Evaluation and Management of Adults with Obstructive Sleep Apnea Syndrome

Non-sleep related outcomes of maxillomandibular advancement, a systematic review

Maxillomandibular advancement has been shown to be an effective treatment for obstructive sleep apnea; however, the literature focuses mainly on sleep-related parameters such as apnea-hypopnea index, respiratory disturbance index and Epworth sleepiness scale. Other factors that may be important to patients, such as esthetics, patient satisfaction, nasality, swallowing problems and so forth have been reported in the literature but have not been systematically studied. Together with an information specialist, an extensive search in Medline, Embase and Scopus yielded 1592 unique articles. Titles and abstracts were screened by two blinded reviewers. In total, 75 articles were deemed eligible for full-text screening and 38 articles were included for qualitative synthesis. The most common categories of non-sleep related outcomes found were surgical accuracy, facial esthetics, functional outcomes, quality of life, patient satisfaction, and emotional health. All categories were reported using heterogenous methods, such that meta-analysis could not be performed. There was lack of consistent methods to assess these outcomes. This work is the first to systematically review non-sleep related outcomes of maxillomandibular advancement. Despite growing interest in evaluating surgical outcomes through patient subjective experiences, this review points to the need of standardized, validated methods to report these outcomes.

Relationship between obstructive sleep apnoea syndrome and gastrointestinal diseases: a systematic review and Meta-analysis

Studies exploring the association between obstructive sleep apnoea syndrome (OSA) and gastrointestinal diseases (GID) are important for enhancing clinical outcomes. This study aimed to systematically assess the association between these two diseases. Adhering to PRISMA guidelines, a comprehensive literature search was conducted across databases including PubMed, Web of Science, Willey Library, Cochrane Library and Scopus. This search focused on English literature published up to January 2024. Literature screening, quality assessment (using the NOS scale) and data extraction were performed by two independent researchers. Statistical analyses were performed using the meta-package of the R.4.2.2 software. An initial screening of 2178 papers was conducted and 11 studies were included. Meta-analysis results showed a significant association between OSA and GID (p < 0.01). Subgroup analyses further indicated a stronger association between OSA and GID in Asian populations compared to Europe and the United States. In addition, both benign and malignant GID were significantly associated with OSA, with a pronounced association for malignant GID than for benign GID. The results of publication bias analysis revealed no significant bias (Begg's test p = 0.45, Egger's test p = 0.60). This study uncovers a notable association between OSA and GID, especially in Asian populations, suggesting that clinicians should consider the potential connection between these two diseases during diagnosis and treatment. However, due to the heterogeneity and limitations of the study, these conclusions need to be further validated through more comprehensive research.

Nocturia and obstructive sleep apnoea

Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.

Evaluation of bi-directional causal association between obstructive sleep apnoea syndrome and diabetic microangiopathy: a Mendelian randomization study

Background

The relationship between obstructive sleep apnea syndrome (OSAS) and diabetic microangiopathy remains controversial.

Objective

This study aimed to use bidirectional two-sample Mendelian Randomization (MR) to assess the causal relationship between OSAS and diabetic microangiopathy.

Methods

First, we used the Linkage Disequilibrium Score Regression(LDSC) analysis to assess the genetic correlation. Then, the bidirectional two-sample MR study was conducted in two stages: OSAS and lung function-related indicators (forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)) were investigated as exposures, with diabetic microangiopathy as the outcome in the first stage, and genetic tools were used as proxy variables for OSAS and lung function-related measures in the second step. Genome-wide association study data came from the open GWAS database. We used Inverse-Variance Weighted (IVW), MR-Egger regression, Weighted median, Simple mode, and Weighted mode for effect estimation and pleiotropy testing. We also performed sensitivity analyses to test the robustness of the results. Furthermore, we performed multivariate and mediation MR analyses.

Results

In the LDSC analysis, We found a genetic correlation between OSAS, FVC, FEV 1, and diabetic microangiopathy. In the MR analysis, based on IVW analysis, genetically predicted OSAS was positively correlated with the incidence of diabetic retinopathy (DR), diabetic kidney disease (DKD), and diabetic neuropathy (DN). In the subgroup analysis of DR, there was a significant causal relationship between OSAS and background diabetic retinopathy (BDR) and proliferative diabetic retinopathy (PDR). The reverse MR did not show a correlation between the incidence of diabetic microangiopathy and OSAS. Reduced FVC had a potential causal relationship with increased incidence of DR and PDR. Reduced FEV1 had a potential causal relationship with the increased incidence of BDR, PDR, and DKD. Multivariate MR analysis showed that the association between OSAS and diabetic microangiopathy remained significant after adjusting for confounding factors. However, we did not find the significant mediating factors.

Conclusion

Our results suggest that OSAS may be a cause of the development of diabetic microangiopathy, and OSAS may also be associated with a high risk of diabetic microangiopathy, providing a reference for a better understanding of the prevention of diabetic microangiopathy.

TRPC5 channel participates in myocardial injury in chronic intermittent hypoxia

OBJECTIVE

The purpose of this study is to develop an animal model of Chronic Intermittent Hypoxia (CIH) and investigate the role of the TRPC5 channel in cardiac damage in OSAHS rats.

METHODS

Twelve male Sprague Dawley rats were randomly divided into the CIH group and the Normoxic Control (NC) group. Changes in structure, function, and pathology of heart tissue were observed through echocardiography, transmission electron microscopy, HE-staining, and TUNEL staining.

RESULTS

The Interventricular Septum thickness at diastole (IVSd) and End-Diastolic Volume (EDV) of rats in the CIH group significantly increased, whereas the LV ejection fraction and LV fraction shortening significantly decreased. TEM showed that the myofilaments in the CIH group were loosely arranged, the sarcomere length varied, the cell matrix dissolved, the mitochondrial cristae were partly flocculent, the mitochondrial outer membrane dissolved and disappeared, and some mitochondria were swollen and vacuolated. The histopathological examination showed that the cardiomyocytes in the CIH group were swollen with granular degeneration, some of the myocardial fibers were broken and disorganized, and most of the nuclei were vacuolar and hypochromic.

CONCLUSION

CIH promoted oxidative stress, the influx of Ca2+, and the activation of the CaN/NFATc signaling pathway, which led to pathological changes in the morphology and ultrastructure of cardiomyocytes, the increase of myocardial apoptosis, and the decrease of myocardial contractility. These changes may be associated with the upregulation of TRPC5.

Effect of Liraglutide in Different Abdominal Fat Layers Measured by Ultrasound: The Importance of Perirenal Fat Reduction

INTRODUCTION

Ultrasonography (US) in patients with obesity allows us to measure different layers of abdominal fat (superficial subcutaneous, deep subcutaneous, preperitoneal, omental, and perirenal), not assessable by DEXA or CT scan. Omental and perirenal fat depots are considered predictors of metabolic complications. Liraglutide is particularly effective in reducing weight in patients with insulin-resistance, but its direct impact on each abdominal fat layer is unknown.

METHODS

We measured, at the L4 level, all 5 abdominal fat depots in 860 patients with obesity (72.8% women, mean age 56.6 ± 1.5 years, BMI 34.4 ± 4.7 kg/m2, body fat 47 ± 2%, abdominal circumference 105.8 ± 3 cm), before and after 6 months of liraglutide treatment. Laboratory tests for glucose, insulin, and lipid profile were routinely done. T-student was used to compare intraindividual differences.

RESULTS

Weight loss was 7.5 ± 2.8 kg (7.96% from baseline), with no differences by sex/age/BMI. Greater loss was observed in patients with higher dosages and NAFLD. All US-measured fat layers showed a significant reduction (p < 0.05) at 6th months. Preperitoneal fat showed a -26 ± 5.5% reduction and 46% of the patients went below metabolic syndrome (MS) risk cut-off values. Omental fat was reduced by -17.8 ± 5% (67% of the patients below MS risk) and perirenal fat by -22.4 ± 4.4% (56% of the patients below MS). Both omental and perirenal fat reduction correlated with total and LDL cholesterol. Higher perirenal fat reduction (-28%) was seen among patients with obesity and hypertension. Perirenal fat also correlated with blood pressure reduction.

CONCLUSION

Liraglutide induces greater fat loss in the layers involved with MS. However, the maximal reduction is seen at perirenal fat, which has been recently related with hypertension and could play an important role in modulating kidney's expansion and intraglomerular pressure. US is a reproducible clinical tool to assess pathologic fat depots in patients living with obesity.

Indications for Dental Specialists for Treating Obstructive Sleep Apnea with Mandibular Advancement Devices: A Narrative Review

Obstructive sleep apnea (OSA) syndrome is characterized by repeated airway collapse during sleep. It determines cardiovascular, pulmonary, and neurocognitive consequences and is associated with several daytime and nighttime symptoms that influence the patient's quality of life. The contribution of the dental specialist in the clinical management of OSA patients entails participating in the screening process as diagnostic sentinels and providing adequate treatment using mandibular advancement devices (MADs). Since the treatment of OSA requires a multidisciplinary approach, including different medical specialists, dentists should have a comprehensive understanding of medical and dental factors that influence the strategy and effectiveness of OSA treatment with MAD. Such expertise is crucial in determining the appropriate treatment indications and helps clinicians establish a consolidated position within the multidisciplinary OSA team. In this regard, this review summarizes the evidence of the clinical indications for MAD treatment and provides the dental specialist with helpful information about medical, functional, and other relevant factors that should be considered during diagnosis, treatment plan, and follow-up stages. Information retrieved was organized and discussed, generating specific domains/queries oriented to the clinical management of OSA patients from the clinical perspective of dental specialists.

Causal role of immune cells in obstructive sleep apnea hypopnea syndrome: Mendelian randomization study

BACKGROUND

Despite being one of the most prevalent sleep disorders, obstructive sleep apnea hypoventilation syndrome (OSAHS) has limited information on its immunologic foundation. The immunological underpinnings of certain major psychiatric diseases have been uncovered in recent years thanks to the extensive use of genome-wide association studies (GWAS) and genotyping techniques using high-density genetic markers (e.g., SNP or CNVs). But this tactic hasn't yet been applied to OSAHS. Using a Mendelian randomization analysis, we analyzed the causal link between immune cells and the illness in order to comprehend the immunological bases of OSAHS.

AIM

To investigate the immune cells' association with OSAHS via genetic methods, guiding future clinical research.

METHODS

A comprehensive two-sample mendelian randomization study was conducted to investigate the causal relationship between immune cell characteristics and OSAHS. Summary statistics for each immune cell feature were obtained from the GWAS catalog. Information on 731 immune cell properties, such as morphologic parameters, median fluorescence intensity, absolute cellular, and relative cellular, was compiled using publicly available genetic databases. The results' robustness, heterogeneity, and horizontal pleiotropy were confirmed using extensive sensitivity examination.

RESULTS

Following false discovery rate (FDR) correction, no statistically significant effect of OSAHS on immunophenotypes was observed. However, two lymphocyte subsets were found to have a significant association with the risk of OSAHS: Basophil %CD33dim HLA DR- CD66b- (OR = 1.03, 95%CI = 1.01-1.03, P < 0.001); CD38 on IgD+ CD24- B cell (OR = 1.04, 95%CI = 1.02-1.04, P = 0.019).

CONCLUSION

This study shows a strong link between immune cells and OSAHS through a gene approach, thus offering direction for potential future medical research.

Anthropometric measures and obstructive sleep apnea in children and adolescents: a systematic review of the literature and meta-analysis

BACKGROUND

Anthropometric measurements can be used to identify children at risk of developing obstructive sleep apnea (OSA). The study aimed to assess which anthropometric measurements (AMs) are most associated with an increased predisposition to develop OSA in healthy children and adolescents.

METHODS

We performed a systematic review (PROSPERO #CRD42022310572) that searched eight databases and gray literature.

RESULTS

In eight studies with low-to-high risk of bias, investigators reported the following AMs: body mass index (BMI), neck circumference, hip circumference, waist-to-hip ratio, neck-to-waist ratio, waist circumference, waist-to-height ratio, and facial AMs. The meta-analysis showed that the OSA group had an average of 1.00 cm greater for the neck circumference (p < 0.001; Cohen's d = 2.26 [0.72, 5.23]), 3.07 cm greater for the waist circumference (p = 0.030; Cohen's d = 0.28 [0.02, 0.53]), 3.96 cm greater for the hip circumference (p = 0.040; Cohen's d = 0.28 [0.02, 0.55]), 5.21° greater for the cervicomental angle (p = 0.020; Cohen's d = 0.31 [0.03, 0.59]), and 1.23° greater for maxillary-mandibular relationship angle (p < 0.001; Cohen's d = 0.47 [0.22, 0.72]) than the control group. The mandibular depth angle had a reduction of 1.86° (p = 0.001; Cohen's d = -0.36° [-0.65, -0.08]) in control than in patients with OSA. The BMI (p = 0.180), waist-to-hip ratio (p = 0.280), neck-to-waist ratio (p = 0.070), maxillary depth angle (p = 0.250), and upper/lower face height ratio (p = 0.070) showed no significant differences between groups.

CONCLUSIONS

Compared to the control group, the OSA group exhibited a greater mean difference in neck circumference, the only anthropometric measurement with high certainty of evidence.

Childhood maltreatment and sleep apnea: Findings from a cross-sectional general population study

OBJECTIVE

Cumulative evidence indicates that childhood maltreatment (CM) is associated with sleep disturbances possibly suggesting sleep apnea. However, the relation between CM and objective measures of sleep apnea as determined by polysomnography (PSG) has not yet been assessed.

METHODS

Using a cross-sectional design and based on PSG measurements from N = 962 subjects from the SHIP-Trend general population study, we used linear regression models to investigate the relationship between apnea-hypopnea (AHI) and oxygen desaturation index (ODI) and Epworth sleepiness scale (ESS) metrics and the Childhood Trauma Questionnaire (CTQ). All significant models were additionally adjusted for obesity, depression, metabolic syndrome, risky health behaviors, and socioeconomic factors.

RESULTS

While both AHI and ESS were positively associated with the CTQ sum score, ODI was not. Investigating the CTQ subscales, ESS was associated with emotional abuse and emotional neglect; AHI was associated with physical and sexual abuse as well as physical neglect. For both the sum score and the subscales of the CTQ, ESS effects were partially mediated by depressive symptoms, while AHI effects were mediated by obesity, risky health behaviors, and metabolic syndrome.

CONCLUSION

The findings of this general population study suggest an association between CM, particularly physical neglect, and objective as well as subjective indicators of sleep apnea, which were partially mediated by depressive symptoms and obesity.

Undiagnosed obstructive sleep apnea syndrome as a treatable cause of new-onset sleepiness in some post-COVID patients

BACKGROUND AND PURPOSE

Infection with COVID-19 can lead to persistent sequelae, such as fatigue, daytime sleepiness or disturbed sleep, that can remain for more than 12 weeks and that are summarized as post-COVID syndrome. The causes remain unclear. The present study investigated the presence of sleep disorders in patients with post-COVID syndrome using polysomnography.

METHODS

Thirty-four patients with post-COVID syndrome and new-onset fatigue and sleepiness after a SARS-CoV2 infection underwent polysomnography in accordance with American Association of Sleep Medicine (AASM) standards as part of their clinical workup. Analysis was performed visually based on AASM criteria (scoring manual version 2.6, 2020).

RESULTS

Polysomnography revealed a sleep efficiency of <80% in 50% of patients and a mean respiratory disturbance index (RDI) of 9.9 ± 15.4/h. Excluding central apneas, 12 patients (35%) had an RDI of ≥5/h, pointing to obstructive sleep apnea syndrome (OSAS; AASM 2014). Patients with a high RDI were significantly older (p = 0.01) and showed a trend towards a higher body mass index (p = 0.08) than patients with a normal RDI but had no other risk factors for OSAS. Six patients agreed to long-term treatment of their OSAS and all reported discontinuation of daytime symptoms.

CONCLUSIONS

Post-COVID symptoms such as daytime sleepiness, fatigue and memory and concentration problems may in part be a result of reduced sleep efficiency and sleep apnea in a relevant percentage of patients. This possibly treatable cause of the symptoms should be kept in mind in patients presenting with post-COVID syndrome.

How to objectively measure snoring: a systematic review

PURPOSE

Snoring is the most common symptom of obstructive sleep apnea. Various objective methods of measuring snoring are available, and even if the measurement is performed the same way, communication is difficult because there are no common reference values between the researcher and clinician with regard to intensity and frequency, among other variables. In other words, no consensus regarding objective measurement has been reached. This study aimed to review the literature related to the objective measurement of snoring, such as measurement devices, definitions, and device locations.

METHODS

A literature search based on the PubMed, Cochrane, and Embase databases was conducted from the date of inception to April 5, 2023. Twenty-nine articles were included in this study. Articles that mentioned only the equipment used for measurement and did not include individual details were excluded from the study.

RESULTS

Three representative methods for measuring snoring emerged. These include (1) a microphone, which measures snoring sound; (2) piezoelectric sensor, which measures snoring vibration; and (3) nasal transducer, which measures airflow. In addition, recent attempts have been made to measure snoring using smartphones and applications.

CONCLUSION

Numerous studies have investigated both obstructive sleep apnea and snoring. However, the objective methods of measuring snoring and snoring-related concepts vary across studies. Consensus in the academic and clinical communities on how to measure and define snoring is required.

Clinical efficacy and mechanism study of mid-frequency anti-snoring device in treating moderate obstructive sleep apnea-hypopnea syndrome

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is primarily caused by airway obstruction due to narrowing and blockage in the nasal and nasopharyngeal, oropharyngeal, soft palate, and tongue base areas. The mid-frequency anti-snoring device is a new technology based on sublingual nerve stimulation. Its principle is to improve the degree of oropharyngeal airway stenosis in OSAHS patients under mid-frequency wave stimulation. Nevertheless, there is a lack of clinical application and imaging evidence.

AIM

To investigate the clinical efficacy and mechanisms of a mid-frequency anti-snoring device in treating moderate OSAHS.

METHODS

We selected 50 patients diagnosed with moderate OSAHS in our hospital between July 2022 and August 2023. They underwent a 4-wk treatment regimen involving the mid-frequency anti-snoring device during nighttime sleep. Following the treatment, we monitored and assessed the sleep apnea quality of life index and Epworth Sleepiness Scale scores. Additionally, we performed computed tomography scans of the oropharynx in the awake state, during snoring, and while using the mid-frequency anti-snoring device. Cross-sectional area measurements in different states were taken at the narrowest airway point in the soft palate posterior and retrolingual areas.

RESULTS

Compared to pretreatment measurements, patients exhibited a significant reduction in the apnea-hypopnea index, the percentage of time with oxygen saturation below 90%, snoring frequency, and the duration of the most prolonged apnea event. The lowest oxygen saturation showed a notable increase, and both sleep apnea quality of life index and Epworth Sleepiness Scale scores improved. Oropharyngeal computed tomography scans revealed that in OSAHS patients cross-sectional areas of the oropharyngeal airway in the soft palate posterior area and retrolingual area decreased during snoring compared to the awake state. Conversely, during mid-frequency anti-snoring device treatment, these areas increased compared to snoring.

CONCLUSION

The mid-frequency anti-snoring device demonstrates the potential to enhance various sleep parameters in patients with moderate OSAHS, thereby improving their quality of life and reducing daytime sleepiness. These therapeutic effects are attributed to the device's ability to ameliorate the narrowing of the oropharynx in OSAHS patients.

Effects of combined exercise training with sleep education in older adults with obstructive sleep apnea: protocol for a randomized clinical trial

Background

Obstructive sleep apnea (OSA) is a common disorder that affects approximately 1 billion people worldwide. Advanced age is a significant risk factor. Various treatment options have been explored to reduce the severity of OSA symptoms and physical exercise has emerged as a potential alternative therapy. Therefore, this study aims to investigate the effects of a combined exercise program with sleep education on sleep quality and on the severity of OSA in older adults.

Methods

This is a randomized clinical trial with two parallel groups that will involve individuals of both genders aged between 60 and 79 years who have an apnea-hypopnea index (AHI) of more than 15 events per hour and who have not received or are currently undergoing treatment for OSA. Older adults who have engaged in regular exercise in the last six months and individuals with contraindications to exercise will be excluded. The study will assess outcomes related to OSA, including AHI, oxygen desaturation index, minimum and mean oxyhemoglobin saturation, sleep efficiency, sleep latency, and the type of respiratory events. Additionally, sleep quality-related outcomes, daytime sleepiness, physical activity, physical fitness, aerobic capacity, cognitive status, anthropometric measures, and health-related quality of life will be analyzed. Participants will be randomized to two groups: a combined exercise group (involving both resistance and aerobic training) with sleep education, and a control group that will receive only educational recommendations for managing OSA. The intervention will last 12 weeks and will consist of three sessions per week, totaling 36 exercise sessions. Sample size calculation indicates a minimum number of 36 participants.

Discussion

If the hypothesis is confirmed, this clinical trial will indicate an effective non-pharmacological intervention for treating OSA in older adults. This intervention could be used as an adjunct to existing approaches designed to improve OSA management.

Clinical trail registration

Brazil Clinical Trials Registry (ReBEC), identifier RBR-9hk6pgz.

Analysis of the cause of retrolingual obstruction in patients with moderate-severe obstructive sleep apnea

PURPOSE

To evaluate the percentage of obstructive sleep apnea (OSA) patients with retrolingual obstruction in all moderate-severe OSA patients and the proportions of different causes in all moderate-severe OSA patients with retrolingual obstruction and to discuss the accuracy of the Friedman tongue position (FTP) and retrolingual cross-sectional area (RCSA) in assessing the retrolingual obstruction.

METHODS

Two hundred and twenty moderate-severe OSA patients were enrolled. After retrolingual obstruction was diagnosed, the percentage of OSA patients with retrolingual obstruction in all moderate-severe OSA patients was calculated. After that, the different causes of retrolingual obstruction were diagnosed based on different diagnostic criteria, and the proportions of different causes in all moderate-severe OSA patients with retrolingual obstruction were calculated. Finally, the correlations between FTP, RCSA, and apnea-hypopnea index after nasopharyngeal tube insertion (NPT-AHI) were analyzed, and the proportions of different causes of retrolingual obstruction based on different FTP and RCSA were observed.

RESULTS

There were 128 patients with retrolingual obstruction, accounting for 58.2% of all moderate-severe OSA patients. In 128 patients with retrolingual obstruction, the proportions of glossoptosis (48.4%), palatal tonsil hypertrophy (28.1%), and lingual hypertrophy (8.6%) were relatively high. Both FTP and RCSA did not correlate with NPT-AHI. The proportion of lingual hypertrophy increased gradually with the increase of FTP and the proportions of glossoptosis in all FTP classifications were high. The patients with RCSA > 180 mm2 were mainly affected by glossoptosis and palatal tonsil hypertrophy, while patients with RCSA ≤ 180 mm2 were mainly affected by lingual hypertrophy.

CONCLUSION

The percentage of patients with retrolingual obstruction in all moderate-severe OSA patients is relatively high, mainly glossoptosis, palatal tonsil hypertrophy, and lingual hypertrophy. FTP classification and RCSA can only reflect the retrolingual anatomical stenosis, but cannot fully reflect the retrolingual functional stenosis, especially the presence of glossoptosis.

The role of the autonomic nervous system in polycystic ovary syndrome

This article reviewed the relationship between the autonomic nervous system and the development of polycystic ovary syndrome (PCOS). PCOS is the most common reproductive endocrine disorder among women of reproductive age. Its primary characteristics include persistent anovulation, hyperandrogenism, and polycystic ovarian morphology, often accompanied by disturbances in glucose and lipid metabolism. The body's functions are regulated by the autonomic nervous system, which consists mainly of the sympathetic and parasympathetic nervous systems. The autonomic nervous system helps maintain homeostasis in the body. Research indicates that ovarian function in mammals is under autonomic neural control. The ovaries receive central nervous system information through the ovarian plexus nerves and the superior ovarian nerves. Neurotransmitters mediate neural function, with acetylcholine and norepinephrine being the predominant autonomic neurotransmitters. They influence the secretion of ovarian steroids and follicular development. In animal experiments, estrogen, androgens, and stress-induced rat models have been used to explore the relationship between PCOS and the autonomic nervous system. Results have shown that the activation of the autonomic nervous system contributes to the development of PCOS in rat. In clinical practice, assessments of autonomic nervous system function in PCOS patients have been gradually employed. These assessments include heart rate variability testing, measurement of muscle sympathetic nerve activity, skin sympathetic response testing, and post-exercise heart rate recovery evaluation. PCOS patients exhibit autonomic nervous system dysfunction, characterized by increased sympathetic nervous system activity and decreased vagal nerve activity. Abnormal metabolic indicators in PCOS women can also impact autonomic nervous system activity. Clinical studies have shown that various effective methods for managing PCOS regulate patients' autonomic nervous system activity during the treatment process. This suggests that improving autonomic nervous system activity may be an effective approach in treating PCOS.

Hsa_circ_0081065 exacerbates IH-induced EndMT via regulating miR-665/HIF-1α signal axis and HIF-1α nuclear translocation

CircRNAs play an important role in various physiological and pathological biological processes. Despite their widespread involvement, the function of circRNAs in intermittent hypoxia (IH) remain incompletely understood. This study aims to clarify the molecular mechanism of it in IH. Differentially expressed circRNAs were identified by transcriptome sequencing analysis in intermittent hypoxia (IH) model. GO and KEGG enrichment analys were performed on the identified differentially expressed circRNAs. The circular characteristics of hsa_circ_0081065 in human umbilical vein endothelial cells (HUVECs) were detected by RT-qPCR. The sublocalization of hsa_circ_0081065 was examined by FISH. The effect of hsa_circ_0081065 on endothelial to mesenchymal transition (EndMT) was estimated by detecting the expression of EndMT related markers. Various techniques, including RNA-pull down, RIP, EMSA, dual-luciferase reporter assay and immunofluorescence staining were used to investigate the relationship among hsa_circ_0081065, miR-665 and HIF-1α. A total of 13,304 circRNAs were identified in HUVECs treatment with IH, among which 73 were differentially expressed, including 24 upregulated circRNAs and 49 downregulated circRNAs. Notably, hsa_circ_0081065 demonstrated a significantly upregulation. Hsa_circ_0081065 exhibited the circular characteristics of circRNA and was predominantly localized in the cytoplasm. Knockdown of hsa_circ_0081065 inhibited EndMT. Mechanically, we demonstrated that hsa_circ_0081065 acts as a sponge for miR-665 to up-regulate HIF-1α and exacerbate HIF-1α nuclear translocation in HUVECs. We have demonstrated that hsa_circ_0081065 is significantly upregulated in HUVECs treated with IH. Our findings indicate that hsa_circ_0081065 exacerbates IH-induced EndMT through the regulation of the miR-665/HIF-1α signal axis and facilitating HIF-1α nuclear translocation. These results provide a theoretical basis for considering of EndMT as a potential therapeutic target for OSAHS intervention.

Asthma and obstructive sleep apnea: Unveiling correlations and treatable traits for comprehensive care

Asthma and obstructive sleep apnea (OSA) are common respiratory disorders. They share characteristics such as airway obstruction, poor sleep quality, and low quality of life. They are often present as comorbidities, along with obesity, gastroesophageal reflux disease (GERD), and allergic rhinitis (AR), which impacts the disease's control. In recent years, there has been discussion about the association between these conditions and their pathophysiological and clinical consequences, resulting in worse health outcomes, increased healthcare resource consumption, prolonged hospital stays, and increased morbidity and mortality. Some studies demonstrate that treatment with continuous positive airway pressure (CPAP) can have a beneficial effect on both pathologies. This review summarizes the existing evidence of the association between asthma and OSA at their pathophysiological, epidemiological, clinical, and therapeutic levels. It intends to raise awareness among healthcare professionals about these conditions and the need for further research.

Effect of comprehensive rehabilitation on apnea hypopnea index in patients with obstructive sleep apnea: a protocol for randomized controlled trial

PURPOSE

The aim of this study is to investigate the effect of comprehensive rehabilitation on apnea hypopnea index (AHI) in patients with obstructive sleep apnea (OSA).

METHODS

Patients diagnosed with OSA and meeting the eligibility criteria will be randomly allocated in the groups. The experimental group will receive comprehensive rehabilitation, and the control group will receive myofunctional therapy. CPAP will be continued by all the participants. Both the groups will receive the interventions for 12 weeks. The primary outcome measures are AHI and Epworth Sleepiness Scale (ESS), and secondary outcomes are Pittsburg Sleep Quality Index (PSQI), Oxygen Desaturation Index (ODI), Snoring Index (SI), Manual Assessment of Respiratory Motion (MARM), Breath Hold Test (BHT), and Self Evaluation of Breathing Questionnaire (SEBQ). The outcomes will be assessed at baseline and at the end of 12 weeks. A follow-up will be taken at the end of 24 weeks. Power analysis suggests that enrollment of 118 patients will required. Repeated measures ANOVA will be used to analyze the effect of the intervention.

CONCLUSION

By performing this research, we may develop insights on a novel comprehensive approach for treatment of patients with OSA.

TRIAL REGISTRATION

CTRI/2023/10/058486.

Idiopathic intracranial hypertension: a step change in understanding the disease mechanisms

The understanding of idiopathic intracranial hypertension (IIH) has evolved over the past few years. Previously, IIH was considered a disease exclusively affecting the neuro-ophthalmic axis, characterized by raised intracranial pressure, headache and papilloedema, and resulting in the risk of severe and permanent visual loss and life-changing disabling headaches. Recent advances have begun to redefine IIH as a probable metabolic disease involving a range of systemic manifestations. More than 95% of individuals affected by the disease are women of reproductive age with obesity. The incidence is rapidly rising and parallels the escalating worldwide obesity rates. Contemporary insights identify associations with insulin resistance, type 2 diabetes and a twofold increased risk of cardiovascular disease in excess of that driven by obesity alone. Adipose distribution in people with IIH, like that in other metabolic diseases, is preferentially centripetal and is associated with changes in intracranial pressure. Evidence now demonstrates adipose tissue dysfunction in people with IIH, involving transcriptional and metabolic priming for lipogenesis and weight gain. Hormonal perturbations are also observed, including a unique phenotype of androgen excess that promotes cerebrospinal fluid secretion. Knowledge of these additional disease features is driving research into novel therapeutic targets and altering the approach to multidisciplinary care.

A systematic review with meta-analysis to assess Alzheimer's disease biomarkers in adults with or without obstructive sleep apnoea

INTRODUCTION

The aim was to design a meta-analysis evaluating the positron emission tomography (PET) uptake and cerebrospinal fluid (CSF), circulating levels of amyloid-β (Aβ), and tau proteins OSA group versus control group, as well as the association of these biomarkers with the severity of OSA.

MATERIAL AND METHODS

Four databases were searched until April 17, 2023, without any restrictions. The effect sizes were the standardized mean difference (SMD) along with a 95% confidence interval (CI).

RESULTS

A total of 21 articles were entered into the meta-analysis. The pooled SMDs of the CSF levels in OSA adults compared to controls were: -0.82 (P=0.004) for Aβ42, -1.13 (P<0.001) for Aβ40, 0.17 (P=0.23) for p-tau, 0.04 (P=0.65) for t-tau, 0.08 (P=0.89) for Aβ42/Aβ40 ratio, and 0.81 (P=0.001) for t-tau/Aβ42 ratio. The pooled SMD for the PET uptake of Aβ burden in OSA adults compared to controls was 0.30 (P=0.03). The pooled SMDs of the circulating levels in OSA adults compared to controls were: 0.67 (P=0.002) for Aβ42, 0.11 (P=0.82) for Aβ40, 0.35 (P=0.06) for p-tau, and 1.41(P=0.005) for t-tau. The pooled SMDs for levels of Aβ42, Aβ40, total Aβ, p-tau, t-tau, and Aβ42/Aβ40 ratio in severe OSA adults compared to mild/moderate OSA adults were -0.15 (P=0.33), 0.25 (P=35), 0.04 (P=87), -2.53 (P=0.24), -0.24 (P=0.52), and -0.28 (P=0.30), respectively.

CONCLUSIONS

The results indicated that CSF levels of Aβ42 and Aβ40 in OSA adults were significantly lower, but the CSF level of t-tau/Aβ42 ratio and PET Aβ burden uptake in OSA adults significantly were higher than in controls.

Serum C-reactive protein level and sleep characteristics in obstructive sleep apnea syndrome comorbid with panic disorder: a preliminary study

OBJECTIVE

Investigate the sleep characteristics of patients with obstructive sleep apnea syndrome (OSAS) comorbidity with panic disorder (PD), exploring its potential association with serum C-reactive protein (CRP) levels.

PATIENTS AND METHODS

Fifty-four patients (25 OSAS patients with PD and 29 without PD) and 25 healthy controls (HCs) were included. The Self-rating anxiety scale (SAS), self-rating depression scale (SDS), and Pittsburgh sleep quality index (PSQI) were used to assess the mood and sleep quality of the subjects. All patients had circulating CRP levels and polysomnography was performed.

RESULTS

OSAS with PD had higher SAS, SDS, PSQI than the OSAS without PD. Compared to OSAS without PD, OSAS with PD had higher percentage of non- rapid eye movement sleep 1 and 2 (N1 and N2%), sleep latency, and a lower percentage of rapid eye movement sleep (REM%). Respiratory-related microarousal index, AHI, and time below 90% oxygen saturation (T90) were low, and the lowest oxygen saturation (LO2) was high. Serum CRP levels in OSAS patients with PD were lower than that in OSAS patients without PD, but higher than that in HCs. In OSAS patients with PD, serum CRP levels were negatively correlated with wake time after sleep onset and SAS scores but positively correlated with sleep efficiency and N2%. Serum CRP levels were positively correlated with T90 and negatively correlated with LO2.

CONCLUSION

OSAS patients with PD had worse sleep quality, less severe OSAS, and low serum CRP levels. Serum CRP levels in OSAS patients with PD were associated with poorer sleep quality and duration of hypoxia rather than AHI.

Effect of tele-yoga on aerobic capacity, respiratory muscle strength, and cognitive performance in patients with obstructive sleep apnea syndrome

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) causes a decrease in aerobic capacity, respiratory muscle strength, and cognitive function, negatively affecting health-related quality of life.

OBJECTIVES

This study aimed to compare aerobic capacity, respiratory muscle strength, cognitive performance, functional capacity, sleep quality and daytime sleepiness in OSAS patients practicing and not practicing tele-yoga (TY).

METHODS

44 OSAS patients (40 M, 4F) were randomized into TY and control groups. TY group underwent live synchronous group-based TY sessions, 60 min/day, three days/week, for 12 weeks. Control group performed unsupervised thoracic expansion exercises at home 4 times daily for 12 weeks. The following were evaluated at baseline and at the end of the 6th and 12th weeks: inspiratory and expiratory respiratory muscle strength (MIP, MEP), cardiopulmonary exercise test, Corsi Block Tapping Test (CBTT) and Stroop TBAG test, six-minute walk test (6MWT), Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS).

RESULTS

TY significantly improved MIP, and exercise test parameters (VE, HRmax,%HR, heart rate recovery in the first minute and RQmax), CBTT (forward) and Stroop TBAG test scores (parts of 3,4,5) compared to the controls (p<0.05). There were no significant changes 6MWT in the TY group compared to the control group (p > 0.05). Sleep duration (min), sleep efficiency, sleep quality of PSQI and ESS score improved significantly in the TY group compared to the control group (p < 0.05).

CONCLUSION

We suggest including TY intervention as a method of exercise in addition to CPAP treatments since it improves the health-related parameters of OSAS patients.

Bidirectional relationship between 56 peripheral inflammatory regulators and sleep apnea syndrome: A Mendelian randomization study

BACKGROUND

Peripheral inflammation plays an potential role in both pathogenesis and outcomes of sleep apnea syndrome (SAS). However, this topic has not been explored at the genetic level.

OBJECTIVES

The aim of the study was to investigate the genetic interaction between a total of 56 peripheral inflammatory regulators and SAS, and to further reveal the genetic association of SAS-related inflammatory regulators with several neurological disorders.

METHODS

Summary data for SAS, cerebral atherosclerosis, vascular dementia and peripheral concentrations of these inflammatory regulators were collected from genome-wide association studies. Instrumental variables were extracted from these data for causal inference of exposure and outcome using Two-sample Mendelian randomization methods. All analyses were performed using R (version 3.5.2).

RESULTS

First, of the included 56 inflammatory regulators, higher IL-25 level and lower IL-23, IL-24, IL-36γ and MIP-1a levels in peripheral circulation significantly increased the risk of SAS (P<0.05). Second, SAS significantly decreased the peripheral levels of IL-17A, IL-23, IL-27, IL-36α and TRAIL (P<0.05). Third, there was no genetic relationship between SAS and other inflammatory regulators (P>0.05). Fourth, in the SAS-related inflammatory regulators mentioned above, decreased levels of IL-17A and IL-27 in peripheral circulation were significantly associated with the increased risk of cerebral atherosclerosis, and decreased level of TRAIL promoted the elevation of vascular dementia risk (P<0.05).

CONCLUSION

There was a interaction between peripheral inflammation and SAS at the genetic level. Furthermore, peripheral inflammation might involved in the mechanism for SAS causing some neurological diseases mentioned above.

The complex relation between obstructive sleep apnoea syndrome, hypogonadism and testosterone replacement therapy

Obstructive sleep apnoea syndrome (OSAS) is an under-recognized medical disease. The main risk factors for OSAS are male sex, older age, obesity, and metabolic syndrome, that are also associated with male hypogonadism (MH). Therefore, obesity has been classically identified as the most evident link between OSAS and MH. However, OSAS is per se linked to the development of MH by a combined effect of hypoxia, increased night-time awakenings, reduced sleep efficiency and fragmented sleep. Similarly, MH might represent a risk factor for OSAS, mainly related to sleep disturbances that are frequently associated with low testosterone. Data on testosterone replacement therapy (TRT) in patients with OSAS are limited. Nevertheless, TRT is generally contraindicated by guidelines in the presence of untreated or severe OSAS. TRT might in fact worse OSAS symptoms in different ways. Furthermore, OSAS has been proposed to be a risk factor for secondary polycythaemia and TRT might exacerbate polycythaemia. Therefore, TRT in hypogonadal men affected by untreated OSAS or severe OSAS should be considered with caution and in a personalised way. Nevertheless, the type and dosage of TRT should be considered, as short-term high-dose TRT might worsen OSAS, whereas long-term lower doses could eventually determine a clinical improvement of symptoms of OSAS. Here we reviewed the data on the association between OSAS, MH and TRT, including the opportunity of assessment of patients who develop signs and symptoms of OSAS during TRT by polysomnography.

Sleep disorder and apnea events detection framework with high performance using two-tier learning model design

Sleep apnea is defined as a breathing disorder that affects sleep. Early detection of sleep apnea helps doctors to take intervention for patients to prevent sleep apnea. Manually making this determination is a time-consuming and subjectivity problem. Therefore, many different methods based on polysomnography (PSG) have been proposed and applied to detect this disorder. In this study, a unique two-layer method is proposed, in which there are four different deep learning models in the deep neural network (DNN), gated recurrent unit (GRU), recurrent neural network (RNN), RNN-based-long term short term memory (LSTM) architecture in the first layer, and a machine learning-based meta-learner (decision-layer) in the second layer. The strategy of making a preliminary decision in the first layer and verifying/correcting the results in the second layer is adopted. In the training of this architecture, a vector consisting of 23 features consisting of snore, oxygen saturation, arousal and sleep score data is used together with PSG data. A dataset consisting of 50 patients, both children and adults, is prepared. A number of pre-processing and under-sampling applications have been made to eliminate the problem of unbalanced classes. Proposed method has an accuracy of 95.74% and 99.4% in accuracy of apnea detection (apnea, hypopnea and normal) and apnea types detection (central, mixed and obstructive), respectively. Experimental results demonstrate that patient-independent consistent results can be produced with high accuracy. This robust model can be considered as a system that will help in the decisions of sleep clinics where it is expected to detect sleep disorders in detail with high performance.

Obstructive sleep apnea hypopnea syndrome in ancient traditional Chinese medicine

In western medicine, obstructive sleep apnea hypopnea syndrome (OSAHS) is an increasingly serious public health hazard, which is exacerbated by the obesity epidemic and an aging population. Ancient medical literature of traditional Chinese medicine (TCM) also recorded OSAHS-like symptoms but described the disease from a completely distinct theoretical perspective. The earliest records of snoring in ancient China can be traced back 2500 years. In TCM, the pathogenesis of OSAHS can be attributed mainly to turbid phlegm and blood stasis. Various TCM prescriptions, herbal medicines, and external therapy have also been proposed for the prevention and therapy of OSAHS. Some of these strategies are still used in current clinical practice. This review highlights historical characterizations of OSAHS and the theory of TCM and also explores its therapy in TCM, which may shed light on future OSAHS research. This is the first systematic English review of the role of TCM in the treatment of OSAHS.

The Effectiveness of Nursing Rehabilitation Interventions on Self-Care for Older Adults with Respiratory Disorders: A Systematic Review with Meta-Analysis

Background: This research work aimed to summarize the rehabilitation nursing interventions published in the scientific literature that most contribute to effective adherence to self-care in older adults with respiratory diseases. Methods: A systematic literature review with meta-analysis was conducted by searching the EBSCOhost platform (CINAHL Complete, MEDLINE Complete, Cochrane, and MedicLatina) using the PRISMA methodology. Five articles were selected for final analysis. Meta-analysis was carried out using Comprehensive Meta-Analysis (CMA) software, and the results were presented in a forest plot. Results: Thirty-one self-promoting rehabilitation nursing interventions were identified, with the most effective being those related to the assessment of progress in physical capacity/activity tolerance (functional status category/domain) and the assessment of the increase in health-related quality of life (health-related quality of life category/domain). Conclusions: Rehabilitation nursing interventions such as self-management programs led by nurses, community-based and home-based rehabilitation programs, and inspiratory muscle training can effectively reduce and enable the effective control of symptoms associated with respiratory disorders, boosting older adults' empowerment to engage in self-care.

Correlation between dental arch form and OSA severity in adult patients: an observational study

BACKGROUND

The role of interdental widths and palatal morphology on the development of obstructive sleep apnea (OSA) has not been well investigated in adult patients yet. The aim of this paper was to assess the morphology of maxilla and mandibular dental arches on three-dimensional (3D) casts and to correlate these measurements with the severity of OSA.

METHODS

Sixty-four patients (8 women and 56 men, mean age 52.4) with a diagnosis of mild-to-moderate OSA were retrospectively enrolled. On each patient, home sleep apnea test and 3D dental models were collected. Apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) were recorded, as well as the dental measurements including inter-molar distance, anterior and posterior widths of maxillary and mandibular arches, upper and lower arch lengths, palatal height, and palatal surface area. The respiratory and dental variables were then correlated.

RESULT

A statistically inverse correlation was found between ODI and anterior width of lower arch, maxillary arch length, palatal height, and palatal area. AHI showed a significant inverse correlation with anterior width of mandibular arch and maxillary length.

CONCLUSION

A significant inverse correlation between maxillary and mandibular morphology and respiratory parameters was shown in the present paper.

Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a common breathing disorder in sleep in which the airways narrow or collapse during sleep, causing obstructive sleep apnea. The prevalence of OSAS continues to rise worldwide, particularly in middle-aged and elderly individuals. The mechanism of upper airway collapse is incompletely understood but is associated with several factors, including obesity, craniofacial changes, altered muscle function in the upper airway, pharyngeal neuropathy, and fluid shifts to the neck. The main characteristics of OSAS are recurrent pauses in respiration, which lead to intermittent hypoxia (IH) and hypercapnia, accompanied by blood oxygen desaturation and arousal during sleep, which sharply increases the risk of several diseases. This paper first briefly describes the epidemiology, incidence, and pathophysiological mechanisms of OSAS. Next, the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed. For example, IH can induce gut microbiota (GM) dysbiosis, impair the intestinal barrier, and alter intestinal metabolites. These mechanisms ultimately lead to secondary oxidative stress, systemic inflammation, and sympathetic activation. We then summarize the effects of IH on disease pathogenesis, including cardiocerebrovascular disorders, neurological disorders, metabolic diseases, cancer, reproductive disorders, and COVID-19. Finally, different therapeutic strategies for OSAS caused by different causes are proposed. Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future, but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.

Changes in Functional Connectivity of Hippocampal Subregions in Patients with Obstructive Sleep Apnea after Six Months of Continuous Positive Airway Pressure Treatment

Previous studies have shown that the structural and functional impairments of hippocampal subregions in patients with obstructive sleep apnea (OSA) are related to cognitive impairment. Continuous positive airway pressure (CPAP) treatment can improve the clinical symptoms of OSA. Therefore, this study aimed to investigate functional connectivity (FC) changes in hippocampal subregions of patients with OSA after six months of CPAP treatment (post-CPAP) and its relationship with neurocognitive function. We collected and analyzed baseline (pre-CPAP) and post-CPAP data from 20 patients with OSA, including sleep monitoring, clinical evaluation, and resting-state functional magnetic resonance imaging. The results showed that compared with pre-CPAP OSA patients, the FC between the right anterior hippocampal gyrus and multiple brain regions, and between the left anterior hippocampal gyrus and posterior central gyrus were reduced in post-CPAP OSA patients. By contrast, the FC between the left middle hippocampus and the left precentral gyrus was increased. The changes in FC in these brain regions were closely related to cognitive dysfunction. Therefore, our findings suggest that CPAP treatment can effectively change the FC patterns of hippocampal subregions in patients with OSA, facilitating a better understanding of the neural mechanisms of cognitive function improvement, and emphasizing the importance of early diagnosis and timely treatment of OSA.

High- and low-intensity expiratory muscle strength training in patients with severe obstructive sleep apnea syndrome using non-invasive mechanical ventilation: A double-blinded, randomized controlled trial

BACKGROUND

The effects of expiratory muscle strength training (EMST) with different intensity on stages of sleep were not examined in patients with obstructive sleep apnea syndrome (OSAS).

OBJECTIVES

The aim of this study was to compare the effects of high- and low-intensity EMST (H-EMST and L-EMST) on disease severity, sleep stages, disease-related symptoms, daytime sleepiness, fatigue severity, and sleep quality in adult patients with severe OSAS using non-invasive mechanical ventilation (NIMV).

METHODS

Thirty-one clinically stable patients with severe OSAS were included in this prospective, randomized controlled, double-blinded study. These were randomly divided into two groups. The H-EMST group underwent training at 60% of maximum expiratory pressure (MEP) and the L-EMST group at 30% of MEP, seven days a week for eight weeks. Apnea hypopnea index (AHI), sleep stages, and respiratory sleep parameters were recorded using polysomnographic sleep analysis.

RESULTS

AHI decreased by 34.57% and 20.20% in the H-EMST and L-EMST groups, respectively. A statistically significant improvement in disease severity classifications distributions was observed in the H-EMST group after training (p = 0.016). A greater number of symptoms improved in the H-EMST. The effects of training on respiratory muscle strength, daytime sleepiness, fatigue perception, and sleep quality levels were comparable between the two groups (p>0.05).

CONCLUSIONS

H-EMST training is more effective in reducing disease severity and disease-related symptoms than L-EMST. Further studies are warranted for evaluating the long-term effects of EMST with larger sample sizes in OSAS.

The Usefulness of Questionnaires in Assessing the Risk of Obstructive Sleep Apnea in Patients in the Managed Care after Acute Myocardial Infarction Program-The Results of a Cross-Sectional Study

Obstructive sleep apnea (OSA) worsens prognosis after myocardial infarction (MI) but often remains undiagnosed. The study aimed to evaluate the usefulness of questionnaires in assessing the risk of OSA in patients participating in managed care after an acute myocardial infarction program. Study group: 438 patients (349 (79.7%) men) aged 59.92 ± 10.92, hospitalized in the day treatment cardiac rehabilitation department 7-28 days after MI. OSA risk assessment: A 4-variable screening tool (4-V), STOP-BANG questionnaire, Epworth sleepiness scale (ESS), and adjusted neck circumference (ANC). The home sleep apnea testing (HSAT) was performed on 275 participants. Based on four scales, a high risk of OSA was found in 283 (64.6%) responders, including 248 (56.6%) based on STOP-BANG, 163 (37.5%) based on ANC, 115 (26.3%) based on 4-V, and 45 (10.3%) based on ESS. OSA was confirmed in 186 (68.0%) participants: mild in 85 (30.9%), moderate in 53 (19.3%), and severe in 48 (17.5%). The questionnaires' sensitivity and specificity in predicting moderate-to-severe OSA were: for STOP-BANG-79.21% (95% confidence interval; CI 70.0-86.6) and 35.67% (95% CI 28.2-43.7); ANC-61.39% (95% CI 51.2-70.9) and 61.15% (95% CI 53.1-68.8); 4-V-45.54% (95% CI 35.6-55.8) and 68.79% (95% CI 60.9-75.9); ESS-16.83% (95% CI 10.1-25.6) and 87.90% (95% CI 81.7-92.6). OSA is common in post-MI patients. The ANC most accurately estimates the risk of OSA eligible for positive airway pressure therapy. The sensitivity of the ESS in the post-MI population is insufficient and limits this scale's usefulness in risk assessment and qualification for treatment.

Therapeutic role of adipose-derived mesenchymal stem cells-derived extracellular vesicles in rats with obstructive sleep apnea hypopnea syndrome

Background

Obstructive sleep apnea hypopnea syndrome (OSAHS) is an underestimated sleep disorder that leads to multiple organ damages, including lung injury (LI). This paper sought to analyze the molecular mechanism of extracellular vesicles (EVs) from adipose-derived mesenchymal stem cells (ADSCs) in OSAHS-induced lung injury (LI) via the miR-22-3p/histone lysine demethylase 6 B (KDM6B)/high mobility group AT-hook 2 (HMGA2) axis.

Methods

ADSCs and ADSCs-EVs were separated and characterized. Chronic intermittent hypoxia (CIH) was used to mimic OSAHS-LI, followed by ADSCs-EVs treatment and hematoxylin and eosin staining, TUNEL, ELISA, and assays of inflammation and oxidative stress (MPO/ROS/MDA/SOD). The CIH cell model was established and treated with ADSCs-EVs. Cell injury was assessed by the assays of MTT, TUNEL, ELISA, and others. Levels of miR-22-3p, KDM6B, histone H3 trimethylation at lysine 27 (H3K27me3), and HMGA2 were determine by RT-qPCR or Western blot analysis. The transfer of miR-22-3p by ADSCs-EVs was observed by fluorescence microscopy. Gene interactions were analyzed by dual-luciferase assay or chromatin immunoprecipitation.

Results

ADSCs-EVs effectively alleviated OSAHS-LI by reducing lung tissue injury, apoptosis, oxidative stress, and inflammation. In vitro, ADSCs-EVs increased cell viability and reduced apoptosis, inflammation and oxidative stress. ADSCs-EVs delivered enveloped miR-22-3p into pneumonocytes to upregulate miR-22-3p expression, inhibit KDM6B expression, increase H3K27me3 levels on the HMGA2 promoter, and decrease HMGA2 mRNA levels. Overexpression of KDM6B or HMGA2 attenuated the protective role of ADSCs-EVs in OSAHS-LI.

Conclusion

ADSCs-EVs transferred miR-22-3p to pneumonocytes and reduced apoptosis, inflammation, and oxidative stress through KDM6B/HMGA2, mitigating OSAHS-LI progression.

Real-Time Detection of Sleep Apnea Based on Breathing Sounds and Prediction Reinforcement Using Home Noises: Algorithm Development and Validation

BACKGROUND

Multinight monitoring can be helpful for the diagnosis and management of obstructive sleep apnea (OSA). For this purpose, it is necessary to be able to detect OSA in real time in a noisy home environment. Sound-based OSA assessment holds great potential since it can be integrated with smartphones to provide full noncontact monitoring of OSA at home.

OBJECTIVE

The purpose of this study is to develop a predictive model that can detect OSA in real time, even in a home environment where various noises exist.

METHODS

This study included 1018 polysomnography (PSG) audio data sets, 297 smartphone audio data sets synced with PSG, and a home noise data set containing 22,500 noises to train the model to predict breathing events, such as apneas and hypopneas, based on breathing sounds that occur during sleep. The whole breathing sound of each night was divided into 30-second epochs and labeled as "apnea," "hypopnea," or "no-event," and the home noises were used to make the model robust to a noisy home environment. The performance of the prediction model was assessed using epoch-by-epoch prediction accuracy and OSA severity classification based on the apnea-hypopnea index (AHI).

RESULTS

Epoch-by-epoch OSA event detection showed an accuracy of 86% and a macro F₁-score of 0.75 for the 3-class OSA event detection task. The model had an accuracy of 92% for "no-event," 84% for "apnea," and 51% for "hypopnea." Most misclassifications were made for "hypopnea," with 15% and 34% of "hypopnea" being wrongly predicted as "apnea" and "no-event," respectively. The sensitivity and specificity of the OSA severity classification (AHI≥15) were 0.85 and 0.84, respectively.

CONCLUSIONS

Our study presents a real-time epoch-by-epoch OSA detector that works in a variety of noisy home environments. Based on this, additional research is needed to verify the usefulness of various multinight monitoring and real-time diagnostic technologies in the home environment.

No Difference in Sleep Desaturations Severity between Patients with Wake-Up and Non-Wake-Up Stroke: A PRESS Study Results

BACKGROUND

Wake-up stroke (WUS) is a certain type of ischemic stroke in which a patient wakes up with a new neurological deficit due to cerebral ischemia. Sleep-disordered breathing is an independent risk factor for stroke, but the role of nocturnal oxygen desaturation in the pathophysiology of WUS is still insufficiently explored. According to several studies, patients with WUS have a significantly more severe sleep apnea syndrome and lower mean blood oxygen saturation. This study aimed to assess the severity of nocturnal desaturations in acute WUS and non-WUS patients using nocturnal pulse oximetry.

MATERIAL AND METHODS

The cohort of 225 consecutive patients with neuroimaging-verified acute cerebral ischemia was prospectively enrolled. For further analyses, 213 subjects with known WUS/non-WUS status were selected (111 males and 102 females, average age 70.4 ±12.9, median baseline NIHSS = 5, median baseline mRS = 3). Patients were divided into the WUS group (n = 45) and the non-WUS group (n = 168). Overnight pulse oximetry was performed within 7 days of the stroke onset and data of both of the studied groups were compared.

RESULTS

We found oxygen desaturation index (ODI) in the WUS group was 14.5 vs. 16.6 (p = 0.728) in the non-WUS group, basal O2 saturation was 92.2% vs. 92.5% (p = 0.475), average low O2 saturation was 90.3% vs. 89.6% (p = 0.375), minimal O2 saturation was 79.5% vs. 80.6% (p = 0.563), and time with O2 saturation <90% (T90) was 4.4% vs. 4.7% (p = 0.729).

CONCLUSIONS

In the studied sample, monitored respiratory parameters including ODI, basal O2 saturation, average low O2 saturation, minimal O2 saturation, and T90 did not significantly differ between groups of WUS and non-WUS patients.

Chronic Breathlessness in Obstructive Sleep Apnea and the Use of Lymphocyte Parameters to Identify Overlap Syndrome among Patients

Little is known about the distribution of etiology in obstructive sleep apnea (OSA) combined with chronic breathlessness. A significant portion of patients in this group have so-called "overlap syndrome (OVS)", characterized by chronic obstructive pulmonary disease (COPD). OVS has more complications and a poorer prognosis compared to patients with either OSA or COPD alone, which makes it important to identify OVS early in OSA. The current study was a retrospective cross-sectional analysis of consecutive adult patients who were diagnosed with OSA (n = 1062), of whom 275 were hospitalized due to chronic breathlessness. Respiratory and cardiac diseases accounted for the vast majority of causes, followed by gastrointestinal and renal disorders. The final study population comprised 115 patients with OSA alone (n = 64) and OVS (n = 51), who had chronic breathlessness as the primary complaint, not secondary as one of many other complaints. Lymphocytes, CD4 counts, neutrophil-to-lymphocyte ratio (NLR), and PLR were differently expressed between the OSA-alone group and OVS group. The NLR, lymphocytes, and CD4 counts had a moderate diagnostic value for OVS in OSA patients, with AUCs of 0.708 (95% CI, 0.614-0.802), 0.719 (95% CI, 0.624-0.813), and 0.744 (95% CI, 0.653-0.834), respectively. The NLR had the highest AUC for predicting a 6-month re-admission of OVS, with a cut-off of 3.567 and a moderate prognostic value. The sensitivity and specificity were 0.8 and 0.732, respectively. In the animal model, the spleen hematoxylin- and eosin-stained, electron microscopy images showed germinal-center damage, chromatin activation, and mitochondrial swelling under the overlapping effect of intermittent hypoxia and cigarette smoke exposure. OSA with chronic breathlessness cannot be overstated. A significant proportion of patients with COPD in this group had poor lung function at initial diagnosis. The NLR is a useful biomarker to differentiate OVS among OSA patients combined with chronic breathlessness.

The Need for Glaucoma Management in Glaucoma Patients with Concurrent Obstructive Sleep Apnea: A Population-Based Cohort Study

We try to evaluate glaucoma management numbers in patients with both glaucoma and obstructive sleep apnea (OSA) using the National Health Insurance Research Database (NHIRD) of Taiwan. A retrospective cohort study was conducted and patients with glaucoma were enrolled and divided into the OSA and non-OSA populations. A total of 11,778 participants were selected in both the OSA and non-OSA groups. The primary outcomes were the number of anti-glaucomatous medications each year and the total number of glaucoma laser and glaucoma surgeries. The Cox proportional hazard regression was utilized to produce the adjusted hazard ratios (AHR) with corresponding 95% confidence intervals (CI) between the two groups. After a study period of 18 years, 286 and 352 events of laser and surgeries for glaucoma were found in the OSA and non-OSA groups, respectively. After considering the effect of potential confounders, no significant difference concerning the numbers of laser trabeculoplasty, trabeculectomy and tube shunt surgery, cyclodestructive procedure and eyeball removal were found between the two groups (all 95% CIs included one). In addition, the multiple anti-glaucomatous medication usages were similar between the two groups (all p > 0.05) In the subgroup analyses, glaucoma patients older than 60 years and with OSA received significantly lesser trabeculectomy and tube shunt surgery compared to glaucoma patients older than 60 years without OSA (AHR: 0.774, 95% CI: 0.611−0.981) while other analyses revealed insignificant results (all 95% CIs included one). In conclusion, the presence of OSA does not increase the need for glaucoma management.

Obstructive Sleep Apnea, Circadian Clock Disruption, and Metabolic Consequences

Obstructive sleep apnea (OSA) is a chronic disorder characterized by recurrent episodes of apnea and hypopnea during sleep. It is associated with various cardiovascular and metabolic complications, including type 2 diabetes mellitus (T2DM) and obesity. Many pathways can be responsible for T2DM development in OSA patients, e.g., those related to HIF-1 and SIRT1 expression. Moreover, epigenetic mechanisms, such as miRNA181a or miRNA199, are postulated to play a pivotal role in this link. It has been proven that OSA increases the occurrence of circadian clock disruption, which is also a risk factor for metabolic disease development. Circadian clock disruption impairs the metabolism of glucose, lipids, and the secretion of bile acids. Therefore, OSA-induced circadian clock disruption may be a potential, complex, underlying pathway involved in developing and exacerbating metabolic diseases among OSA patients. The current paper summarizes the available information pertaining to the relationship between OSA and circadian clock disruption in the context of potential mechanisms leading to metabolic disorders.

Sleep Apnea and Cardiovascular Risk in Patients with Prediabetes and Type 2 Diabetes

Obstructive sleep apnea (OSA) is a common but largely undiagnosed clinical condition, which is turning into a serious public health issue. Of note is that its prevalence is gradually increasing in parallel with the obesity and type 2 diabetes mellitus (T2DM) epidemics. The aim of this article is to comprehensively review the literature in order to evaluate the cardiovascular (CV) risk among patients with OSA and prediabetes or T2DM. OSA seems to be an independent risk factor for the development as well as the progression of T2DM, whereas it is associated with T2DM-related macrovascular and microvascular complications. OSA may also act as a potential risk factor for the presentation and development of CV disease, such as hypertension, coronary artery disease, heart failure, pulmonary hypertension, atrial fibrillation and other cardiac arrythmias, as well as stroke. OSA and T2DM also share common pathophysiological mechanisms leading to atherosclerosis. Considering that the coexistence of OSA and T2DM is an independent and cumulative risk factor for CV mortality, more so than the two diseases separately, clinicians and healthcare professionals should be aware of and screen for OSA in patients with T2DM. Notably, targeted therapy for both conditions seems to substantially improve CV prognosis.

Hydrogen Sulfide: A Gaseous Mediator and Its Key Role in Programmed Cell Death, Oxidative Stress, Inflammation and Pulmonary Disease

Hydrogen sulfide (H₂S) has been acknowledged as a novel gaseous mediator. The metabolism of H₂S in mammals is tightly controlled and is mainly achieved by many physiological reactions catalyzed by a suite of enzymes. Although the precise actions of H₂S in regulating programmed cell death, oxidative stress and inflammation are yet to be fully understood, it is becoming increasingly clear that H₂S is extensively involved in these crucial processes. Since programmed cell death, oxidative stress and inflammation have been demonstrated as three important mechanisms participating in the pathogenesis of various pulmonary diseases, it can be inferred that aberrant H₂S metabolism also functions as a critical contributor to pulmonary diseases, which has also been extensively investigated. In the meantime, substantial attention has been paid to developing therapeutic approaches targeting H₂S for pulmonary diseases. In this review, we summarize the cutting-edge knowledge on the metabolism of H₂S and the relevance of H₂S to programmed cell death, oxidative stress and inflammation. We also provide an update on the crucial roles played by H₂S in the pathogenesis of several pulmonary diseases. Finally, we discuss the perspective on targeting H₂S metabolism in the treatment of pulmonary diseases.

Association between Berlin questionnaire index and blood pressure, organ damage and metabolic profilein a general population

We evaluated the relationships between Berlin questionnaire (BQ) scores, hypertension and other metabolic variables in 598 subjects (age: 65.8 ± 10 years, mean ± SD) enrolled in the PAMELA (Pressioni Arteriose Monitorate E Loro Associazioni) study representative of the general population, treated or untreated with antihypertensive drugs. Two hundred and eleven subjects (35%) had a positive BQ with two or more positive categories of the inquiry. Compared to those without sleep disorders these subjects showed a greater male prevalence (55.9%), worse serum cholesterol, triglycerides and glucose profile, greater body mass index (BMI) (28.9 ± 4.9 vs. 24.9 ± 3.4 kg/m² ), higher office (and to a lesser extent 24-h) BP and HR values, higher serum creatinine values and greater rate of echocardiographic left ventricular (LV) hypertrophy (25% vs. 13%). These differences were not detected when the data analysis was restricted to treated hypertensive patients. Thus, BQ scores allow to identify among subjects belonging to a general population those with elevated BP, organ damage and altered metabolic. When antihypertensive drug treatment is present, however, the approach fails to detect differences between groups with low or high BQ index.

Danlou Tablet May Alleviate Vascular Injury Caused by Chronic Intermittent Hypoxia through Regulating FIH-1, HIF-1, and Angptl4

Background

Danlou tablet (DLT), the traditional Chinese medicine has been commonly used for dyslipidemia, atherosclerosis, and coronary heart disease. Whether it was effective against vascular injury caused by CIH has remained unknown. The aim of the current study was to observe the effects of DLT on chronic intermittent hypoxia (CIH)-induced vascular injury via regulation of blood lipids and to explore potential mechanisms.

Methods

Sixteen 12-week-old male ApoE^−/− mice were randomly divided into four groups. The sham group was exposed to normal room air, whereas the other three groups were exposed to CIH. Mice in the CIH + normal saline (NS) group were gavaged with NS. Mice in the CIH + Angptl4-ab group were intraperitoneally injected with Angptl4-antibody. Mice in the CIH + DLT group were gavaged with DLT. After four weeks of intervention, serum lipid concentrations, and serum lipoprotein lipase (LPL) activity were detected. The changes in atherosclerosis in vascular tissue were detected by hematoxylin and eosin (H&E) staining. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis were applied to detect the expression levels of hypoxia-induciblefactor-1 (HIF-1), factor-inhibiting HIF-1 (FIH-1), angiopoietin-like 4 (Angptl4), and LPL in different tissues.

Results

CIH exposure increases serum lipid levels, decreases serum LPL activity, and exacerbates atherosclerosis. Both Angptl4-ab and DLT treatment reversed the changes in lipid concentration, LPL activity, and atherosclerosis caused by CIH. In the epididymal fat pad, CIH exposure decreased the expression of FIH-1 and increased the expression of HIF-1, whereas DLT treatment increased the expression of FIH-1 and LPL and inhibited the expression of HIF-1 and Angptl4. In heart tissue, the expression levels of LPL and Angptl4 were not affected by modeling or treatment.

Conclusions

DLT improved vascular damage by improving the increase in blood lipids induced by CIH, potentially by upregulating FIH-1 and downregulating HIF-1 and Angptl4 in adipose tissue. Therefore, DLT may be a promising agent for the prevention and treatment of CIH-induced vascular injury.

Effects of Exercise on Patients with Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

With exercise being more frequently utilized in treatment for obstructive sleep apnea (OSA), a systematic review of the intervention efficacy of exercise on OSA is necessary. PubMed, EBSCO, Web of Science, VIP, and CNKI databases were searched to collect randomized controlled trials (RCTs) of exercise applied to OSA from January 2000 to January 2022. The literature screening, data extraction, and risk of bias assessment of included studies were conducted independently by two reviewers. Meta-analysis was then performed using Rev Man 5.4 software. A total of 9 RCTs were included, including 444 patients. Compared with the control group, exercise made an improvement in apnea-hypopnea index (AHI) [MD = -6.65, 95% CI (-7.77, -5.53), p < 0.00001], minimum oxygen saturation (SaO_2min%) [MD = 1.67, 95% CI (0.82, 2.52), p = 0.0001], peak oxygen uptake (VO_2peak) [SMD = 0.54, 95% CI (0.31, 0.78), p < 0.00001], Pittsburgh sleep quality index (PSQI) [MD = -2.08, 95% CI (-3.95, -0.21), p = 0.03], and Epworth Sleepiness Scale (ESS) values [MD = -1.64, 95% CI, (-3.07, -0.22), p = 0.02]. However, there were no significant changes in body mass index (BMI). As for the results of subgroup analysis, aerobic exercise combined with resistance exercise [MD = -7.36, 95% CI (-8.64, -6.08), p < 0.00001] had a better effect on AHI reduction than aerobic exercise alone [MD = -4.36, 95% CI (-6.67, -2.06), p = 0.0002]. This systematic review demonstrates that exercise reduces the severity of OSA with no changes in BMI, and the effect of aerobic exercise combined with resistance training is better than aerobic exercise alone in AHI reduction. Exercise also improves cardiopulmonary fitness, sleep quality, and excessive daytime sleepiness.

Association of Obstructive Sleep Apnea Syndrome (OSA/OSAHS) with Coronary Atherosclerosis Risk: Systematic Review and Meta-Analysis

Objective

Obstructive sleep apnea syndrome (OSA) is the most common type of sleep disorders. This study aimed to systematically review the correlation between OSA and the risk of coronary atherosclerosis.

Methods

Literature on case-control studies on the relationship between coronary heart disease (CHD) and sleep apnea syndrome was collected and collated, and the incidence of SAS in CHD and non-CHD patients was observed and compared. RevMan 5.2 analysis software and Stata12SE analysis software were used for heterogeneity test and combination analysis of the included studies. The results were expressed with odds ratio (OR), 95% confidence intervals (CI) were calculated, and publication bias and sensitivity tests were evaluated.

Results

There was a statistical difference in OSA associated with the risk of coronary atherosclerosis between the experimental group and the control group [OR = 1.38, 95% CI (1.18, 1.62), P < 0.0001, I ² = 0%, Z = 3.93]. OSA associated with vascular endothelial injury [OR = 3.59, 95% CI (3.00, 4.29), P < 0.00001, I ² = 90%, Z = 14.09]. OSA is associated with vascular oxidation emergency [OR = 2.19, 95% CI (2.05, 2.33), P < 0.00001, I ² = 94%, Z = 23.40]; OSA is associated with chronic vascular inflammation [OR = 1.70, 95% CI (1.39, 2.07), P < 0.00001, I ² = 16%, Z = 5.18].

Conclusion

The incidence of obstructive sleep apnea in patients with CHD was higher than that in non-CHD patients, and obstructive sleep apnea was a risk factor for CHD.

Associations of Chronic Diabetes Complications and Cardiovascular Risk with the Risk of Obstructive Sleep Apnea in Patients with Type 2 Diabetes

Background: Type 2 diabetes mellitus (T2DM) is associated with increased mortality and morbidity, including cardiovascular diseases and obstructive sleep apnea (OSA). The aim of this study was to assess the associations between cardiovascular risk, chronic diabetes complications and the risk of OSA in adult patients with T2DM. Methods: The study included 529 patients with T2DM in whom moderate-to-severe OSA risk was assessed using the STOP-Bang questionnaire, dividing the subjects into two groups: group 1: STOP-Bang score <5, and group 2: STOP-Bang score ≥5, respectively. In all the subjects, cardiovascular risk was assessed using the UKPDS risk engine. Statistical analysis was performed using SPSS 26.0, the results being statistically significant if p value was <0.05. Results: 59% of the subjects scored ≥5 on the STOP-Bang questionnaire. We recorded statistically significant differences between the two groups regarding diabetes duration, HbA1c, HOMA-IR, albuminuria, as well as cardiovascular risk at 10 years for both coronary heart disease (CHD) and stroke (p < 0.05). Furthermore, through logistic regression, adjusting for confounding factors, we demonstrated that the STOP-Bang score ≥ 5 is a risk factor for 10-year fatal and nonfatal CHD risk. Conclusions: It is extremely important to screen and diagnose OSA in patients with T2DM, in order to improve the primary and secondary prevention of cardiovascular events in these patients.

Risk factors for Barrett's esophagus: Recent advances

Esophageal adenocarcinoma (EAC) is the most common malignant tumor of the esophagus in the West. During the past few decades, its morbidity has been increasing in China. Barrett's esophagus (BE) is defined as the replacement of normal squamous epithelium in the lower esophagus by metaplasia of columnar epithelium. BE is closely related to the occurrence of EAC. Knowledge regarding the risk factors for the occurrence and development of BE is of great significance for early screening and diagnosis of BE and prevention of EAC. In this paper, we review the clinical, demographics-related, lifestyle-related, and medications-related risk factors for BE to provide more valuable scientific evidence for the prevention and treatment of BE.

Diagnostic value of smartphone in obstructive sleep apnea syndrome: A systematic review and meta-analysis

Objectives

To assess the diagnostic utility of smartphone-based measurement in detecting moderate to severe obstructive sleep apnea syndrome (OSAS).

Methods

Six databases were thoroughly reviewed. Random-effect models were used to estimate the summary sensitivity, specificity, negative predictive value, positive predictive value, diagnostic odds ratio, summary receiver operating characteristic curve and measured the areas under the curve. To assess the accuracy and precision, pooled mean difference and standard deviation of apnea hypopnea index (AHI) between smartphone and polysomnography (95% limits of agreement) across studies were calculated using the random-effects model. Study methodological quality was evaluated using the QUADAS-2 tool.

Results

Eleven studies were analyzed. The smartphone diagnostic odds ratio for moderate-to-severe OSAS (apnea/hypopnea index > 15) was 57.3873 (95% confidence interval [CI]: [34.7462; 94.7815]). The area under the summary receiver operating characteristic curve was 0.917. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.9064 [0.8789; 0.9282], 0.8801 [0.8227; 0.9207], 0.9049 [0.8556; 0.9386], and 0.8844 [0.8234; 0.9263], respectively. We performed subgroup analysis based on the various OSAS detection methods (motion, sound, oximetry, and combinations thereof). Although the diagnostic odds ratios, specificities, and negative predictive values varied significantly (all p < 0.05), all methods afforded good sensitivity (> 80%). The sensitivities and positive predictive values were similar for the various methods (both p > 0.05). The mean difference with standard deviation in the AHI between smartphone and polysomnography was -0.6845 ± 1.611 events/h [-3.8426; 2.4735].

Conclusions

Smartphone could be used to screen the moderate-to-severe OSAS. The mean difference between smartphones and polysomnography AHI measurements was small, though limits of agreement was wide. Therefore, clinicians should be cautious when making clinical decisions based on these devices.

OSA and Chronic Respiratory Disease: Mechanisms and Epidemiology

Obstructive sleep apnea (OSA) is a highly prevalent disorder that has profound implications on the outcomes of patients with chronic lung disease. The hallmark of OSA is a collapse of the oropharynx resulting in a transient reduction in airflow, large intrathoracic pressure swings, and intermittent hypoxia and hypercapnia. The subsequent cytokine-mediated inflammatory cascade, coupled with tractional lung injury, damages the lungs and may worsen several conditions, including chronic obstructive pulmonary disease, asthma, interstitial lung disease, and pulmonary hypertension. Further complicating this is the sleep fragmentation and deterioration of sleep quality that occurs because of OSA, which can compound the fatigue and physical exhaustion often experienced by patients due to their chronic lung disease. For patients with many pulmonary disorders, the available evidence suggests that the prompt recognition and treatment of sleep-disordered breathing improves their quality of life and may also alter the course of their illness. However, more robust studies are needed to truly understand this relationship and the impacts of confounding comorbidities such as obesity and gastroesophageal reflux disease. Clinicians taking care of patients with chronic pulmonary disease should screen and treat patients for OSA, given the complex bidirectional relationship OSA has with chronic lung disease.