Snoring-generated fluid droplets as a potential mechanistic link between sleep-disordered breathing and pneumonia.

The soft palate and back of the throat represent vulnerable early infection sites for SARS-CoV-2, influenza, streptococci, and many other pathogens. We demonstrate that snoring causes aerosolization of pharyngeal fluid that covers these surfaces, which previously has escaped detection because the inspired airstream carries the micron-sized droplets into the lung, inaccessible to traditional aerosol detectors. While many of these droplets will settle in the lower respiratory tract, a fraction of the respirable smallest droplets remains airborne and can be detected in exhaled breath. We distinguished these exhaled droplets from those generated by the underlying breathing activity by using a chemical tracer, thereby proving their existence. The direct transfer of pharyngeal fluids and their pathogens into the deep lung by snoring represents a plausible mechanistic link between the previously recognized association between sleep-disordered breathing and pneumonia incidence.

Development and validation of an oropharyngeal obstruction evaluation score.

OBJECTIVE: To identify standard clinical parameters that can predict the presence and severity of obstructive sleep apnea. SUBJECTS AND METHODS: Adult patients with habitual snoring completed comprehensive polysomnography and anthropometric measurements, including sex, age, body mass index (BMI), neck circumference, tonsil size grading, modified Mallampati score, and nasofibroscopy-assisted Muller's maneuver (NMM). Spearman's correlation coefficient was used to screen the significant variables. Stepwise multiple linear regression analysis was then conducted to identify the independent variables. receiver operating characteristic (ROC) curve analysis was used to quantify the predictability of the formed oropharyngeal obstruction scoring system. RESULTS: A total of 163 adults (127 men) were enrolled in the study. Tonsil size grading, modified Mallampati score, and NMM grading maneuver were predictive of  OSA and incorporated into a scoring system. This score ranged between 3 and 12, and threshold values of ≥ 8 and ≥ 9 seemed to be appropriate to identify patients at an increased risk of at least mild (AHI ≥ 5/h; AUROC = 0.935, 95%CI = 0.900-0.970, P < 0.001) and severe OSA (AHI ≥ 30/h; AUROC = 0.939, 95%CI = 0.899-0.969, P < 0.001), respectively. CONCLUSION: This study established an evaluation score for assessing the degree of oropharhygeal obstruction. The findings of the study suggest that the score may help identify patients at risk of oropharyngeal-related OSA who should have a full sleep evaluation.

Consumer sleep technology for the screening of obstructive sleep apnea and snoring: current status and a protocol for a systematic review and meta-analysis of diagnostic test accuracy.

There are concerns about the validation and accuracy of currently available consumer sleep technology for sleep-disordered breathing. The present report provides a background review of existing consumer sleep technologies and discloses the methods and procedures for a systematic review and meta-analysis of diagnostic test accuracy of these devices and apps for the detection of obstructive sleep apnea and snoring in comparison with polysomnography. The search will be performed in four databases (PubMed, Scopus, Web of Science, and the Cochrane Library). Studies will be selected in two steps, first by an analysis of abstracts followed by full-text analysis, and two independent reviewers will perform both phases. Primary outcomes include apnea-hypopnea index, respiratory disturbance index, respiratory event index, oxygen desaturation index, and snoring duration for both index and reference tests, as well as the number of true positives, false positives, true negatives, and false negatives for each threshold, as well as for epoch-by-epoch and event-by-event results, which will be considered for the calculation of surrogate measures (including sensitivity, specificity, and accuracy). Diagnostic test accuracy meta-analyses will be performed using the Chu and Cole bivariate binomial model. Mean difference meta-analysis will be performed for continuous outcomes using the DerSimonian and Laird random-effects model. Analyses will be performed independently for each outcome. Subgroup and sensitivity analyses will evaluate the effects of the types (wearables, nearables, bed sensors, smartphone applications), technologies (e.g., oximeter, microphone, arterial tonometry, accelerometer), the role of manufacturers, and the representativeness of the samples.

Nocturnal oximetry parameters as predictors of sleep apnea severity in resource-limited settings.

Nocturnal oximetry is an alternative modality for evaluating obstructive sleep apnea syndrome (OSAS) severity when polysomnography is not available. The Oxygen Desaturation (≥3%) Index (ODI3) and McGill Oximetry Score (MOS) are used as predictors of moderate-to-severe OSAS (apnea-hypopnea index-AHI >5 episodes/h), an indication for adenotonsillectomy. We hypothesised that ODI3 is a better predictive parameter for AHI >5 episodes/h than the MOS. All polysomnograms performed in otherwise healthy, snoring children with tonsillar hypertrophy in a tertiary hospital (November 2014 to May 2019) were analysed. The ODI3 and MOS were derived from the oximetry channel of each polysomnogram. Logistic regression was applied to assess associations of ODI3 or MOS (predictors) with an AHI >5 episodes/h (primary outcome). Receiver operating characteristic (ROC) curves and areas under ROC curves were used to compare the ODI3 and MOS as predictors of moderate-to-severe OSAS. The optimal cut-off value for each oximetry parameter was determined using Youden's index. Polysomnograms of 112 children (median [interquartile range] age 6.1 [3.9-9.1] years; 35.7% overweight) were analysed. Moderate-to-severe OSAS prevalence was 49.1%. The ODI3 and MOS were significant predictors of moderate-to-severe OSAS after adjustment for overweight, sex, and age (odds ratio [OR] 1.34, 95% confidence interval [CI] 1.19-1.51); and OR 4.10, 95% CI 2.06-8.15, respectively; p < 0.001 for both). Area under the ROC curve was higher for the ODI3 than for MOS (0.903 [95% CI 0.842-0.964] versus 0.745 [95% CI 0.668-0.821]; p < 0.001). Optimal cut-off values for the ODI3 and MOS were ≥4.3 episodes/h and ≥2, respectively. The ODI3 emerges as preferable or at least a complementary oximetry parameter to MOS for detecting moderate-to-severe OSAS in snoring children when polysomnography is not available.

Association between snoring, daytime sleepiness and cardiovascular disease in Chinese rural adults.

BACKGROUNDS AND AIMS: Evidence on the association between habitual snoring, excessive daytime sleepiness (EDS), and cardiovascular diseases (CVDs) remains uncertain and limited. The study aimed to explore the independent and joint association between habitual snoring, EDS, and CVDs in rural Chinese adults. METHODS AND RESULTS: A total of 28,140 participants from the Henan rural cohort study were included. Sleep status information was obtained by self-reported. Based on their sleep status, the participants were classified into four groups: "no snoring and no EDS (NSNS) (reference group)", "snoring and no EDS (SNS)", "no snoring and EDS (NSS)", "snoring and EDS (SS)." The logistic regression models were used to calculate independent and joint odds ratios (OR) and 95% confidence intervals (CI) between the snoring, EDS status and stroke, CHD, and CVD. Of the 28,140 participants, 740 subjects reported snoring and sleepiness. The ORs and (95% CIs) for CVDs in the adjusted model were 1.31 (1.20-1.43) for participants who snored frequently and 2.44 (1.76-3.39) for frequent sleepiness compared with no snoring and no sleepiness. Individuals with both snoring and sleepiness had higher odds of CVDs compared with no snoring and no sleepiness (OR: 2.18, 95%CI: 1.80-2.62). CONCLUSION: Habitual snoring and excessive daytime sleepiness were independently and jointly associated with CVDs in the Chinese rural population. More studies are needed to explore the mechanisms of the relationship. CLINICAL TRIAL REGISTRATION: The Henan Rural Cohort Study has been registered at the Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-52 07-06. http://www.chictr.org.cn/showproj.aspx?proj=11375.

Risk factors for habitual snoring among children aged 2-14 years in Chengdu, Sichuan.

PURPOSE: Habitual snoring (HS) is a prominent symptom of sleep-disordered breathing; thus, it is also important to consider the associated, multidimensional risk factors for HS in children. This study was aimed to identify risk factors for HS in children. METHODS: A cross-sectional survey was performed in Chengdu. Children aged 2-14 years from four districts were randomly chosen to participate. Questionnaires were voluntarily completed by the children's guardians. RESULTS: The survey included 926 boys and 622 girls, who were an average of 6.4 ± 3.0 years old. The sample included 463 habitual snorers (30.4%), 683 occasional snorers (44.8%), and 402 nonsnorers (26.4%). HS was found in 51.8% of children under 7 years old and 26.6% of children aged 7 years old or older. The prevalence of pregnancy complications was significantly lower in mothers who bore children with HS (p = .006). Among the HS group, 86.6% had an immediate family member who snores. Breastfeeding duration among the HS group was significantly less than among the occasional snoring and nonsnoring groups. History of symptoms of allergic rhinitis, rhinosinusitis, tonsillitis, and pneumonia/bronchitis in the past 6 months was associated with HS. Likewise, maternal smoking during pregnancy, maternal exposure to secondhand smoke during pregnancy, and child exposure to secondhand smoke were also associated with HS. CONCLUSION: The prevalence of HS was higher in children under 7 years old. Having a mother with more education, a family history of snoring, a shorter period of breastfeeding, upper respiratory tract inflammation, and passive smoking are important risk factors for HS. Pregnancy complications may be associated with lower prevalence of snoring in childhood.

Predictive value of NoSAS questionnaire combined with the modified Mallampati grade for hypoxemia during routine sedation for gastrointestinal endoscopy.

BACKGROUND: The incidence of hypoxemia during painless gastrointestinal endoscopy remains a matter of concem. To date, there is no recognized simple method to predict hypoxemia in digestive endoscopic anesthesia. The NoSAS (neck circumference, obesity, snoring, age, sex) questionnaire, an objective and simple assessment scale used to assess obstructive sleep apnea (OSA), combined with the modified Mallampati grade (MMP), may have certain screening value. This combination may allow anesthesiologists to anticipate, manage, and consequently decrease the occurrence of hypoxemia. METHODS: This study was a prospective observational trial. The primary endpoint was the incidence of hypoxaemia defined as pulse oxygen saturation (SpO2) < 95% for 10 s. A total of 2207 patients admitted to our hospital for painless gastrointestinal endoscopy were studied. All patients were measured for age, height, weight, body mass index, neck circumference, snoring, MMP, and other parameters. Patients were divided into hypoxemic and non-hypoxemic groups based on the SpO2. The ROC curve was plotted to evaluate the screening value of the NoSAS questionnaire separately and combined with MMP for hypoxemia. The total NoSAS score was evaluated at cut-off points of 8 and 9. RESULTS: With a NoSAS score ≥ 8 as the critical value for analysis, the sensitivity for hypoxemia was 58.3%, the specificity was 88.4%, and the area under the ROC was 0.734 (P < 0.001, 95% CI: 0.708-0.759). With a NoSAS score ≥ 9 as a critical value, the sensitivity for hypoxemia was 36.50%, the specificity rose to 96.16%, and the area under the ROC was 0.663 (P < 0.001, 95% CI: 0.639-0.688). With the NoSAS Score combined with MMP for analysis, the sensitivity was 78.4%, the specificity was 84%, and the area under the ROC was 0.859 (P < 0.001, 95%CI:0.834-0.883). CONCLUSIONS: As a new screening tool, the NoSAS questionnaire is simple, convenient, and useful for screening hypoxemia. This questionnaire, when paired withMMP, is likely to be helpful for the screening of hypoxemia.

AHI estimation of OSAHS patients based on snoring classification and fusion model.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a chronic and common sleep-breathing disease that could negatively influence lives of patients and cause serious concomitant diseases. Polysomnography(PSG) is the gold standard for diagnosing OSAHS, but it is expensive and requires overnight hospitalization. Snoring is a typical symptom of OSAHS. This study proposes an effective OSAHS screening method based on snoring sound analysis. Snores were labeled as OSAHS related snoring sounds and simple snoring sounds according to real-time PSG records. Three models were used, including acoustic features combined with XGBoost, Mel-spectrum combined with convolution neural network (CNN), and Mel-spectrum combined with residual neural network (ResNet). Further, the three models were fused by soft voting to detect these two types of snoring sounds. The subject's apnea-hypopnea index (AHI) was estimated according to these recognized snoring sounds. The accuracy and recall of the proposed fusion model achieved 83.44% and 85.27% respectively, and the predicted AHI has a Pearson correlation coefficient of 0.913 (R2 = 0.834, p < 0.001) with PSG. The results demonstrate the validity of predicting AHI based on analysis of snoring sound and show great potential for monitoring OSAHS at home.

Evaluation of sleeping parameters with peripheral arterial tonometry in childhood sleep apnea and snoring: a clinical feasibility study.

PURPOSE: The influence of adenoidectomy ± tonsillotomy/tonsillectomy on objective sleep parameters in children with Obstructive Sleep Apnea (OSA) was determined with the help of ambulatory polygraphy (WatchPat300®, Neucomed Ltd., Vienna, Austria). These results were compared with the findings of the OSA-18 questionnaire. METHODS: 27 children treated with adenoidectomy ± tonsillotomy/tonsillectomy at the Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Innsbruck, were consecutively included in this prospective clinical trial. Pre- and postoperative objective sleeping parameters were assessed with outpatient polygraphy (WatchPat300®) and subjective symptoms with the OSA-18 questionnaire. RESULTS: Most of the children presented with severe OSA (41%, 11/27). The mean preoperative AHI was 10.2 (± 7.4). Postoperatively it declined to 3.7 (± 1.8; p < 0.0001). Following surgery 19/24 (79%) children had a mild OSA and 8/24 (21%) a moderate OSA. None of the children suffered from severe OSA anymore after surgery. The postoperative AHI did not correlate with the age (p = 0.3), BMIp (p = 0.6) or extent of surgery (p = 0.9). The mean postoperative OSA-18 survey score was significantly lower than the preoperative one (70.7 ± 26.7 vs. 34.5 ± 10.5; p < 0.0001). The postoperative OSA-18 questionnaire showed a normal survey score below 60 in 23/24 (96%) of the children. CONCLUSIONS: The WatchPat® device might be a feasible way for objective assessment of pediatric OSA in children older than 3 years. Adenoidectomy ± tonsillotomy/tonsillectomy caused a significant decrease of the AHI in children with OSA. This effect was especially pronounced in children with severe OSA and none of the children had persistent severe OSA after surgery.

[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound]. / Die Analyse von Schnarchen bei Patienten mit obstruktiver Schlafapnoe (OSA) anhand von Polysomnographie und LEOSound.

INTRODUCTION: Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring. METHODS AND INTENTION: In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57±11 years. Average weight was 100±19 kg by a mean body mass index (BMI) of 33±7 kg/m2. 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound. RESULTS: 3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0%), polysomnography in 2229 (58,8%) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound. DISCUSSION: In nearly 60% of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60% of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.

Orofacial dysfunction screening examinations in children with sleep-disordered breathing symptoms.

Orofacial myofunctional disorders (OMD) and sleep-disordered breathing (SDB) may present as comorbidities. Orofacial characteristics might serve as a clinical marker of SDB, allowing early identification and management of OMD and improving treatment outcomes for sleep disorders. The study aims to characterize OMD in children with SDB symptoms and to investigate possible relationships between the presence of various components of OMD and symptoms of SDB. A cross-sectional study of healthy children aged 6-8 from primary schools was conducted in central Vietnam in 2019. SDB symptoms were collected using the parental Pediatric Sleep Questionnaire, Snoring Severity Scale, Epworth Daytime Sleepiness Scale, and lip-taping nasal breathing assessment. Orofacial myofunctional evaluation included assessment of tongue mobility, as well as of lip and tongue strength using the Iowa Oral Performance Instrument, and of orofacial characteristics by the protocol of Orofacial Myofunctional Evaluation with Scores. Statistical analysis was used to investigate the relationship between OMD components and SDB symptoms. 487 healthy children were evaluated, of whom 46.2% were female. There were 7.6% of children at high risk of SDB. Children with habitual snoring (10.3%) had an increased incidence of restricted tongue mobility and decreased lip and tongue strength. Abnormal breathing patterns (22.4%) demonstrated lower posterior tongue mobility and lower muscle strength. Daytime sleepiness symptoms were associated with changes in muscle strength, facial appearance, and impaired orofacial function. Lower strengths of lip and tongue or improper nasal breathing were more likely to be present in children with reported sleep apnea (6.6%). Neurobehavioral symptoms of inattention and hyperactivity were linked to anomalous appearance/posture, increases in tongue mobility and oral strength. This study demonstrates a prevalence of orofacial myofunctional anomalies in children exhibiting SDB symptoms. Children with prominent SDB symptoms should be considered as candidates for further orofacial myofunctional assessment.

Office Blood Pressure Monitoring in Children with Obesity and Obstructive Sleep Apnea.

OBJECTIVE: To investigate the relative contributions of obesity and obstructive sleep apnea (OSA) to unfavorable blood pressure in children. STUDY DESIGN: Children aged 3-18 years with OSA-related symptoms were recruited. All children underwent office blood pressure (BP) monitoring and full-night polysomnography. Obesity was defined as a body mass index ≥95th percentile. OSA severity was divided into primary snoring (apnea-hypopnea index [AHI] <1), mild OSA (5> AHI ≥1), and moderate to severe OSA (AHI ≥5). Age- and sex-adjusted logistic regression analysis was performed to determine the associations among OSA, obesity, and elevated BP. RESULTS: This cross-sectional study enrolled 1689 children (66% boys), with a mean age of 7.9 years. Compared with children with primary snoring, children with moderate to severe OSA had significantly higher systolic BP (108.1 mmHg vs 105.6 mmHg), diastolic BP (75.0 mmHg vs 70.4 mmHg), systolic BP percentile (75.0 vs 70.4), and diastolic BP percentile (74.0 vs 69.2). The rate of unfavorable BP (ie, elevated BP or hypertension level BP) also was significantly higher in children with more severe OSA. Children with obesity had higher BP and BP percentile. Logistic regression analysis revealed that children with obesity and moderate to severe OSA have a 3-fold greater risk of unfavorable BP compared with children without obesity and primary snoring. CONCLUSIONS: We identified a 3-fold greater risk of unfavorable BP in children with obesity and moderate to severe OSA.

Sleep apnea severity based on estimated tidal volume and snoring features from tracheal signals.

Sleep apnea can be characterized by reductions in the respiratory tidal volume. Previous studies showed that the tidal volume can be estimated from tracheal sounds and movements called tracheal signals. Additionally, tracheal sounds include the sounds of snoring, a common symptom of obstructive sleep apnea. This study investigates the feasibility of estimating the severity of sleep apnea, as quantified by the apnea/hypopnea index (AHI), using the estimated tidal volume and snoring sounds extracted from tracheal signals. Tracheal signals were recorded simultaneously with polysomnography (PSG). The tidal volume was estimated from tracheal signals. The reductions in the tidal volume were detected as potential respiratory events. Additionally, features related to snoring sounds, which quantified variability, temporal clusters, and dominant frequency of snores, were extracted. A step-wise regression model and a greedy search algorithm were used sequentially to select the optimal set of features to estimate the apnea/hypopnea index and classify participants into healthy individuals and patients with sleep apnea. Sixty-one participants with suspected sleep apnea (age: 51 ± 16, body mass index: 29.5 ± 6.4 kg/m2 , apnea/hypopnea index: 20.2 ± 21.2 event/h) who were referred for a sleep test were recruited. The estimated apnea/hypopnea index was strongly correlated with the polysomnography-based apnea/hypopnea index (R2  = 0.76, p < 0.001). The accuracy of detecting sleep apnea for the apnea/hypopnea index cutoff of 15 events/h was 78.69% and 83.61% with and without using snore-related features. These findings suggest that acoustic estimation of airflow and snore-related features can provide a convenient and reliable method for screening of sleep apnea.

Sleep Apnea Screening in Children With Sickle Cell Anemia.

BACKGROUND: Screening for obstructive sleep apnea (OSA) is recommended by current guidelines in children with sickle cell anemia (SCA), but no specific approach is described. The Pediatric Sleep Questionnaire (PSQ) is a validated detection tool for OSA in children. We assessed the utility of PSQ to screen for OSA in children with concomitant SCA and snoring. MATERIALS AND METHODS: A prospective study, in children 4 to 18 years old with SCA. Subjects were assessed for snoring and PSQ administered at the same visit. All children with snoring were then referred for polysomnography. RESULTS: A total of 106 subjects were screened. Habitual snoring prevalence was 51/106 (48.1%). In the snoring group, OSA was detected in 83.9% (apnea-hypopnea index [AHI] ≥1.0/h) and 22.6% (AHI ≥5.0/h), respectively. Sensitivity and specificity of PSQ in children with snoring was 46.2% and 20.0% (AHI ≥1.0/h), and 57.1% and 50.0% (AHI ≥5.0/h), respectively. Physician assessment for snoring had a high sensitivity of 70.3% but low specificity of 58.4% (AHI ≥1.0/h), and 87.5% and 41.5% (AHI ≥5.0/h), respectively. CONCLUSION: PSQ is a poor screening tool for detection of OSA in those children with SCA who snore. Physician assessment for snoring could however be an initial approach before polysomnography.

Snoring and napping independently increased the serum uric acid levels and hyperuricemia risk: The Henan Rural Cohort Study.

BACKGROUND AND AIMS: Evidence on the association of snoring, daily sleep duration (daytime napping and night sleep duration) with hyperuricemia (HUA) was limited, especially in the resources-poor areas. This study aimed to investigate the independent effect of snoring frequency and daily sleep duration on HUA prevalence in rural Chinese adults. METHODS AND RESULTS: 29,643 participants aged 18-79 years were included in the final cross-sectional analysis from the Henan Rural Cohort Study. Multivariate logistic regression and linear regression models with HUA and serum uric acid (SUA) levels as dependent variables were conducted, respectively. Of the 29,643 included adults, 3498 suffered from HUA. Compared to never snoring, the adjusted odds ratio (OR) and 95% confidence interval (CI) of HUA for rare snoring, occasional snoring, and habitual snoring were 1.35 (1.17, 1.56), 1.30 (1.14, 1.47), and 1.59 (1.47, 1.73), respectively (P for trend <0.001). Compared with no napping, participants who had daytime napping of 61-90 and > 91 min were associated with a 29% and 30% increase in the prevalence of HUA, respectively (P for trend <0.001). But in night sleep duration groups, no significant associations were observed. The positive associations between snoring and HUA were attenuated in people aged ≥65 and people with type 2 diabetes mellitus (both P for interaction <0.05). CONCLUSION: Habitual snoring or longer daytime napping was independently associated with increased HUA prevalence and SUA levels in rural Chinese adults, which indicates the significance of early intervention and treatment of snoring and longer daytime napping to prevent hyperuricemia.

Accuracy of the sleep clinical record for the diagnosis of pediatric moderate-to-severe obstructive sleep apnea syndrome.

PURPOSE: The sleep clinical record (SCR) has been used to diagnose obstructive sleep apnea syndrome (OSAS) in children when access to polysomnography (PSG) is limited. Our aim was to determine the best SCR score that could facilitate diagnosis of moderate-to-severe OSAS in children with snoring. METHODS: Healthy children with history of snoring, who were referred for PSG, were prospectively recruited. The SCR score was calculated. Receiver operating characteristic curves (ROCs) were plotted to determine the area under curve (AUC), and the optimum SCR cutoff value was determined using the Youden index (J). RESULTS: Two hundred and seventy-three children were recruited (mean age 6.3 ± 2.5 years; median obstructive apnea-hypopnea index 1.5 episodes/h; range 0-61.1). The mean SCR score was 6.9 ± 3.6. Forty-six children had moderate-to-severe OSAS. Subjects with moderate-to-severe OSAS had a significantly higher mean SCR score (10.2 ± 2.9) than those with mild OSAS (6.2 ± 3.3; P < 0.001). Based on the plotted ROC, the AUC was 0.811 (95% confidence interval: 0.747-0.876; P < 0.001). Calculation of J, based on its ROC coordinates, indicated that the optimum cutoff SCR score to predict moderate-to-severe OSAS was 8.25, corresponding to a sensitivity of 83% and a specificity of 70%. CONCLUSION: Among children with history of snoring, an SCR score above 8.25 can identify those with moderate-to-severe OSAS.

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.

The acoustical and perceptual features of snore-related sounds in patients with obstructive sleep apnea sleeping with the dynamic mandibular advancement system MATRx plus®.

PURPOSE: The effect of snoring on the bed partner can be studied through the evaluation of in situ sound records by the bed partner or unspecialized raters as a proxy of real-life snoring perception. The aim was to characterize perceptual snore events through acoustical features in patients with obstructive sleep apnea (OSA) with an advanced mandibular position. METHODS: Thirty-minute sound samples of 29 patients with OSA were retrieved from overnight, in-home recordings of a study to validate the MATRx plus® dynamic mandibular advancement system. Three unspecialized raters identified sound events and classified them as noise, snore, or breathing. The raters provided ratings for classification certainty and annoyance. Data were analyzed with respect to respiratory phases, and annoyance. RESULTS: When subdividing perceptual events based on respiratory phase, the logarithm-transformed Mean Power, Spectral Centroid, and Snore Factor differed significantly between event types, although not substantially for the spectral centroid. The variability within event type was high and distributions suggested the presence of subpopulations. The general linear model (GLM) showed a significant patient effect. Inspiration segments occurred in 65% of snore events, expiration segments in 54%. The annoyance correlated with the logarithm of mean power (r = 0.48) and the Snore Factor (0.46). CONCLUSION: Perceptual sound events identified by non-experts contain a non-negligible mixture of expiration and inspiration phases making the characterization through acoustical features complex. The present study reveals that subpopulations may exist, and patient-specific features need to be introduced.

Sleep-Disordered Breathing in Pregnancy.

Sleep-disordered breathing (SDB) is a spectrum of abnormal respiratory events including habitual snoring and increased upper airway resistance and obstructive episodes. The uncertainties concerning the incidence and recognition of SDB during pregnancy and the importance of the issue for fetal and maternal health prompted us to screen pregnant women for SDB. The study included 312 women in the third trimester of pregnancy aged 17-46 of whom 51 were preselected, based on the results of SDB questionnaires, for a nighttime home screening using a portable ApneaLink Air device. We found that single or multiple episodes of apnea were present in 35 (69%) women. The mean apnea/hypopnea index (AHI) was 1.8 ± 1.8 episodes/h of sleep, which did not exceed the prevalence in the general young-adult female population. However, we noticed a substantial number of inspiratory airflow limitation (IFL) episodes most often accompanied by snoring and more frequent in pregnant women with a greater weight gain. IFLs, although not fulfilling the quantifiable criteria of hypopnea, raise the possibility of hardly recognizable oxygenation and cardiovascular disturbances in pregnancy, reflected in an increased risk index for SDB. We conclude that pregnancy encompasses the risk of revealing or intensifying pre-existing SDB which can jeopardize maternal and fetal health. The risk particularly applies to overweight women. We submit that women in late pregnancy should be carefully screened for possible SDB.

Automatic classification of the obstruction site in obstructive sleep apnea based on snoring sounds.

OBJECTIVES: Snoring is a common symptom of obstructive sleep apnea (OSA) which is considered to be potential predictors of the obstruction site. Successful treatment of OSA depend on the determination the types of obstruction site. This study aimed to develop a machine learning-based model to detect obstruction site using snoring sound. METHODS: Patients with OSA underwent drug-induced sleep endoscopy (DISE) and the snoring sounds were recorded simultaneously. We extracted acoustic features based on Mel-frequency cepstral coefficients (MFCC). A k-nearest neighbors (KNN) was used for snore classification. RESULTS: Total 42 patients with OSA were enrolled. The accuracy of model was 85.55 %, F1 score was 85.04. With combined age, gender and Body Mass Index (BMI), the accuracy of model was 87.98 %, and F1 score was 87.96. The model exhibited accuracies of 83 %, 93 % and 92 %; an AUC of 85.88, 89.22 and 88.17 in detecting retropalatal, retrolingual and multilevel obstructions. CONCLUSION: Our results suggest that combing snoring sound with age, gender and BMI, the machine learning based model can help automatically assess obstruction site. The model may have potential utility as a clinical tool to help for clinical decision-making.