLUSIONS

Short sleep duration and OSA risk are separately and jointly associated with poor CVH in hemodialysis patients. Suitable interventions for sleep may minimize the risk of developing cardiovascular disease.

Sleep apnoea syndrome prevalence in chronic kidney disease and end-stage kidney disease patients: a systematic review and meta-analysis

Background

Several studies have examined the frequency of sleep apnoea (SA) in patients with chronic kidney disease (CKD), reporting different prevalence rates. Our systematic review and meta-analysis aimed to define the clinical penetrance of SA in CKD and end-stage kidney disease (ESKD) patients.

Methods

Ovid-MEDLINE and PubMed databases were explored up to 5 June 2023 to identify studies providing SA prevalence in CKD and ESKD patients assessed by different diagnostic methods, either sleep questionnaires or respiration monitoring equipment [such as polysomnography (PSG), type III portable monitors or other diagnostic tools]. Single-study data were pooled using the random-effects model. The Chi2 and Cochrane-I2 tests were used to assess the presence of heterogeneity, which was explored performing sensitivity and/or subgroup analyses.

Results

A cumulative analysis from 32 single-study data revealed a prevalence of SA of 57% [95% confidence interval (CI) 42%-71%] in the CKD population, whereas a prevalence of 49% (95% CI 47%-52%) was found pooling data from 91 studies in ESKD individuals. The prevalence of SA using instrumental sleep monitoring devices, including classical PSG and type III portable sleep monitors, was 62% (95% CI 52%-72%) and 56% (95% CI 42%-69%) in CKD and ESKD populations, respectively. Sleep questionnaires revealed a prevalence of 33% (95% CI 16%-49%) and 39% (95% CI 30%-49%).

Conclusions

SA is commonly seen in both non-dialysis CKD and ESKD patients. Sleep-related questionnaires underestimated the presence of SA in this population. This emphasizes the need to use objective diagnostic tools to identify such a syndrome in kidney disease.

Demographic and clinical risk factors for diagnosis of sleep disorders in ESRD patients

BACKGROUND

Sleep disturbances in patients with end-stage renal disease (ESRD) are common and more prevalent than in the general population. This study aims to assess the demographic and clinical risk factors for the diagnosis of sleep disorders in ESRD patients.

METHODS

This study is a retrospective analysis of the United States Renal Data System (USRDS) to evaluate risk factors for the diagnosis of sleep disorders, including hypersomnolence, insomnia, restless leg syndrome (RLS), or obstructive or central sleep apnea (OSA/CSA). All ESRD subjects enrolled in the USRDS between 2004-2015 were eligible for inclusion. The risk factors analyzed were age, race, sex, ethnicity, access type, dialysis modality, and the Charlson Comorbidity Index (CCI). All statistical analysis was performed using SAS 9.4, and statistical significance was assessed using an alpha level of 0.05. Descriptive statistics on all variables overall and by each sleep diagnosis were determined.

RESULTS

Increasing age, black race, other race, and Hispanic ethnicity were associated with decreased risk of each sleep diagnosis while CCI was associated with increased risk. Females were at increased risk of RLS and insomnia while males were at increased risk of OSA/CSA. Catheter and graft access decreased risk of RLS but increased risk of insomnia compared to AVF access. Catheter access increased risk of OSA/CSA compared to graft access. Hemodialysis increased risk of OSA/CSA compared to peritoneal dialysis.

CONCLUSIONS

Some ESRD patients are at an increased risk for diagnosis of sleep disorders based on age, race, sex, comorbid health conditions, and dialysis modality.

Effectiveness and safety of Linggui Zhugan decoction for the treatment of premature contraction in patients with coronary heart disease: A systematic review and meta-analysis

Objective

To evaluate the effectiveness and safety of Linggui Zhugan decoction (LZD) as an adjunct treatment of premature contraction in patients with coronary heart disease.

Methods

PubMed, Embase, Web of Science, ClinicalTrials.gov Cochrane Library, Chinese Knowledge Infrastructure, Wanfang database, Sino Med, and VIP database were searched from inception until July 2022. Two reviewers independently selected randomized controlled trials assessing the effectiveness of LZD combined with conventional antiarrhythmic drugs in treating premature contraction in patients with coronary heart disease compared to conventional antiarrhythmic drugs only. The clinical effectiveness was considered as the primary outcome, and the times of premature junctional beats in 24 h after treatment along with adverse reactions were considered secondary outcomes. The Cochrane risk of bias 2 tool was used for the risk of bias assessment. Meta-analysis was conducted using RevMan 5.4.1. and RStudio software.

Results

A total of 14 studies including 1,236 participants were included. The primary outcome indicated that, compared with antiarrhythmic drugs alone (especially β receptor blockers), the combination of LZD and conventional antiarrhythmic drugs resulted in higher clinical effectiveness (RR = 1.29, 95% CI: [1.22,1.36]) and lower number of premature junctional beats in 24 h (MD = −71.14, 95% CI: [−76.23, −66.06]) at end-of-intervention. The differences in adverse reactions (RR = 0.42, 95%CI: [0.15, 1.14], p = 0.09) were not significant. The risk of bias was marginally high among the studies. Funnel plot and Harbord’s test (t = 1.63, p = 0.1346) indicated no existence of publication bias.

Conclusion

The current evidence shows that LZD can increase the effectiveness of conventional antiarrhythmic drugs for treating premature contraction in patients with coronary heart disease. However, the results should be interpreted with caution because of the high overall risk of bias. Future studies with appropriate randomization and double-blind methods are warranted to confirm these findings.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=296628], identifier [CRD42022296628].

Aggravating effect of obstructive sleep apnoea on left ventricular remodelling and function disorder in patients with type 2 diabetes mellitus: a case-control study by 3D speckle tracking echocardiography

OBJECTIVES

The purpose of this study was to evaluate the early alterations of left ventricular (LV) structure and function in type 2 diabetes mellitus (T2DM) patients with or without obstructive sleep apnoea (OSA) using 3 D speckle tracking echocardiography (3DSTE).

METHODS

Eighty T2DM patients with preserved LVEF were included, half of whom had OSA as co-morbidity. Forty age- and sex-matched controls were also enrolled. LV structure and function were evaluated by conventional echocardiography and 3DSTE. LV global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS), and global radial strain (GRS) were all measured by 3DSTE.

RESULTS

Four geometric patterns (normal geometry, concentric remodelling, concentric and eccentric hypertrophy) occupied significantly different proportions within the three groups (p = .014). LV remodelling made up higher shares in two T2DM groups than in the controls, whereas LV hypertrophy appeared most frequently in the patients with T2DM and OSA. The patients with T2DM alone had significantly lower GLS and GCS than the controls (both p < .01). The patients with T2DM and OSA had significantly lower GLS, GCS, GAS, and GRS than the controls and the patients with T2DM alone (all p < .01). Fasting plasma glucose (FPG), OSA and BMI had negative impacts on all and part of the strain values in T2DM patients. The T2DM patients with moderate-to-severe OSA showed significantly lower GLS, GCS, GAS, and GRS than those with mild OSA (all p < .05).

CONCLUSIONS

The 3DSTE plus conventional echocardiography could detect the sub-clinical LV alterations in T2DM patients with or without OSA.

Hidden risks associated with conventional short intermittent hemodialysis: A call for action to mitigate cardiovascular risk and morbidity

The development of maintenance hemodialysis (HD) for end stage kidney disease patients is a success story that continues to save many lives. Nevertheless, intermittent renal replacement therapy is also a source of recurrent stress for patients. Conventional thrice weekly short HD is an imperfect treatment that only partially corrects uremic abnormalities, increases cardiovascular risk, and exacerbates disease burden. Altering cycles of fluid loading associated with cardiac stretching (interdialytic phase) and then fluid unloading (intradialytic phase) likely contribute to cardiac and vascular damage. This unphysiologic treatment profile combined with cyclic disturbances including osmotic and electrolytic shifts may contribute to morbidity in dialysis patients and augment the health burden of treatment. As such, HD patients are exposed to multiple stressors including cardiocirculatory, inflammatory, biologic, hypoxemic, and nutritional. This cascade of events can be termed the dialysis stress storm and sickness syndrome. Mitigating cardiovascular risk and morbidity associated with conventional intermittent HD appears to be a priority for improving patient experience and reducing disease burden. In this in-depth review, we summarize the hidden effects of intermittent HD therapy, and call for action to improve delivered HD and develop treatment schedules that are better tolerated and associated with fewer adverse effects.

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

The bidirectional relationship between sleep disordered breathing and chronic kidney disease (CKD) has recently gained a lot of interest. Several lines of evidence suggest the high prevalence of coexistent obstructive sleep apnea (OSA) in patients with CKD and end-stage renal disease (ESRD). In addition, OSA seems to result in loss of kidney function in some patients, especially in those with cardio-metabolic comorbidities. Treatment of CKD/ESRD and OSA can alter the natural history of each other; still better phenotyping with selection of appropriate treatment approaches is urgently needed. The aim of this narrative review is to provide an update of recent studies on epidemiological associations, pathophysiological interactions, and management of patients with OSA and CKD or ESRD.

The Contribution of Known Familial Cardiovascular Disease Genes to Sudden Cardiac Death in Patients Undergoing Hemodialysis

INTRODUCTION

Patients with chronic kidney disease experience high rates of cardiovascular mortality and morbidity. When kidney disease progresses to the need for dialysis, sudden cardiac death (SCD) accounts for 25-35% of all cardiovascular deaths. The objective was to determine if rare genetic variants known to be associated with cardiovascular death in the general population are associated with SCD in patients undergoing hemodialysis.

METHODS

We performed a case-control study comparing 126 (37 African American [AfAn] and 89 European ancestry [EA]) SCD subjects and 107 controls (34 AfAn and 73 EA), matched for age, sex, self-reported race, dialysis duration (<2, 2-5 and >5 years), and the presence or absence of diabetes mellitus. To target the coding regions of genes previously reported to be associated with 15 inherited cardiac conditions (ICCs), we used the TruSight Cardio Kit (Illumina, San Diego, CA, USA) to capture the genetic regions of interest. In all, the kit targets 572-kb regions that include the protein-coding regions and 40-bp 5' and 3' end-flanking regions of 174 genes associated with the 15 ICCs. Using the sequence data, burden tests were conducted to identify genes with an increased number of variants among SCD cases compared to matched controls.

RESULTS

Eleven genes were associated with SCD, but after correction for multiple testing, none of the 174 genes were identified as having more variants in the SCD cases than the matched controls, including previously identified genes. Secondary burden tests grouping variants based on diseases and gene function did not produce statistically significant associations.

DISCUSSION/CONCLUSIONS

We found no associations between genes known to be associated with ICCs and SCD in our sample of patients undergoing hemodialysis. This suggests that genetic causes are unlikely to be a major pathogenic factor in SCD in hemodialysis patients, although our sample size limits definitive conclusions.

Sudden death in individuals with obstructive sleep apnoea: a systematic review and meta-analysis

Objectives

Over 1 billion individuals worldwide experience some form of sleep apnoea, and this number is steadily rising. Obstructive sleep apnoea (OSA) can negatively influence one’s quality of life and potentially increase mortality risk. However, the association between OSA and mortality has not been reliably estimated. This meta-analysis estimates the risk of all-cause and cardiovascular mortality in individuals with OSA.

Design

Systematic review and meta-analysis.

Data sources

MEDLINE, Cochrane Library, Scopus and Joanna Briggs Institute Evidence-Based Practice databases were searched from inception through 1 January 2020.

Eligibility criteria for selecting studies

We included observational studies assessing the association of sudden deaths in individuals with and without OSA.

Data extraction and synthesis

Two independent reviewers (AES and ESH) extracted data and assessed the risk of bias using the Newcastle-Ottawa Scale quality assessment tool. Data were pooled using the random-effects models and reported as risk ratios (RRs) with 95% CIs. Heterogeneity was quantified with I² statistic.

Results

We identified 22 observational studies (n=42 099 participants). The mean age was 62 years and 64% were men. OSA was associated with all-cause sudden death (RR=1.74, 95% CI: 1.44 to 2.10, I²=72%) and cardiovascular mortality (RR=1.94, 95% CI: 1.39 to 2.70, I²=32%). A marginally significant dose–response relationship between severity of OSA and the risk of death was observed (p for interaction=0.05): mild OSA (RR=1.16, 95% CI: 0.70 to 1.93), moderate OSA (RR=1.72, 95% CI: 1.11 to 2.67) and severe OSA (RR=2.87, 95% CI: 1.70 to 4.85). Meta-regression analysis showed that older age was a significant contributing factor in the relationship between OSA and mortality. The median study methodological quality was considered high.

Conclusions

OSA is a significant risk factor for all-cause mortality and cardiac mortality. Prevention and treatment strategies to optimise survival and quality of life in individuals with OSA are urgently needed.

PROSPERO registration number

CRD42020164941.

Sudden cardiac death in dialysis patients: different causes and management strategies

Sudden cardiac death (SCD) represents a major cause of death in end-stage kidney disease (ESKD). The precise estimate of its incidence is difficult to establish because studies on the incidence of SCD in ESKD are often combined with those related to sudden cardiac arrest (SCA) occurring during a haemodialysis (HD) session. The aim of the European Dialysis Working Group of ERA-EDTA was to critically review the current literature examining the causes of extradialysis SCD and intradialysis SCA in ESKD patients and potential management strategies to reduce the incidence of such events. Extradialysis SCD and intradialysis SCA represent different clinical situations and should be kept distinct. Regarding the problem, numerically less relevant, of patients affected by intradialysis SCA, some modifiable risk factors have been identified, such as a low concentration of potassium and calcium in the dialysate, and some advantages linked to the presence of automated external defibrillators in dialysis units have been documented. The problem of extra-dialysis SCD is more complex. A reduced left ventricular ejection fraction associated with SCD is present only in a minority of cases occurring in HD patients. This is the proof that SCD occurring in ESKD has different characteristics compared with SCD occurring in patients with ischaemic heart disease and/or heart failure and not affected by ESKD. Recent evidence suggests that the fatal arrhythmia in this population may be due more frequently to bradyarrhythmias than to tachyarrhythmias. This fact may partly explain why several studies could not demonstrate an advantage of implantable cardioverter defibrillators in preventing SCD in ESKD patients. Electrolyte imbalances, frequently present in HD patients, could explain part of the arrhythmic phenomena, as suggested by the relationship between SCD and timing of the HD session. However, the high incidence of SCD in patients on peritoneal dialysis suggests that other risk factors due to cardiac comorbidities and uraemia per se may contribute to sudden mortality in ESKD patients.

Functional outcomes of sleep predict cardiovascular intermediary outcomes and all-cause mortality in incident hemodialysis patients

STUDY OBJECTIVES

Patients with end-stage kidney disease (ESKD) commonly experience sleep disturbances. Sleep disturbance has been inconsistently associated with mortality risk in hemodialysis patients, but the burden of symptoms from sleep disturbances has emerged as a marker that may shed light on these discrepancies and guide treatment decisions. This study examines whether functional outcomes of sleep are associated with increased risk of intermediary CV outcomes or mortality among adults initiating hemodialysis.

METHODS

In 228 participants enrolled in the Predictors of Arrhythmic and Cardiovascular risk in ESRD (PACE) study, the Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10), which assesses functional outcomes of daytime sleepiness, was administered within 6 months of enrollment. Intermediary CV outcomes included QTc [ms], heart rate variance [ms²], left ventricular mass index [g/m², LVMI], and left ventricular hypertrophy [LVH]. The association of FOSQ-10 score with all-cause mortality was examined using proportional hazards regression. Results: Mean age was 55 years, median BMI was 28 kg/m² (IQR 24,33), with 70% African Americans. Median FOSQ-10 score was 19.7 (IQR: 17.1,20.0). A 10% lower FOSQ-10 score was associated with increased mortality risk (HR 1.09, 95%CI 1.01-1.18). Lower FOSQ-10 scores were associated with longer QTc duration and lower heart rate variance, but not LVMI or LVH.

CONCLUSIONS

In adults initiating dialysis, sleep-related functional impairment is common and is associated with intermediary cardiovascular disease measures and increased mortality risk. Future studies should assess the impact of screening for sleep disturbances in ESKD patients to identify individuals at increased risk for cardiovascular complications and death.

Bidirectional association between chronic kidney disease and sleep apnea: a systematic review and meta-analysis

BACKGROUND

Previous data have suggested a link between chronic kidney disease (CKD) and sleep apnea (SA). However, the prevalence and risk association of both disease entities are not uniformly described.

METHODS

Ovid MEDLINE, EMBASE, and the Cochrane Library were searched for eligible publications that included patients aged ≥ 18 years diagnosed with CKD or SA. Included studies were divided into two cohorts: (1) a cohort of CKD or end-stage kidney disease (ESKD) patients reporting the prevalence of SA or odds ratio (OR) for SA (CKD cohort) and (2) a cohort of SA patients reporting the prevalence of CKD/ESKD or OR for CKD/ESKD (SA cohort).

RESULTS

CKD cohort: Of 16 studies (n = 340,587), the pooled estimated prevalence of SA among CKD/ESKD patients was 47.5% (95% CI 28.8-66.9). The pooled adjusted OR for SA among CKD/ESKD patients was 1.961 (95% CI 1.702-2.260). Male sex, history of diabetes, and lower BMI were associated with increased prevalence of SA. SA cohort: Of 12 studies (n = 3,103,074), the pooled prevalence of CKD/ESKD among patients with SA was 8.2% (95% CI 4.7-13.7), whereas the pooled adjusted OR for CKD/ESKD among patients with SA was 2.088 (95% CI 1.777-2.452). Increasing age, higher BMI, male sex, white race, and history of diabetes were associated with higher prevalence of CKD/ESKD.

CONCLUSION

There was a bidirectional association between CKD/ESKD and SA. Interventions aiming to prevent the progression of either CKD or SA are important.

Chronic kidney disease and concomitant sleep apnea are associated with increased overall mortality: a meta-analysis

PURPOSE

Sleep apnea (SA) is common in advanced chronic kidney disease (CKD) patients. However, the association between CKD with concomitant SA and overall mortality remains inconclusive.

METHODS

Ovid MEDLINE, EMBASE, and the Cochrane Library were searched for eligible publications, including non-transplant CKD patients aged > 18 years with co-existing SA. CKD is defined by estimated glomerular filtration rate of < 60 mL/min/1.73 m².

RESULTS

Seven observational studies (n = 186,686) were included in the meta-analyses. 94.2% had end-stage kidney disease (ESKD) requiring hemodialysis (HD), 5.0% had ESKD requiring peritoneal dialysis (PD), and 0.8% had non-dialysis CKD. The mean age was 76.8 ± 2.2 years. Most patients were male (53.4%) and white (76.8%). Up to 39.3% had diabetes. The mean body mass index was 26.0 ± 0.6 kg/m². Among patients with advanced CKD and SA, the pooled estimated odds ratios (OR) for overall mortality and cardiovascular events were 2.092 (95% CI, 1.594-2.744) and 1.020 (95% CI, 0.929-1.119), respectively, compared to patients with CKD alone. The OR was 2.145 (95% CI, 1.563-2.944) when studies with polysomnography-diagnosed SA were examined independently. No potential publication bias was detected. There were no significant differences in odds ratios for overall mortality, based on subgroup analyses.

CONCLUSION

Co-existence between advanced CKD and SA is associated with increased overall mortality, but not cardiovascular (CV) events when compared with CKD alone. The analysis of CV events requires additional studies to confirm our findings. Moreover, clinical interventions aiming to prevent the progression of SA and CKD are encouraged.

Sleep Apnea and the Kidney

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 influence of cognitive-behavioral therapy on depression in dialysis patients - meta-analysis

INTRODUCTION

Depressive disorders are the most common mental health problem among patients undergoing dialysis. Furthermore, depression is an independent factor increasing the mortality and frequency of hospitalization in this group of patients, yet psychological intervention programs aimed at improving the mental health of dialysis patients have still not been developed. This meta-analysis aimed to assess the effects of cognitive-behavioral therapy on depressive symptoms in dialysis patients. The main hypothesis of this study is that cognitive-behavioral therapy is an effective psychological method of reducing the severity of depression symptoms among patients undergoing dialysis.

MATERIAL AND METHODS

A systematic search was conducted using Medline, PubMed, Web of Science, Scopus and Google Scholar. Data extraction was carried out by two independent researchers. The severity of depression symptoms in the included studies was measured by the Beck Depression Inventory. A random-effects model was used to estimate the pooled mean difference of these values between patients undergoing CBT and the controls.

RESULTS

Four of the 1841 search results met the inclusion criteria with data from 226 patients who had undergone dialysis therapy due to renal disorders and psychological intervention based on cognitive-behavioral therapy. This therapy significantly reduced the level of depression symptoms in all studies included in the meta-analysis (mean difference = -5.3, p = 0.001; 95% CI: -7.95 to -2.66).

CONCLUSIONS

The study showed that the use of psychological intervention based on cognitive- behavioral therapy was an effective method of decreasing the severity of depressive symptoms in hemodialyzed patients. For the sake of patient well-being, it seems reasonable to extend renal replacement therapy with psychological intervention such as cognitive-behavioral therapy.

Residual Renal Function and Obstructive Sleep Apnea in Peritoneal Dialysis: A Pilot Study

PURPOSE

Obstructive sleep apnea is common in patients with end-stage renal disease, and there is increasing evidence that clinical factors specific to end-stage renal disease contribute pathophysiologically to obstructive sleep apnea. It is not known whether circumstances specific to dialysis modality, in this case peritoneal dialysis, affect obstructive sleep apnea. Our study aimed to investigate the prevalence of obstructive sleep apnea in the peritoneal dialysis population and the relevance of dialysis-specific measures and kidney function in assessing this bidirectional relationship.

METHODS

Participants with end-stage renal disease who were treated with nocturnal automated peritoneal dialysis for at least 3 months were recruited from a hospital-based dialysis center. Laboratory measures of dialysis adequacy, peritoneal membrane transporter status, and residual renal function were gathered by chart review. Patients participated in a home sleep apnea test using a level III sleep apnea monitor.

RESULTS

Of fifteen participants recruited, 33% had obstructive sleep apnea diagnosed by apnea-hypopnea index ≥ 5 events per hour of sleep. Renal creatinine clearance based upon 24-h urine collection was negatively correlated with apnea-hypopnea index (ρ = - 0.63, p = 0.012). There were no significant associations between anthropometric measures, intra-abdominal dwell volume, or peritoneal membrane transporter status and obstructive sleep apnea measures.

CONCLUSIONS

The prevalence of obstructive sleep apnea and sleep disturbances is high in participants receiving peritoneal dialysis. Elevated apnea-hypopnea index is associated with lower residual renal function, whereas dialysis-specific measures such as intra-abdominal dwell volume and peritoneal membrane transporter status do not correlate with severity of obstructive sleep apnea.