Prevalence of Obstructive Sleep Apnea Syndrome: A Single-Center Retrospective Study

A meta-analysis of the correlation between obstructive sleep apnea syndrome and renal injury

OBJECTIVE

To conduct a meta-analysis on the correlation between obstructive sleep apnea syndrome (OSAS) and renal injury.

METHODS

Literature search was carried out in PubMed, Embase and Ovid-Medline databases between the date of database establishment and June 30th 2024. The keywords included obstructive sleep apnea hypopnea syndrome, sleep apnea hypopnea syndrome, renal injury, and correlation. Two researchers 1st independently screened the titles and abstracts based on the eligibility criteria, then extracted the data and evaluated the quality, and used Review Manager 5.3 for data processing. All analysis methods were based on PRISMA.

RESULTS

Finally, 8 studies that matched the inclusion criteria were included, and the relationship between obstructive sleep apnea syndrome and serum cystatin C was analyzed. The homogeneity test showed (P < 0.01, I2 = 98%), and from the meta-analysis results, it could be known that the level of serum cystatin C in sufferers with OSAS was obviously greater than the control one (OR = 1.12, 95% CI 0.96-1.28, P < 0.01). The relationship between OSAS and serum creatinine was analyzed, and homogeneity test showed (P < 0.01, I2 = 96%). From the meta analysis result, it could be known that the serum creatinine level of obstructive sleep apnea syndrome was obviously greater than the control one (OR = 1.01, 95% CI 0.85 ~ 1.17, P < 0.01). The relationship between obstructive sleep apnea syndrome with serum urea nitrogen was analyzed, and homogeneity test showed (P < 0.01, I2 = 91%). From the meta-analysis results, it could be known that serum urea nitrogen of OSAS was obviously greater than the control one (OR = 1.38, 95% CI 01.17 ~ 1.59, P < 0.01).

CONCLUSIONS

Eight articles have been included to determine the correlation between obstructive sleep apnea syndrome and renal injury, and it has been found that obstructive sleep apnea syndrome is closely related to renal injury, and the two may be risk factors for each other.

Update on the clinical applications of SGLTis: Insight to benefits beyond hypoglycemic and cardiorenal protection

Sodium glucose cotransporter inhibitor (SGLTi) drugs have been widely used in clinical practice. In addition to their benefits in hyperglycemia, heart failure (HF), and kidney disease, their effects on obesity, metabolic dysfunction-associated steatotic liver disease (MASLD, formerly named nonalcoholic fatty liver disease [NAFLD]), polycystic ovarian syndrome (PCOS), abnormal lipid metabolism, hyperuricemia, obstructive sleep apnea syndrome (OSAS), anemia, and syndrome of inappropriate antidiuresis (SIAD, formerly named syndrome of inappropriate antidiuretic hormone [SIADH]) have been explored. In this review, we searched the data of clinical randomized controlled trials (RCTs) and meta-analyses of SGLTis in patients with diabetes from the PubMed library between January 1, 2020, and February 1, 2024. According to our review, certain SGLTis exhibit relatively superior clinical safety and effectiveness for treating the abovementioned diseases. Proper utilization of SGLTis in these patients can provide additional medication options for patients with different disease scenarios. However, studies of SGLTis in these diseases are relatively rare, with shortcomings such as small sample sizes and short intervention periods. Therefore, further large-scale, long-term, well-designed studies are needed to clarify the findings.

The impact of duration and severity of obesity exposure on cardiometabolic health

PURPOSE

Duration and severity of exposure to excess adipose tissue are important risk factors for complications, but are generally not examined in conjunction. We developed a metric considering both factors to examine the relationship between obesity-related complications and parameters of cardiometabolic health in patients undergoing a metabolic bariatric procedure (MBS).

MATERIALS & METHODS

Data from patients screened for primary MBS between 2017 and 2021 were analyzed. The Obesity Exposure score (OBES), based on self-reported years of life with a BMI ≥ 25 kg/m2, was calculated with increased weighting applied for higher BMI categories. Multivariate logistic regression analysis was performed, adjusting for multiple potential confounders.

RESULTS

In total, 2441 patients were included (76% female, age 42.1 ± 11.9 years, BMI 42.0 ± 4.9 kg/m2). OBES was positively related to myocardial infarction, atrial fibrillation and renal function loss (per 10 OBES-units: OR 1.31, 95%CI [1.11-1.52], p = 0.002; OR 1.23, 95% CI [1.06-1.44], p = 0.008; and OR 1.26, 95% CI [1.04-1.51], p = 0.02). OBES was negatively associated with obstructive sleep apnea syndrome (OSAS) (OR 0.90, 95% CI [0.83-0.98], p = 0.02). In patients without obesity-related complications, OBES was related to lower HbA1c and higher HDL-cholesterol levels (ß -0.5 95% CI [-0.08-.0.02] p < 0.001 and ß 0.02 [0.00-0.04] p = 0.01).

CONCLUSION

OBES was related to myocardial infarction, atrial fibrillation and renal function loss in patients applying for MBS. OBES was negatively related to OSAS, possibly because undiagnosed years were not taken into account. In the absence of obesity-related complications, OBES was not related to metabolic blood markers. Our data may aid in improving perioperative risk assessments.

Sleep Disorders in Connective Tissue Diseases-Coexisting Diseases or Disease Components?

This comprehensive review examines the complex relationship between sleep disorders and rheumatic diseases, supported by findings from the latest research articles. It encompasses various rheumatic conditions, including rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis. The review reveals the bidirectional relationship between sleep disorders and these diseases, emphasizing their impact on disease progression and quality of life. Conventional and alternative therapeutic interventions for connective tissue diseases are presented, focusing on improving sleep quality and alleviating rheumatic symptoms. The role of pro-inflammatory cytokines and their potential modulation through pharmacological agents is also discussed. In the treatment of sleep disorders, various options are proposed, such as cognitive behavioral therapy for insomnia, physical activity, dietary modifications, and alternative approaches like reflexology and acupuncture. Thus, this review offers a nuanced understanding of the connection between sleep disorders and rheumatic diseases, supported by evidence from diverse studies. Such an approach is particularly important because it enhances sleep quality for overall patient well-being in the holistic management of rheumatic conditions.

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.

Right Versus Left Cuff Position for Upper Airway Stimulation

OBJECTIVE

Upper airway stimulation (UAS) is a treatment option for obstructive sleep apnea in which electrical stimulation is applied to the hypoglossal nerve. Nerve branches that control tongue protrusion are located inferiorly. Due to positioning, left-sided implants are typically placed with an inferiorly oriented electrode cuff (L-down) as opposed to superiorly on the right (R-up). In this study, we assess the impact of left- versus right-sided UAS on patient outcomes.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary Academic Medical Center.

METHODS

Patients who underwent UAS implantation between 2016 and 2021 with an L-down or R-up oriented cuff as confirmed by X-ray were included. Data were collected retrospectively. Most recent sleep study variables were used for analysis.

RESULTS

A total of 190 patients met the inclusion criteria. The average age was 61.0 ± 11.0 years, with 55 (28.9%) females. L-down orientation was present in 21 (11.1%) patients vs 169 (88.9%) R-up. Indications for L-down included hunting/shooting (n = 15), prior radiation/surgery (n = 4), central port (n = 1), and brachial plexus injury (n = 1). Adherence was higher among L-down patients (47.1 vs 41.0 hours use/week, P = .037) in univariate analysis, with a similar time to adherence data collection (4.4 vs 4.2 months, P = .612), though this finding was not maintained in the multivariate regression analysis. Decrease in apnea-hypopnea index (21.3 vs 22.8, P = .734), treatment success (76.5% vs 84.0%, P = .665), functional threshold (1.5 vs 1.6, P = .550), therapeutic amplitude (2.3 vs 2.4, P = .882), and decrease in Epworth Sleepiness Scale (4.9 vs 2.6, P = .060) were not significantly different between cohorts.

CONCLUSION

This study is the first to examine the orientation of the UAS electrode cuff concerning the electrodes' natural position and the potential effect on postoperative outcomes. Our study found no significantly different treatment outcomes between the L-down versus R-up cohort, with the exception of device adherence, which was significantly higher in the L-down group on univariate analysis though not on multivariate analysis. Future studies with larger patient cohorts are needed to further investigate this potential relationship between treatment outcomes and electrode cuff orientation.

Relationship between periodontal disease and obstructive sleep apnea in adults: A systematic review

The purpose of this systematic review was to evaluate whether there are scientific evidence regarding the association between periodontitis and obstructive sleep apnea (OSA) in adults. An electronic search was performed on MEDLINE/PubMed for prospective and retrospective longitudinal studies, cohort studies, and case-control studies conducted in human adults affected by both OSA and periodontitis. Two reviewers extracted the data using a custom Excel spreadsheet. A methodological assessment of the quality of the studies was performed using the Newcastle-Ottawa Scale. Fourteen studies were included. All studies evaluated the association between periodontitis and OSA. None of the studies evaluated the cause-effect relationship. Eleven studies found a significant positive relationship between periodontitis and OSA, whereas three found no statistically significant association. Several study limitations were observed, such as lack of standardization of study groups, diagnosis of periodontitis and OSA, and differences in study design. Evidence of a plausible association between periodontitis and OSA was found. The possible relationship could be explained by systemic inflammation, oral breathing, and the comorbid relationship attributable to common risk factors. Observational and randomized controlled studies are needed to clarify the mechanism of interaction between the two conditions.

Prevalence of Obstructive Sleep Apnea Among Atrial Fibrillation Patients: A Cross-Sectional Study from Jordan

Background

Obstructive Sleep Apnea (OSA) is a common respiratory disorder that causes intermittent upper airway collapse during sleep and can lead to various acute cardiovascular complications. Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with an increased risk of cardiovascular hospitalization and all-cause mortality. Our study aimed to investigate the prevalence of individuals with AF and those considered at high risk for OSA.

Methods

A cross-sectional study was conducted with a population comprising patients who had visited KAUH cardiology clinics between 2017-2019; subjects were categorized into AF patients and general cardiology patients. Patients were surveyed for OSA using the Berlin Questionnaire to assess the degree of OSA symptoms and to classify patients into high- or low-risk groups based on their responses.

Results

Of the 656 patients, 545 met our inclusion criteria, of whom 192 were diagnosed with AF. Comparable demographic characteristics were observed between the AF and non-AF groups, barring higher rates of obesity (p=0.001) and smoking (p=0.042) in the AF group. The prevalence of high-risk OSA was significantly higher in AF patients (68.2%) compared to non-AF patients (29.4%), with an adjusted odds ratio of 2.473 times (95% CI: 1.434 -4.266, p=0.001) greater for AF. The age, gender, and BMI categories did not differ significantly between the two groups. Binary logistic regression revealed significant associations between OSA and risk factors such as asthma (OR=4.408, 95% CI: 2.634-7.376, p=0.001).

Conclusion

These results serve to display a statistically significant increase in high-risk OSA in existing AF patients, irrespective of the presence of conventional OSA risk factors; this could imply a more immediate and direct relationship between both diseases and calls to include routine screening for OSA in patients diagnosed, newly or otherwise, with AF.

Prospective clinical validation of the Empatica EmbracePlus wristband as a reflective pulse oximeter

Introduction

Respiratory diseases such as chronic obstructive pulmonary disease, obstructive sleep apnea syndrome, and COVID-19 may cause a decrease in arterial oxygen saturation (SaO2). The continuous monitoring of oxygen levels may be beneficial for the early detection of hypoxemia and timely intervention. Wearable non-invasive pulse oximetry devices measuring peripheral oxygen saturation (SpO2) have been garnering increasing popularity. However, there is still a strong need for extended and robust clinical validation of such devices, especially to address topical concerns about disparities in performances across racial groups. This prospective clinical validation aimed to assess the accuracy of the reflective pulse oximeter function of the EmbracePlus wristband during a controlled hypoxia study in accordance with the ISO 80601-2-61:2017 standard and the Food & Drug Administration (FDA) guidance.

Methods

Healthy adult participants were recruited in a controlled desaturation protocol to reproduce mild, moderate, and severe hypoxic conditions with SaO2 ranging from 100% to 70% (ClinicalTrials.gov registration #NCT04964609). The SpO2 level was estimated with an EmbracePlus device placed on the participant's wrist and the reference SaO2 was obtained from blood samples analyzed with a multiwavelength co-oximeter.

Results

The controlled hypoxia study yielded 373 conclusive measurements on 15 subjects, including 30% of participants with dark skin pigmentation (V-VI on the Fitzpatrick scale). The accuracy root mean square (Arms) error was found to be 2.4%, within the 3.5% limit recommended by the FDA. A strong positive correlation between the wristband SpO2 and the reference SaO2 was observed (r = 0.96, P < 0.001), and a good concordance was found with Bland-Altman analysis (bias, 0.05%; standard deviation, 1.66; lower limit, -4.7%; and upper limit, 4.8%). Moreover, acceptable accuracy was observed when stratifying data points by skin pigmentation (Arms 2.2% in Fitzpatrick V-VI, 2.5% in Fitzpatrick I-IV), and sex (Arms 1.9% in females, and 2.9% in males).

Discussion

This study demonstrates that the EmbracePlus wristband could be used to assess SpO2 with clinically acceptable accuracy under no-motion and high perfusion conditions for individuals of different ethnicities across the claimed range. This study paves the way for further accuracy evaluations on unhealthy subjects and during prolonged use in ambulatory settings.

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.

The Effects of the Myobrace® System on Peripheral Blood Oxygen Saturation (SpO2) in Patients with Mixed Dentition with Oral Dysfunction

INTRODUCTION

Myobrace® is an orthodontic device that has the purpose of correcting oral dysfunctions, thus predisposing the physiological growth of the jaws, aligning teeth, and optimizing face development. This device is usually associated with Myobrace® Activities to reach this target. Considering the lack of studies in the literature about peripheral blood oxygen saturation (SpO2) and the use of preformed oral devices, the aim of this study is to quantify the change in blood oxygen saturation (SpO2) in patients treated with the Myobrace® System in mixed dentition.

MATERIALS AND METHODS

In this study, 23 children (11 females and 12 males) were involved, who were affected by different oral dysfunctions and were treated with a Myobrace®. Blood oxygen saturation measurements were taken at baseline and after every four months for a year. The SpO2 measurements were taken in the rest position and with a closed mouth for a total of 12 min-6 min with and 6 min without the Myobrace® oral device. All data points were anonymized and recorded on an Excel spreadsheet. A statistical analysis was carried out.

RESULTS

Therapy with a Myobrace® in patients with mixed dentition resulted in a statistically significant increase in oxygen saturation. In particular, in patients with a closed mouth, a statistically significant increase in oxygen saturation was observed, bringing it from 97.66% to 99.00%, while in the rest position, the increase was from 98.03% to 99.07%.

CONCLUSIONS

The use of Myobrace® devices in patients with mixed dentition could lead to a significant improvement in blood oxygen saturation.

Association between Obstructive Sleep Apnea and Chronic Kidney Disease According to Sex, Long Working Hours: The Korean National Health and Nutrition Examination Survey (2019-2020)

This study aimed to investigate whether obstructive sleep apnea (OSA) is associated with an increased risk of chronic kidney disease (CKD) and to perform subgroup analysis by sex and working hours. This cross-sectional study was conducted on 8157 subjects who participated in the Korea National Health and Nutrition Examination Survey (KNHANES). The adults completed the STOP-BANG score to measure their risk of OSA, and blood and urine samples were collected to ascertain the severity of CKD based on the estimated glomerular filtration rate and urine albumin-to-creatinine ratio. Multivariate logistic regression was used for complex sample analysis. After fully adjusting for the confounding variables, the high-risk OSA group showed a significantly higher risk of developing albuminuria and CKD than the low-risk group, particularly among men. Odds ratio (OR) 1.72, 95% confidence interval (CI) 1.13-2.6 and (OR 1.67, 95% CI 1.14-2.45), respectively. Additionally, men who worked for 40 h/week showed a significant association between OSA, CKD, and albuminuria. This study supports the link between OSA and the risk of kidney disease, especially among men and those who work long hours. Screening and treating OSA may be a crucial strategy for preventing kidney disease, particularly in high-risk populations.

Is sleep apnea truly associated with hearing loss? A nationwide, population-based study with STOP-BANG questionnaire

Objectives

We aimed to investigate the effect of obstructive sleep apnea (OSA) on hearing ability.

Methods

We retrospectively reviewed the population-based survey data collected by the Korean National Health and Nutrition Examination Survey between January 1, 2019 and December 31, 2020. The data included 3,575 participants who completed the STOP-BANG questionnaire (SBQ) and pure-tone audiometry. OSA risk was assessed using the SBQ, and the hearing level was compared between the risk groups.

Results

Among the 3,575 participants, 2,152 (60.2%), 891 (24.9%), and 532 (14.9%) were classified as being low, intermediate, and high risk, respectively. The intermediate- and high-risk groups showed significantly worse hearing levels than the low-risk group. When age and sex were adjusted, the hearing level did not differ between the risk groups.

Conclusion

The study found that the presence of OSA minimally affected hearing level. Because hearing loss due to hypoxic damage develops over a long period of time, further research on the association between the duration of OSA, rather than the presence or severity of OSA, and hearing loss is needed.

Genome-wide association study of obstructive sleep apnoea in the Million Veteran Program uncovers genetic heterogeneity by sex

BACKGROUND

Genome-wide association studies (GWAS) for obstructive sleep apnoea (OSA) are limited due to the underdiagnosis of OSA, leading to misclassification of OSA, which consequently reduces statistical power. We performed a GWAS of OSA in the Million Veteran Program (MVP) of the U.S. Department of Veterans Affairs (VA) healthcare system, where OSA prevalence is close to its true population prevalence.

METHODS

We performed GWAS of 568,576 MVP participants, stratified by biological sex and by harmonized race/ethnicity and genetic ancestry (HARE) groups of White, Black, Hispanic, and Asian individuals. We considered both BMI adjusted (BMI-adj) and unadjusted (BMI-unadj) models. We replicated associations in independent datasets, and analysed the heterogeneity of OSA genetic associations across HARE and sex groups. We finally performed a larger meta-analysis GWAS of MVP, FinnGen, and the MGB Biobank, totalling 916,696 individuals.

FINDINGS

MVP participants are 91% male. OSA prevalence is 21%. In MVP there were 18 and 6 genome-wide significant loci in BMI-unadj and BMI-adj analyses, respectively, corresponding to 21 association regions. Of these, 17 were not previously reported in association with OSA, and 13 replicated in FinnGen (False Discovery Rate p-value < 0.05). There were widespread significant differences in genetic effects between men and women, but less so across HARE groups. Meta-analysis of MVP, FinnGen, and MGB biobank revealed 17 additional, previously unreported, genome-wide significant regions.

INTERPRETATION

Sex differences in genetic associations with OSA are widespread, likely associated with multiple OSA risk factors. OSA shares genetic underpinnings with several sleep phenotypes, suggesting shared aetiology and causal pathways.

FUNDING

Described in acknowledgements.

The Management of Obstructive Sleep Apnea Patients during the COVID-19 Pandemic as a Public Health Problem-Interactions with Sleep Efficacy and Mental Health

With the onset of the COVID-19 outbreak, it was stipulated that patients with obstructive sleep apnea (OSA) may have a greater risk of morbidity and mortality and may even experience changes in their mental health. The aim of the current study is to evaluate how patients managed their disease (sleep apnea) during the COVID-19 pandemic, to determine if continuous positive airway pressure (CPAP) usage changed after the beginning of the pandemic, to compare the stress level with the baseline, and to observe if any modifications are related to their individual characteristics. The present studies highlight the level of anxiety, which was high among patients with OSA during the COVID-19 pandemic (p < 0.05), with its influence on weight control (62.5% of patients with high levels of stress gained weight) and sleep schedule (82.6% reported a change in sleep schedule). Patients with severe OSA and high levels of stress increased their CPAP usage (354.5 min/night vs. 399.5 min/night during the pandemic, p < 0.05). To conclude, in OSA patients, the presence of the pandemic led to a greater level of anxiety, changes in sleep schedule and weight gain because of job loss, isolation, and emotional changes, influencing mental health. A possible solution, telemedicine, could become a cornerstone in the management of these patients.

Prevalence of risk and factors associated with obstructive sleep apnea-hypopnea syndrome in an adult population in Kinshasa, Democratic Republic of Congo

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an underdiagnosed and lesser known disease in sub-Saharan Africa. We believe that this is the first descriptive and analytical cross-sectional study in Kinshasa (from February 1 to October 31, 2021), which included respondents aged ≥18 years. The study aimed to determine the prevalence of the risk and factors associated with OSAHS. Each participant signed a free and informed consent. Statistical analyses were performed using XLStat 2020 and the Statistical Package for the Social Sciences version 24 for Windows. Odds ratios (ORs) were calculated to determine the degree of association between these variables and a high risk of OSAHS. The significance threshold was p < 0.05 and confidence interval (CI) at 95%. There were 4,162 participants, including 2,287 men (54.9%), with an mean (SD) age of 32 ± 12.6 years. The prevalence of OSAS risk was 17.4% and 7.9% for men and women, respectively. The associated risk factors were male sex (OR 4, 95% CI 3.20-5.54), hypertension (OR 6.7, 95% CI 4.87-9.30), age ≥60 years (OR 8.7, 95% CI 4.07-18.88), obesity/overweight (OR 1.94, 95% CI 1.13-3.78), and excessive daytime sleepiness (OR 2.63, 95% CI 2.05-3.56). The risk of OSAS in Kinshasa is high and it increases with age, male sex, obesity, and hypertension. The Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and male Gender (STOP-BANG) questionnaire is an easy-to-use tool for diagnostic orientation.

A Deep Learning Framework for Automatic Sleep Apnea Classification Based on Empirical Mode Decomposition Derived from Single-Lead Electrocardiogram

BACKGROUND

Although polysomnography (PSG) is a gold standard tool for diagnosing sleep apnea (SA), it can reduce the patient's sleep quality by the placement of several disturbing sensors and can only be interpreted by a highly trained sleep technician or scientist. In recent years, electrocardiogram (ECG)-derived respiration (EDR) and heart rate variability (HRV) have been used to automatically diagnose SA and reduce the drawbacks of PSG. Up to now, most of the proposed approaches focus on machine-learning (ML) algorithms and feature engineering, which require prior expert knowledge and experience. The present study proposes an SA detection algorithm to differentiate a normal and apnea event using a deep-learning (DL) framework based on 1D and 2D deep CNN with empirical mode decomposition (EMD) of a preprocessed ECG signal. The EMD is ideally suited to extract essential components which are characteristic of the underlying biological or physiological processes. In addition, the simple and compact architecture of 1D deep CNN, which only performs 1D convolutions, and pretrained 2D deep CNNs, are suitable for real-time and low-cost hardware implementation.

METHOD

This study was validated using 7 h to nearly 10 h overnight ECG recordings from 33 subjects with an average apnea-hypopnea index (AHI) of 30.23/h originated from PhysioNet Apnea-ECG database (PAED). In preprocessing, the raw ECG signal was normalized and filtered using the FIR band pass filter. The preprocessed ECG signal was then decomposed using the empirical mode decomposition (EMD) technique to generate several features. Several important generated features were selected using neighborhood component analysis (NCA). Finally, deep learning algorithm based on 1D and 2D deep CNN were used to perform the classification of normal and apnea event. The synthetic minority oversampling technique (SMOTE) was also applied to evaluate the influence of the imbalanced data problem.

RESULTS

The segment-level classification performance had 93.8% accuracy with 94.9% sensitivity and 92.7% specificity based on 5-fold cross-validation (5fold-CV), meanwhile, the subject-level classification performance had 83.5% accuracy with 75.9% sensitivity and 88.7% specificity based on leave-one-subject-out cross-validation (LOSO-CV).

CONCLUSION

A novel and robust SA detection algorithm based on the ECG decomposed signal using EMD and deep CNN was successfully developed in this study.

Change in the Constricted Airway in Patients after Clear Aligner Treatment: A Retrospective Study

This retrospective study evaluated changes in the pharyngeal portion of the upper airway in patients with constricted and normal airways treated with clear aligners (Invisalign, Align). Additionally, we assessed the change of tongue position in the oral cavity from a lateral view. Evaluation was performed with specialized software (Invivo 6.0, Anatomage) on pretreatment and post-treatment pairs of cone beam computed tomography imaging (CBCT) data. The level of airway constriction, volume, cross-section minimal area and tongue profile were evaluated. Patients with malocclusion, with pair or initial and finishing CBCT and without significant weight change between the scans, treated with Invisalign clear aligners were distributed into two groups. Group A consisted of fifty-five patients with orthodontic malocclusion and constricted upper airway. Control group B consisted of thirty-one patients with orthodontic malocclusions without any airway constriction. In the group with airway constriction there was a statistically significant increase in volume during therapy (p < 0.001). The surface of the most constricted cross-section of the airway did not change significantly after treatment in any of the groups. The final tongue position was different from the initial position in 62.2% of all clear aligner treatments. The position of the smallest clearance of the airway in the pharynx was similar for both groups localized at the level of 2nd cervical vertebra.

At-Home Orthodontic Treatment for Severe Teeth Arch Malalignment and Severe Obstructive Sleep Apnea Syndrome in a Child with Cerebral Palsy

Children with cerebral palsy typically have severe teeth arch malalignment, causing swallowing and respiration dysfunction. Malalignment in cerebral palsy, especially in children, worsens dysphagia and respiratory disorders; sometimes, it is also noted with obstructive sleep apnea. However, no study has reported on the improvement in obstructive sleep apnea after at-home orthodontic treatment in children with cerebral palsy. We herein present a pediatric case of cerebral palsy wherein obstructive sleep apnea improved with at-home orthodontic treatment for malalignment. We administered at-home orthodontic treatment to a 15-year-old boy with quadriplegia, due to spastic-type cerebral palsy, having no oral intake, obstructive sleep apnea, and teeth arch malalignment. After treatment, a decline in the severity of sleep apnea was observed. Perioral muscle hypertension and oral intake difficulties cause maxillary protrusion, narrowed teeth arch, and tilting of teeth in children with cerebral palsy. We expanded the oral cavity volume by orthodontic treatment to relieve muscle hypertension and correct the tongue position, thereby remarkably improving obstructive sleep apnea. Our findings suggest that at-home orthodontic treatment for malalignment effectively improves perioral muscle hypertension, glossoptosis, and obstructive sleep apnea.

Effects of Hypoxic Environment on Periodontal Tissue through the ROS/TXNIP/NLRP3 Inflammasome Pathway

There is low evidence for the possible association between obstructive sleep apnea-hypopnea syndrome (OSAHS) and periodontitis, necessitating further research. This study was aimed at investigating this association. For the in vitro study, 8-day-old Wistar rats were divided into the unilateral nasal obstruction group (UNO) and the sham surgery group (SHAM). Rats in the former group were subjected to UNO by cauterization of the external nostril at the age of 8 days. Immunofluorescence analysis, quantitative real-time polymerase chain reaction, and western blot were performed to assess the expression of thioredoxin-interacting protein (TXNIP), NLR family pyrin domain-containing 3 (NLRP3) inflammasome-associated factors, and interleukin-1β (IL-1β). Throughout the experimental period, the weights of rats in the two groups were similar. The mRNA and protein expression of TXNIP and IL-1β was significantly higher in the UNO than in the SHAM groups. Compared with SHAM, NLRP3 inflammasome-associated factors were activated in the UNO group. For the in vitro study, a cellular hypoxia model was established by treating human periodontal ligament cells (HPDLCs) with cobalt chloride. The studies showed that hypoxia can induce an excessive production and accumulation of reactive oxygen species (ROS) in HPDLCs and induce abnormal expression of TNXIP, NLRP3 inflammasome-related factors, and IL-1β. More importantly, N-acetylcysteine induced reduction of ROS in HPDLCs, downregulated TXNIP expression, inhibited the expression and aggregation of NLRP3 inflammasome-related factors, and abrogated the inflammatory response to hypoxia. In conclusion, hypoxia-induced ROS can activate the TXNIP/NLRP3 inflammasome signaling pathway in response to oxidative stress, resulting in the increased expression of inflammatory factors in HPDLCs. Our findings provide evidence for the mechanism underlying the possible association between OSAHS and periodontal disease.

Quantitative Changes in Muscular and Capillary Oxygen Desaturation Measured by Optical Sensors during Continuous Positive Airway Pressure Titration for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common sleep disorder, and continuous positive airway pressure (CPAP) is the most effective treatment. Poor adherence is one of the major challenges in CPAP therapy. The recent boom of wearable optical sensors measuring oxygen saturation makes at-home multiple-night CPAP titrations possible, which may essentially improve the adherence of CPAP therapy by optimizing its pressure in a real-life setting economically. We tested whether the oxygen desaturations (ODs) measured in the arm muscle (arm_OD) by gold-standard frequency-domain multi-distance near-infrared spectroscopy (FDMD-NIRS) change quantitatively with titrated CPAP pressures in OSA patients together with polysomnography. We found that the arm_OD (2.08 ± 1.23%, mean ± standard deviation) was significantly smaller (p-value < 0.0001) than the fingertip OD (finger_OD) (4.46 ± 2.37%) measured by a polysomnography pulse oximeter. Linear mixed-effects models suggested that CPAP pressure was a significant predictor for finger_OD but not for arm_OD. Since FDMD-NIRS measures a mixture of arterial and venous OD, whereas a fingertip pulse oximeter measures arterial OD, our results of no association between arm_OD and finger_OD indicate that the arm_OD mainly represented venous desaturation. Arm_OD measured by optical sensors used for wearables may not be a suitable indicator of the CPAP titration effectiveness.