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

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.

Adaptive responses to chronic intermittent hypoxia: contributions from the European Sleep Apnoea Database (ESADA) Cohort

Obstructive sleep apnoea (OSA) is a common disease in the general population, and is associated with increased cardiovascular risk and several comorbidities. Obesity favours upper airway collapsibility, but other pathophysiological traits have been identified, i.e. upper airway muscle activity, modulation of the respiratory drive, and the arousal threshold. OSA causes chronic intermittent hypoxia, inflammatory activation and autonomic imbalance with diurnal and nocturnal sympathetic hyperactivity. Disentangling so many components to investigate the pathogenesis of OSA's consequences is very hard clinically. However, albeit imperfect, clinical medicine constitutes a major source of inspiration for basic research, and a mutual exchange of information is essential between clinicians and physiologists to improve our understanding of disease states. OSA is no exception, and this narrative review will summarize the results of clinical studies performed over the years by the European Sleep Apnoea Database (ESADA) Study Group, to explore the variables linked to markers of intermittent hypoxia as opposed to the traditional assessment of OSA severity based on the frequency of respiratory events during sleep (the Apnoea Hypopnoea Index). The results of the clinical studies indicate that intermittent hypoxia variables are associated with several comorbidities, although evidence of a cause-effect relationship is still missing in many cases. It is also possible that adaptive rather than maladaptive responses could be evoked by intermittent hypoxia. The intensity, duration and frequency of intermittent hypoxia episodes causing adaptive rather than maladaptive responses, and their clinical implications, deserve further investigation.

Meta-analysis of the effects of CPAP therapy on estimated glomerular filtration rate in patients with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is highly prevalent in patients with chronic kidney disease and may lead to a loss of kidney function. However, it remains unclear whether or not continuous positive airway pressure (CPAP) treatment improves the estimated glomerular filtration rate (eGFR) in patients with OSA. This meta-analysis was designed to investigate the effect of CPAP therapy on eGFR in patients with OSA.

METHODS

We searched the electronic databases Web of Science, Cochrane Library, PubMed, and Embase through June 1, 2022. Information about patients, CPAP duration, gender distribution, pre- and post-CPAP treatment eGFR, and age of patients were collected for further analysis. We applied the standardized mean difference (SMD) with a 95%confidence interval (CI) to analyze the pooled effects. Both Stata 12.0 software and Review Manager 5.2 software were employed for all statistical analyses.

RESULTS

A sample of 13 studies with 519 patients was included in the meta-analysis. There was no significant change of eGFR levels before and after CPAP usage for patients with OSA (SMD =  - 0.05, 95%CI: - 0.30 to 0.19, Z = 0.43, p = 0.67). However, subgroup analysis revealed that the level of eGFR was obviously decreased after CPAP therapy in patients with OSA and CPAP use duration > 6 months (SMD =  - 0.30, 95% CI =  - 0.49 to - 0.12, z = 3.20, p = 0.001), and elderly patients (> 60 years) (SMD =  - 0.32, 95% CI =  - 0.52 to - 0.11, z = 3.02, p = 0.002).

CONCLUSIONS

Meta-analysis confirmed that OSA treatment with CPAP has no clinically significant effect on eGFR.

Kidney transplantation: a possible solution to obstructive sleep apnea in patients with end-stage kidney disease

INTRODUCTION

Obstructive sleep apnea (OSA) is frequently reported among patients with chronic kidney disease resulting in considerable morbidity and mortality. OSA may cause repetitive stimulation of the sympathetic nervous system and elevations in pulmonary artery pressure leading to an elevated risk of cardiac and vascular complications in patients with chronic kidney disease. Furthermore, OSA is associated with progressive worsening of kidney injury and loss of renal function.

METHODS

In this systematic review and meta-analysis, we evaluated the effect of renal transplantation on the progression of OSA in patients with end-stage kidney disease.

RESULTS

The meta-analysis included eight studies with a total of 401 patients. Findings showed that kidney transplantation does not lead to a statistically significant effect on the apnea-hypopnea index (MD 2.6 events/hr, 95% CI -3.2 to 8.3, p = 0.21), total sleep time (MD 14.7 min/night, 95% CI -8.4 to 37.8, p = 0.76), sleep efficiency (MD 2.5%, 95% CI -1.4 to 6.3, p = 0.57), slow wave sleep (MD 0.4% of total sleep time, 95% CI -7.5 to 8.4, p = 0.05), and rapid eye movement sleep (MD 0.6% of total sleep time, 95% CI -2.2 to 3.3, p = 0.98). There was no statistically significant effect of kidney transplantation on OSA in patients with chronic renal disease.