Craniofacial profile in Asian and white subjects with obstructive sleep apnoea

Morphometric measures and desaturations: Proposal for an index with improved accuracy for obstructive sleep apnea screening

STUDY OBJECTIVE

To evaluate the sensitivity and specificity of the combined Kushida morphometric model (KMM) and the oxygen desaturation index (ODI) for screening individuals with obstructive sleep apnea.

METHODS

Diagnostic test study with adults >18 years, both sexes, polysomnography, body mass index, neck circumference and intraoral measurements.

RESULTS

144 patients were invited; of these, 75 met the exclusion criteria. 55 individuals presented AHI ≥5 ev/h and 14, an AHI <5 ev/h. Three AHI cut-off points were evaluated: AHI ≥5, ≥15, ≥30 ev/h. When adopting the cut-off point of AHI ≥5 ev/h, the KMM showed sensitivity (SE) = 60.0 %, specificity (SP) = 71.4 % and 95 % confidence interval of the area under the curve (95 % CI of AUC) = 0.655; the combination of KMM and ODI (KMM + ODI) revealed SE = 73.0 %, SP = 71.4 % (95 % CI of AUC = 0.779) and the ODI showed SE = 76.4 % and SP = 92.9 % (95 % CI of AUC = 0.815). At the cut-off point of AHI ≥15 ev/h, the KMM presented SE = 64.1 %, SP = 76.7 % (95 % CI of AUC = 0.735); the KMM + ODI showed SE = 82.1 %, SP = 83.3 % (95 % CI of AUC = 0.895); and the ODI presented SE = 76.9 %, SP = 100.0 % (95 % CI of AUC = 0.903). For the cut-off point of AHI ≥30 ev/h, the KMM showed SE = 56.0 %, SP = 77.2 % (95 % CI of AUC = 0.722); the KMM + ODI revealed SE = 92.0 %, SP = 79.5 % (95 % CI of AUC = 0.926); and the ODI showed SE = 92.0 %, SP = 90.9 % (95 % CI of AUC = 0.941).

CONCLUSION

The combination of oxygen desaturation index and Kushida morphometric model improved the sensitivity and specificity of this model regardless of obstructive sleep apnea severity suggesting greater effectiveness in risk prediction.

Validity of Modified STOP-Bang Questionnaire as a Screening Tool for Obstructive Sleep Apnea

OBJECTIVES

The aim of this study was to evaluate the validity of a modified STOP-Bang questionnaire with different body mass index reference as a screening tool for obstructive sleep apnea in Korean population.

METHODS

The medical records of 1417 participants who underwent overnight Level I polysomnography were retrospectively analyzed. Predictive parameters were calculated for each of the 3 groups classified by obstructive sleep apnea severity with a cut-off value of 3 or 4. Responses to modified and traditional questionnaires were comparatively analyzed by receiver-operator characteristic curves and area under the receiver-operator characteristic curves.

RESULTS

The optimal cut-off values of the modified and traditional questionnaires were both 3.5. The area under the receiver-operator characteristic curve of modified STOP-Bang questionnaire for any obstructive sleep apnea group was 0.786 ± 0.018, which was significantly higher than that of the traditional questionnaire. The modified STOP-Bang questionnaire with a cut-off value ≥4 showed significantly higher sensitivity than the traditional one for any obstructive sleep apnea group. The diagnostic accuracy of the modified questionnaire was also significantly higher for the any obstructive sleep apnea group when the cut-off value was 4.

CONCLUSION

The modified STOP-Bang questionnaire, with a cut-off value of 4, can be used as an alternative to the traditional screening tool for the Korean population.

Difficult Tracheal Intubation and Airway Outcomes after Radiation for Nasopharyngeal Carcinoma

OBJECTIVE

The aim of the study was to characterize the incidence and management of difficult tracheal intubations (DTIs) in nasopharyngeal carcinoma (NPC) after primary radiation therapy (RT).

METHODS

The study was a retrospective review of airway assessment and outcomes in post-RT NPC patients. Primary analysis was performed on patients who underwent post-RT procedures, who were split into non-DTI and DTI groups. Patients were classified as DTI if they (i) required >1 attempt to intubate, (ii) failed to be intubated, or (iii) experienced complications attributed to airway management. Secondary analysis was performed between patients who underwent post-RT procedures (procedure group) and those who did not (control group).

RESULTS

One-hundred and fifty patients were included, and 71.3% underwent post-RT procedures, with no differences in characteristics between the procedure and control groups. One-hundred and fifty procedures were identified, and 28.0% were categorized as DTI. There was no difference in patient characteristics or airway assessment measures between DTI and non-DTI groups. Regression analysis revealed concurrent cervical mobility restriction, and trismus increased DTI incidence by 7.1-fold (p = 0.011). Being non-White was an independent predictor of DTI. The incidence of high-grade intraoperative laryngoscopic view was lower in the non-DTI compared to the DTI group (20.4% vs. 64.3%, p < 0.0001). Failure to intubate occurred in 2.0% of cases, and 6.0% cases had perioperative complications. Based on preoperative assessment, sensitivity of predicting DTI was 54.8% and specificity was 63.9%.

CONCLUSION

NPC patients frequently undergo post-RT procedures requiring complex airway management. Rates of DTI and failed intubation are significantly higher than those in the general surgical population, and the ability to predict DTI with standard preoperative airway measures is poor.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:120-126, 2024.

Anthropometric 3D evaluation of the face in patients with sleep related breathing disorders

PURPOSE

To evaluate craniofacial measurements on 3D-stereophotogrammetry and see if particular measurements are more typical in obstructive sleep apnea (OSA) and have a correlation with its severity.

METHODS

Subjects included were adults undergoing a diagnostic polysomnography. Age, BMI, neck, abdominal and hip circumference (cm) were recorded. 3D-stereophotogrammetry was performed and landmarks were placed on the 3D-image. Different linear, angular and volume measurements were performed to gauge facial and neck anatomy. The relationship between these measurements and the severity of OSA, based on the obstructive apnea/hypopnea index (OAHI, events/h), was assessed by multiple linear regression, and adjusted for BMI and sex.

RESULTS

Of 91 subjects included (61 male), mean age was 46 ± 12 years, BMI 30.1 ± 6.5 kg/m2, OAHI 19.3 ± 18.8/h. BMI was higher (p = 0.0145) in females (32.9 ± 7.7) than in males (28.6 ± 5.3). This was also true for hip circumference (118 ± 15 vs 107 ± 10, p = 0.0006), while the neck circumference was higher (p < 0.0001) in males (41 ± 4 vs 37 ± 4). The following parameters could predict the logOAHI (r2-adjusted = 0.51): sex (p < 0.0001), BMI (p = 0.0116), neck-depth/mandibular-length (p = 0.0002), mandibular-width angle (p = 0.0118), neck-depth euclidean distance/surface distance (E/S) (p = 0.0001) and the interaction terms between sex and neck-depth/mandibular-length (p = 0.0034), sex and neck-depth E/S (p = 0.0276) and BMI and neck-depth E/S (p = 0.0118). The interaction between sex and neck-depth/mandibular-length showed a steeper linear course in females. This is also true for the interaction term BMI with neck-depth E/S in patients with a higher BMI. With a same neck-depth ratio, the OAHI is larger in men.

CONCLUSION

Measurements involving the width of the face and addressing the soft tissue in the upper neck were found to have a significant relation with OSA severity. We found remarkable differences between non-obese/obese subjects and between males and females.

Overnight changes in uric acid, xanthine oxidoreductase and oxidative stress levels and their relationships with sleep-disordered breathing in patients with coronary artery disease

Serum uric acid (UA) level is associated with the high cumulative incidence or prevalence of coronary artery disease (CAD), and hyperuricemia is considered as an independent risk marker for CAD. Sleep-disordered breathing (SDB) is also associated with an increased risk of CAD. Several studies have shown that SDB is associated with hyperuricemia, but the mechanisms are unclear. We measured serum levels of UA and xanthine oxidoreductase (XOR) activity and urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), all of which were assessed at 6 p.m. and the following 6 a.m. in males with CAD. In addition, nocturnal pulse oximetry was performed for the night. Overall 32 eligible patients with CAD were enrolled. Serum UA levels significantly increased overnight. (5.32 ± 0.98 mg/dl to 5.46 ± 1.02 mg/dl, p < 0.001) Moreover, XOR activity and urinary 8-OHdG levels significantly increased from 6 p.m. to 6 a.m. Furthermore, 3% Oxygen desaturation index (ODI) was correlated with the overnight changes in XOR activity (r = 0.36, P = 0.047) and urinary 8-OHdG levels (r = 0.41, P = 0.02). In addition, 3%ODI was independently correlated with the changes in XOR activity (correlation coefficient, 0.36; P = 0.047) and 8-OHdG (partial correlation coefficient, 0.63; P = 0.004) in multivariable analyses. SDB severity was associated with the overnight changes in XOR activity and urinary 8-OHdG, suggesting that SDB may be associated with oxidative stress via UA production. This trial is registered at University Hospital Medical Information Network (UMIN), number: UMIN000021624.

Development and validation of a regression model with nomogram for difficult video laryngoscopy in Chinese population: a prospective, single-center, and nested case-control study

Background

Airway management failure is associated with increased perioperative morbidity and mortality. Airway-related complications can be significantly reduced if difficult laryngoscopy is predicted with high accuracy. Currently, there are no large-sample studies on difficult airway assessments in Chinese populations. An airway assessment model based on the Chinese population is urgently needed to guide airway rescue strategy.

Methods

This prospective nested case-control study took place in a tertiary hospital in Shanghai, China. Information on 10,549 patients was collected, and 8,375 patients were enrolled, including 7,676 patients who underwent successful laryngoscopy and 699 patients who underwent difficult laryngoscopy. The baseline characteristics, medical history, and bedside examinations were included as predictor variables. Laryngoscopy was defined as 'successful laryngoscopy' based on a Cormack-Lehane Grades of 1-2 and as 'difficult laryngoscopy' based on a Cormack-Lehane Grades of 3-4. A model was developed by incorporating risk factors and was presented in the form of a nomogram by univariate logistic regression, least absolute shrinkage and selection operator, and stepwise logistic regression. The main outcome measures were area under the curve (AUC), sensitivity, and specificity of the predictive model.

Result

The AUC value of the prediction model was 0.807 (95% confidence interval [CI]: 0.787-0.828), with a sensitivity of 0.730 (95% CI, 0.690-0.769) and a specificity of 0.730 (95% CI, 0.718-0.742) in the training set. The AUC value of the prediction model was 0.829 (95% CI, 0.800-0.857), with a sensitivity of 0.784 (95% CI, 0.73-0.838) and a specificity of 0.722 (95% CI, 0.704-0.740) in the validation set.

Conclusion

Our model had accurate predictive performance, good clinical utility, and good robustness for difficult laryngoscopy in the Chinese population.

Epidemiology of Robin sequence in the UK and Ireland: an active surveillance study

BACKGROUND

Birth prevalence of Robin sequence (RS) is commonly reported as 1 case per 8000-14 000 live births. These estimates are based on single-source case ascertainment and may miss infants who did not require hospital admission or those without overt upper airway obstruction at birth.

OBJECTIVES

To identify the true birth prevalence of RS with cleft palate in the UK and Ireland from a population-based birth cohort with high case ascertainment.

METHODS

Active surveillance of RS with cleft palate was carried out in the UK/Ireland using dual sources of case ascertainment: British Paediatric Surveillance Unit (BPSU) reporting card and nationally commissioned cleft services. Clinical data were collected from notifying clinicians at two time points.

RESULTS

173 live-born infants met the surveillance case definition, giving a birth prevalence of 1 case per 5250 live births (19.1 per 100 000 (95% CI 16.2 to 21.9)), and 1:2690 in Scotland. 47% had non-isolated RS, with Stickler syndrome the most common genetic diagnosis (12% RS cases). Birth prevalence derived from the combined data sources was significantly higher than from BPSU surveillance alone.

CONCLUSIONS

Birth prevalence of RS in the UK/Ireland derived from active surveillance is higher than reported by epidemiological studies from several other countries, and from UK-based anomaly registries, but consistent with published retrospective data from Scotland. Dual case ascertainment sources enabled identification of cases with mild or late-onset airway obstruction that were managed without hospital admission. Studies of aetiology and equivalent well-designed epidemiological studies from other populations are needed to investigate the identified geographical variability in birth prevalence.

[Digital technology and children's maxillofacial management]

The maxillofacial region has multiple functions such as breathing, language, and facial expressions. Children's maxillofacial development is a complex and long process, which is affected by many factors such as genetics, diseases, bad habits and trauma. Early detection, early diagnosis, and early treatment are important concepts in children's maxillofacial management. Digital technology medicine is an emerging technology based on medical imaging and anatomy that has emerged in recent years. The application of this technology in the field of clinical medicine will undoubtedly bring great benefits to children's maxillofacial management. This article summarizes the research on digital technology in children's maxillofacial management, and focuses on the research on children's malocclusion, children's OSA, cleft lip and palate and other related diseases.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Epidemiology of adverse events attributed to airway management in paediatric anaesthesia: protocol for the prospective, multicentre, registry-based, cross-sectional Japan Pediatric Difficult Airway in Anesthesia study (J-PEDIA)

INTRODUCTION

Failure to secure an airway during general anaesthesia is a major cause of adverse events (AEs) in children. The safety of paediatric anaesthesia may be improved by identifying the incidence of AEs and their attributed risk factors. The aim of the current study is to obtain real-world data on the incidence of adverse peri-intubation events and assess their association with patient characteristics (including the prevalence of difficult airway features) and choice of anaesthesia management. These data can be used to develop a targeted education programme for anaesthesia providers towards quality improvement activities.

METHODS AND ANALYSIS

This prospective, multicentre, registry-based, cross-sectional study will be conducted in four tertiary care hospitals in Japan from June 2022 to May 2025. Children <18 years of age undergoing surgical and/or diagnostic test procedures under general anaesthesia or sedation by anaesthesiologists will be enrolled in this study. Data on patient characteristics, discipline of anaesthesia providers and methodology of airway management will be collected through a standardised verification system. The exposure of interest is the presence of difficult airway features defined based on the craniofacial appearance. The primary and secondary endpoints are all AEs associated with airway management and reduced peripheral capillary oxygen saturation values. Potential confounders are related to the failure to secure the airway and variations in the anaesthesia providers' levels, adjusted using hierarchical multivariable regression models with mixed effects. The sample size was calculated to be approximately 16 000 assuming a 99% probability of obtaining a 95% Wilson CI with±0.3% of the half-width for the 2.0% of the incidence of critical AEs.

ETHICS AND DISSEMINATION

The study protocol was approved by the Institutional Review Board at Aichi Children's Health and Medical Center (2021051). The results will be reported in a peer-reviewed journal and a relevant academic conference.

TRIAL REGISTRATION NUMBER

UMIN000047351.

Risk of suicide after a diagnosis of sleep apnea: A nationwide longitudinal study

Previous studies have presented evidence on the association between sleep apnea and suicidal ideation and planning, but the relationship between a clinical diagnosis of sleep apnea and suicide attempts remains unknown. We investigated the risk of suicide after a diagnosis with sleep apnea using data from a nationwide community-based population database, i.e., the Taiwan National Health Insurance Research Database. We recruited 7,095 adults with sleep apnea and 28,380 age-, sex-, and comorbidity-matched controls between 1998 and 2010 and followed them up until the end of 2011. Individuals who exhibited any (once or repeated) suicide attempts were identified during the follow-up period. The E value was calculated for unmeasured bias. Sensitivity analysis was conducted. Patients with sleep apnea were more likely to carry out any suicide attempt (hazard ratio: 4.53; 95% confidence interval: 3.48-5.88) during the follow-up period than the controls after adjusting for demographic data, mental disorders, and physical comorbidities. The hazard ratio remained significant after excluding individuals with mental disorders (4.23; 3.03-5.92). The hazard ratio was 4.82 (3.55-6.56) for male patients and 3.86 (2.33-6.38) for female patients. Consistent findings of increased risk of repeated suicide attempt were found among patients with sleep apnea. No association was found between continuous positive airway pressure treatment and suicide risk. The calculated E values support suicide risk after the diagnosis of sleep apnea. The risk of suicide was 4.53-fold higher in patients diagnosed with sleep apnea than in their counterparts without sleep apnea.

Transforming the perioperative medicine care model: The Singapore experience

More than 300 million surgeries are performed worldwide annually. Established perioperative centres in the UK, USA and Australia have demonstrated the impact of improving perioperative care in reducing costs, increasing patient satisfaction and improving population health. Likewise, the surgical burden of care in Asia is increasing, but with sociocultural, economic and epigenetic differences compared to the west. As Singapore's largest hospital, the Singapore General Hospital pre-admission perioperative clinic sees about 20,000 patients annually. We aim to illustrate Singapore General Hospital's perioperative model of care to contribute to the paucity of literature describing perioperative programme implementation within Asia, and to encourage the cross-sharing of perioperative practices internationally. Our perioperative framework navigates risk assessment, risk counselling, and mitigation of health, medical and functional risks to better patients' perioperative outcomes and population health. We have implemented evidence-based pathways for common conditions such as anaemia and malnutrition, including a multidisciplinary programme for the elderly to tackle frailty and reduce length of stay. We describe how we have enhanced local risk profiling with the Combined Assessment of Risk Encountered in Surgery surgical risk calculator derived locally using a gradient boosting machine learning model. Finally, we report clinical outcomes of these interventions and discuss further challenges and new initiatives at each tier of our perioperative model. Our perioperative care model provides a framework that other centres can adopt to promote value-driven care, while catering for differences in the Asian population, thereby promoting evidence-based improvements in the area of perioperative medicine.

Platypnoea-orthodeoxia syndrome affects nocturnal oxygen desaturation: A case report

A woman in her late 20s who had received an implantable cardioverter defibrillator in childhood for ventricular arrhythmia was diagnosed with severe obstructive sleep apnoea (apnoea-hypopnoea index, 77.1/h), and she began continuous positive airway pressure treatment. Before initiating this treatment, she had moderate hypoxaemia of unknown cause. She was admitted for adjustment of the position of her implantable cardioverter defibrillator, which had caused purple discoloration and ulceration of the overlying skin. On admission, she had dyspnoea and her arterial oxygen saturation by pulse oximetry significantly decreased while sitting. This led to detection of a patent foramen ovale and a right-to-left shunt while sitting. We diagnosed platypnoea-orthodeoxia syndrome with an atrial septal defect. Atrial septal defects should be suspected in hypoxic patients with obstructive sleep apnoea.

Dependable algorithm for visualizing snoring duration through acoustic analysis: A pilot study

Snoring is a nuisance for the bed partners of people who snore and is also associated with chronic diseases. Estimating the snoring duration from a whole-night sleep period is challenging. The authors present a dependable algorithm for visualizing snoring durations through acoustic analysis. Both instruments (Sony digital recorder and smartphone's SnoreClock app) were placed within 30 cm from the examinee's head during the sleep period. Subsequently, spectrograms were plotted based on audio files recorded from Sony recorders. The authors thereby developed an algorithm to validate snoring durations through visualization of typical snoring segments. In total, 37 snoring recordings obtained from 6 individuals were analyzed. The mean age of the participants was 44.6 ± 9.9 years. Every recorded file was tailored to a regular 600-second segment and plotted. Visualization revealed that the typical features of the clustered snores in the amplitude domains were near-isometric spikes (most had an ascending-descending trend). The recorded snores exhibited 1 or more visibly fixed frequency bands. Intervals were noted between the snoring clusters and were incorporated into the whole-night snoring calculation. The correlative coefficients of snoring rates from digitally recorded files examined between Examiners A and B were higher (0.865, P < .001) than those with SnoreClock app and Examiners (0.757, P < .001; 0.787, P < .001, respectively). A dependable algorithm with high reproducibility was developed for visualizing snoring durations.

Study of pharyngeal airway morphology with CBCT: Benefits of four premolar extraction orthodontic treatments

BACKGROUND AND AIM

Four premolars extractions are routine procedures for correction of malocclusion, but will inevitably lead to a reduction of tongue space, whether this will weaken the pharyngeal airway remains a controversy.

PATIENTS AND METHODS

Cone-beam computed tomography (CBCT) radiographs of 80 patients who completed four premolar extraction orthodontic treatments were collected and divided into three anteroposterior skeletal groups according to the ANB (angle subspinale to nasion to supramentale) value. Linear, angular, cross-sectional area, and volumetric dimensions of the pharyngeal airway were measured using Dolphin Imaging 11.9 software. One-way analysis of variance and Pearson's correlation coefficient test were performed to assess the intergroup comparisons. Treatment changes were evaluated with two-sample t-tests.

RESULTS

In intergroup comparisons, vertical linear and cross-sectional area differences were identified in S-Go/N-Me, VD1, VD1/N-Me, VD2/N-Me, AA, OAA and OMINI (p<0.05), while other measurements showed no significant differences. Angle2, the tilting degree of the pharyngeal airway, showed a positive correlation with ANB (p<0.05). As for the treatment changes, a significant increase was found in the pharyngeal airway in the Class I group (OUA p<0.05, VD1 p<0.001, VD2 p<0.05) and Class II group (VD1 p<0.001. VD2, p<0.05), and inversely, a significant decrease was found in the pharyngeal airway in the Class III group (OAA p<0.05, OMINI p<0.05, OUA p<0.05). No volumetric difference was identified. Interestingly, regarding the preoperative pharyngeal airway size, values trended to the mean value significantly.

CONCLUSION

Four premolar extraction orthodontic treatments did not affect the pharyngeal airway volume except for the vertical liner and cross-sectional area dimensions. The trend of the gold standard suggested a positive influence of four premolar extraction orthodontic treatments.

Classification of facial phenotypes in Asian patients with obstructive sleep apnea

BACKGROUD

The facial phenotypes of Asian obstructive sleep apnea (OSA) patients remain unclear.

OBJECTIVES

(1) To describe the facial features of OSA patients. (2) To develop a model based on facial contour indicators to predict OSA. (3) To classify the facial phenotypes of Asian OSA patients.

MATERIALS AND METHODS

110 patients with OSA (apnea-hypopnea index [AHI] ≥ 10/h) and 50 controls (AHI< 10/h) were selected to measure facial contour indicators. Indicators were compared between OSA patients and the control group. We used multivariable linear regression analysis to predict OSA severity and K-means cluster analysis to classify OSA patients into different phenotypes.

RESULTS

We built a model to predict OSA which explained 49.1% of its variance and classified OSA patients into four categories. Cluster 1 (Skeletal type) had the narrowest facial width indicators with narrowing of the retroglossal airway. Cluster 2 (Obese type) had the widest face, and narrowest hard palate, retropalatal, and hypopharyngeal airways. Cluster 3 (Nose type) had the narrowest nasal cavity. Cluster 4 (Long type) had the longest airway length.

CONCLUSIONS AND SIGNIFICANCE

Patients with OSA were classified into four categories, each of which identified different anatomic risk factors that can be used to select the treatment.

Correlation between Apnea Severity and Sagittal Cephalometric Features in a Population of Patients with Polysomnographically Diagnosed Obstructive Sleep Apnea

Background and Objective: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder featuring a repeated closure of the upper airway during sleep. Craniofacial anatomy is a potential risk and worsening factor for OSA. This study aims to assess the relationship between cephalometric features of craniofacial morphology and OSA severity in a population of patients with OSA. Material and Methods: A sample of forty-two patients (n = 42, M = 76%, mean age = 57.8 ± 10.8) with a polysomnographically (PSG) confirmed diagnosis of OSA were recruited and underwent cephalometric evaluation of 16 cephalometric variables. In addition, the apnea−hypopnea index (AHI), oxygen desaturation (SatMin), Epworth sleepiness scale (ESS), and body mass index (BMI) were assessed. Then t-tests were performed to compare the values of all cephalometric variables between two AHI severity-based groups (mild-to-moderate = AHI ≤ 30; severe = AHI > 30). Single- and multiple-variable regression analyses were performed to assess the associations between AHI scores and cephalometric features. Results: Mean AHI, SatMin, and BMI were 31.4 ev/h, 78.7%, and 28.1, respectively. The cephalometric variables were not significantly different between the two OSA-severity groups (p > 0.05). Multiple-variable regression analyses showed that gonial angle and nasopharynx space were negatively associated with AHI, explaining 24.6% of the total variance. Conclusion: This investigation reported that severity of AHI scores in patients with OSA showed a negative correlation with gonial angle and nasopharynx space. As a general remark, although maxillofacial anatomy can be a predisposing factor for OSA, disease severity depends mainly upon other variables.

Brazilian Thoracic Association Consensus on Sleep-disordered Breathing

Sleep is essential for the proper functioning of all individuals. Sleep-disordered breathing can occur at any age and is a common reason for medical visits. The objective of this consensus is to update knowledge about the main causes of sleep-disordered breathing in adult and pediatric populations, with an emphasis on obstructive sleep apnea. Obstructive sleep apnea is an extremely prevalent but often underdiagnosed disease. It is often accompanied by comorbidities, notably cardiovascular, metabolic, and neurocognitive disorders, which have a significant impact on quality of life and mortality rates. Therefore, to create this consensus, the Sleep-Disordered Breathing Department of the Brazilian Thoracic Association brought together 14 experts with recognized, proven experience in sleep-disordered breathing.

Helping early obstructive sleep apnea diagnosis with machine learning: A systematic review (Preprint)

Background

American Academy of Sleep Medicine guidelines suggest that clinical prediction algorithms can be used to screen patients with obstructive sleep apnea (OSA) without replacing polysomnography, the gold standard.

Objective

We aimed to identify, gather, and analyze existing machine learning approaches that are being used for disease screening in adult patients with suspected OSA.

Methods

We searched the MEDLINE, Scopus, and ISI Web of Knowledge databases to evaluate the validity of different machine learning techniques, with polysomnography as the gold standard outcome measure and used the Prediction Model Risk of Bias Assessment Tool (Kleijnen Systematic Reviews Ltd) to assess risk of bias and applicability of each included study.

Results

Our search retrieved 5479 articles, of which 63 (1.15%) articles were included. We found 23 studies performing diagnostic model development alone, 26 with added internal validation, and 14 applying the clinical prediction algorithm to an independent sample (although not all reporting the most common discrimination metrics, sensitivity or specificity). Logistic regression was applied in 35 studies, linear regression in 16, support vector machine in 9, neural networks in 8, decision trees in 6, and Bayesian networks in 4. Random forest, discriminant analysis, classification and regression tree, and nomogram were each performed in 2 studies, whereas Pearson correlation, adaptive neuro-fuzzy inference system, artificial immune recognition system, genetic algorithm, supersparse linear integer models, and k-nearest neighbors algorithm were each performed in 1 study. The best area under the receiver operating curve was 0.98 (0.96-0.99) for age, waist circumference, Epworth Somnolence Scale score, and oxygen saturation as predictors in a logistic regression.

Conclusions

Although high values were obtained, they still lacked external validation results in large cohorts and a standard OSA criteria definition.

Trial Registration

PROSPERO CRD42021221339; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=221339

Long-term benefits of a new oral appliance on adult snoring: a trend analysis

Background: Snoring constitutes a worldwide public health concern that may be associated with daytime fatigue, endothelial dysfunction, vascular injury, stroke, cardiovascular diseases, and diabetes among female patients. This study explored the effects of the so-called Lin Oral Appliance (LOA) on Taiwanese adults’ snoring rates.Methods: A time series analysis was conducted to examine the associations between LOAs’ tongue compressors of different lengths, and snoring rates were calculated using the SnoreClock app. The LOA comprises 2 components: custom-made dental braces and tongue compressors of adjustable lengths; different versions had different-length compressors.Results: Our multiple linear regression time-series model revealed the effects of the LOA on snoring rates. The results indicated the following: i) LOA tongue compressor lengths of 1 and 2.5 cm (LOA-1 and LOA-2.5, respectively) were associated with reduced snoring rates; ii) sleep durations of 5.5-7.5 h and daytime sleepiness were associated with increased snoring rates; and iii) among participants with snoring rates above 10%, the snoring rates observed 1-7 days before a given day constituted a significant factor influencing snoring rates on the given day.Conclusions: We discovered that the LOA could reduce snoring rates and that the 2.5-cm compressor length in the LOA produced the best results.

Racial Disparities in Surgical Treatment of Obstructive Sleep Apnea

Objective

Determine risk factors for failure to receive surgical treatment among patients with obstructive sleep apnea.

Study Design

Population-based observational longitudinal cohort study.

Setting

Population-based database.

Methods

Multivariate analysis of 500,792 individuals with obstructive sleep apnea from Optum's deidentified Clinformatics Data Mart database (2004-2018).

Results

Black race, increased age, diabetes, atrial fibrillation, obesity, and congestive heart failure were independently associated with a decreased rate of surgery for obstructive sleep apnea. Asian race, hypertension, arrhythmias other than atrial fibrillation, pulmonary disease, and liver disease were independently associated with an increased rate of surgery for obstructive sleep apnea.

Conclusion

Racial disparities in health outcomes related to health care access and in economic resources have an enormous impact on public health and social equity. We found differences in rates of surgery for obstructive sleep apnea based on race. These data are consistent with others demonstrating disparities in medical treatment of sleep apnea with positive pressure and underline a need for a change in awareness and treatment in these populations.

Sound frequency spectra of snore in relation to the site of obstruction among snorers

Objective

This study aimed to describe the sound frequency of snoring in relation to the site of upper airway vibration among snorers.

Methods

383 snores from 40 participants who complained of snoring were digitally recorded during natural and induced sleep using a level III polysomnography monitor with a built-in microphone. During drug-induced sleep endoscopy (DISE), the real-time site of upper airway obstruction was assessed, and the sound frequency of snoring was recorded synchronously.

Results

The mean peak of snoring frequency for unilevel palatal, oropharynx and epiglottis obstruction were 522.5, 482.4 and 300.0 Hz, respectively. Most participants showed multilevel obstruction at the palate and oropharynx, in which the mean for bi-peak snoring frequency were 402.90 Hz and 1086.96 Hz, respectively. Severity of OSA was significantly associated with multilevel obstruction.

Conclusions

There was a significant association between the snoring sound frequency and site of unilevel obstruction. Palatal or oropharyngeal obstruction produced sound at mid-frequency range, while the epiglottis produced a low frequency range. Multilevel obstruction documented a bi-peak snoring frequency.

Application of personalized medicine to obstructive sleep apnea in China

Obstructive sleep apnea (OSA) is a common sleep disorder whose prevalence is increasing in China consistent with rising obesity trends. OSA is a heterogeneous disorder depends on anatomical and nonanatomical risk factors. Ethnicity differentially influences the attribution of these OSA risk factors. Chinese patients had more craniofacial bony restriction and Caucasians were more obese. This suggests ethnic differences in potential applications for diagnostics and therapeutics. However, current strategies for the management of OSA reflect a one-size-fits-all approach based on the apnea-hypopnea index (AHI). Although continuous positive airway pressure (CPAP) remains the first-line and most efficacious treatment for OSA, the acceptance is unacceptably low in China. Therefore, targeted therapies to treat OSA need to be developed. This review summarizes the differences in OSA pathogenesis of Chinese patients and analyzes the current condition of personalized medicine to patients with OSA in China. The application of personalized medicine to OSA in the Chinese population is still a long way off.

Obstructive Sleep Apnea Is Associated With Low Testosterone Levels in Severely Obese Men

Background

Disrupted sleep affects cardio-metabolic and reproductive health. Obstructive sleep apnea syndrome represents a major complication of obesity and has been associated with gonadal axis activity changes and lower serum testosterone concentration in men. However, there is no consistent opinion on the effect of obstructive sleep apnea on testosterone levels in men.

Objective

The aim of this study was to determine the influence of obstructive sleep apnea on total and free testosterone levels in severely obese men.

Materials and methods

The study included 104 severely obese (Body Mass Index (BMI) ≥ 35 kg/m2) men, aged 20 to 60, who underwent anthropometric, blood pressure, fasting plasma glucose, lipid profile, and sex hormone measurements. All participants were subjected to polysomnography. According to apnea-hypopnea index (AHI) patients were divided into 3 groups: <15 (n = 20), 15 - 29.9 (n = 17) and ≥ 30 (n = 67).

Results

There was a significant difference between AHI groups in age (29.1 ± 7.2, 43.2 ± 13.2, 45.2 ± 10.2 years; p < 0.001), BMI (42.8 ± 5.9, 43.2 ± 5.9, 47.1 ± 7.8 kg/m2; p = 0.023), the prevalence of metabolic syndrome (MetS) (55%, 82.4%, 83.6%, p = 0.017), continuous metabolic syndrome score (siMS) (4.01 ± 1.21, 3.42 ± 0.80, 3.94 ± 1.81, 4.20 ± 1.07; p = 0.038), total testosterone (TT) (16.6 ± 6.1, 15.2 ± 5.3, 11.3 ± 4.44 nmol/l; p < 0.001) and free testosterone (FT) levels (440.4 ± 160.8, 389.6 ± 162.5, 294.5 ± 107.0 pmol/l; p < 0.001). TT level was in a significant negative correlation with AHI, oxygen desaturation index (ODI), BMI, MetS and siMS. Also, FT was in a significant negative correlation with AHI, ODI, BMI, age, MetS and siMS. The multiple regression analysis revealed that both AHI and ODI were in significant correlation with TT and FT after adjustment for age, BMI, siMS score and MetS components.

Conclusion

Obstructive sleep apnea is associated with low TT and FT levels in severely obese men.

Upper Airway Characteristics in Young Individuals With Class II Division 1 Malocclusion: A Retrospective Inter-Ethnic Cephalometric Comparison

ABSTRACT

This study aimed to compare the upper-airway morphology between strictly matched Syrian (n = 43) and Hungarian (n = 43) adolescents with Class II/1 malocclusion and identify potential associations between upper airway depths and skeletofacial characteristics. Lateral cephalograms were analyzed, and independent-samples tests and correlation coefficients were used for the statistical analyses. The upper-pharyngeal airway was significantly narrower and the soft palate angle was significantly greater in the Syrian adolescents. Alternatively, the hyoid bone was more posteriorly positioned in the Hungarian adolescents when compared to their counterparts. Depths of the upper and middle pharynx were moderately correlated with sagittal and vertical skeletal dimensions only among Syrian subjects. The depth of the lower pharynx was moderately correlated with hyoid bone position, cervical length, and lip-chin-throat angle only among Hungarian subjects. These findings might have potential implications for optimizing the effects of orthognathic/orthodontic treatments on airway structures in these 2 groups.

Validation of snoring detection using a smartphone app

Purpose

Snoring is closely related to obstructive sleep apnea in adults. The increasing abundance and availability of smartphone technology has facilitated the examination and monitoring of snoring at home through snoring apps. However, the accuracy of snoring detection by snoring apps is unclear. This study explored the snoring detection accuracy of Snore Clock—a paid snoring detection app for smartphones.

Methods

Snoring rates were detected by smartphones that had been installed with the paid app Snore Clock. The app provides information on the following variables: sleep duration, snoring duration, snoring loudness (in dB), maximum snoring loudness (in dB), and snoring duration rate (%). In brief, we first reviewed the snoring rates detected by Snore Clock; thereafter, an ear, nose, and throat specialist reviewed the actual snoring rates by using the playback of the app recordings.

Results

In total, the 201 snoring records of 11 patients were analyzed. Snoring rates measured by Snore Clock and those measured manually were closely correlated (r = 0.907). The mean snoring detection accuracy rate of Snore Clock was 95%, with a positive predictive value, negative predictive value, sensitivity, and specificity of 65% ± 35%, 97% ± 4%, 78% ± 25%, and 97% ± 4%, respectively. However, the higher the snoring rates, the higher were the false-negative rates for the app.

Conclusion

Snore Clock is compatible with various brands of smartphones and has a high predictive value for snoring. Based on the strong correlation between Snore Clock and manual approaches for snoring detection, these findings have validated that Snore Clock has the capacity for at-home snoring detection.

Potential patient screening for late-onset Pompe disease in suspected sleep apnea: a rationale and study design for a Prospective Multicenter Observational Cohort Study in Japan (PSSAP-J Study)

BACKGROUND

Pompe disease is an autosomal recessive disorder caused by deficiency of the acid α-glucosidase (GAA) enzyme. GAA deficiency induces progressive glycogen accumulation which leads to weakness of the respiratory muscle including the diaphragm. Pompe disease is one of the few myopathies, for which an established therapy is available. Thus, earlier detection of potential late-onset Pompe disease (LOPD) and earlier intervention would have a significant clinical impact.

PURPOSE

Our hypothesis is that sleep problems including sleep disordered breathing (SDB) and clinical symptoms may indicate an early stage of LOPD since decreased respiratory muscle activity generally first presents during sleep. Thus, the aims of this prospective, multicenter observational cohort study in Japan (PSSAP-J) are to demonstrate a higher prevalence of LOPD in a sleep lab-based population (primary outcome), and to identify predictive factors for LOPD from findings in diagnostic polysomnography (PSG) and clinical symptoms (secondary outcomes).

METHODS

The study design is a prospective multicenter observational cohort study. Consecutive patients who present to sleep labs due to suspected SDB for an overnight PSG will be enrolled. All patients will be measured for creatine kinase, GAA activity, and if necessary, genetic analysis of GAA. Furthermore, chest X-ray, pulmonary function test, and arterial blood gas analysis will be collected. Then, prevalence and specific findings of LOPD will be assessed.

RESULT

Congenital myopathy shows a shift from slow-deep to rapid-shallow breathing during transition from wakefulness to sleep accompanying a symptom of waking with gasping (actual further results are pending).

DISCUSSION

The distribution in respiratory physiology between during wakefulness and sleep specific to LOPD may provide insights into early-stage detection.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000039191, UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr ).

Predictive anatomical factors of lung aerosol deposition in obese individuals. Would modified mallampati score be relevant? Clinical trial

BACKGROUND

Obesity is a highly prevalent condition worldwide that aggravates symptoms of already existing conditions such as asthma and COPD. The limited effectiveness of inhaled medications in these individuals may be related to anatomic characteristics of their upper airways, mainly due to compressive factors.

METHODS

Controlled clinical trial with obese and nonobese individuals. The following variables were evaluated: anthropometric characteristics, Lung and airway deposition of radiolabeled aerosol (pulmonary scintigraphy), upper airways anatomy (CT scans), and modified Mallampati score.

RESULTS

29 subjects (17 nonobese and 12 obese) participated. Obese volunteers presented 30% lower aerosol lung deposition compared to nonobese. Moreover, obese subjects Mallampati classification of 4 presented an aerosol lung deposition two times lower than nonobese subjects (p = 0.021). The cross-sectional area of the retropalatal region and retroglossal region were lower in obese patients (p < 0.05), but no correlation to aerosol lung deposition was observed. BMI was associated with 32% of the variance of lung deposition (p < 0.001; β -0.28; 95% CI -0.43 to -0.11).

CONCLUSION

High BMI correlated to reduced percentage lung deposition. Also, modified Mallampati class 4 was even more detrimental to aerosol delivery into the lungs. Obese subjects have narrower upper airways, compared to nonobese, but this is not reflected in higher radiolabeled aerosol impaction into their oropharynx and does not predict the percentage of lung deposition in this group.

CLINICAL TRIAL REGISTRATION

NCT03031093 (clinicaltrials.org).

Ultrasound Shear-Wave Elastography of the Tongue in Adults with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a chronic breathing disorder characterized by intermittent sleep state-dependent upper airway (UA) collapse. The tongue comprises the primary UA dilator muscle and plays an essential role in the pathogenesis of OSA. We examined whether tongue stiffness measurement using ultrasound (US) shear wave elastography (SWE) is useful for predicting the existence of OSA. Forty-six participants (20 healthy controls and 26 patients with OSA) underwent transcutaneous submental SWE using a US system. Quantification with a shear modulus of 0-200 kPa was recorded during normal breathing and Müller's maneuver (MM). Polysomnography was used as the reference standard. Mid-sagittal tongue stiffness was significantly higher in awake patients with OSA than in controls during normal breathing and the MM (p < 0.0001). The posterior third of the tongue in patients with OSA had the highest value of shear modulus during the MM (p < 0.001). With cut-offs of 27.6 and 35.2 kPa for the whole tongue and posterior third during the MM, respectively, the sensitivity obtained was 69.2% and 76.9%, and the specificity was 85% and 95%, respectively, for detecting OSA. The corresponding areas under the receiver operating characteristic curve were 0.82 and 0.88, respectively. US SWE may have the potential for non-invasive tongue stiffness measurement in OSA.

Prevalence and patterns of tongue deformation in obstructive sleep apnea: A whole-night simultaneous ultrasonographic and polysomnographic study

Tongue deformation during whole-night natural sleep in adult patients with obstructive sleep apnea has not been well evaluated. Through simultaneous ultrasonography and polysomnography during whole-night sleep, we examined the prevalence and patterns of tongue depth changes and their relationship with the severity of obstructive sleep apnea. Sixty consecutive eligible adults presenting with symptoms suggesting obstructive sleep apnea were enrolled. We observed that 88.4% (38/43) of patients with obstructive sleep apnea exhibited a significant increase in the maximum ultrasonographic tongue depth when hypopnea or apnea occurred during sleep. A mixed-model analysis of variance demonstrated that compared with patients with primary snoring or mild obstructive sleep apnea, those with moderate to severe obstructive sleep apnea have significantly greater maximum ultrasonographic tongue depth during respiratory events (p = .0047). We identified three different ultrasonographic patterns of tongue deformation, namely en bloc, tongue body and tongue base. Approximately 82% (27/33) of patients with moderate to severe obstructive sleep apnea demonstrated an en bloc tongue deformation. By contrast, 70% (19/27) of primary snorers or patients with mild obstructive sleep apnea showed a tongue body obstruction. Recognizing the prevalence and patterns of tongue deformation during sleep may provide insights into pathogenesis and treatment decisions in patients with obstructive sleep apnea. Future studies are warranted to verify the treatment results of various tongue procedures by using this approach.

Global burden of sleep-disordered breathing and its implications

One-seventh of the world's adult population, or approximately one billion people, are estimated to have OSA. Over the past four decades, obesity, the main risk factor for OSA, has risen in striking proportion worldwide. In the past 5 years, the WHO estimates global obesity to affect almost two billion adults. A second major risk factor for OSA is advanced age. As the prevalence of the ageing population and obesity increases, the vulnerability towards having OSA increases. In addition to these traditional OSA risk factors, studies of the global population reveal select contributing features and phenotypes, including extreme phenotypes and symptom clusters that deserve further examination. Untreated OSA is associated with significant comorbidities and mortality. These represent a tremendous threat to the individual and global health. Beyond the personal toll, the economic costs of OSA are far-reaching, affecting the individual, family and society directly and indirectly, in terms of productivity and public safety. A better understanding of the pathophysiology, individual and ethnic similarities and differences is needed to better facilitate management of this chronic disease. In some countries, measures of the OSA disease burden are sparse. As the global burden of OSA and its associated comorbidities are projected to further increase, the infrastructure to diagnose and manage OSA will need to adapt. The use of novel approaches (electronic health records and artificial intelligence) to stratify risk, diagnose and affect treatment are necessary. Together, a unified multi-disciplinary, multi-organizational, global approach will be needed to manage this disease.

Associations of Inflammation, Physical Activity, and Sleep in a Diverse Population of Women

Background: Cardiovascular disease (CVD) is the leading cause of mortality in United States with a recent rise seen in young adults, particularly women. Systemic inflammation, physical activity, and sleep are each individually linked to CVD risk. Whether there is an interaction of these variables, however, is unclear. We evaluated physical activity and sleep among racially ethnically diverse women, ages 20-79 years, to assess associations with systemic inflammation. Methods: We performed a cross-sectional study of 506 women (61% racial/ethnic minority; mean (standard deviation [SD]) age = 37 [15.7] years, body mass index 26.0 [5.7] kg/m²) enrolled in the American Heart Association (AHA) Go Red for Women Strategically Focused Research Network at Columbia University Irving Medical Center (CUIMC). Inflammation, assessed by C-reactive protein (CRP), was analyzed in the Biomarkers Core Laboratory at CUIMC. Physical activity and sleep were assessed using validated questionnaires. Multivariable models adjusted for demographic and clinical confounders were used to evaluate associations between CRP, physical activity, and sleep. Results: Mean (SD) physical activity was 282 (557.2) minutes/week, and mean (SD) sleep duration was 6.75 (1.24) hours/night. Mean CRP was 2.08 (3.56), and 17% of participants were categorized as high risk for obstructive sleep apnea (OSA). Participants who slept <6 hours/night were less likely to be physically active ≥150 minutes/week (odds ratios, ORs [95% confidence interval, CI]: 0.53 [0.33-0.84]). This association was nonsignificant after adjustment. High risk of OSA was associated with CRP ≥2 mg/L (OR [95% CI]: 1.91 [1.11-3.30]) following adjustment. Stratification by race/ethnicity showed that high risk of OSA was associated with CRP ≥2 mg/L among racial/ethnic minorities but not white women (OR [95% CI]: 2.75 [1.43-5.30] vs. 0.94 [0.31-2.88]). Conclusion: High risk of OSA and elevated CRP was significantly associated in women, particularly minority women. Both play a role in CVD, highlighting potential causes for the increased risk of CVD in younger women.

Clustering-based characterization of clinical phenotypes in obstructive sleep apnoea using severity, obesity, and craniofacial pattern

OBJECTIVES

To identify and characterize the phenotypes of adult obstructive sleep apnoea (OSA) patients based on clustering using OSA severity, obesity, and craniofacial pattern.

MATERIAL AND METHODS

The samples consisted of 89 adult OSA patients whose polysomnography and lateral cephalogram were available. With cluster analysis using apneahypopnea index (AHI, events/hour), body mass index (BMI, kg/m2), ANB (degree), and mandibular plane angle (MPA, degree), three clusters were identified. Cephalometric variables including craniofacial, soft palate, hyoid bone, and pharyngeal space compartments were compared among clusters by one-way analysis of variance or Kruskal-Wallis test. Multivariable linear regression analysis was performed to find contributing factors to OSA severity within each cluster.

RESULTS

Cluster-1 (obesity type; 49.4 per cent) exhibited moderate OSA, obesity, and normal sagittal and vertical skeletal pattern (AHI, 22.4; BMI, 25.5; ANB, 3.2 degrees; MPA, 26.3 degrees) without significant upper airway abnormality. Cluster-2 (skeletal type; 33.7 per cent) was characterized by moderate OSA, severe skeletal Class II hyperdivergent pattern with narrow pharyngeal airway spaces, without obesity (AHI, 27.9; BMI, 23.5; ANB, 7.5 degrees; MPA, 36.6 degrees). Cluster-3 (complex type; 16.8 per cent) included severe OSA, obesity, skeletal Class II hyperdivergent pattern (AHI, 52.8; BMI, 28.0; ANB, 4.5 degrees; MPA, 32.2 degrees), with posteriorly displaced hyoid and retroclined soft palate. The main contributing factors to AHI were obesity in Cluster-1; hyperdivergent vertical pattern with narrow pharyngeal space in Cluster-2; and hyperdivergent pattern, obesity, displaced hyoid, and soft palate in Cluster-3.

CONCLUSION

Three OSA phenotypes resulted from this study provide a clinical guideline for differential diagnosis and orthodontic intervention in the interdisciplinary treatment for OSA patients.

Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis

BACKGROUND

There is a scarcity of published data on the global prevalence of obstructive sleep apnoea, a disorder associated with major neurocognitive and cardiovascular sequelae. We used publicly available data and contacted key opinion leaders to estimate the global prevalence of obstructive sleep apnoea.

METHODS

We searched PubMed and Embase to identify published studies reporting the prevalence of obstructive sleep apnoea based on objective testing methods. A conversion algorithm was created for studies that did not use the American Academy of Sleep Medicine (AASM) 2012 scoring criteria to identify obstructive sleep apnoea, allowing determination of an equivalent apnoea-hypopnoea index (AHI) for publications that used different criteria. The presence of symptoms was not specifically analysed because of scarce information about symptoms in the reference studies and population data. Prevalence estimates for obstructive sleep apnoea across studies using different diagnostic criteria were standardised with a newly developed algorithm. Countries without obstructive sleep apnoea prevalence data were matched to a similar country with available prevalence data; population similarity was based on the population body-mass index, race, and geographical proximity. The primary outcome was prevalence of obstructive sleep apnoea based on AASM 2012 diagnostic criteria in individuals aged 30-69 years (as this age group generally had available data in the published studies and related to information from the UN for all countries).

FINDINGS

Reliable prevalence data for obstructive sleep apnoea were available for 16 countries, from 17 studies. Using AASM 2012 diagnostic criteria and AHI threshold values of five or more events per h and 15 or more events per h, we estimated that 936 million (95% CI 903-970) adults aged 30-69 years (men and women) have mild to severe obstructive sleep apnoea and 425 million (399-450) adults aged 30-69 years have moderate to severe obstructive sleep apnoea globally. The number of affected individuals was highest in China, followed by the USA, Brazil, and India.

INTERPRETATION

To our knowledge, this is the first study to report global prevalence of obstructive sleep apnoea; with almost 1 billion people affected, and with prevalence exceeding 50% in some countries, effective diagnostic and treatment strategies are needed to minimise the negative health impacts and to maximise cost-effectiveness.

FUNDING

ResMed.

The effect of body position on airway patency in obstructive sleep apnea: CT imaging analysis

PURPOSE

Positional change during sleep influences upper airway patency. However, few studies have used imaging techniques to demonstrate the change. This study aims to determine the effect of positional change on the upper airway space.

METHODS

A total of 118 subjects with sleep breathing disorders were analyzed. Participants underwent upper airway CT scans in the supine and lateral decubitus positions (right and left). They were divided into non-obstructive sleep apnea (n = 28) and obstructive sleep apnea (n = 90) groups. We measured the minimal cross-sectional area of the retropalatal/retroglossal spaces and compared the differences of those two spaces in the supine and lateral positions. CT was performed while patients were awake.

RESULTS

The minimal cross-sectional area in the OSA group was significantly smaller than non-OSA group in both supine (median[interquartile range], 8.3[0.0-25.1] vs 22.2[1.0-39.6]; P = 0.018) and lateral decubitus positions (5.2[0.0-16.9] vs 21.3[6.1-38.4]; P = 0.002). As the body position of OSA patients shifted from supine to lateral, the retroglossal space increased significantly (67.3[25.1-116.3] vs 93.3[43.4-160.1]; P < 0.001). However, there was no significant difference in the retropalatal space between the supine and lateral decubitus positions.

CONCLUSIONS

Positional change from the supine to lateral decubitus position expands the upper airway lumen, especially the retroglossal space. Positional OSA may be related to anatomical change of the upper airway lumen based on body position.

A Global Comparison of Anatomic Risk Factors and Their Relationship to Obstructive Sleep Apnea Severity in Clinical Samples

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a global health issue and is associated with obesity and oropharyngeal crowding. Global data are limited on the effect of ethnicity and sex on these relationships. We compare associations between the apnea-hypopnea index (AHI) and these risk factors across ethnicities and sexes within sleep clinics.

METHODS

This is a cross-sectional, multicenter study of patients with OSA from eight sleep centers representing the Sleep Apnea Global Interdisciplinary Consortium (SAGIC). Four distinct ethnic groups were analyzed, using a structured questionnaire: Caucasians (Australia, Iceland, Germany, United States), African Americans (United States), Asians (Taiwan), and South Americans (Brazil). Regression analyses and interaction tests were used to assess ethnic and sex differences in relationships between AHI and anthropometric measures (body mass index [BMI], neck circumference, waist circumference) or Mallampati score.

RESULTS

Analyses included 1,585 individuals from four ethnic groups: Caucasian (60.6%), African American (17.5%), Asian (13.1%), and South American (8.9%). BMI was most strongly associated with AHI in South Americans (7.8% increase in AHI per 1 kg/m² increase in BMI; P < .0001) and most weakly in African Americans (1.9% increase in AHI per 1 kg/m² increase in BMI; P = .002). In Caucasians and South Americans, associations were stronger in males than females. Mallampati score differed between ethnicities but did not influence AHI differently across groups.

CONCLUSIONS

We demonstrate ethnic and sex variations in associations between obesity and OSA. For similar BMI increases, South American patients show greatest AHI increases compared to African Americans. Findings highlight the importance of considering ethnicity and sex in clinical assessments of OSA risk.

Craniofacial and upper airway profile assessment in North Indian patients with obstructive sleep apnea

Introduction

Upper airway imaging can often identify the anatomical risk factors for sleep apnea and provide sufficient insight into the pathophysiology of obstructive sleep apnea (OSA).

Materials and Methods

We conducted a case-control, observational study at a tertiary care hospital in North India. All cases and controls underwent lateral cephalometry and magnetic resonance imaging (MRI) for craniofacial and upper airway evaluation. Only the cases had polysomnography testing for confirmation of OSA and assessing the severity of disease.

Results

Forty cases and an equal number of matched controls were recruited. On X-ray cephalometry, it was observed that the cases had a significantly larger hyoid mandibular distance and soft palate length; and shorter mandibular length. The MRI cephalometric variables were significantly different, the soft palate length, tongue length, and submental fat were longer while the retropalatal and retroglossal distance was shorter amongst the cases. A statistically significant positive correlation was found between the cephalometric parameters and the indices of severity of OSA. An increased hyoid mandibular distance and soft palate length, and a decrease in the lower anterior facial height were found to be predictive of severe OSA (Apnea-Hypopnea Index ->30/h). An increased hyoid mandibular distance, soft palate length, and the tongue length and a reduced mandibular length were found to be predictive of need for continuous positive airway pressure (CPAP) pressures of ≥15 cm H₂O. There were significant differences between the cephalometric parameters of the Indian OSA patients and patients from other ethnicities reported in the literature.

Conclusions

OSA patients had a significantly smaller upper airway compared to age-, sex-, and body mass index-matched controls and cephalometric variables correlated with the indices of OSA severity. The cephalometric assessment was also predictive of severe OSA and the need for higher pressures of CPAP. This indicates the important role of upper airway anatomy in the pathogenesis of OSA.

The Prevalence of Sleep Apnea in Iran: a Systematic Review and Meta-Analysis

BACKGROUND

Sleep apnea is a common sleep disorder which is associated with cardiovascular diseases, diabetes and stroke. Different studies conducted in Iran have reported different prevalence for sleep apnea. The aim of the present study was to determine the prevalence of sleep apnea in Iran.

MATERIALS AND METHODS

In this study, 42 studies that have been published in Farsi and English languages were selected with no time limit up to the March of 2018. Article search was conducted using "prevalence", "frequency", "sleep apnea" and "obstructive sleep apnea" keywords in Scientific Information Database (SID), MagIran, Google Scholar, Science Direct, PubMed and Scopus databases. Data were analyzed using meta-analysis and random effect model methods. Heterogeneity between the studies was evaluated using I² test. Data were analyzed using Stata software version 11.2.

RESULTS

The total prevalence of metabolic syndrome was 44% (95% CI: 35% to 53%). The highest prevalence of sleep apnea distinguished by the disease belonged to patients with sleep disorders (74%, 95% CI: 66%-82%), diabetes mellitus (61%; 95% CI: 46%-76%) and cardiovascular disease (55%; 95% CI: 47%-63%).

CONCLUSION

Given high prevalence of sleep apnea in Iran, identifying people at risk and providing instructional materials for controlling and treating sleep apnea is necessary.

Craniofacial Phenotyping in Chinese and Caucasian Patients With Sleep Apnea: Influence of Ethnicity and Sex

STUDY OBJECTIVES

Craniofacial abnormalities are a risk factor for obstructive sleep apnea (OSA). We have previously shown that phenotypic information derived from craniofacial photographs predict OSA in sleep clinic populations. However, there are likely ethnic and sex differences in craniofacial phenotypes related to OSA. We aimed to assess the use of craniofacial photography to identify interactions between OSA, ethnicity, and sex in craniofacial phenotype.

METHODS

Frontal and profile craniofacial photographs were analyzed from two sleep clinic populations of different ethnicity (Hong Kong Chinese, Australian Caucasians). OSA was defined as apnea-hypopnea index (AHI) > 10 events/h. Ten craniofacial measurements (three angles relating to jaw position and seven ratios describing proportions of the face) were examined for interactions between OSA status and sex or ethnicity) using factorial analysis of variance.

RESULTS

A total of 363 subjects (25% female) were included (n = 200 Chinese, n = 163 Caucasian), of which 33% were controls. There were two-way interactions for OSA with both sex (mandibular plane angle [F = 7.0, P = .009], face / eye width ratio [F = 4.7, P = .032], maxillary / mandibular volume ratio [F = 9.2, P = .003]) and ethnicity (face / nose width ratio [F = 4.0, P = .045], mandibular width / length ratio [F = 5.1, P = .024], maxillary / mandibular volume ratio [F = 11.0, P = .001]).

CONCLUSIONS

We provide evidence of ethnic and sex differences in facial phenotype related to OSA. Furthermore, we demonstrate that craniofacial photography can be used as a phenotypic tool to assess these differences and allow investigation of OSA phenotypes in large samples. This has relevance to personalizing OSA recognition strategies across different populations.

Symptom-Based Subgroups of Koreans With Obstructive Sleep Apnea

STUDY OBJECTIVES

Recently, the Icelandic Sleep Apnea Cohort (ISAC) identified three subgroups in patients with obstructive sleep apnea (OSA) recruited from the sleep clinic based on clinical symptoms and comorbidities: excessively sleepy, minimally symptomatic, and disturbed sleep. This study sought to determine whether the three OSA subgroups are applicable to a population-based cohort in Korea.

METHODS

Study subjects are participants of an ongoing cohort study in Korea. Of the 2,918 participants, 422 new moderate to severe OSA cases (apneahypopnea index [AHI] ≥ 15 events/h) were diagnosed by home sleep studies. All participants completed a detailed questionnaire on sleep-related symptoms, comorbidities, medication, and other information. A latent class analysis was performed.

RESULTS

When examining solutions for up to 10 clusters, the a priori three-cluster solution was the optimal clustering solution. The three-cluster solution demonstrated a subgroup presentation similar to the clusters identified in the ISAC. The minimally symptomatic subgroup was most prevalent (55.7%) in the Korean cohort. Among the three subgroups, there were no differences in mean AHI and body mass index; however, the disturbed sleep subgroup was older and had more females.

CONCLUSIONS

Combined with the ISAC data, we suggest that the three-symptom cluster solution for patients with OSA may be more widely applicable, irrespective of ethnicity and study population.

Three-dimensional photography for the evaluation of facial profiles in obstructive sleep apnoea

BACKGROUND AND OBJECTIVE

Craniofacial structure is an important determinant of obstructive sleep apnoea (OSA) syndrome risk. Three-dimensional stereo-photogrammetry (3dMD) is a novel technique which allows quantification of the craniofacial profile. This study compares the facial images of OSA patients captured by 3dMD to three-dimensional computed tomography (3-D CT) and two-dimensional (2-D) digital photogrammetry. Measurements were correlated with indices of OSA severity.

METHODS

Thirty-eight patients diagnosed with OSA were included, and digital photogrammetry, 3dMD and 3-D CT were performed. Distances, areas, angles and volumes from the images captured by three methods were analysed.

RESULTS

Almost all measurements captured by 3dMD showed strong agreement with 3-D CT measurements. Results from 2-D digital photogrammetry showed poor agreement with 3-D CT. Mandibular width, neck perimeter size and maxillary volume measurements correlated well with the severity of OSA using all three imaging methods. Mandibular length, facial width, binocular width, neck width, cranial base triangle area, cranial base area 1 and middle cranial fossa volume correlated well with OSA severity using 3dMD and 3-D CT, but not with 2-D digital photogrammetry.

CONCLUSION

3dMD provided accurate craniofacial measurements of OSA patients, which were highly concordant with those obtained by CT, while avoiding the radiation associated with CT.