Obstructive Sleep Apnea and Kidney Disease: A Potential Bidirectional Relationship?

Exploring the Relationship Between Obstructive Sleep Apnea and Olfactory Function

Obstructive sleep apnea (OSA) is increasingly recognized as a chronic condition that is closely interrelated to olfactory disorders, with a significant contribution to quality of health and overall quality of life. This narrative review aims to provide a thorough overview of the emerging evidence that now integrates these two previously considered distinct physiologic systems. Studies published recently have reported a significantly higher frequency of olfactory dysfunction among OSA patients compared to the general population, which raises the possibility of a causal relationship. We explore the postulated mechanisms behind this association, namely, the chronic intermittent hypoxia, local inflammatory effect, and neuroanatomical changes attributed to OSA. The review further explores the clinical impacts of this relationship through proposing the potential for an olfactory assessment to be used as a diagnostic modality for OSA and the effects of OSA treatment on olfactory function. Thus, we explore the difficulties in treating patients who experience both and suggest future areas for research. This review attempts to bridge the gap between the existing literature and impending investigation necessary for a better management of the interaction of sleep apnea and the human sense of smell.

Nonlinear association between blood urea nitrogen to creatinine ratio and obstructive sleep apnea: a cross-sectional study from NHANES

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder that is closely associated with metabolic conditions. The Blood Urea Nitrogen to Creatinine Ratio(BUCR) is commonly utilized as a tool for evaluating renal function, particularly in cases where there are concerns about pre-renal or renal causes of azotemia. However, the connection between OSA and BUCR is not yet fully understood.

METHODS

This study examined the link between BUCR and OSA in adults over 20 using National Health and Nutrition Examination Surveys(NHANES) data from 2005-2008. Logistic regression models adjusted for multiple variables were used to analyze the relationship. The non-direct correspondence relationship were explored with a smooth curve and a two-part linear regression model, which revealed a threshold effect. Subgroup analyses were conducted to assess variations among different populations.

RESULTS

The survey, encompassing a total of 8826 participants, revealed that the median age of all respondents was 48 years, with a notable OSA prevalence of 51.3%. Upon adjusting for pertinent covariates using Model III(age, sex, marital status, education level, BMI, smoking status, drinking, hypertension, and diabetes), our findings indicated a significant association between OSA and BUCR, as evidenced by an odds ratio (OR) of 1.01 (95% CI: 1.00-1.02, P = 0.005). Furthermore, the risk association was found to be non-linear, featuring an inflection point for BUNR at 10.86. This non-linear relationship adds complexity to our understanding of the interplay between OSA and BUCR. In addition, a subgroup analysis underscored the influence of diabetes on the association between BUCR and OSA.

CONCLUSION

This study reveals a significant correlation between elevated BUCR levels and the incidence of OSA, particularly in the presence of diabetes. This discovery underscores the necessity for additional research to investigate the underlying mechanisms and ramifications of this connection within the diabetic context.

Prevalence of Obstructive Sleep Apnea Among Lebanese Patients With Chronic Kidney Disease: Its Repercussion on Disease Trajectory and Its Effect on Patients' Quality of Life

Background and Objectives: Chronic kidney disease (CKD) remains a public health threat and a major cause of morbidity and mortality worldwide. A bidirectional relationship is found between sleep disorders and CKD worldwide. However, to our knowledge, this study is the first to assess the prevalence of obstructive sleep apnea (OSA) and to evaluate its impact on the progression of other comorbidities among Lebanese patients with CKD. Materials and Methods: The study is an observational cross-sectional study, carried out between September and November 2021. Lebanese patients with any stage of CKD were included. Patients' characteristics were collected via electronic health record and baseline questionnaires. We screened for obstructive sleep apnea using the STOP-Bang questionnaire. Results: We included 168 patients. The prevalence of OSA among our patients was 47.6%. The prevalence of OSA is higher in males compared with females (81.2% vs. 18.8%, p=0.002). Obesity was more prevalent in patients with OSA compared with patients without OSA (42.5% vs. 19.3%, p=0.002). Among the 168 patients, 69.6% had hypertension, with a significantly higher prevalence among those with OSA compared with those without OSA (81.2% vs. 59.1%, p=0.003). Patients with OSA reported significantly lower scores compared with those without OSA in several domains of physical and emotional health, including physical functioning (54.06 vs. 66.88, p=0.002), role limitations due to physical health (42.19 vs. 63.07, p=0.001), role limitations due to emotional problems (49.17 vs. 69.32, p=0.004), pain (61.31 vs. 70.45, p=0.019), and physical component score (52.53 vs. 69.53, p=0.002). All the abovementioned parameters were also examined in two subpopulations: patients with CKD and ESRD. Similarly, some comorbidities and a lower physical QOL score were observed more in patients with OSA in these two subpopulations. Conclusion: Patients with OSA in our study have higher probability of being male, obese, and hypertensive as well as poorer QOL compared with their counterparts without OSA. Implementing more effective screening and treatment of OSA in CKD patients is necessary.

Effects of continuous positive airway pressure on renal function in adults with obstructive sleep apnea: a systematic review and meta-analysis

PURPOSE

Obstructive sleep apnea (OSA) is associated with increased risk of chronic kidney disease (CKD). OSA is highly prevalent among patients with CKD, suggesting a bidirectional link between the two conditions. Recent studies reported that continuous positive airway pressure (CPAP) may benefit renal function in OSA patients; however, uncertainties regarding their effects persist. Therefore, we examined the effects of CPAP treatment on renal function in adults with OSA.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Library, Web of Science, and ClinicalTrials.gov for relevant studies from their inception until January 2024. Pooled estimates for all outcomes were calculated using a random-effects model. Primary outcome measures were the estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR).

RESULTS

Four randomized controlled trials (RCTs) and seven non-RCTs (NRCTs) (n = 2,660) were included. Compared with the control group, the CPAP group exhibited a significantly minimal alleviation in eGFR decline in NRCT (mean difference [MD] = 1.95, 95% confidence interval [CI] = 0.80 to 3.11, p < 0.001), but not in RCT (MD = 1.42, 95% CI = - 0.99 to 3.82, p = 0.25). No significant associations were found between CPAP therapy and UACR (MD = - 0.05, 95% CI = - 0.41 to 0.30, p = 0.77).

CONCLUSION

Current research provides a low to moderate certainty of evidence, suggesting that CPAP therapy has little to no effect on alleviating the decline in renal function. However, further RCTs with larger sample sizes and extended follow-up periods are required.

Association between obstructive sleep apnea and chronic kidney disease: A cross-sectional and Mendelian randomization study

Previous observational studies have shown that obstructive sleep apnea (OSA) was associated with chronic kidney disease(CKD). Early diagnosis of OSA usually helps better prevent the occurrence of CKD. This cross-sectional investigation was conducted using data from the National Health and Nutrition Examination Survey, which was carried out between 2007 to 2008 and 2015 to 2016. Logistic regression model was employed to assess the impact of OSA on CKD. We did a mediation analysis to assess how much of the effect of OSA on CKD was mediated through mediators. Additionally, Mendelian randomization (MR) analysis assessed the causal link between OSA and various measures of renal impairment and possible mediators: obesity, hypertension and type 2 diabetes mellitus. In the cross-sectional study, the results of unadjusted model showed that participants with OSA had a higher risk of CKD compared to non-OSA (OR = 1.14, 95% confidence intervals [CI]: 1.01-1.28, P < .05). In mediation analysis, the proportion of hypertension and obesity mediating the effect of OSA on CKD was 41.83% and 30.74%, respectively. Univariate MR analysis results showed that: genetically predicted OSA was associated with decreased estimated glomerular filtration ratecystatin c (eGFRcystatin c) level (OR = 0.997, 95% CI: 0.995-0.999, P < .05), increased blood urea nitrogen (BUN) levels (OR = 1.023, 95% CI: 1.008-1.038, P < .05), increased serum creatinine levels (OR = 1.010, 95% CI: 1.002-1.018, P < .05), increased serum cystatin C levels (OR = 1.015, 95% CI: 1.005-1.026, P < .05). Multivariable MR results showed that obesity mediated the causal effect of OSA on eGFRcystatin c, BUN levels and serum cystatin C levels. The cross-sectional study revealed a positive relationship between OSA and CKD, which was mediated by hypertension and obesity. The MR analysis suggest that OSA was associated with several measures of renal impairment, which was mediated by obesity. These findings may inform prevention and intervention strategies against CKD.

Cognitive impairment in CKD patients: a guidance document by the CONNECT network

Cognitive impairment is a prevalent and debilitating complication in patients with chronic kidney disease (CKD). This position paper, developed by the Cognitive Decline in Nephro-Neurology: European Cooperative Target network, provides guidance on the epidemiology, risk factors, pathophysiology, diagnosis and clinical management of CKD-related cognitive impairment. Cognitive impairment is significantly more common in CKD patients compared with the general population, particularly those undergoing haemodialysis. The development of cognitive impairment is influenced by a complex interplay of factors, including uraemic neurotoxins, electrolytes and acid-base disorders, anaemia, vascular damage, metabolic disturbances and comorbidities like diabetes and hypertension. Effective screening and diagnostic strategies are essential for early identification of cognitive impairment utilizing cognitive assessment tools, neuroimaging and circulating biomarkers. The impact of various drug classes, including antiplatelet therapy, oral anticoagulants, lipid-lowering treatments and antihypertensive drugs, on cognitive function is evaluated. Management strategies encompass pharmacological and non-pharmacological interventions, with recommendations for optimizing cognitive function while managing CKD-related complications. This guidance highlights the importance of addressing cognitive impairment in CKD patients through early detection, careful medication management and tailored therapeutic strategies to improve patient outcomes.

I Brazilian guideline on hypertension in dialysis of the Brazilian Society of Nephrology

Hypertension in dialysis patients (HTND) has a high prevalence, affecting at least 80% or more of patients, and its management in the nephrology practice is heterogeneous and often empirical. Knowing how to define, understand the pathophysiology, diagnose, monitor and treat with lifestyle changes, and adjust antihypertensive drugs to achieve the recommended blood pressure (BP) target - to reduce morbidity and mortality - requires specific knowl-edge and approaches within the contexts of hemodialysis (HD) and peritoneal dialysis (PD). This document is the first guideline of the Brazilian Society of Nephrology, developed by the departments of Hypertension and Dialysis. It aims to guide physicians who provide care in dialysis centers on how to manage patients with HTND, in a comprehensive and individualized manner, based on the critical appraisal of the best available scientific evidence. When such evidence is scarce or unavailable, the opinion of specialists should be recommended. The different topics covered include HTND definition (pre-HD BP ≥ 140/90 mmHg and post-HD BP ≥ 130/80 mmHg), epidemiology, and pathophysiology; diagnosis of HTND preferably with BP measurements outside the dialysis setting (BP ≥ 130/80 mmHg); complementary assessment; blood pressure targets; non-pharmacological treatment; use of the most appropriate antihypertensive medications; special situations; and complications of HTND, predominantly cardiovascular ones.

Association between Obstructive Sleep Apnea and Age-related Macular Degeneration Development and Progression

OBJECTIVE

To evaluate the risk of age-related macular degeneration (AMD) development and progression in individuals with diagnosed obstructive sleep apnea (OSA).

DESIGN

Retrospective cohort study.

SUBJECTS

Before propensity score matching (PSM), 60 652 and 1 173 723 individuals with OSA or not, respectively, were included in the study. After PSM and applying inclusion/exclusion criteria, 58 700 individuals in each cohort were subsequently analyzed.

METHODS

Data were collected using TriNetX, a deidentified electronic health records research network. Individuals with an International Classification of Diseases, 10th Revision, code for OSA confirmed with polysomnography and an additional code for continuous positive airway pressure use were compared with individuals without diagnosed OSA (control cohort) for the development of main outcome measures at 5 years. Secondary analyses were included to assess nonadvanced AMD progression in individuals with and without diagnosed OSA at 5 years.

MAIN OUTCOME MEASURES

The main outcome measures were the incidence of AMD, macular hemorrhage, legal blindness, and requiring anti-VEGF intervention at 5 years. Individuals with nonadvanced AMD with and without an OSA diagnosis were separately analyzed for progression to late AMD and the development of macular hemorrhage, legal blindness, and requiring anti-VEGF therapy at 5 years.

RESULTS

At 5 years, individuals with diagnosed OSA had a significantly elevated risk of nonexudative AMD (hazard ratio [HR], 2.64; 95% confidence interval [CI], 2.37-2.96; P < 0.001), exudative AMD (HR, 2.48; 95% CI, 1.99-3.11; P = 0.002), and requiring anti-VEGF therapy (HR, 2.85; 95% CI, 2.26-3.59; P < 0.001) compared with the control cohort. In the secondary analysis, individuals with nonadvanced AMD with diagnosed OSA were associated with an elevated risk of geographic atrophy (HR, 7.00; 95% CI, 4.47-11.0; P = 0.03), exudative AMD (HR, 2.87; 95% CI, 2.37-3.48; P = 0.03), and requiring anti-VEGF injections (HR, 4.72; 95% CI, 3.59-6.22; P = 0.02) compared with those with nonadvanced AMD without diagnosed OSA.

CONCLUSIONS

In a large, heterogeneous database, an elevated risk of developing AMD and progression to later stages of the disease was observed among individuals with diagnosed OSA.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Impact of obstructive sleep apnoea on postoperative outcomes of patients undergoing coronary artery bypass grafting: a systematic review and meta-analysis

OBJECTIVE

To assess the association between obstructive sleep apnoea (OSA) and postoperative complications in patients after coronary artery bypass graft (CABG).

METHODS

PubMed, Embase, Web of Science and Scopus databases were explored to identify relevant observational studies that reported incidences of OSA in CABG patients, and assessed OSA using standard objective methods such as polysomnography (PSG). The primary outcomes of interest were risk of major adverse cardiac and cerebrovascular events (MACCE) and all-cause mortality. Pooled effect sizes were reported as odds ratio (OR) with 95% confidence intervals.

RESULTS

Twelve studies were included. All studies, except one, had a prospective cohort design. CABG patients with OSA had increased risk of MACCE (OR 1.71, 95% CI: 1.16, 2.53), myocardial infarction (MI) (OR 2.21, 95% CI: 1.19, 4.13), pulmonary complications (OR 1.86, 95% CI: 1.03, 3.38), renal complications (OR 8.14, 95% CI: 2.07, 32.1), heart failure (OR 1.86, 95% CI: 1.19, 2.89) and need for revascularization (OR 2.80, 95% CI: 1.01, 7.75). However, risk of all-cause mortality (OR 1.63, 95% CI: 0.75, 3.52) was comparable in all patients.

CONCLUSION

This study showed that OSA significantly correlates with the increased risk of major adverse events. Our results indicate that recognizing and managing OSA in CABG patients is crucial for mitigating associated risks.

Pulmonary hypertension in patients affected by sleep-related breathing disorders: up to date from the literature

Sleep-related breathing disorders (SBD) are conditions of abnormal and difficult respiration during sleep, including chronic snoring, obstructive sleep apnea (OSA), central sleep apnea (CSA), sleep-related hypoventilation disorders and sleep-related hypoxemia. Some of them have a limited impact on health, but others (e.g., OSA) can have serious consequences, because of their dangerous effects on sleep and the hematic balance of oxygen and carbon dioxide. According to several population-based studies, prevalence of OSA is relatively high, approximately 3-7% for adult males and 2-5% for adult females in the general population. However, methodological differences and difficulties in characterizing this syndrome yielded to variability in estimates. Moreover, it is estimated that only about 40% of patients with OSA are diagnosed, which can lead to underestimation of disease prevalence. OSA is directly correlated with age and male sex and to risk factors such as obesity. Several studies found that OSA is associated with an increased risk of diabetes, some cancer types, cardiovascular and cerebrovascular diseases, such as hypertension, coronary artery disease and stroke. Pulmonary hypertension (PH), a noted cardiovascular disease, is significantly associated with sleep-related breathing disorders and lot of scientific studies published in the literature demonstrated a strong link between these conditions and the development of pulmonary hypertension PH. PH is relatively less common than sleep-related breathing disorders. The purpose of this systematic review is to analyze both the current knowledge around the consequences that SBD may have on pulmonary hemodynamics and the effects resulting from pharmacological and non-pharmacological treatments of SDB on PH.

Associations between obstructive sleep apnea and sleep characteristics with chronic kidney disease in rural Pennsylvania

STUDY OBJECTIVES

To examine the association between moderate-severe obstructive sleep apnea (msOSA) and sleep characteristics with chronic kidney disease (CKD) in a population of rural and urban adults in Pennsylvania.

METHODS

A cross-sectional study of 23,643 adults who underwent polysomnography (PSG) at a rural healthcare system in Pennsylvania between 2009 and 2019. Serum creatinine was abstracted from electronic health records to calculate estimated glomerular filtration rate (eGFR). CKD was defined as an eGFR <60 mL/min/1.73 m2. msOSA was defined as an apnea-hypoxia index (AHI) ≥15 events/hour. Poisson regression was performed to estimate the prevalence ratio (PR) of CKD for various sleep measures while adjusting for age, sex, race, smoking (never, former, current), body mass index, diabetes, and hypertension at time of PSG.

RESULTS

In this clinically-referred sample comprised of over one-third (35 %) rural individuals, the prevalence of CKD and msOSA was 9.4 % and 32.1 %, respectively. Patients with CKD had more severe OSA based on AHI and intermittent hypoxia profile and presented worse sleep quality across all studied measures. Having OSA was associated with a 13 % higher prevalence of CKD (95%CI: 1.04, 1.22). In addition, for every 5 % increment in sleep efficiency, the prevalence of CKD was 3 % lower (PR = 0.97, 95%CI: 0.96, 0.98). Significant associations that were in the expected direction were observed across most sleep characteristics in adjusted models.

CONCLUSIONS

Moderate-severe OSA, nocturnal hypoxemia, and disruptions to normal sleep duration, continuity, and architecture are associated with increased CKD prevalence in Pennsylvania adults. Management of OSA and/or sleep disturbances may be an opportunity to improve CKD outcomes. The unique health disparities among vulnerable rural populations are deserving of future study.

Bidirectional association of sleep disorders with chronic kidney disease: a systematic review and meta-analysis

Background

Published studies have suggested a link between chronic kidney disease (CKD) and sleep disorders, although the exact nature of this association has not been uniformly described. Clarifying this relationship may facilitate evidence-based interventions that address the interplay between these disease entities. Such interventions could prevent obstructive sleep apnea (OSA) from worsening CKD and improve the quality of life for CKD patients by reducing the risk of developing OSA. Therefore, the objective of this meta-analysis is to assess the bidirectional association between sleep disorders and CKD.

Methods

Following a PROSPERO-registered protocol, three blinded reviewers conducted a systematic review of the Medline/PubMed, Embase, Cochrane Library and Cumulative Index of Nursing and Allied Health (CINAHL) databases for observational studies pertaining to the relationship between sleep disorders and CKD. A meta-analysis was conducted in risk ratios (RRs).

Results

From 63 studies (26 777 524 patients), OSA [RR 1.68; 95% confidence interval (CI) 1.45 to 1.93], albuminuria (RR 1.54; 95% CI 1.18 to 1.99), restless leg syndrome (RLS) (RR 1.88; 95% CI 1.48 to 2.38) and insomnia (RR 1.24; 95% CI 1.01 to 1.54) were significantly associated with CKD. There was a significant association between OSA (RR 1.77; 95% CI 1.56 to 2.01) with incident CKD. There was a significant association of OSA (RR 1.74; 95% CI 1.55 to 1.96), RLS (RR 1.73; 95% CI 1.32 to 2.25) and insomnia (RR 1.14; 95% CI 1.03 to 1.27) in patients with CKD compared with healthy controls. CKD was also significantly associated with incident OSA (RR 1.60; 95% CI 1.35 to 1.89).

Conclusion

The bidirectional associations of obstructive sleep apnea with CKD remained consistent across different stages of CKD, modes of diagnosis of sleep disorder and geographical region. A bidirectional association was observed between CKD and obstructive sleep apnea, RLS and insomnia. The treatment of sleep disorders may reduce the risk of CKD, and vice versa.

Causal effects of obstructive sleep apnea on chronic kidney disease and renal function: a bidirectional Mendelian randomization study

Background

Observational studies have suggested an association between obstructive sleep apnea (OSA), chronic kidney disease (CKD), and renal function, and vice versa. However, the results from these studies are inconsistent. It remains unclear whether there are causal relationships and in which direction they might exist.

Methods

We used a two-sample Mendelian randomization (MR) method to investigate the bidirectional causal relation between OSA and 7 renal function phenotypes [creatinine-based estimated glomerular filtration rate (eGFRcrea), cystatin C-based estimated glomerular filtration rate (eGFRcys), blood urea nitrogen (BUN), rapid progress to CKD, rapid decline of eGFR, urinary albumin to creatinine ratio (UACR) and CKD]. The genome-wide association study (GWAS) summary statistics of OSA were retrieved from FinnGen Consortium. The CKDGen consortium and UK Biobank provided GWAS summary data for renal function phenotypes. Participants in the GWAS were predominantly of European ancestry. Five MR methods, including inverse variance weighted (IVW), MR-Egger, simple mode, weighted median, and weighted mode were used to investigate the causal relationship. The IVW result was considered the primary outcome. Then, Cochran's Q test and MR-Egger were used to detect heterogeneity and pleiotropy. The leave-one-out analysis was used for testing the stability of MR results. RadialMR was used to identify outliers. Bonferroni correction was applied to test the strength of the causal relationships (p < 3.571 × 10-3).

Results

We failed to find any significant causal effect of OSA on renal function phenotypes. Conversely, when we examined the effects of renal function phenotypes on OSA, after removing outliers, we found a significant association between BUN and OSA using IVW method (OR: 2.079, 95% CI: 1.516-2.853; p = 5.72 × 10-6).

Conclusion

This MR study found no causal effect of OSA on renal function in Europeans. However, genetically predicted increased BUN is associated with OSA development. These findings indicate that the relationship between OSA and renal function remains elusive and requires further investigation.

The association of sleep duration with the risk of chronic kidney disease: a systematic review and meta-analysis

Background and hypothesis

Published literature suggests that sleep duration and quality may be affected in adults with chronic kidney disease. However, the relationship between these two entities remains a matter of debate. The objective of this systematic review and meta-analysis is to assess the effect of sleep duration and quality on chronic kidney disease.

Methods

A systematic review of the Medline/PubMed, Embase, Cochrane Library, and CINAHL databases was conducted for articles pertaining to the association between sleep duration and quality on chronic kidney disease. The main outcome was the hazard/risk ratio of chronic kidney disease in patients of varying sleep durations and quality.

Results

In total, 42 studies (2 613 971 patients) with a mean age of 43.55 ± 14.01 years were included in the meta-analysis. Compared with a reference range of 7 to 8 hours of sleep, short sleep durations of ≤4 hours (RR 1.41, 95% CI: 1.16 to 1.71, P < 0.01), ≤5 hours (RR 1.46, 95% CI: 1.22 to 1.76, P < 0.01), ≤6 hours (RR 1.18, 95% CI: 1.09 to 1.29, P < 0.01), and ≤7 hours (RR 1.19, 95% CI: 1.12 to 1.28, P < 0.01) were significantly associated with an increased risk of incident chronic kidney disease. Long sleep durations of ≥8 hours (RR 1.15, 95% CI: 1.03 to 1.28, P < 0.01) and ≥9 hours (RR 1.46, 95% CI: 1.28 to 1.68, P < 0.01) were also significantly associated with an increased risk of incident chronic kidney disease. Meta-regression did not find any significant effect of age, gender, geographical region, and BMI and an association with sleep duration and risk of incident chronic kidney disease.

Conclusion

Both short and long sleep durations were significantly associated with a higher risk of chronic kidney disease. Interventions targeted toward achieving an optimal duration of sleep may reduce the risk of incident chronic kidney disease.

Prevalence and assessment of risk factors of chronic kidney disease in the ASIR region of Saudi Arabia

Introduction

Chronic kidney disease (CKD) is a major health concern in Saudi Arabia. The prevalence of CKD and associated risk factors in Saudi Arabia's general population are not efficiently studied. The goal of this research is to determine the prevalence rate of CKD in the ASIR region and its associated epidemiological risk factors.

Methodology

This is a cross-sectional study that used a comprehensive direct questionnaire to collect data on CKD prevalence and risk factors in the ASIR region of Saudi Arabia. The study was carried out in different age groups. Demographic characteristics, presence of CKD, and associated factors such as a history of acute kidney disease, obstructive sleep apnoea, family history, history of non-steroid anti-inflammatory drugs (NSAID), smoking status, comorbidities, and history of periodontal diseases were asked. The survey tool was validated through a pilot study, and a statistical p value of 0.05 was considered significant.

Results

A total of 967 participants were included in the study, with a CKD prevalence rate of 1.9%. Sex, history of acute kidney disease, obstructive sleep apnoea, family history of kidney disease, smoking, diabetes, peptic ulcer disease, hypertension and hyperlipidemia were commonly found to be associated with CKD. A binary logistic regression model was carried out to assess the risk factors for CKD. Sex, history of acute kidney disease, family history of kidney disease, obstructive sleep apnoea, smoking status, peptic ulcer, diabetes, hypertension, hyperlipidemia, hypertension and diabetes, two or more comorbidities and NSAID use had an increased risk of CKD.

Conclusion

Sex, history of acute kidney disease, obstructive sleep apnoea, family history, smoking, diabetes, hypertension, peptic ulcer, hyperlipidemia, multi-comorbidity, and use of NSAIDs are all associated with an increased risk of CKD. The prevalence of CKD in this study is comparatively lower when compared to other regions in Saudi Arabia.

Management Challenges of Sleep-Disordered Breathing in a Child With Chronic Kidney Disease: A Case Report of a Child on Peritoneal Dialysis

Chronic kidney disease in children is a challenging condition that requires careful management. When combined with sleep-disordered breathing, it can pose even greater difficulties. This case report highlights the management challenges of a child with chronic kidney disease and sleep-disordered breathing. Through careful analysis and effective intervention, we were able to address the challenges and improve the child's quality of life. Understanding the complex interaction between these two conditions is crucial for healthcare professionals to provide effective care for children with chronic kidney disease and sleep-disordered breathing.

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

Association of mildly elevated pulmonary vascular resistance with major cardiovascular events in pulmonary hypertension and chronic kidney disease: A retrospective cohort analysis

Pulmonary hypertension (PH) is associated with adverse outcomes in chronic kidney disease (CKD) patients. Our study suggests mildly elevated pulmonary vascular resistance ( > 2 to ≤ 3) is independently associated with major adverse cardiovascular events at 1-year follow-up. Early diagnosis of precapillary PH in CKD patients can potentially improve clinical outcomes.

Increasing obstructive sleep apnea risk is associated with albuminuria in Korean adults: cross-sectional analysis

Several studies have shown an association between albuminuria and obstructive sleep apnea (OSA). However, studies on the relationship between the STOP-BANG questionnaire that can screen for OSA and microalbuminuria are still insufficient. Therefore, this study attempted to clarify the relationship between microalbuminuria and OSA risk using the STOP-BANG questionnaire in Korean adults. A total of 7478 participants (3289 men and 4189 women) aged over 40 were enrolled in the Korean National Health and Nutrition Examination Survey from 2019 to 2020. STOP-BANG questionnaire to screen OSA was obtained from subjects. The urinary albumin/creatinine ratio (ACR) and proteinuria were measured via a single dipstick to evaluate renal function. The high OSA risk group had a higher mean ACR value than the low OSA risk group (36.8 ± 172.2 vs 17.7 ± 82.5; P < 0.001). The proportion of subjects with values of 30 ≤ ACR < 300 mg/g (11.9% vs 6.1%; P < 0.001) and ACR > 300 mg/g (2.1% vs 0.7%; P < 0.001) was significantly higher in high OSA risk group. Multivariate logistic regression results confirmed that microalbuminuria (OR 1.279, 95% confidence interval (CI) 1.068-1.532, P = 0.008) was significantly correlated with high OSA risk. In addition, significant correlation with high OSA risk was also found in macroalbuminuria (OR 1.684, 95% CI 1.073-2.530, P = 0.022) and proteinuria (OR 1.355, 95% CI 1.030-1.783, P = 0.030). We confirmed a significant correlation between high OSA risk and albuminuria/proteinuria in Korean adults. Therefore, renal function evaluation is required in high OSA risk patients, and OSA diagnosis through PSG test and treatment is necessary.

Association of obstructive sleep apnea and diurnal variation of cystatin C

PURPOSE

Obstructive sleep apnea is a known risk factor for the progression of chronic kidney disease. To find early signs of the progression in subjects with obstructive sleep apnea., we assessed the diurnal variation of kidney biomarkers.

METHODS

A prospective observational study was conducted at Kangwon National University Hospital, Chuncheon, South Korea. All participants underwent in-laboratory polysomnography and phlebotomy in the evening before the polysomnography and in the morning after the polysomnography. Kidney biomarkers, including serum creatinine, blood urea nitrogen, and serum cystatin C, were measured. Delta kidney biomarkers were calculated by subtracting the evening level of the biomarkers from the morning level.

RESULTS

Twenty-six of 50 participants had severe obstructive sleep apnea. Delta cystatin C was significantly correlated with apnea-hypopnea index, oxygen desaturation index, and total arousal index with coefficients of -0.314, -0.323, and -0.289, respectively. In participants without severe obstructive sleep apnea, the morning cystatin C level (0.84 ± 0.11 mg/L) was significantly higher than the evening cystatin C level (0.81 ± 0.11 mg/L) (P = 0.005). With severe obstructive sleep apnea, the cystatin C levels were not different between the morning (0.85 ± 0.11 mg/L) and the evening (0.85 ± 0.10 mg/L).

CONCLUSIONS

Cystatin C level was increased in the morning in participants without severe obstructive sleep apnea, but not in participants with severe obstructive sleep apnea.

Anemia and Hypoxia Impact on Chronic Kidney Disease Onset and Progression: Review and Updates

Chronic kidney disease (CKD) is caused by hypoxia in the renal tissue, leading to inflammation and increased migration of pathogenic cells. Studies showed that leukocytes directly sense hypoxia and respond by initiating gene transcription, encoding the 2-integrin adhesion molecules. Moreover, other mechanisms participate in hypoxia, including anemia. CKD-associated anemia is common, which induces and worsens hypoxia, contributing to CKD progression. Anemia correction can slow CKD progression, but it should be cautiously approached. In this comprehensive review, the underlying pathophysiology mechanisms and the impact of renal tissue hypoxia and anemia in CKD onset and progression will be reviewed and discussed in detail. Searching for the latest updates in PubMed Central, Medline, PubMed database, Google Scholar, and Google search engines were conducted for original studies, including cross-sectional studies, cohort studies, clinical trials, and review articles using different keywords, phrases, and texts such as "CKD progression, anemia in CKD, CKD, anemia effect on CKD progression, anemia effect on CKD progression, and hypoxia and CKD progression". Kidney tissue hypoxia and anemia have an impact on CKD onset and progression. Hypoxia causes nephron cell death, enhancing fibrosis by increasing interstitium protein deposition, inflammatory cell activation, and apoptosis. Severe anemia correction improves life quality and may delay CKD progression. Detection and avoidance of the risk factors of hypoxia prevent recurrent acute kidney injury (AKI) and reduce the CKD rate. A better understanding of kidney hypoxia would prevent AKI and CKD and lead to new therapeutic strategies.

The relationship between obstructive sleep apnea and risk of renal impairment in patients with hypertension, a longitudinal study

OBJECTIVE

Association of obstructive sleep apnea (OSA) with renal damage is undetermined, especially in the population with hypertension, a high-risk group for chronic kidney disease. Therefore, we aimed to explore whether OSA is an independent risk factor for renal impairment in patients with hypertension, by considering the effects of gender, age, obesity and OSA severity.

METHODS

The longitudinal observational study included patients with hypertension and suspected OSA without renal damage at baseline who visited Hypertension Center between January 2011 and December 2018, and followed up till renal outcomes, death, loss to follow-up, or May 31, 2022, using annual health check-ups, hospital readmission or out-patient visits. Main renal outcome was chronic kidney disease (CKD), defined as estimated glomerular filtration rate <60 ml/min per 1.73 m2 and/or positive proteinuria. Cox proportional hazard models were used to evaluate the association, and repeated after propensity score matching. Sensitivity analysis were performed by excluding those with primary aldosteronism.

RESULTS

7961 patients with hypertension were included with 5022 ones with OSA, and 82% were followed up. During median follow-up of 3.42 years, 1486 patients developed CKD. Per 1000 person-year incidence of CKD was 56.72 in OSA group. In Cox regression analysis, OSA and severe OSA group respectively showed 1.21 (95% CI: 1.08-1.35) and 1.27 (95% CI: 1.09-1.47) fold risk for CKD in total, compared with non-OSA group. Overall results remained consistent in propensity score matching and sensitivity analysis.

CONCLUSION

OSA is independently associated with higher risk of chronic kidney disease in hypertension.

Renin-angiotensin system activation: may it increase frequency of obstructive sleep apnea in patients with autosomal dominant polycystic kidney disease?

PURPOSE

Renin-angiotensin system (RAS) hyperactivity is a common entity in both autosomal dominant polycystic kidney disease (ADPKD) and obstructive sleep apnea (OSA). We aimed to investigate the frequency of OSA in adults with ADPKD either with stages 3-4 or stages 1-2 chronic kidney disease (CKD) and evaluate the effect of RAS blockade on OSA in these patients.

METHODS

This is a comparative, prospective, two-center clinical study. Eligible patients with ADPKD were enrolled in a polysomnography (PSG) study. Presence of OSA in patients with ADPKD was compared with individuals who underwent polisomnography study due to OSA symptoms. A subgroup analysis was performed in terms of the presence of OSA in ADPKD with eGFR values lower or higher than 60 ml/min/1.73 m2 (stages 3-4 and stages 1-2 CKD, respectively).

RESULTS

Frequency of OSA (65%) was higher than in the general population and similar between the two groups (p = 0.367). Patients with ADPKD and eGFR ≥ 60 ml/min/1.73 m2 presented a similar frequency of OSA to the control group (p = 0.759). However, OSA was significantly more frequent in ADPKD with eGFR < 60 ml/min/1.73 m2 (p = 0.018). Subgroup analysis revealed that presence of OSA also was significantly higher in ADPKD with lower eGFR levels (eGFR < 60 ml/min/1.73 m2 and eGFR > 60 ml/min/1.73 m2) 14/17 (82%) and 12/23 (52%), respectively (p: 0.048).

CONCLUSION

As kidney disease progresses, uremia and related factors of renal failure rather than RAS activation seem to play a more important role for the development of OSA in patients with ADPKD.

Obstructive sleep apnea and ambulatory blood pressure abnormalities in children with chronic kidney disease

BACKGROUND

Obstructive sleep apnea (OSA) and hypertension are common complications in children with chronic kidney disease (CKD). Progression of CKD can aggravate OSA and hypertension whereas worsening sleep apnea can make hypertension difficult to treat in CKD patients. We, therefore, conducted a prospective study to evaluate the association between OSA and hypertension in pediatric patients with CKD.

METHOD

In this prospective observational study consecutive children with CKD stage 3-5 (nondialysis dependent) underwent overnight polysomnography and 24-h ambulatory blood pressure monitoring (ABPM). The detailed clinical features and investigations were recorded in a prestructured performa.

RESULTS

Twenty-two children completed overnight polysomnography and 24-h ABPM was performed within 48 h of performing polysomnography. The median (IQR) age of the study population was 11 (8.5-15.5) years, with an age range of 5-18 years. Moderate-severe OSA defined as apnea-hypopnea index (AHI ≥5) was seen in 14 (63.6%) children, periodic limb movement syndrome in 20 (91%) and poor sleep efficacy in 9 (40.9%) children. Ambulatory blood pressure was abnormal in 15 (68.2%) children with CKD. Of them, 4 (18.2%) had ambulatory hypertension, 9 (40.9%) had severe ambulatory hypertension and 2 (9.1%) had masked hypertension. A statistically significant correlation of sleep efficiency with nighttime DBP SD score/Z score (SDS/Z) (r = -0.47; P = 0.02); estimated glomerular filtration rate with SBP loads (r = -0.61; P < 0.012); DBP loads (r = -0.63; P < ) and BMI with SBP load (r = 0.46; P = 0.012) was found.

CONCLUSION

Our preliminary findings suggest that ambulatory blood pressure abnormalities, OSA, periodic limb movement syndrome and poor sleep efficiency are highly prevalent in children with CKD stages 3-5.

History of Sleep Disorders in Chronic Kidney Disease: First Approach

OBJECTIVES

In this study, we examined the history of sleep disorders in chronic kidney disease, 60 years after the advent of hemodialysis and renal transplant of genetically nonrelated organs, which have spurred a critical mass of data.

MATERIALS AND METHODS

We analyzed selected literature on sleep disorders in chronic kidney disease from 1959 onward.

RESULTS

Sleep disturbances are present in the general population. They cause loss of renal function and progressive nephron loss. Insomnia, sleep apnea, restless leg syndrome, and periodic limb movements represent sleep disturbances in chronic kidney disease. These symptoms manifest early in chronic kidney disease and are a rule in patients on dialysis and kidney transplant recipients. Sleep disturbances cause fatigue, excessive daily sleepiness, impaired daytime function, impaired health-related quality of life, increased morbidity, and increased mortality.

CONCLUSIONS

Sleep disorders affect most patients with chronic kidney disease. No ascertained pharmacological therapy exists, and even a successful transplant does not totally restore a refreshing sleep. Longer nocturnal hemodialysis is of benefit. Sleep apnea may be cured with continuous positive airway pressure.

Continuous positive airway pressure treatment reduces renal tubular damage in patients with obstructive sleep apnea: A retrospective single-center cohort study

BACKGROUND

Chronic intermittent hypoxia (IH) plays a significant role in the pathogenesis of obstructive sleep apnea (OSA) comorbidities. The prevalence of chronic kidney disease is higher in patients with OSA than the general population, and renal function decline is well correlated with renal tubular injury. However, little is known about the impact of OSA-induced chronic IH on the renal tubules.

METHODS

We conducted a retrospective survey of clinical records performing multiple regression analysis and cluster analysis with particular attention to the 3% oxygen desaturation index (ODI) and urinary N-acetyl-β-d-glucosaminidase (NAG).

RESULTS

In patients with suspicion of OSA, urinary NAG creatinine ratio (UNCR) was elevated as their 3% ODI increased (n = 197, p < 0.001), and the elevated UNCR decreased following CPAP treatment in patients with OSA (n = 46, p = 0.014). Multiple regression analysis showed that 3% ODI was associated with UNCR. Cluster analysis identified three clusters of patients with OSA, including two younger age clusters, one of which was characterized by high BMI, high 3% ODI, and high prevalence of major comorbidities. In a comparative analysis of younger age cases (age ≤ 55, n = 82), the UNCR level was higher in patients with severe 3% ODI (3% ODI > 40 events/h, n = 24) (p = 0.014).

CONCLUSIONS

Our results indicate that even at younger ages, OSA patients with severe chronic IH and major comorbidities are susceptible to renal tubular damage. Early treatment with CPAP may attenuate renal tubular injury and progression toward end-stage renal disease.

[Cerebral microangiopathy in men with obstructive sleep apnea syndrome]

OBJECTIVE

To determine factors associated with the development of small vessel disease (SVD) in patients with obstructive sleep apnea syndrome (OSA).

MATERIAL AND METHODS

One hundred and fifty-two patients with risk factors for the development of cerebrovascular diseases were examined. Based on the results of polysomnography, patients were divided into groups with- (n=84) and without (n=68) OSA. The groups were matched by age, prevalence of arterial hypertension and diabetes mellitus. SVD was diagnosed using brain MRI. Laboratory tests included an assessment of parameters of lipid metabolism, glucose metabolism, concentration of C-reactive protein (CRP), levels of homocysteine and creatinine with the calculation of glomerular filtration rate (GFR).

RESULTS

Patients with OSA, compared with those without OSA, were characterized by a statistically significant number of gliosis foci, with their large sizes, more frequent changes on the Fazekas scales and the Hassan scale. The most severe degree of damage according to the Hassan scale in patients with OSA was detected more often (55 (66%) and 27 (39%) OR=2.89, 95% CI 1.47-5.67, p=0.002). More pronounced atrophic changes in the brain, an increase in the size of the III ventricle and the index of the anterior horns, significantly lower GFR and higher levels of CRP were noted in the OSA group. Patients with OSA and duration of nocturnal hypoxia for more than 2 minutes were more likely to have hyperintensity of subcortical regions. In patients with OSAS, pronounced manifestations of SMD were associated with a significantly higher level of morning systolic blood pressure (MAP): 140 [120; 150] vs. 127 [120; 130] p=0.029; increased levels of blood homocysteine: 14 [11; 17.8] vs. 13 [9.7; 12.5] p=0.049; a decrease in GFR: 79 [71; 87.3] vs. 89.8 [80.3; 94] p=0.002, respectively.

CONCLUSION

OSA and intermittent nocturnal hypoxia are independent risk factors for SMD. A more severe micro-focal vascular lesion in OSA is associated with a decrease in renal filtration function, an increase in morning blood pressure and an elevation in homocysteine level.

Role of precision medicine in obstructive sleep apnoea

Obstructive sleep apnoea is a substantial clinical and public health problem because it contributes to harmful effects on quality of life, daytime symptoms, road traffic incidents, and cardiometabolic disease. Increasingly, obstructive sleep apnoea is recognised as a heterogeneous disease, and patients have varied susceptibility to long term complications and different responses to treatment. This narrative review summarises the current knowledge of precision medicine in obstructive sleep apnoea, particularly the role of symptom clusters, polysomnogram phenotypes, physiological endotypes, and circulating biomarkers in defining subtypes. In the near future, the prognostic accuracy of these measures in predicting long term complications in obstructive sleep apnoea will likely be improved, together with better matching of treatments to disease subtypes.

CircRNA expression profiles and functional analysis in a mouse model of chronic intermittent hypoxia-induced renal injury: new insight into pathogenesis

Increasing evidence has demonstrated that circular RNAs (circRNAs) play crucial roles in the pathogenesis of multiple diseases. However, the functions of circRNAs in renal injury induced by obstructive sleep apnea (OSA) are poorly understood. The aim of this current study is to identify the global changes of circRNAs expression in OSA-induced renal damage. The mouse model of OSA treated by chronic intermittent hypoxia (CIH) was established. We assessed the expression profiles of circRNAs in CIH caused renal injury by microarray analysis. Bioinformatic analyses were further performed by us to assess those differentially expressed circRNAs. Quantitative realtime PCR (qRT-PCR) were then conducted to assure the data of microarray. Finally, a circRNA-miRNA -mRNA competing endogenous RNA (ceRNA) regulatory network was constructed. We found 11 upregulated and 13 downregulated circRNAs in CIH-induced renal injury. The qRT-PCR validated that the six selected circRNAs were identical to the results of microarray. Both Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were further employed to annotate the potential functions of dysregulated circRNAs. Finally, we established a ceRNA network to predict the target genes of circRNAs. In general, our results first illustrate that circRNAs are aberrantly expressed in OSA-induced renal injury, which might aid in offering novel genetic insights into this disease and potential therapeutic targets for OSA-associated chronic kidney disease.

Prevalence of sleep disorders in children with chronic kidney disease: a meta-analysis

BACKGROUND

The reported prevalence of sleep disorders in children with chronic kidney disease (CKD) varies greatly. A quantitative meta-analysis to estimate the prevalence of sleep disorders among pediatric CKD patients may provide further information.

OBJECTIVES

The objective of this study is to estimate the prevalence of sleep disorders in children with CKD. The study protocol was registered on PROSPERO (registration number CRD42021268378).

DATA SOURCES

Two authors independently searched the PubMed, MEDLINE, EMBASE, and Cochrane review databases up to June 2021.

STUDY ELIGIBILITY CRITERIA

Eligible studies include data of prevalence of sleep disorders in children with CKD.

STUDY APPRAISAL AND SYNTHESIS METHODS

The prevalence of restless legs syndrome, sleep-disordered breathing, pediatric obstructive sleep apnea (i.e., apnea-hypopnea index &gt; 1 event/h in polysomnography), excessive daytime sleepiness, and insomnia/insufficient sleep was estimated using a random-effects model. Subgroup analyses were conducted to compare the prevalence of sleep disorders between children on dialysis and not on dialysis. This meta-analysis included 12 studies with 595 children (mean age: 12.9 years; gender ratio: 55.6% boys; mean sample size: 49.6 patients).

RESULTS

The prevalence of restless legs syndrome in children with CKD was 21% (95% confidence interval [CI], 14-30%). The prevalence of sleep-disordered breathing, pediatric obstructive sleep apnea, excessive daytime sleepiness, and insomnia/insufficient sleep was 22% (95% CI, 12-36%), 34% (95% CI, 19-53%), 27% (95% CI, 17-41%), and 14% (95% CI, 7-27%), respectively. Subgroup analysis revealed the pooled prevalence of excessive daytime sleepiness was significantly higher in children on dialysis than in children not on dialysis (43.3% vs. 11.2%; P = 0.018). Children on dialysis also had a high prevalence of other sleeping disorders, although the differences did not reach statistical significance. Children with CKD exhibited a 3.9-fold (95% CI, 1.37 to 10.93) increased risk of restless legs syndrome and a 9.6-fold (95% CI, 3.57 to 25.76) increased risk of excessive daytime sleepiness compared with controls.

LIMITATIONS

The selected papers are of small sample size, lack of a control group, and exhibit substantial heterogeneity.

CONCLUSIONS

Sleep disorders are common in children with CKD. Our results indicate that while the prevalence rates of various sleep disorders were higher in children on dialysis than in children not on dialysis, the prevalence of excessive daytime sleepiness was statistically significant in children on dialysis. A higher resolution version of the Graphical abstract is available as Supplementary information.

Heart Failure with Preserved Ejection Fraction and Obstructive Sleep Apnea: A Novel Paradigm for Additional Cardiovascular Benefit of SGLT2 Inhibitors in Subjects With or Without Type 2 Diabetes

After examining the complex interplay between heart failure (HF) in its various clinical forms, metabolic disorders like nonalcoholic fatty liver disease (NAFLD), and obstructive sleep apnea (OSA) syndrome, in this mini-review we described possible favorable effects of sodium-glucose cotransporter 2 inhibitors (SGLT2is) on HF with preserved (i.e., ≥ 50%) ejection fraction (HFpEF) through enhanced cardiorenal function and visceral-subcutaneous body fat redistribution. In greater detail, on the basis of pathophysiological mechanisms underlying OSA onset and the direct positive SGLT2i effect on renal function benefiting chronic kidney disease, we emphasized the promising role of SGLT2is in prevention, rehabilitation, and treatment of patients with OSA regardless of coexisting type 2 diabetes (T2DM). Indeed, SGLT2is enhance lipolysis and fatty acid beta-oxidation. These phenomena might prevent OSA by reducing the size of visceral and subcutaneous adipose tissue and, as proven in humans and animals with T2DM, counteract NAFLD onset and progression. The aforementioned mechanisms may represent an additional SGLT2i cardioprotective effect in terms of HFpEF prevention in patients with OSA, whose NAFLD prevalence is estimated to be over 50%.

National strategy on the integration of sleep and circadian rhythms into public health research and policies: Report from the Canadian Sleep and Circadian Network

Scientists in sleep and circadian rhythms, public health experts, healthcare providers, partners, and stakeholders convened in 2020 for a 2-day meeting organized by the Canadian Sleep and Circadian Network to develop a national strategy for the integration of sleep and circadian rhythms into public health and policies in Canada. The objective of this paper is to present the national strategy that emerged from this meeting of 60 participants from across Canada. The meeting focused on 4 key target priorities: (1) atypical working schedules, (2) sleep and circadian rhythms of children and adolescents, (3) insomnia, and (4) impact of sleep apnea on health. Following constructive discussions over 2 days, it was decided that the following 4 strategic objectives should be prioritized to accelerate the integration of sleep and circadian rhythms into public health policies in Canada: (1) Increase public health sleep and circadian rhythm research, (2) Increase public health education and knowledge mobilization on sleep, (3) Inform and support public health sleep interventions and policies, and (4) Promote sleep health training. The participants recommended that research and public health efforts should address the needs along the continuum of sleep health. The committee noted that strategies and interventions could differ across contexts, settings, sectors, and jurisdictions. The national strategy also identified high-priority research questions in public health and recommended mechanisms to build research capacity, providing a path forward for the integration of sleep and circadian rhythms into public health research and policies.

Sleep dysregulation in sympathetic-mediated diseases: implications for disease progression

The autonomic nervous system (ANS) plays an important role in the coordination of several physiological functions including sleep/wake process. Significant changes in ANS activity occur during wake-to-sleep transition maintaining the adequate cardiorespiratory regulation and brain activity. Since sleep is a complex homeostatic function, partly regulated by the ANS, it is not surprising that sleep disruption trigger and/or evidence symptoms of ANS impairment. Indeed, several studies suggest a bidirectional relationship between impaired ANS function (i.e. enhanced sympathetic drive), and the emergence/development of sleep disorders. Furthermore, several epidemiological studies described a strong association between sympathetic-mediated diseases and the development and maintenance of sleep disorders resulting in a vicious cycle with adverse outcomes and increased mortality risk. However, which and how the sleep/wake control and ANS circuitry becomes affected during the progression of ANS-related diseases remains poorly understood. Thus, understanding the physiological mechanisms underpinning sleep/wake-dependent sympathetic modulation could provide insights into diseases involving autonomic dysfunction. The purpose of this review is to explore potential neural mechanisms involved in both the onset/maintenance of sympathetic-mediated diseases (Rett syndrome, congenital central hypoventilation syndrome, obstructive sleep apnoea, type 2 diabetes, obesity, heart failure, hypertension, and neurodegenerative diseases) and their plausible contribution to the generation of sleep disorders in order to review evidence that may serve to establish a causal link between sleep disorders and heightened sympathetic activity.

Bidirectional relationships of comorbidity with obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is frequently associated with comorbidities that include metabolic, cardiovascular, renal, pulmonary and neuropsychiatric. There is considerable evidence that OSA is an independent risk factor for many of these comorbidities but, more recently, there is evidence that some of these comorbidities may predispose to the development of OSA. Thus, there is growing evidence of a bidirectional relationship between OSA and comorbidity, especially for heart failure, metabolic syndrome and stroke. Potential mechanisms of bidirectional relationships differ in individual comorbidities with fluid retention and redistribution being especially important in heart failure and end-stage renal disease, whereas neural mechanisms may be more important in diabetes mellitus and stroke. The evidence for other comorbidities, such as hypertension and atrial fibrillation, support these being more a consequence of OSA with limited evidence to support a bidirectional relationship. The present review explores the evidence for such bidirectional relationships with a particular perspective on comorbidities that may predispose to OSA. The impact of therapy in bidirectional relationships is also reviewed, which highlights the clinical importance of accurate diagnosis. This aspect is especially true of COPD, where the identification of co-existing OSA has important implications for optimum therapy.

Obstructive sleep apnoea (OSA) is an independent risk factor for comorbidity, especially cardiometabolic. However, some comorbidities may be risk factors for OSA, supporting a bidirectional relationship that may have important implications for treatment.https://bit.ly/3BbJy6V

Correlation of Dyslipidemia and Inflammation With Obstructive Sleep Apnea Severity

Introduction: Obstructive sleep apnea (OSA) is a serious condition linked with various metabolic disorders and associated with increased all-cause and cardiovascular mortality. Although the potential mechanisms of pathophysiological processes related to OSA are relatively well known, the data regarding the correlation between obstructive sleep apnea, dyslipidemia, and systemic inflammation are still inconclusive.

Methods: The study was conducted as a retrospective cohort study including 328 patients with newly diagnosed obstructive sleep apnea during the period between April 2018, and May 2020, in University Clinical Hospital Center “Bezanijska kosa”, Belgrade, Serbia. Polysomnography was performed in all patients according to the protocol. Numerous demographic, antropometric, laboratory, and clinical data were correlated to Apnea-Hypopnea Index (AHI) as a dependent variable, with a particular review on the relation between lipid abnormalities, inflammatory parameters, and obstructive sleep apnea severity. Multivariate logistic regression model was used to assess predictors of severe OSA (AHI ≥30 per hour).

Results: A total of 328 patients were included in the study. The mean age of the patients was 54.0 ± 12.5 years and more than two-thirds were male (68.8%). The majority of the patients had an AHI of at least 30 events per hour. Patients with severe OSA were more frequently male, obese, hypertensive and hyperlipidemic, and had increased neck circumference (both male and female patients). One hundred and thirty-two patients had metabolic syndrome. Patients with severe OSA more frequently had metabolic syndrome and significantly higher levels of glucose, creatinine, uric acid, AST, ALT, CK, microalbumine/creatinine ratio, triglyceride, total cholesterol, HDL, total cholеsterol to HDL‐C ratio, CRP, and ESR. In the multivariate linear regression model with AHI (≥30 per hour) as a dependent variable, of demographic and clinical data, triglycerides ≥1.7 mmol/L and CRP >5 mg/L were significantly associated with AHI≥30 per hour.

Conclusion: The present study on 328 patients with newly diagnosed obstructive sleep apnea revealed significant relation of lipid abnormalities, inflammatory markers, and other clinically important data with obstructive sleep apnea severity. These results can lead to a better understanding of the underlying pathophysiological processes and open the door to a new world of potentially useful therapeutic modalities.

Obstructive sleep apnea: transition from pathophysiology to an integrative disease model

Obstructive sleep apnea (OSA) is characterised by recurring episodes of upper airway obstruction during sleep and the fundamental abnormality reflects the inability of the upper airway dilating muscles to withstand the negative forces generated within the upper airway during inspiration. Factors that result in narrowing of the oropharynx such as abnormal craniofacial anatomy, soft tissue accumulation in the neck, and rostral fluid shift in the recumbent position increase the collapsing forces within the airway. The counteracting forces of upper airway dilating muscles, especially the genioglossus, are negatively influenced by sleep onset, inadequacy of the genioglossus responsiveness, ventilatory instability, especially post arousal, and loop gain. OSA is frequently associated with comorbidities that include metabolic, cardiovascular, renal, pulmonary, and neuropsychiatric, and there is growing evidence of bidirectional relationships between OSA and comorbidity, especially for heart failure, metabolic syndrome, and stroke. A detailed understanding of the complex pathophysiology of OSA encourages the development of therapies targeted at pathophysiological endotypes and facilitates a move towards precision medicine as a potential alternative to continuous positive airway pressure therapy in selected patients.

Sleep pattern in a group of patients undergoing hemodialysis compared to control

Background

Patients with chronic kidney disease progress regularly every year to end-stage renal disease and have to undergo dialysis. Sleep disturbances have been reported to be frequent among patients receiving dialysis and contributing to the increase of their mortality and morbidity. The present research aimed to study the sleep pattern in hemodialysis patients and the risk factors associated. This cross-sectional case-control study included 40 subjects divided into 2 groups: 20 cases recruited from Ain Shams University Hospital’s dialysis unit and 20 in the control group with normal Pittsburgh Sleep Quality Index score matched for age and sex. Both groups were subjected to overnight polysomnography, and the cases group was assessed by the Pittsburgh Sleep Quality Index to determine their sleep quality.

Results

Nearly all polysomnographic parameters were significantly abnormal in the cases group except for sleep onset latency (P > 0.05), showing obstructive sleep apnea and periodic limb movement (P value 0.001). Based on their Pittsburgh Sleep Quality Index score, 30% were classified as good sleepers and 70% as bad sleepers. On comparing both groups, a significant difference was found. Poor sleepers had more worse sleep efficiency (62.9%), spent longer time during their sleep in stage 1 (26.6%) with shorter REM onset latency (113.5 ± 99.5), and had a longer duration of illness with lower serum creatinine level compared to good sleepers.

Conclusions

The prevalence of obstructive sleep apnea and periodic limb movement in hemodialysis patients is high; patients with longer time on dialysis are at more risk of sleep disorders, whereas hemoglobin levels, BUN, and other demographic factors do not seem to play a role in sleep disorder. Hence, patients on hemodialysis need to be screened for sleep disorders so as to improve their mortality and morbidity.

Irisin Is Correlated with Blood Pressure in Obstructive Sleep Apnea Patients

BACKGROUND

Despite approximately 95% primary cases of hypertension, secondary hypertension seems to be common with resistant forms. Notably, obstructive sleep apnea (OSA) is known as a common cause of secondary hypertension and has a major characteristic of obesity. Irisin acts as a link between muscles and adipose tissues in obesity, playing an essential role in human blood pressure (BP) regulation. However, whether irisin is associated with secondary hypertension caused by OSA and how it takes effect essentially have not been elucidated.

PURPOSE

To investigate the changes of irisin and its relationship with BP in OSA.

METHODS

72 snoring patients finished Epworth Sleep Scale (ESS) evaluation before polysomnography (PSG). BP was the average of three brachial BP values by mercury sphygmomanometer. Serum irisin level was determined by enzyme-linked immunosorbent assay (ELISA). Results were analyzed by SPSS software.

RESULTS

Irisin was higher in the severe and quite severe group than that in control and nonsevere groups (p < 0.05). For BP, significant differences were found between the control group and the other three groups (p < 0.05) and between the quite severe and the other three groups (p ≤ 0.001). Positive correlations were found between irisin and apnea-hypopnea index (AHI), AHI and BP, and irisin level and BP. Negative correlations were between irisin and SpO2 nadir and SpO2 nadir and BP. Positive correlation still existed between AHI and irisin even after adjusting for some obesity-related variables.

CONCLUSIONS

Irisin may serve as a potential biomarker for severity of OSA independently of obesity and imply the development of hypertension.

Risk of chronic kidney disease in patients with obstructive sleep apnea

STUDY OBJECTIVES

Chronic kidney disease (CKD) is a global health concern and a major risk factor for cardiovascular morbidity and mortality. Obstructive sleep apnea (OSA) may exacerbate this risk by contributing to the development of CKD. This study investigated the prevalence and patient awareness of the risk of CKD progression in individuals with OSA.

METHODS

Adults referred to five Canadian academic sleep centers for suspected OSA completed a questionnaire, a home sleep apnea test or in-lab polysomnography and provided blood and urine samples for measurement of estimated glomerular filtration rate (eGFR) and the albumin:creatinine ratio (ACR), respectively. The risk of CKD progression was estimated from a heat map incorporating both eGFR and ACR.

RESULTS

1295 adults (42% female, 54±13y) were categorized based on the oxygen desaturation index (4% desaturation): <15 (no/mild OSA, n=552), 15-30 (moderate OSA, n=322), and >30 (severe OSA, n=421). After stratification, 13.6% of the no/mild OSA group, 28.9% of the moderate OSA group, and 30.9% of the severe OSA group had a moderate-to-very high risk of CKD progression (p<0.001), which was defined as an eGFR < 60 mL/min/1.73m2, an ACR ≥3 mg/mmol, or both. Compared to those with no/mild OSA, the odds ratio for moderate-to-very high risk of CKD progression was 2.63 (95% CI: 1.79-3.85) for moderate OSA and 2.96 (2.04-4.30) for severe OSA after adjustment for CKD risk factors. Among patients at increased risk of CKD progression, 73% were unaware they had abnormal kidney function.

CONCLUSION

Patients with moderate and severe OSA have an increased risk of CKD progression independent of other CKD risk factors; most patients are unaware of this increased risk.

Fatigue in CKD: Epidemiology, Pathophysiology, and Treatment

Fatigue is a commonly reported and debilitating symptom among patients with CKD, yet little is known about its epidemiology, pathogenesis, and treatment. Various measurement tools have been used in published studies to identify and quantify fatigue. These include several single-item measures embedded in longer questionnaires for assessing depression, quality of life, or symptom burden in patients with kidney disease. Approximately 70% of patients with CKD report fatigue, with up to 25% reporting severe symptoms. Patient-reported fatigue is associated with death, dialysis initiation, and hospitalization among individuals with CKD. The pathophysiology is multifactorial and likely includes decreased oxygen delivery and increased reliance on anaerobic metabolism, thus generating lactic acidosis in response to exertion; the effects of chronic metabolic acidosis and hyperphosphatemia on skeletal muscle myocytes; protein-energy wasting and sarcopenia; and depression. Physical activity has been shown to improve fatigue in some small but promising trials, and so should be recommended, given the additional benefits of exercise. Targeting higher hemoglobin levels with erythropoiesis-stimulating agents may improve fatigue, but potential adverse cardiovascular effects preclude their use to solely treat fatigue without the presence of another indication. Current guidelines recommend cautious individualization of hemoglobin targets for those at low cardiovascular risk who still experience fatigue or functional limitation despite a hemoglobin level of 10 g/dl. Sodium bicarbonate supplementation for the treatment of metabolic acidosis may also improve functional status. Selective serotonin reuptake inhibitors have not been consistently shown to improve fatigue in patients with kidney disease, but an ongoing trial will evaluate the effect of alternative antidepressant drug and behavioral activation therapy on fatigue in patients with CKD. Overall, more research is needed to further clarify underlying mechanisms of fatigue and identify effective, targeted treatments for patients with CKD.

Possible Preventative/Rehabilitative Role of Gliflozins in OSA and T2DM. A Systematic Literature Review-Based Hypothesis

Obstructive sleep apnoea (OSA) is characterized by frequent apnoea episodes during sleep due to upper airway obstruction. The present review summarizes current knowledge on inter-relationships between OSA and type 2 diabetes mellitus (T2DM) and suggests the former as a possible target for sodium-glucose co-transporter-2 inhibitors (SGLT-2i). Based on pathophysiological mechanisms underlying OSA onset and renal SGLT-2 effects, we suggest that SGLT-2i indications might expand beyond current ones, including glucose, lipids, uric acid, blood pressure, and body weight control as well as chronic heart failure and kidney disease prevention.

Sleep apnea is associated with residual kidney function and mortality in patients with peritoneal dialysis: Prospective cohort study

INTRODUCTION

Fluid overload and sleep apnea (SA) are known risk factors for mortality in dialysis patients. Although incidence and severity of SA were shown higher in peritoneal dialysis (PD) patients than in hemodialysis patients, data regarding the association of SA with body fluid status and mortality are limited. Therefore, the association of SA with body fluid status and mortality were investigated in a prospective cohort with patients undergoing PD.

METHODS

The present study included 103 prevalent PD patients who were followed up for median 70 months. At baseline, the subjects underwent in-home polysomnography, bioelectrical impedance analysis, and urea kinetics. Excessive daytime sleepiness and sleep quality were assessed using sleep questionnaires. SA was defined as apnea/hypopnea index higher than 15 events per hour.

RESULTS

Sleep apnea was diagnosed in 57 (55.3%) patients (SA group); the subjects had significantly higher extracellular water (10.3 ± 1.4 vs. 9.2 ± 1.8, p = 0.001) and lower residual kidney function (RKF) (3.3 ± 3.3 vs. 5.9 ± 7.2, p = 0.02) compared with subjects in the non-SA group. SA was significantly associated with RKF [odds ratio, 0.84; 95% confidence interval (CI), 0.73-0.97] in multivariable logistic regression analysis. In multivariable Cox regression models, SA was a significant predictor of mortality in PD patients (adjusted hazard ratio, 5.74; 95% CI, 1.09-30.31) after adjusting for well-known risk factors.

CONCLUSIONS

Sleep apnea was very common in PD patients and significantly associated with lower RKF. SA was also a novel risk predictor of mortality in PD patients.

Comparison of Jaw Elevation Device vs. Conventional Airway Assist during Sedation in Chronic Kidney Diseases Undergoing Arteriovenous Fistula Surgery: A Randomized Controlled Trial

Patients with chronic renal failure (CRF) are likely to have obstructive sleep apnea (OSA) underdiagnosed, and maintaining airway patency is important during sedation. This study compared Jaw elevation device (JED) with conventional airway interventions (head lateral rotation, neck extension, oral or nasal airway insertion, and jaw thrust maneuver) during sedation and hypothesized that JED may be effective to open the airway. A total of 73 patients were allocated to a conventional group (n = 39) and a JED group (n = 34). The number of additional airway interventions was the primary outcome. Percentage of patients with no need of additional interventions and apnea-hypopnea index (AHI) were secondary outcomes. The number of additional interventions was significantly less in the JED group compared to the conventional group (0 (0–0) vs. 1 (0–2); p = 0.002). The percentage of patients with no requirement for additional interventions was significantly higher in the JED group compared to the conventional group (76.5% vs. 43.6%; p = 0.004). AHI was significantly lower in the JED group compared to the conventional group (4.5 (1.5–11.9) vs. 9.3 (3.8–21.9), p = 0.015). In conclusion, JED seems to be effective in opening the airway patency during sedation in CRF patients.

Vascular and renal telomere shortening in mice exposed to chronic intermittent hypoxia

Obstructive sleep apnea (OSA) is a chronic condition characterized by chronic intermittent hypoxia (IH) and is associated with cardiovascular (CVD) and chronic kidney diseases (CKD). Patients with OSA have increased biomarkers of aging such as telomere shortening. We used PCR to report shortened telomere lengths in aortic and renal tissues from mice exposed to 8 weeks of IH. Our data indicate that IH, a hallmark of OSA, accelerates vascular and renal aging that may contribute to OSA-induced CVD and CKD.

Prevalence and Risk Factors of Obstructive Sleep Apnea in Hypertensive Emergency

INTRODUCTION

Obstructive sleep apnea (OSA) is a common factor associated with hypertensive crises. There is limited evidence of prevalence and risk factors of OSA in hypertensive emergency.

METHODS

This study recruited adult patients who diagnosed as hypertensive emergency and tested for OSA. The study period was between July 2019 and January 2020. The patients were categorized as OSA and non-OSA groups by the evidence from polysomnography. Prevalence and risk factors for OSA were executed.

RESULTS

During the study, there were 52 eligible patients. Of those, 30 patients (57.69%) were diagnosed with OSA. The stepwise logistic regression analysis for predicting OSA had two remaining factors: body mass index and diastolic blood pressure. Only body mass index was independently associated with OSA with an adjusted odds ratio of 1.166 (95% confidence interval of 1.033, 1.316). The body mass index of 25.02 kg/m2 gave sensitivity and specificity of 80.00% and 59.09%, respectively. The area under the receiver operating characteristic curve was 70.98%.

CONCLUSION

OSA had high incidence rate in patients with hypertensive emergency. High body mass index was a predictor for OSA associated with hypertensive emergency.

Effect of laparoscopic sleeve gastrectomy on vasoactive mediators in obese hypertensive patients: A prospective study

INTRODUCTION

The causal relationship between obesity and high blood pressure is established; however, the detailed pathways for such association are still under research. This work aims to assess the changes in neprilysin, vasoconstrictor and vasodilatory molecules in obese hypertensive patients undergoing laparoscopic sleeve gastrectomy (LSG).

PATIENTS

The present prospective study was done on 59 hypertensive obese patients in whom LGS was performed. Blood pressure, as well as blood samples for neprilysin, angiotensinogen, angiotensin II, renin, endothelin-1 "ET-1", aldosterone, atrial natriuretic peptide "ANP" and B-type natriuretic peptide "BNP", were assessed before and 15 months after surgery. Patients were divided into two groups according to the remission of hypertension (HTN).

RESULTS

After 15 months, remission of hypertension was seen in 42 patients (71%). The declines in the following measurements were significantly higher in patients with remission than those with persistent HTN: aldosterone (p = .029567), angiotensin II (p < .000001), angiotensinogen (p = .000021), neprilysin (p = .000601), renin (p = .000454) and endothelin-1(p = .000030). There was a significantly higher increment in ANP (p = .000002) and a non-significant increment in BNP (p = .081740). Angiotensin II 15 months after LSG and Δ ANP % were significant independent predictors of persistent HTN.

CONCLUSION

In the setting of LSG, aldosterone, angiotensinogen, angiotensin II, renin and neprilysin were significantly lower in patients with remission of HTN after 15 months than those with persistent HTN, and natriuretic peptides were significantly higher. A lower postoperative level of angiotensin II and a larger percentage increment of ANP are independently associated with hypertension remission after LSG.

Decreased glomerular filtration rate and increased albuminuria for identification of cardiovascular autonomic neuropathy in subjects with and without diabetes

OBJECTIVE

The purpose of this study was to determine the relationship between chronic kidney disease (CKD) and cardiovascular autonomic neuropathy (CAN).

RESEARCH DESIGN AND METHODS

From October 2008 to May 2011, we enrolled 218 patients with diabetes and 62 nondiabetic subjects. Heart rate variability was represented as the maximal heart rate minus the minimal heart rate (HR_max-min) during a one-minute deep breathing test. Normal, impaired cardiovascular autonomic function and CAN were defined as s HR_max-min > 15 beats/min, HR_max-min of 10-15 beats/min and HR_max-min < 10 beats/min, respectively. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) was <60/min/1.73 m² or albuminuria.

RESULTS

In our sample, 19.4% of nondiabetic subjects and 49.5% of diabetic subjects had CKD. The prevalence of CAN was higher among patients with diabetes than among nondiabetic subjects (26.4 vs. 4.9%). A significant association was observed between eGFR and HR_max-min. CAN was independently associated with CKD with an adjusted odds ratio of 2.77 (95% CI, 1.15-6.68) in diabetic patients. A positive linear trend was observed for the odds of CAN with increasing CKD severity in diabetes. The areas under the curve (AUCs) for the predictive ability of eGFR for the risk of impaired cardiovascular autonomic function for nondiabetic group and CAN for the diabetic group were 0.734 and 0.703, respectively. Adding age, sex, body mass index, and albuminuria to the prediction model increased the AUCs to 0.852 and 0.791, respectively.

CONCLUSION

CKD is associated with the risk of CAN in both nondiabetic and diabetic subjects. eGFR and albuminuria improve the prediction of CAN.