Sleep Characteristics in Early Stages of Chronic Kidney Disease in the HypnoLaus Cohort

Short or long sleep duration was associated with chronic kidney disease in a Chinese nationwide cohort study

OBJECTIVE

Sleep duration is an important factor influencing health outcomes. The association between sleep duration and kidney function remains elusive. This study aimed to explore the association between sleep duration and chronic kidney disease (CKD) amongst Chinese adults.

METHODS

We conducted a cross-sectional study based on the China Health and Nutrition Survey (CHNS) in the wave of 2009. Participants were divided into three groups: ≤ 6 h/day (short sleepers), 7-8 h/day (regular sleepers) and ≥ 9 h/day (long sleepers) according to self-reported sleep duration. CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2.

RESULTS

A total of 8096 Chinese adults (45.9% men) with a mean age of 50.6 years were included in the study. Compared with regular sleepers, both short and long regular sleepers had a higher prevalence of CKD. A U-shaped relationship between sleep duration and CKD was displayed by restricted cubic spline curve (P-overall < 0.001, P-nonlinear < 0.001). Multivariate logistic regression models revealed that both short and long sleep duration were clinically associated with higher odds of CKD, after adjustments for covariates [adjusted odds ratio (OR) 1.25 and 1.30; 95% confidence interval (CI) 1.00-1.56 and 1.08-1.54, for short and long sleep duration, respectively]. In subgroup analyses, we found the association was still observed in participants without hypertension or diabetes mellitus.

CONCLUSION

Short or long sleep duration was associated with CKD in the general population.

Cross-cultural adaptation and psychometric properties of the Persian version of the Geriatric Sleep Questionnaire (P-GSQ)

OBJECTIVE

This study aimed to validate the Geriatric Sleep Questionnaire (GSQ) for assessing subjective sleep quality among elderly individuals in Iran.

METHODS

The GSQ underwent evaluation for face and content validity. Participants were selected via convenience sampling from five healthcare centers. Sociodemographic variables, including gender, number of children, recreational activities, budget deficits, and family conflicts were analyzed. Confirmatory factor analysis was conducted to verify the results. Internal consistency was assessed using Cronbach's α, and test-retest reliability was evaluated using the intraclass correlation coefficient (ICC).

RESULTS

200 older adults (mean age 66.8 years) completed the questionnaires. Face and content validity were confirmed by 30 experts (S-CVI/average = 0.96). The final model exhibited good fit indices (χ2/df = 2.89, CFI = 0.96). The scale demonstrated acceptable internal consistency (α = 0.81) and test-retest reliability (ICC = 0.98).

CONCLUSION

The Persian GSQ demonstrates high reliability and validity for assessing sleep quality in older adults, aiding research in this field.

Association between Chronic kidney disease and restless leg syndrome (RLS): a systematic review and meta-analysis

Restless leg syndrome (RLS) is characterized by unpleasant nocturnal sensations in the lower limbs, and it has emerged as the fourth leading cause of insomnia and is often an underdiagnosed medical condition among sleep disorders. The symptoms of RLS are more common in chronic kidney disease patients than in the general population. Therefore, we performed the first meta-analysis to estimate the risk of RLS among chronic kidney disease patients. We conducted a comprehensive search in Embase, Ovid-MEDLINE, PubMed, Scopus, Web of Science, and CINAHL databases. Data were analyzed with the random-effects model using Comprehensive Meta-Analysis (CMA) software to find the odds ratio (OR). The heterogeneity was checked with the I2 test and Cochran's Q-statistic, and we performed the moderator analysis to find potential sources of heterogeneity. The study quality was assessed using the Newcastle-Ottawa Scale. Of 1175 studies, we found nine studies, with a total of 18,983 participants. The pooled OR of RLS among chronic kidney disease was 5.64 (95%CI 2.70-11.78). Regarding moderator analysis results, it was observed that higher body mass index and abnormal laboratory results would increase the risk of RLS; however, the statistical test was not significant in the current study. The findings reveal a substantial sixfold increase in the likelihood of RLS when compared to the general population. Therefore, health professionals should encourage patients to adhere to the treatment and practice a healthy lifestyle to manage their condition and reduce the risk of RLS. Moreover, future research can develop an intervention to reduce RLS symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-024-00513-4.

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.

Sleep quality, fatigue, societal participation and health-related quality of life in kidney transplant recipients: a cross-sectional and longitudinal cohort study

BACKGROUND

Fatigue and impaired health-related quality of life (HRQoL) are common among kidney transplant recipients (KTR). We hypothesized that both may partially be attributable to poor sleep.

METHODS

Cross-sectional and longitudinal data of KTR enrolled in the TransplantLines Biobank and Cohort Study were used. Sleep quality was assessed using the Pittsburgh Sleep Quality Index questionnaire. Individual strength (i.e. a composite of fatigue, concentration, motivation and physical activity), societal participation and HRQoL were assessed using validated questionnaires.

RESULTS

We included 872 KTR (39% female, age 56 ± 13 years) and 335 healthy controls. In total, 33% of male KTR and 49% of female KTR reported poor sleep quality, which was higher compared with male and female healthy controls (19% and 28%, respectively, P < .001 for both). In logistic regression analyses, female sex, anxiety, active smoking, low protein intake, physically inactive lifestyle, low plasma magnesium concentration, using calcineurin inhibitors, not using mTOR inhibitors and using benzodiazepine agonists were associated with poor sleep quality. In adjusted linear regression analyses, poor sleep was strongly and independently associated with lower individual strength [standardized β (st.β) = 0.59, 95% confidence interval (CI) 0.45 to 0.74, P < .001], poorer societal participation (frequency: st.β = -0.17, 95% CI -0.32 to -0.01, P = .04; restrictions: st.β = -0.36, 95% CI -0.51 to -0.21, P < .001; satisfaction: st.β = -0.44, 95% CI -0.59 to -0.28, P < .001) and lower HRQoL (physical: st.β = -0.53, 95% CI -0.68 to -0.38, P < .001; mental: st.β = -0.64, 95% CI -0.78 to -0.50, P < .001). The associations with poorer societal participation and lower HRQoL were strongly mediated by individual strength (P < .001 for all), yet the suggested direct effects of poor sleep quality on HRQoL remained significant (Pphysical = .03, Pmental = .002). Longitudinal data of 292 KTR showed that sleep quality improves after kidney transplantation in males (P < .001), but not in females (P = .9).

CONCLUSIONS

Poor sleep quality is common among KTR, and may be a potential target to improve fatigue, societal participation and HRQoL among KTR.

The Relationship Between Sleep and Brain Function in Older Adults With Chronic Kidney Disease and Self-Identified Cognitive Impairment

Older adults with chronic kidney disease (CKD) are at risk for cognitive impairment and sleep disturbances. The purpose of the current study was to investigate the relationship between sleep and brain structure/function in older adults with CKD and self-identified cognitive impairment. The sample (N = 37) had a mean age of 68 years (SD = 4.9 years), estimated glomerular filtration rate of 43.7 mL/min/1.73m2 (SD = 10.98), median sleep time of 7.4 hours, and was 70% female. Sleeping <7.4 hours, compared to ≥7.4 hours, was associated with better attention/information processing (β = 11.46, 95% confidence interval [CI] [3.85, 19.06]) and better learning/memory (β = 2.06, 95% CI [0.37, 3.75]). Better sleep efficiency was associated with better global cerebral blood flow (β = 3.30, 95% CI [0.65, 5.95]). Longer awake length after sleep onset was associated with worse fractional anisotropy of the cingulum (β = -0.01, 95% CI [-0.02, -0.003]). Sleep duration and continuity may be related to brain function in older adults with CKD and self-identified cognitive impairment. [Journal of Gerontological Nursing, 49(7), 31-39.].

Association of Self-Reported Nighttime Sleep Duration with Chronic Kidney Disease: China Health and Retirement Longitudinal Study

INTRODUCTION

The cohort study aimed to assess the association of nighttime sleep duration and the change in nighttime sleep duration with chronic kidney disease (CKD) and whether the association between nighttime sleep duration and CKD differed by daytime napping.

METHODS

This study included 11,677 individuals from the China Health and Retirement Longitudinal Study (CHARLS) and used data from the 2011 baseline survey and four follow-up waves. Nighttime sleep duration was divided into three groups: short (<7 h per night), optimal (7-9 h), and long nighttime sleep duration (>9 h). Daytime napping was divided into two groups: no nap and with a nap. We used Cox proportional hazards model to examine the effect of nighttime sleep duration at baseline and change in nighttime sleep duration on incident CKD and a joint effect of nighttime sleep duration and nap time on onset CKD.

RESULTS

With a follow-up of 7 years, the incidence of CKD among those with short, optimal, and long nighttime sleep duration was 9.89, 6.75, and 9.05 per 1,000 person-years, respectively. Compared to individuals with optimal nighttime sleep duration, short nighttime sleepers had a 44% higher risk of onset CKD (hazard ratio [HR]: 1.44, 95% confidence interval [CI]: 1.21-1.72). Compared to participants with persistent optimal nighttime sleep duration, those with persistent short or long nighttime sleep duration had an increased risk of incident CKD (HR: 1.44, 95% CI: 1.15-1.80). We found a lower incidence of CKD in participants with short nighttime sleep duration and a nap (HR: 0.74, 95% CI: 0.60-0.93), compared to those with short nighttime sleep duration and no nap.

CONCLUSION

Short nighttime sleep duration and persistent long or short nighttime sleep duration were associated with a higher risk of onset CKD. Keeping persistent optimal nighttime sleep duration may help reduce CKD risk later in life. Daytime napping may be protective against CKD incidence.

The genetic etiology of periodic limb movement in sleep

STUDY OBJECTIVES

Periodic limb movement in sleep is a common sleep phenotype characterized by repetitive leg movements that occur during or before sleep. We conducted a genome-wide association study (GWAS) of periodic limb movements in sleep (PLMS) using a joint analysis (i.e., discovery, replication, and joint meta-analysis) of four cohorts (MrOS, the Wisconsin Sleep Cohort Study, HypnoLaus, and MESA), comprised of 6843 total subjects.

METHODS

The MrOS study and Wisconsin Sleep Cohort Study (N = 1745 cases) were used for discovery. Replication in the HypnoLaus and MESA cohorts (1002 cases) preceded joint meta-analysis. We also performed LD score regression, estimated heritability, and computed genetic correlations between potentially associated traits such as restless leg syndrome (RLS) and insomnia. The causality and direction of the relationships between PLMS and RLS was evaluated using Mendelian randomization.

RESULTS

We found 2 independent loci were significantly associated with PLMS: rs113851554 (p = 3.51 × 10-12, β = 0.486), an SNP located in a putative regulatory element of intron eight of MEIS1 (2p14); and rs9369062 (p = 3.06 × 10-22, β = 0.2093), a SNP located in the intron region of BTBD9 (6p12); both of which were also lead signals in RLS GWAS. PLMS is genetically correlated with insomnia, risk of stroke, and RLS, but not with iron deficiency. Pleiotropy adjusted Mendelian randomization analysis identified a causal effect of RLS on PLMS.

CONCLUSIONS

Because PLMS is more common than RLS, PLMS may have multiple causes and additional studies are needed to further validate these findings.

Insomnia and Poor Sleep in CKD: A Systematic Review and Meta-analysis

Rationale & Objective

Poor sleep quality and insomnia are pervasive among patients with advanced chronic kidney disease (CKD); however, these health issues have not been systematically evaluated.

Study Design

Systematic review and meta-analysis.

Setting & Study Populations

Adult patients with CKD not receiving kidney replacement therapy (KRT), as well as adults receiving KRT, including hemodialysis, peritoneal dialysis, and kidney transplantation.

Selection Criteria for Studies

A systematic literature search using PubMed, Embase, and PsycNET, was conducted for articles published between January 1, 1990, and September 28, 2018.

Data Extraction

Data on the prevalences of poor sleep quality and insomnia in patients with CKD, including those receiving and not receiving KRT, were extracted.

Analytical Approach

Pooled prevalences were estimated using a random-effects meta-analysis and were stratified according to age, CKD stage, World Health Organization region, risk of bias, Pittsburgh Sleep Quality Index score, and the different criteria for insomnia that were used at diagnosis.

Results

Of 3,708 articles, 93 were selected, and significant methodological heterogeneity was present. The pooled prevalences of poor sleep quality for CKD without KRT, hemodialysis, peritoneal dialysis, and kidney transplantation were 59% (95% CI, 44%-73%), 68% (95% CI, 64%-73%), 67% (95% CI, 44%-86%), and 46% (95% CI, 34%-59%), respectively. The corresponding prevalences of insomnia were 48% (95% CI, 30%-67%), 46% (95% CI, 39%-54%), 61% (95% CI, 41%-79%), and 26% (95% CI, 9%-49%), respectively. Insomnia was significantly more prevalent among patients aged 51-60 years and those aged >60 years than among those aged <50 years. The prevalence of insomnia in the European region was the lowest of all World Health Organization regions.

Limitations

High interstudy heterogeneity.

Conclusions

Approximately half of the patients with advanced CKD had poor sleep quality or insomnia, and the prevalence was even higher among those who received KRT. Kidney transplantation may reduce the burden of poor sleep quality and insomnia.

Comparison of the Quality of Sleep in Patients With Chronic Kidney Disease and End-Stage Renal Disease

Objective

In this study, we aimed to compare the quality of sleep between patients with (CKD) and those with end-stage renal disease (ESRD).

Methodology

We performed a cross-sectional study between August 2020 and January 2021. We included 240 patients, among which 178 (74.2%) were CKD patients and 62 (25.8%) were ESRD patients on maintenance hemodialysis (MHD). Demographic data were collected on a pre-designed proforma. The quality of sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI). PSQI assesses subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. A PSQI score >5 indicates poor sleep quality.

Results

Out of the 240 patients, 159 (66%) had poor sleep quality. We found a significant difference in mean PSQI scores between CKD and ESRD patients (9.6 ± 12.4 vs. 11.4 ± 3.9 respectively), indicating poorer sleep quality in ESRD patients as compared to those with CKD (p<0.001). In our study, among all comorbidities, poor sleep was significantly associated with ischemic heart disease (IHD) (p = 0.025), after adjusting for confounding factors.

Conclusions

Our study showed that two-thirds of the study population had poor sleep quality. ESRD patients suffered from more disturbed sleep as compared to CKD patients.

The mediating effect of sleep quality and fatigue between depression and renal function in nondialysis chronic kidney disease: a cross-sectional study

BACKGROUND

Depressive symptoms, fatigue, and poor sleep quality are associated with renal function deterioration in patients with nondialysis chronic kidney disease (CKD-ND). This study was designed to examine whether fatigue and sleep quality are mediators of the association between depression and renal function.

METHODS

This study adopted a cross-sectional study design. Patients with CKD-ND aged 20 years or older were recruited by purposive sampling at a medical center in Central Taiwan from December 2020 to July 2021. Data were collected using the Emotional and Social Support Scale, Fatigue Scale, Beck Depression Inventory-II (BDI-II), and Pittsburgh Sleep Quality Index. Medical records were reviewed to obtain the estimated glomerular filtration rate (eGFR) for the next month. The relationships among variables were analyzed using structural equation modeling to assess the goodness-of-fit of the model. Then, the bootstrapping method was used to analyze the mediated effect.

RESULTS

Two hundred forty-two participants (mean age 70.5 years and 53% males) were included in the analysis. About 39% of the participants met the criteria for depressive symptoms in BDI-II, and 91% reported having sleep disturbances. Participants' degree of fatigue was not high (20.4 ± 13.3). The average eGFR was 25.45 mL/min/1.73 m ² (± 13.36). The results showed that fatigue, sleep quality, and eGFR were significantly correlated with depression. The total effect size was - 0.8304 (95% confidence interval [CI], - 0.9602 to - 0.7006), and the indirect effect size was - 0.1738 (95% CI, - 0.2812 to - 0.0651), which was a statistically significant difference, indicating that the model has a mediating effect. According to mediation analysis, fatigue and sleep quality had a significant indirect effect on the relationship between depression and renal function (95% CI, - 0.0587 to - 0.0039).

CONCLUSIONS

The findings suggest that fatigue and poor sleep quality may mediate the association between depression and renal function.

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 association of nighttime sleep duration and quality with chronic kidney disease in middle-aged and older Chinese: a cohort study

OBJECTIVE

This cohort study aimed to assess the associations between sleep duration and quality with the risk of incident chronic kidney disease (CKD) in middle-aged and older Chinese.

METHODS

We used the 2011 and 2015 surveys of the China Health and Retirement Longitudinal Study (CHARLS). Nighttime sleep duration was categorized into five groups: ≤4, (4-6], (6-8], (8-10], and >10 h/night. Sleep quality was assessed by restless days in the past week (<1, 1-2, 3-4, and 5-7 days/week). Multivariate logistic regression was used to assess the association between sleep duration and quality with incident CKD.

RESULTS

A total of 11,339 participants free of CKD at baseline were included in this study. After four years follow-up, the incidence of CKD was 7.8%. There was a "U-shaped" association between sleep duration and risk of CKD. Compared to 6-8 h of nighttime sleep duration, those who slept ≤4 h/night (RR: 1.639, 95% CI: 1.287-2.087) or >10 h/night (RR: 2.342, 95% CI: 1.007-5.451) had increased risk of developing CKD after adjustment for confounders. Participants with 5-7 restless days per week had significantly increased risk of CKD (adjusted RR: 1.686, 95% CI: 1.352-2.102), compared to those who rarely or never had a restless sleep.

CONCLUSIONS

Extreme nighttime sleep duration and poor sleep quality were associated with increased risk of CKD in middle-aged and older Chinese. Obtaining an optimal nighttime sleep duration and better sleep quality might reduce the risk of CKD.

Disturbed sleep quality and architecture in adolescents with type 1 diabetes mellitus: Relation to glycemic control, vascular complications and insulin sensitivity

BACKGROUND

Insufficient sleep duration and poor sleep quality have been linked to insulin resistance and impaired glucose metabolism. However, the relation between sleep disruption and type1 diabetes (T1D) hasn't been thoroughly explored.

AIM

To study the association between sleep parameters and glycemic control, insulin resistance and micro-vascular complications among adolescent with T1D.

METHODOLOGY

Sixty adolescents with T1D were compared to 60 matched controls. Diabetes-duration, insulin-therapy, fundus, Epworth Sleepiness Scale-Child Adolescent and the neuropathy disability score were assessed. Fasting lipids, fraction-C of glycosylated hemoglobin(HbA1c) and urinary albumin-excretion were measured with calculation of the insulin sensitivity score(ISS). Overnight polysomnography(PSG) was done.

RESULTS

Adolescents with T1D had significantly lower sleep efficiency and rapid eye movement(REM) sleep than controls with significantly higher sleep onset latency, non-REM sleep and arousal index(P < 0.001). Although ISS was negatively correlated to total sleep time(P = 0.002); it was positively correlated to sleep efficiency(P < 0.001). HbA1C was negatively correlated to sleep efficiency(<0.001) and REM sleep(P = 0.003) and positively correlated to sleep onset latency(P = 0.005). T1D adolescents with micro-vascular complications had significantly lower sleep efficiency and REM sleep than those without micro-vascular complications.

CONCLUSION

Poor sleep quality and architecture among adolescents with T1D are associated with impaired glycemic control, insulin resistance and micro-vascular complications.

A Narrative Review of Management Strategies for Common Symptoms in Advanced CKD

Patients with advanced chronic kidney disease (CKD) experience multiple bothersome symptoms, undermining their quality of life (QOL). With growing attention to the importance of symptom management in advanced CKD, the evidence regarding symptoms is increasing. In this review, we briefly summarize the current evidence of effective pharmacologic and nonpharmacologic interventions to improve symptoms and QOL in patients with advanced CKD, including those on dialysis. We focused on symptoms that are commonly experienced by patients, such as pain, fatigue, sleep disturbances, itching, nausea and vomiting, cognitive impairment, and anxiety and depression. We noted that research in symptom science focused on improving symptom management in CKD is still very limited. In addition to the lack of clinical practice guidelines to address those common symptoms, the major gaps in the current literature include the evidence regarding mechanistic pathways to inform the development of effective symptom management for CKD populations, the evidence to confirm effective pharmacologic interventions in other populations for CKD populations, and research on how to incorporate effective symptom management approaches into clinical care. Although improving mortality remains as an important area in the kidney community, there is an urgent need to focus on improving symptom management to improve QOL in advanced CKD.

Patient experiences of sleep in dialysis: systematic review of qualitative studies

RATIONALE AND OBJECTIVE

Sleep problems affect more than half of patients receiving dialysis and are associated with increased risk of mortality, cardiovascular events, depression and impaired functioning and quality of life. Symptoms such as fatigue and exhaustion may be attributed to sleep problems or sleep disorders, as well as the burden of kidney disease and treatment. This study aims to describe the patient perspectives on the reasons, impact and management of sleep problems in dialysis.

STUDY DESIGN

Systematic review and thematic synthesis of qualitative studies that report patient experience and perspectives on sleep in dialysis.

SETTING AND POPULATION

Patients receiving dialysis.

SEARCH STRATEGY AND SOURCES

MEDLINE, Embase, PsycINFO, CINAHL, reference lists and PhD dissertations were searched from inception to August 2019.

DATA EXTRACTION

All text from the results/conclusion of the primary studies.

ANALYTICAL APPROACH

Thematic synthesis.

RESULTS

We included 48 studies involving 1156 participants from 16 countries. We identified six themes: dominating demands of treatment (with subthemes of: demanding and relentless schedule, regret for wasted time); scheduling and control (managing sleep routines, napping and nocturnal sleep disruption, meditative aids); disruptions due to dialysis (unsettled sleep, hypervigilance and worry); symptoms depriving sleep (difficulty falling asleep, constant waking); overwhelmed and without choice (futility of sleep, uncontrollable exhaustion, restlessness is irrepressible); and as a coping mechanism (avoiding anxiety, alleviating symptoms, combating boredom).

LIMITATIONS

Most studies were conducted in high-income, English-speaking countries.

CONCLUSION

The treatment and symptom burden of dialysis disrupts and deprives patients of sleep, which leads to overwhelming and uncontrollable exhaustion. Better management of symptoms and effective strategies to manage sleep routines may improve sleep quality for better overall health in patients receiving dialysis.

How Do I Manage Hypertension in Patients with Advanced Chronic Kidney Disease Not on Dialysis? Perspectives from Clinical Practice

In the general population, the prevalence of moderate and severe chronic kidney disease (CKD) is usually below 5% but this figure is often higher in specific groups of patients such as those with type 2 diabetes. Patients with advanced CKD (CKD stage 3b and 4) are at high or very high cardiovascular risk, and their risk of progressing towards end-stage kidney disease (CKD stage 5) and the need of renal replacement therapy are elevated. Hypertension is a major cause of poor cardiovascular and renal outcomes in severe CKD. Therefore, an adequate control of blood pressure (BP) is mandatory. However, normalizing BP is often challenging in these patients because the clinical management of hypertension in advanced CKD is not well defined and rarely supported by large randomized controlled trials. In the present review, we discuss the characteristics of hypertension in advanced CKD, excluding dialysis, and its management integrating data from recent clinical studies and a pragmatic approach enriched by a long-standing clinical experience.

Effects of sleep apnea and kidney dysfunction on objective sleep quality in nondialyzed patients with chronic kidney disease: an ESADA study

STUDY OBJECTIVES

Patients with chronic kidney disease (CKD) often report poor sleep quality, but they commonly exhibit OSA. The aim of this study was to evaluate the influence of OSA severity and of estimated glomerular filtration rate impairment on objective sleep quality in nondialyzed patients with CKD, defined as an estimated glomerular filtration rate <60 mL/min/1.73m².

METHODS

Polysomnographic sleep characteristics were compared between patients with (n = 430) and without CKD (n = 6,639) in the European Sleep Apnea Database cohort. Comparisons were repeated in 375 patients with CKD and 375 control patients without CKD matched for sleep center, age, sex, and AHI, and in 310 matched CKD and non-CKD patients without psychiatric disturbances.

RESULTS

Among all patients with and without CKD, total sleep time was similar but sleep stage N1 (median 8.7% [IQR 4.8-18.0] vs 6.7% [3.6-12.7], respectively) and sleep stage R (12.6% [6.8-17.7] vs 14.2% [8.8-19.8], respectively) significantly differed (P < .0001). No difference in sleep characteristics was observed between matched patients either with or without psychiatric disturbances. After subdividing the matched patients according to AHI tertile (<25, ≥25 to <49, and ≥49 events/h) and estimated glomerular filtration rate (≥60, 45 to <60, <45 mL/min/1.73m²), we found a significant effect of AHI on sleep stages N2, N3, and R (P < .001), but there was no effect of CKD.

CONCLUSIONS

In nondialyzed patients with CKD, objective sleep quality is influenced similarly by AHI as in patients without CKD but is not affected by CKD severity. Previously reported poor sleep quality in CKD may partly result from the high prevalence of OSA in CKD.

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.

Sleep disorders in children and adolescents on regular hemodialysis

Sleep disorders in children with chronic kidney disease have been assessed in a limited number of studies. Our aim was to characterize the types of sleep disorders in children on regular hemodialysis and to detect the predictors of sleep efficiency in those children. Forty children and adolescents on regular hemodialysis and another 40 age- and gender-matched control groups were interviewed to answer a questionnaire-based survey, a modified Epworth Sleepiness Scale, to assess excess daytime sleepiness. Also, they underwent an overnight in-laboratory polysomnography to assess total sleep time, sleep efficiency, sleep staging, apnea/hypopnea index, and periodic limb movement index. We found poor sleep efficiency in 20% of cases, and periodic limb movement index higher than 5 in 45%, and apnea/hypopnea index higher than 5 in 40%. There was significant negative correlation between sleep efficiency on one hand, and serum potassium, serum creatinine, and sleep onset on other hand (p < 0.001, p < 0.001, and p < 0.001, respectively). There was significant decrease in hemoglobin, serum iron, and transferrin saturation in patients with excess daytime sleepiness (p < 0.001, p = 0.003, and p = 0.010, respectively). By using multivariate linear regression analysis, we found that serum creatinine was the single independent predictor of sleep efficiency.Conclusion: Poor sleep quality is not uncommon in hemodialysis children. Our results show a lower frequency of sleep disorders in comparison with previous studies. There is a strong association between kidney dysfunction and poor sleep quality in HD children.What is known:• Sleep disturbances can adversely affect a child's daytime performance.• Sleep disorders in children with chronic kidney disease have been assessed in only a limited number of studies.What is new:• Poor sleep quality is not uncommon in hemodialysis children.• There is a strong association between kidney dysfunction and poor sleep quality in hemodialysis children.

The effects of depression and age on sleep disturbances in patients with non-dialysis stage 3-5 chronic kidney disease: a single-center study

PURPOSE

Sleep disturbances have a negative impact on the prognosis of chronic kidney disease (CKD). However, information on the prevalence and predictors is limited. This study aimed to evaluate the prevalence and explore clinical factors affecting the quality of sleep in patients with non-dialysis CKD.

METHODS

Participants included 152 adult non-dialysis patients with stage 3-5 CKD. Demographic and clinical data were collected. Sleep quality and depression were assessed using the Pittsburgh Sleep Quality Index (PSQI) and Beck Depression Inventory (BDI), respectively. Sleep disturbances were defined as a PSQI score ≥ 5. Logistic regression was conducted to explore the independent factors of sleep disturbances. Clinical parameters were correlated with BDI scores using linear regression models.

RESULTS

The total prevalence of patients with sleep disturbances was 66.4%. Older age, higher BDI scores, lower estimated glomerular filtration rate (eGFR) changes per month (△eGFR/m) before the study, and lower serum magnesium levels were found in patients with sleep disturbances. BDI scores (odds ratio [OR] 1.224, 95% confidence interval [CI] 1.091-1.373, p = 0.001) and age (OR 1.041, 95% CI 1.013-1.069, p = 0.003) were independent predictors of sleep disturbances. Serum uric acid levels (β - 0.629, 95% CI - 1.244 to - 0.013, p = 0.046), △eGFR/m before the study (β - 0.454, 95% CI - 0.885 to - 0.024, p = 0.039), and daily protein intake (β - 0.052, 95% CI - 0.102 to - 0.002, p = 0.043) were negatively associated with BDI scores.

CONCLUSION

A high overall prevalence of sleep disturbances was found in patients with non-dialysis stage 3-5 CKD. Depression, as a manageable predictor, should be managed, especially in elderly patients.

Prevalence and correlates of sleep apnea among US Veterans with chronic kidney disease

The prevalence and correlates of sleep apnea (SA) among Veterans with chronic kidney disease (CKD), a population at high risk of both SA and CKD, are unknown. We performed a cross-sectional analysis of 248 Veterans (18-89 years) selected only for presence of moderate to severe CKD. All participants underwent full, unattended polysomnography, measurement of renal function and a sleepiness questionnaire. Logistic regression with backward selection was used to identify predictors of prevalent SA (apnea-hypopnea index [AHI, ≥15 events/hr] and prevalent nocturnal hypoxia [NH, % of total sleep time spent at <90% oxygen saturation]). The mean age of our cohort was 73.2 ± 9.6 years, 95% were male, 78% were Caucasian and the mean body mass index (BMI) was 30.3 ± 4.8 kg/m² . The prevalence of SA was 39%. There was no difference in daytime sleepiness among those with and without SA. In the final model, older age, higher BMI and diabetes mellitus (DM) were associated with higher odds of SA, after controlling for age, BMI, race and sex. Higher BMI, DM, unemployed/retired status, current smoking and higher serum bicarbonate level were associated with prevalent NH. To sum, SA was common among Veterans with moderate to severe CKD. Although some traditional risk factors for SA were associated with SA in this population, sleepiness did not correlate with SA. Further study is needed to validate our findings and understand how best to address the high burden of SA among Veterans with CKD.

Cardiometabolic correlates of sleep-disordered breathing in renal transplant children

Sleep-disordered breathing, a prevalent condition among adult renal transplant (RTx) recipients, has become an established independent risk factor of MetS, and furthermore, it might contribute to increased CV risk. Despite the proven correlations in adults, there is a lack of evidence for its significance in the pediatric RTx population. In this study, we aimed at assessing the prevalence and the clinical correlates of SDB in RTx children. Data of 13 patients (age [mean ± SD]: 14.2 ± 2.7 years) were analyzed. SDB was evaluated by PSG, as severity score OAHI was applied. Carbohydrate metabolism was characterized by OGTT, whereas CV status was studied by ABPM. Three composite end-points were calculated as sum of z-scores: daytime systolic and diastolic BP; nighttime systolic and diastolic BP; and glucose and insulin levels at 120 minutes. Eight patients (61.5%) were diagnosed with SDB of whom five patients (38.5%) had moderate or severe SDB. In linear regression analysis, OAHI during REM was associated with the CV variables (daytime BP P = 0.032, ß = 0.748; nighttime BP P = 0.041, ß = 0.715), and the correlations remained significant after adjustments for BMI. However, we did not confirm a significant association with the metabolic variables. The prevalence of SDB was high, and its severity during REM was a predictor of the BP suggesting that RTx children with SDB might be at risk of developing CV complications, especially HTN similarly to adults.

Snoring and incident chronic kidney disease: a community-based prospective cohort study

OBJECTIVES

Previous studies have shown that symptoms of sleep-disordered breathing are associated with metabolic derangements and vascular disease development. However, the relationship between snoring and renal function is not well investigated. The association between snoring and the development of incident chronic kidney disease (CKD) in subjects with normal renal function was evaluated.

DESIGN

Prospective cohort study.

SETTING

Ansung (rural community) and Ansan (urban community) cities.

PARTICIPANTS

Community-based cohort participants aged 40-69 years.

METHODS

A total of 9062 participants in the Ansung-Ansan cohort study were prospectively followed up from 2001 to 2014. The participants were classified into three groups: non-snorer, <1 day/week and ≥1 day/week. The main outcome was incident CKD, which was defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m² during the follow-up period.

PRIMARY OUTCOME

Incident CKD.

RESULTS

The mean subject age was 52.0±8.9 years, and 4372 (48.2%) subjects were male. The non-snorer,<1 day/week and ≥1 day/week groups included 3493 (38.5%), 3749 (41.4%), and 1820 (20.1%) subjects, respectively. Metabolic syndrome was more prevalent in the snoring groups than in the non-snoring group. Snoring frequency showed a significant positive relationship with age, waist:hip ratio, fasting glucose, total cholesterol (Tchol) and low-density lipoprotein cholesterol. During a mean follow-up of 8.9 years, 764 (8.4%) subjects developed CKD. Cox proportional hazards model analysis revealed that the risk of CKD development was significantly higher in subjects who snored ≥1 day/week than in non-snorers, even after adjustments for confounding factors (HR 1.23, 95% CI 1.09 to 1.38, p<0.01).

CONCLUSION

Snoring may increase the risk of CKD development in subjects with normal renal function.

Male Patients on Peritoneal Dialysis Have a Higher Risk of Sleep Apnea

STUDY OBJECTIVES

Peritoneal dialysis (PD) is a renal replacement therapy. One concern is whether patients on PD have a higher risk of sleep apnea (SA) due to intra-abdominal pressure increase and worsened ultrafiltration capacity. Despite this concern, to date, whether the risk of SA differs between PD, hemodialysis (HD), and groups without uremia is still uncertain.

METHODS

In this retrospective cohort study, data were obtained from the National Health Insurance Research Database of Taiwan. This database enrolled almost all patients on dialysis in the country. A total of 7,645 incident patients on PD and 38,225 incident patients on HD were enrolled. In addition, 38,225 patients without uremia were selected as the comparison cohort. Individuals were monitored for the occurrence of SA until 2013.

RESULTS

The results showed that patients on PD, regardless of sex, all had a higher risk of SA than non-dialysis groups. In contrast, the risk of SA in patients on HD was not significantly different from that of patients without uremia. We also compared the risk of SA between patients on PD and HD directly. The results showed that male patients on PD had a significantly higher risk of SA risk than male patients on HD. However, the risk of SA did not differ between female patients on PD and HD.

CONCLUSIONS

Patients on PD should receive regular SA assessments and that an increased awareness and a higher index of suspicion for SA should be maintained in these patients, especially male patients.

Chronic kidney disease in patients with obstructive sleep apnea. A narrative review

Prevalence of both chronic kidney disease (CKD) and obstructive sleep apnea (OSA) is continuously increasing. Moreover, the prevalence of OSA increases as kidney function declines and is higher among patients with end-stage renal disease (ESRD). In addition, OSA is recognized as a potential nontraditional risk factor for development and progression of CKD. Continuous positive airway pressure (CPAP) plays a pivotal role in the management of OSA, eliminating patients' symptoms and improving their quality of life. Recent studies suggested that CPAP treatment may have beneficial effects on kidney function among patients with OSA. This narrative review summarizes the existing knowledge on the association between CKD and OSA, with emphasis on the epidemiology, the pathophysiology of the development of CKD in OSA and vice versa, as well as the effect of CPAP on renal function.

Interventions for improving sleep quality in people with chronic kidney disease

BACKGROUND

Sleep disorders are commonly experienced by people with chronic kidney disease (CKD). Several approaches for improving sleep quality are used in clinical practice including relaxation techniques, exercise, acupressure, and medication.

OBJECTIVES

To assess the effectiveness and associated adverse events of interventions designed to improve sleep quality among adults and children with CKD including people with end-stage kidney disease (ESKD) treated with dialysis or kidney transplantation.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 8 October 2018 with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-randomised RCTs of any intervention in which investigators reported effects on sleep quality. Two authors independently screened titles and abstracts of identified records.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias for included studies. The primary outcomes were sleep quality, sleep onset latency, sleep duration, sleep interruption, and sleep efficiency. Risks of bias were assessed using the Cochrane tool. Evidence certainty was assessed using the GRADE approach. We calculated treatment estimates as risk ratios (RR) for dichotomous outcomes or mean difference (MD) or standardised MD (SMD) for continuous outcomes to account for heterogeneity in measures of sleep quality.

MAIN RESULTS

Sixty-seven studies involving 3427 participants met the eligibility criteria. Thirty-six studies involving 2239 participants were included in meta-analyses. Follow-up for clinical outcomes ranged between 0.3 and 52.8 weeks (median 5 weeks). Interventions included relaxation techniques, exercise, acupressure, cognitive-behavioural therapy (CBT), educational interventions, benzodiazepine treatment, dopaminergic agonists, telephone support, melatonin, reflexology, light therapy, different forms of peritoneal dialysis, music, aromatherapy, and massage. Incomplete reporting of key methodological details resulted in uncertain risk of bias in many studies.In very low certainty evidence relaxation techniques had uncertain effects on sleep quality and duration, health-related quality of life (HRQoL), depression, anxiety, and fatigue. Studies were not designed to evaluate the effects of relaxation on sleep latency or hospitalisation. Exercise had uncertain effects on sleep quality (SMD -1.10, 95% CI -2.26 to 0.05; I² = 90%; 5 studies, 165 participants; very low certainty evidence). Exercise probably decreased depression (MD -9.05, 95% CI -13.72 to -4.39; I² = 0%; 2 studies, 46 participants; moderate certainty evidence) and fatigue (SMD -0.68, 95% CI -1.07 to -0.29; I² = 0%; 2 studies, 107 participants; moderate certainty evidence). Compared with no acupressure, acupressure had uncertain effects on sleep quality (Pittsburgh Sleep Quality Index (PSQI) scale 0 - 21) (MD -1.27, 95% CI -2.13 to -0.40; I² = 89%; 6 studies, 367 participants: very low certainty evidence). Acupressure probably slightly improved sleep latency (scale 0 - 3) (MD -0.59, 95% CI -0.92 to -0.27; I² = 0%; 3 studies, 173 participants; moderate certainty evidence) and sleep time (scale 0 - 3) (MD -0.60, 95% CI -1.12 to -0.09; I² = 68%; 3 studies, 173 participants; moderate certainty evidence), although effects on sleep disturbance were uncertain as the evidence certainty was very low (scale 0 - 3) (MD -0.49, 95% CI -1.16 to 0.19; I² = 97%). In moderate certainty evidence, acupressure probably decrease fatigue (MD -1.07, 95% CI -1.67 to -0.48; I² = 0%; 2 studies, 137 participants). Acupressure had uncertain effects on depression (MD -3.65, 95% CI -7.63 to 0.33; I² = 27%; 2 studies, 137 participants; very low certainty evidence) while studies were not designed to evaluate the effect of acupressure on HRQoL, anxiety, or hospitalisation. It was uncertain whether acupressure compared with sham acupressure improved sleep quality (PSQI scale 0 to 21) because the certainty of the evidence was very low (MD -2.25, 95% CI -6.33 to 1.82; I² = 96%; 2 studies, 129 participants), but total sleep time may have been improved (SMD -0.34, 95% CI -0.73 to 0.04; I² = 0%; 2 studies, 107 participants; low certainty evidence). ² =² =There were no studies designed to directly examine and/or correlate efficacy of any interventions aimed at improving sleep that may have been attempted for the spectrum of sleep disordered breathing. No studies reported treatment effects for children. Adverse effects of therapies were very uncertain.

AUTHORS' CONCLUSIONS

The evidence base for improving sleep quality and related outcomes for adults and children with CKD is sparse. Relaxation techniques and exercise had uncertain effects on sleep outcomes. Acupressure may improve sleep latency and duration, although these findings are based on few studies. The effects of acupressure were not confirmed in studies in which sham acupressure was used as the control. Given the very low certainly evidence, future research will very likely change the evidence base. Based on the importance of symptom management to patients, caregivers and clinicians, future studies of sleep interventions among people with CKD should be a priority.

Subjective Sleep Quality and Excessive Daytime Sleepiness in Hemodialysis Patients Waitlisted for Renal Transplant

OBJECTIVE

Sleep disturbances are common in hemodialysis (HD) patients, impeding their daily activities and reducing their overall quality of life. The aim of this study was to investigate sleep quality and excessive daytime sleepiness (EDS) in HD patients waitlisted for renal transplant.

METHODS

The study included 137 patients (84 men and 53 women) undergoing HD three times per week; the mean age was 49.74±12.49 years. I used the Pittsburgh Sleep Quality Index (PSQI) to identify poor sleepers and the Epworth Sleepiness Scale (ESS) to identify those with EDS.

RESULTS

PSQI scores classified 87 of the 137 patients (63.5%) as poor sleepers, and ESS scores indicated that 47 patients (34.3%) had EDS. Among the 87 poor sleepers, 46% presented with EDS. Among the patients with EDS, 85% were also poor sleepers. Multivariate analysis revealed a positive correlation between the PSQI and ESS scores (P=0.002).

CONCLUSIONS

Poor sleep quality and EDS are quite common among patients receiving HD, but these sleep disturbances often go undiagnosed or untreated. Better awareness and treatment of SDs could improve quality of life for HD patients waitlisted for renal transplant.

Sleep Quality and Sleep Duration with CKD are Associated with Progression to ESKD

BACKGROUND AND OBJECTIVES

Shorter or longer sleep duration and poor sleep quality are risk factors for numerous cardio-metabolic diseases, cardiovascular disease, and mortality in subjects with normal kidney function. The association of sleep duration and sleep quality with health outcomes in patients with CKD remains uncertain.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A 4-year prospective cohort study in 17 nephrology centers in Japan, the CKD Japan Cohort (CKD-JAC) Study, assessed an association of self-reported sleep duration and sleep quality, on the basis of the Pittsburgh Sleep Quality Index (PSQI) questionnaire, with incidence of ESKD in 1601 patients with eGFR 10-59 ml/min per 1.73 m2 using multivariable-adjusted Cox proportional hazards models.

RESULTS

Baseline sleep duration and PSQI global score for the 1601 patients were mean±SD 7.0±1.3 hours and median 4 (interquartile range, 3-7), respectively. Poor sleep quality (PSQI global score ≥6) was common (n=588 [37%]). During a median of 4.0 (2.6-4.3) years of the follow-up period, 282 (18%) patients progressed to ESKD. After adjusting for age, sex, eGFR, urinary albumin excretion, smoking status, body mass index, history of diabetes and cardiovascular disease, systolic BP, blockade of the renin-angiotensin system, use of hypnotics, and Beck depression inventory score, both shorter (≤5 hour) and longer (>8 hour) sleep duration were associated with ESKD (adjusted hazard ratios [95% confidence intervals] for ≤5.0, 5.1-6.0, 6.1-7.0, 7.1-8.0, and ≥8.0 hours were 2.05 [1.31 to3.21], 0.98 [0.67 to 1.44], 1.00 [reference], 1.22 [0.89 to 1.66], and 1.48 [1.01 to 2.16]), suggesting a U-shaped relationship between sleep duration and ESKD. PSQI global score ≥6 was also associated with incidence of ESKD (adjusted hazard ratios [95% confidence intervals] for PSQI global score ≤5 and ≥6 were 1.00 [reference] and 1.33 [1.03 to 1.71]).

CONCLUSIONS

Shorter (≤5 hour) and longer (>8 hour) sleep duration and poor sleep quality (PSQI global score ≥6) were associated with ESKD in patients with CKD.

Gender differences in the relationships between chronic kidney disease, asymmetric dimethylarginine, and sleep quality: The HEIJO-KYO cohort

The association between chronic kidney disease (CKD), serum levels of asymmetric dimethylarginine (ADMA), and sleep quality has not been studied in large populations. In this cross-sectional study of 1115 elderly individuals (mean age, 71.9 years), we measured serum levels of ADMA, and objective and subjective sleep quality using actigraphy and a standardized self-reported questionnaire, respectively. Multivariable analysis adjusted for potential confounders revealed that in females, compared with the non-CKD/low-ADMA group (n=312), sleep efficiency was significantly lower in the CKD/high-ADMA group (n=52) by 3.5% for objective sleep quality [95% confidence interval (CI), 1.1-5.9] and by 4.2% (95% CI, 0.3-8.0) for subjective sleep quality but not in the non-CKD/high-ADMA (n=179) and CKD/low-ADMA (n=36) groups. In males, no significant associations between CKD, ADMA levels, and sleep quality were observed. Wake time after sleep onset was significantly longer by 11.3 min (95% CI, 3.0-19.6) for objective sleep quality and by 25.9 min (95% CI, 4.9-46.9) for subjective sleep quality in the CKD/high-ADMA group than in the non-CKD/low-ADMA group in females but not in males. Mediation analysis revealed a significant effect of serum ADMA levels on the association between renal function and parameters of sleep quality among females. In conclusions, both objective and subjective sleep quality were poorer in elderly females with CKD/high-ADMA than in those with non-CKD/low-ADMA, but not in males. Association between CKD and sleep disturbances might be mediated by ADMA levels.

Sleep-Disordered Breathing and Prevalent Albuminuria in Hispanics/Latinos

Introduction

Although sleep-disordered breathing has been found to be associated with higher urine albumin excretion, this association has not been evaluated in Hispanic/Latino populations, which experience a high burden of end-stage renal disease compared with non-Hispanics. We evaluated the association of sleep-disordered breathing with prevalent albuminuria among US Hispanics/Latinos.

Methods

This was a cross-sectional study of baseline data from participants in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a population-based study that enrolled 16,415 adults in 4 US communities. Sleep-disordered breathing was assessed using a home sleep apnea monitor for overnight recording and was defined using 3 thresholds of the apnea−hypopnea index (AHI; 3% desaturation): ≥5, ≥15, and ≥30. Albuminuria was defined as a urine albumin-to-creatinine ratio of ≥30 mg/g.

Results

There were 12,572 participants with complete data available for analysis. The age- and sex-adjusted prevalence of albuminuria was 9.1%. Mean age was 41 years, and 48% were men. Age- and sex-adjusted prevalence of sleep-disordered breathing was higher among individuals with albuminuria compared with those without albuminuria (36% vs. 25% had AHI ≥5, 18% vs. 9% had AHI ≥15, and 9% vs. 4% had AHI ≥30). In multivariable logistic regression analyses, AHIs ≥5, ≥15, and ≥30 were associated with greater odds of albuminuria compared with those with AHIs <5, <15, and <30 (odds ratio [OR] 1.42, 95% confidence interval [CI]: 1.14−1.76; OR: 1.71, 95% CI: 1.33−2.20; and OR 1.93, 95% CI 1.34−2.79), respectively. This association varied by Hispanic/Latino background group.

Conclusion

In US Hispanic/Latinos, sleep-disordered breathing was independently associated with higher odds of prevalent albuminuria.

A comparison of quality of sleep between patients with chronic kidney disease not on hemodialysis and end-stage renal disease on hemodialysis in a developing country

Few studies have compared quality of sleep between pre-dialysis chronic kidney disease (pre-dialysis CKD) patients and end-stage renal disease patients on dialysis (ESRD) and have found inconsistent results. Objective of this study is to compare quality of sleep between patients with pre-dialysis CKD and ESRD in a developing country. This study was conducted in an out-patient department and hemodialysis unit of a tertiary care facility. Patients included had either pre-dialysis CKD or ESRD. Assessment of quality of sleep was done using Pittsburgh sleep quality index (PSQI). A total of 152 patients were included in the study. Out of these patients, 79 (52%) had ESRD and 73 (48%) had pre-dialysis CKD. Median PSQI score was 6 (IQR 3-8.8). Poor sleep quality (PSQI ≥5) was present in 100 (65.8%) patients. Only hemoglobin (β = -0.39, p < .01), depression (β = 0.56, p < .01) and history of cardiovascular disease (β = 0.22, p < .01) were associated with PSQI global score in a multiple linear regression analysis. There was no significant association between ESRD vs. pre-dialysis CKD and PSQI global scores and no significant co-relation between eGFR and global PSQI score (r = -0.34, p value .80) in pre-dialysis CKD patients. Poor sleep quality is common in patients with CKD including hemodialysis patients in a developing country, which is independent of kidney function in non-dialysis patients. There is no difference in quality of sleep between pre-dialysis CKD and ESRD patients.

Association of symptoms of insomnia and sleep parameters among kidney transplant recipients

OBJECTIVE

Insomnia complaints are frequent among kidney transplant (kTx) recipients and are associated with fatigue, depression, lower quality of life and increased morbidity. However, it is not known if subjective insomnia symptoms are associated with objective parameters of sleep architecture. Thus, we analyze the association between sleep macrostructure and EEG activity versus insomnia symptoms among kTx recipients.

METHODS

Participants (n₁=100) were selected from prevalent adult transplant recipients (n₀=1214) followed at a single institution. Insomnia symptoms were assessed by the Athens Insomnia Scale (AIS) and standard overnight polysomnography was performed. In a subgroup of patients (n₂=56) sleep microstructure was also analyzed with power spectral analysis.

RESULTS

In univariable analysis AIS score was not associated with sleep macrostructure parameters (sleep latency, total sleep time, slow wave sleep, wake after sleep onset), nor with NREM and REM beta or delta activity in sleep microstructure. In multivariable analysis after controlling for covariables AIS score was independently associated with the proportion of slow wave sleep (β=0.263; CI: 0.026-0.500) and REM beta activity (β=0.323; CI=0.041-0.606) (p<0.05 for both associations).

CONCLUSIONS

Among kTx recipients the severity of insomnia symptoms is independently associated with higher proportion of slow wave sleep and increased beta activity during REM sleep but not with other parameters sleep architecture. The results suggest a potential compensatory sleep protective mechanism and a sign of REM sleep instability associated with insomnia symptoms among this population.

The systemic nature of CKD

The accurate definition and staging of chronic kidney disease (CKD) is one of the major achievements of modern nephrology. Intensive research is now being undertaken to unravel the risk factors and pathophysiologic underpinnings of this disease. In particular, the relationships between the kidney and other organs have been comprehensively investigated in experimental and clinical studies in the last two decades. Owing to technological and analytical limitations, these links have been studied with a reductionist approach focusing on two organs at a time, such as the heart and the kidney or the bone and the kidney. Here, we discuss studies that highlight the complex and systemic nature of CKD. Energy balance, innate immunity and neuroendocrine signalling are highly integrated biological phenomena. The diseased kidney disrupts such integration and generates a high-risk phenotype with a clinical profile encompassing inflammation, protein-energy wasting, altered function of the autonomic and central nervous systems and cardiopulmonary, vascular and bone diseases. A systems biology approach to CKD using omics techniques will hopefully enable in-depth study of the pathophysiology of this systemic disease, and has the potential to unravel critical pathways that can be targeted for CKD prevention and therapy.

Sleep duration and quality in relation to chronic kidney disease and glomerular hyperfiltration in healthy men and women

Background

It is unclear whether sleep duration and quality are associated with chronic kidney disease (CKD) and glomerular hyperfiltration. The aim of this study was to examine the association of sleep duration and quality with CKD and glomerular hyperfiltration in young and middle-aged adults.

Methods

We conducted a cross-sectional study of men and women who underwent a health checkup examination, including assessment of sleep duration and quality (n = 241,607). Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m², and glomerular hyperfiltration was defined as eGFR above the age-/sex-specific 95^th percentile.

Results

In a multinomial logistic regression analysis adjusting for relevant confounders, the adjusted prevalence ratios for CKD (95% confidence interval) comparing sleep durations of ≤ 5, 6, 8, and 9 hours with 7 hours were 1.22 (0.95–1.55), 0.93 (0.75–1.14), 0.97 (0.75–1.26), and 1.56 (1.06–2.30) in men and 0.98 (0.68–1.43), 1.03 (0.72–1.46), 1.39 (0.97–2.00), and 1.31 (0.78–2.22) in women, respectively. The corresponding prevalence ratios (95% confidence interval) for glomerular hyperfiltration were 1.00 (0.93–1.08), 0.97 (0.91–1.03), 1.03 (0.94–1.13), and 1.39 (1.13–1.72) in men and 1.04 (0.95–1.14), 0.96 (0.90–1.04), 1.11 (1.02–1.20), and 1.28 (1.14–1.45) in women, respectively. Poor subjective sleep quality was associated with glomerular hyperfiltration in men and women.

Conclusion

In this large study of young and middle-aged adults, we found that long sleep duration was associated with CKD and glomerular hyperfiltration. Additionally, poor subjective sleep quality was associated with increased prevalence of glomerular hyperfiltration, suggesting the importance of adequate quantity and quality of sleep for kidney function.

Depressive Symptoms Are Associated With Objectively Measured Sleep Parameters in Kidney Transplant Recipients

STUDY OBJECTIVES

Both depression and sleep complaints are very prevalent among kidney transplant (kTx) recipients. However, details of the complex relationship between sleep and depression in this population are not well documented. Thus, we investigated the association between depressive symptoms and sleep macrostructure parameters among prevalent kTx recipients.

METHODS

Ninety-five kTx recipients participated in the study (54 males, mean ± standard devation age 51 ± 13 years, body mass index 26 ± 4 kg/m2, estimated glomerular filtration rate 53 ± 19 ml/min/1.73 m2). Symptoms of depression were assessed by the Center for Epidemiologic Studies - Depression Scale (CES-D). After 1-night polysomnography each recording was visually scored and sleep macrostructure was analyzed.

RESULTS

The CES-D score was significantly associated with the amount of stage 2 sleep (r = 0.20, P < .05), rapid eye movement (REM) latency (r = 0.21, P < .05) and REM percentage (r = -0.24, P < .05), but not with the amount of slow wave sleep (r = -0.12, P > .05). In multivariable linear regression models the CES-D score was independently associated with the amount of stage 2 sleep (β: 0.205; confidence interval: 0.001-0.409; P = .05) and REM latency (β: 0.234; confidence interval: 0.001-0.468; P = .05) after adjustment for potential confounders.

CONCLUSIONS

Depressive symptoms among kTx recipients are associated with increased amount of stage 2 sleep and prolonged REM latency. Further studies are needed to confirm our findings and understand potential clinical implications.