Relationship Between Snoring Intensity and Severity of Obstructive Sleep Apnea

Validation of Downloadable Mobile Snore Applications by Polysomnography (PSG)

Purpose

Obstructive sleep apnea (OSA) is a common breathing disorder during sleep that is associated with symptoms such as snoring, excessive daytime sleepiness, and breathing interruptions. Polysomnography (PSG) is the most reliable diagnostic test for OSA; however, its high cost and lengthy testing duration make it difficult to access for many patients. With the availability of free snore applications for home-monitoring, this study aimed to validate the top three ranked snore applications, namely SnoreLab (SL), Anti Snore Solution (ASS), and Sleep Cycle Alarm (SCA), using PSG.

Patients and Methods

Sixty participants underwent an overnight PSG while simultaneously using three identical smartphones with the tested apps to gather sleep and snoring data.

Results

The study discovered that all three applications were significantly correlated with the total recording time and snore counts of PSG, with ASS showing good agreement with snore counts. Furthermore, the Snore Score, Time Snoring of SL, and Sleep Quality of SCA had a significant correlation with the natural logarithm of apnea hypopnea index (lnAHI) of PSG. The Snore Score of SL and the Sleep Quality of SCA were shown to be useful for evaluating snore severity and for pre-diagnosing or predicting OSA above moderate levels.

Conclusion

These findings suggest that some parameters of free snore applications can be employed to monitor OSA progress, and future research could involve adjusted algorithms and larger-scale studies to further authenticate these downloadable snore and sleep applications.

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.

The World Trade Center Health Program: Obstructive sleep apnea best practices

The events of September 11, 2001 exposed nearly half a million community residents and workers engaged in rescue and recovery and clean-up to dust, debris and toxic chemicals, as well as psychologic and physical stressors. Early studies showed an excess of aerodigestive diseases including rhinosinusitis and gastroesophageal reflux. Several studies of World Trade Center (WTC) responders report an excess of obstructive sleep apnea among patients who developed new onset or worsening chronic rhinosinusitis. High quality clinical diagnostic and treatment guidelines are available from The American Academy of Sleep Medicine and the Department of Veterans Affairs/Department of Defense. For enrolled members, the WTC program covers diagnostic evaluation and treatment for sleep apnea in members diagnosed with WTC-related upper and lower respiratory disease and gastroesophageal reflux.

Effects of demographic and sleep-related factors on snoring sound parameters

OBJECTIVE

To investigate the effect of frequently reported between-individual (viz., age, gender, body mass index [BMI], and apnea-hypopnea index [AHI]) and within-individual (viz., sleep stage and sleep position) snoring sound-related factors on snoring sound parameters in temporal, intensity, and frequency domains.

METHODS

This study included 83 adult snorers (mean ± SD age: 42.2 ± 11.3 yrs; male gender: 59%) who underwent an overnight polysomnography (PSG) and simultaneous sound recording, from which a total of 131,745 snoring events were extracted and analyzed. Data on both between-individual and within-individual factors were extracted from the participants' PSG reports.

RESULTS

Gender did not have any significant effect on snoring sound parameters. The fundamental frequency (FF; coefficient = -0.31; P = 0.02) and dominant frequency (DF; coefficient = -12.43; P < 0.01) of snoring sounds decreased with the increase of age, and the second formant increased (coefficient = 22.91; P = 0.02) with the increase of BMI. Severe obstructive sleep apnea (OSA; AHI ≥30 events/hour), non-rapid eye movement sleep stage 3 (N3), and supine position were all associated with more, longer, and louder snoring events (P < 0.05). Supine position was associated with higher FF and DF, and lateral decubitus positions were associated with higher formants.

CONCLUSIONS

Within the limitations of the current patient profile and included factors, AHI was found to have greater effects on snoring sound parameters than the other between-individual factors. The included within-individual factors were found to have greater effects on snoring sound parameters than the between-individual factors under study.

The risk factors for insomnia and sleep-disordered breathing in military communities: A meta-analysis

BACKGROUND

Many reviews and meta-analyses had been conducted to investigate risk factors for sleep disorders in the general population. However, no similar research has been performed in the military population though insomnia and sleep-disordered breathing are quite prevalent in that population.

OBJECTIVES

To investigate risk factors for insomnia and sleep-disordered breathing in military personnel.

METHODS

A systematic literature search was performed from inception to March 2021 and 6496 records were produced. Two authors independently screened records for eligibility. Results were presented as odds ratios, and a random-effect model was used to pool results. Data analysis was performed respectively according to military personnel type (i.e., veteran, active-duty personnel). Risk factors were sorted into three categories: sociodemographic, army-specific, and comorbidity. This meta-analysis was registered in PROSPERO before data analysis (registration No: CRD42020221696).

RESULTS

Twenty-seven articles were finally included in the quantitative analysis. For sleep-disordered breathing in active-duty personnel, four sociodemographic (i.e., overweight/obesity, higher body mass index, male gender, >35 years old) and one comorbidity (i.e., depression) risk factors were identified. For insomnia in active-duty personnel, four sociodemographic (i.e., aging, alcohol dependence, white race, and female gender), two army-specific (i.e., deployment experience, combat experience), and four comorbidity (i.e., depression, post-traumatic stress disorder, traumatic brain injury, and anxiety) risk factors were identified. For insomnia in veterans, one army-specific (i.e., combat experience) and one comorbidity (i.e., post-traumatic stress disorder) risk factor was identified.

CONCLUSIONS

Several risk factors were identified for insomnia and sleep-disordered breathing in the current meta-analysis. Risk factors for veterans and active-duty personnel were partially different. Research on sleep breathing disorders remains limited, and more convincing evidence would be obtained with more relevant studies in the future.

[Quantification of the loudness of snoring according to Watch-PAT-200 and its relationship with the severity of obstructive sleep apnea syndrome]

PURPOSE OF THE STUDY

Evaluate the capabilities of Watch-PAT-200 in obtaining data to determine the relationship between the loudness of snoring and the severity of obstructive sleep apnea syndrome (OSAS).

MATERIAL AND METHODS

From 2017 to 2019, 208 patients with complaints of nocturnal snoring were examined. Apnea / hypopnea indices (AHI) and respiratory distress index (RDI) were assessed. The study was carried out on a Watch-PAT-200 portable device (Itamar Medical, Israel). The average volume of snoring (dB) and the proportion (%) of sleep time with the intensity of snoring over 50.60 and 70 dB were measured. The correlation of the obtained data with the AHI and RDI indices is estimated.

RESULTS

During the study, it was found that the volume of snoring increases as the severity of OSAS increases, therefore, the volume of snoring can be an indicator of the severity of OSAS. There are ample opportunities for screening diagnostics of the loudness of snoring with the subsequent consultation of a somnologist and timely prescription of treatment. Due to the objectivity of the obtained data and ease of use, the Watch-PAT-200 device can be used in outpatient practice for screening diagnostics of snoring and OSAS in the population.

Use of mandibular advancement devices for the treatment of primary snoring with or without obstructive sleep apnea (OSA): A systematic review

The aim of this review was to systematically evaluate the available scientific evidence on the benefit of mandibular advancement devices (MADs) in the treatment of primary snoring (PS). From 905 initially identified articles, 18 were selected. Papers that provided indirect information regarding obstructive sleep apnea syndrome (OSAS) and/or sleep breathing disorders (SBD) were included. Information was obtained on monoblock and duoblock appliances from the selected studies. The devices were most commonly able to achieve 50%-70% of the maximum mandibular protrusion. The frequently used outcome measurements were the apnea-hypopnea index, Epworth sleepiness scale, and oxygen desaturation index, which all yielded positive post-treatment results. The most common side effects were temporomandibular joint pain and excessive salivation, which improved with time. Our findings indicated that the use of MADs, even with varying designs, improved outcomes in all the reported patient populations (PS, OSAS, and SBD). Despite the lack of studies on PS, the available evidence supports the use of MADs for treatment of PS. Snoring should be treated from a preventive and psychosocial perspective to avoid progression to more severe diseases that could have a significant medical and economic impact.

Snoring patterns during home polysomnography. A proposal for a new classification

PURPOSE

Snoring is a very common disorder, but, at present, there is no universally accepted classification for the condition. The main aim of this paper is to introduce a home sleep monitoring-based classification of common snoring patterns in simple snorers and in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

MATERIALS AND METHODS

In total, 561 consecutive patients with a history of snoring, either simple or associated with apnea, were enrolled in this home sleep monitoring study. Analysis of the polysomnographic traces and the snoring sensor allowed the main patterns of snoring and their characteristics to be determined.

RESULTS

Four patterns of snoring were identified. In a spectrum of increasing severity (mild, moderate or severe), snoring can be episodic, positional, continuous, or alternating, whereas in obstructive sleep apnea syndrome, the snoring events only occur between successive respiratory obstructive events. In mild snoring, the episodic pattern is the most frequent, whereas in moderate and severe snoring, the continuous snoring pattern occurs in most cases.

CONCLUSIONS

The proposed classification of snoring patterns would be beneficial for providing a realistic disturbance index, for the selection and evaluation of the outcomes of surgical techniques.

Snoring time versus snoring intensity: Which parameter correlates better with severity of obstructive sleep apnea syndrome?

Objective:

The relationship between the severity of obstructive sleep apnea syndrome (OSAS) and both snoring intensity and rate measured objectively has not been sufficiently investigated. The aim of this study was to evaluate the relationship between severity of OSAS and snoring parameters including snoring intensity and rate.

Patients and Methods:

A total of 150 records of individuals who complained of snoring were analyzed. Patients were classified into four groups according to apnea–hypopnea index (AHI). Polygraphy recordings including the snoring intensity and the snoring rate (defined as the percentage of snoring time during the total sleep time) and the clinical data were compared and analyzed.

Results:

AHI was significantly correlated, respectively, with snoring rate (r = 0.341; P < 0.0001) and maximal intensity of snoring (r = 0.362; P < 0.0001). However, no correlation was found between the average intensity of snoring and AHI (P = 0.33). When assessing each respiratory event individually, snoring rate was more correlated with hypopnea index (r = 0.424; P < 0.0001) than with AI (r = 0.233; P = 0.004). The snoring rate (%) in the severe OSAS group (31.79 ± 19.3) was significantly higher than that in the mild OSAS group (18.02 ± 17; P = 0.001) and the control group (17 ± 16.57; P = 0.011). Similarly, the maximal intensity of snoring (db) in the severe OSAS group (90.45 ± 13.79) was higher than that in the mild OSAS group (86.46 ± 15.07; P = 0.006) and the control group (84.75 ± 6.65; P < 0.001).

Conclusion:

The snoring rate and maximal intensity of snoring correlate better with the severity of OSAS than average snoring intensity.

Prediction of Apnea-Hypopnea Index Using Sound Data Collected by a Noncontact Device

OBJECTIVE

To predict the apnea-hypopnea index (AHI) in patients with obstructive sleep apnea (OSA) using data from breathing sounds recorded using a noncontact device during sleep.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral hospital.

SUBJECT AND METHODS

Audio recordings during sleep were performed using an air-conduction microphone during polysomnography. Breathing sounds recorded from all sleep stages were analyzed. After noise reduction preprocessing, the audio data were segmented into 5-second windows and sound features were extracted. Estimation of AHI by regression analysis was performed using a Gaussian process, support vector machine, random forest, and simple linear regression, along with 10-fold cross-validation.

RESULTS

In total, 116 patients who underwent attended, in-laboratory, full-night polysomnography were included. Overall, random forest resulted in the highest performance with the highest correlation coefficient (0.83) and least mean absolute error (9.64 events/h) and root mean squared error (13.72 events/h). Other models resulted in somewhat lower but similar performances, with correlation coefficients ranging from 0.74 to 0.79. The estimated AHI tended to be underestimated as the severity of OSA increased. Regarding bias and precision, estimation performances in the severe OSA subgroup were the lowest, regardless of the model used. Among sound features, derivative of the area methods of moments of overall standard deviation demonstrated the highest correlation with AHI.

CONCLUSION

AHI was fairly predictable by using data from breathing sounds generated during sleep. The prediction model may be useful not only for prescreening but also for follow-up after treatment in patients with OSA.

Detecting central sleep apnea in adult patients using WatchPAT-a multicenter validation study

Study objectives

To assess the accuracy of WatchPAT (WP—Itamar-Medical, Caesarea, Israel) enhanced with a novel systolic upstroke analysis coupled with respiratory movement analysis derived from a dedicated snoring and body position (SBP) sensor, to enable automated algorithmic differentiation between central sleep apnea (CSA) and obstructive sleep apnea (OSA) compared with simultaneous in-lab sleep studies with polysomnography (PSG).

Methods

Eighty-four patients with suspected sleep-disordered breathing (SDB) underwent simultaneous WP and PSG studies in 11 sleep centers. PSG scoring was blinded to the automatically analyzed WP data.

Results

Overall WP apnea-hypopnea index (AHI; mean ± SD) was 25.2 ± 21.3 (range 0.2–101) versus PSG AHI 24.4 ± 21.2 (range 0–110) (p = 0.514), and correlation was 0.87 (p < 0.001). Using a threshold of AHI ≥ 15, the sensitivity and specificity of WP versus PSG for diagnosing sleep apnea were 85% and 70% respectively and agreement was 79% (kappa = 0.867). WP central AHI (AHIc) was 4.2 ± 7.7 (range 0–38) versus PSG AHIc 5.9 ± 11.8 (range 0–63) (p = 0.034), while correlation was 0.90 (p < 0.001). Using a threshold of AHI ≥ 15, the sensitivity and specificity of WP versus PSG for diagnosing CSA were 67% and 100% respectively with agreement of 95% (kappa = 0.774), and receiver operator characteristic (ROC) area under the curve of 0.866, (p < 0.01). Using a threshold of AHI ≥ 10 showed comparable overall sleep apnea and CSA diagnostic accuracies.

Conclusions

These findings show that WP can accurately detect overall AHI and effectively differentiate between CSA and OSA.

Risk Factors for Snoring in Two Canadian First Nations Communities

Snoring may be an important predictor of sleep-disordered breathing. Factors related to snoring among First Nations people are not well understood in a population with high rates of smoking and excess body weight. An interviewer-administered survey was conducted among 874 individual participants from 406 households in 2012 and 2013 in two Canadian First Nations communities. The survey collected information on demographic variables, individual and contextual determinants of respiratory health and snoring (classified as present versus absent) and self-reported height and weight. Multiple logistic regression analyses were conducted to examine relationships between snoring and potential risk factors adjusting for age and sex. Snoring was present in 46.2% men and 47.0% women. Considering body mass index, 259 people (30.3%) were overweight and 311 (36.4%) were considered obese. The combined current/former smoking rate was 90.2%. Being overweight, obesity, sinus trouble, current smoking status and former smoking were significantly associated with snoring. Exposure to home dampness and mold were suggestive of an association with snoring. To the degree that snoring may be a predictor of possible sleep-disordered breathing, these results indicate that environmental conditions such as smoking and home exposures may be important factors in the pathogenesis of these conditions.

Associations of snoring frequency and intensity in pregnancy with time-to-delivery

BACKGROUND

Sleep-disordered breathing (SDB) is linked to adverse pregnancy outcomes. However, little is known about the association of SDB with timing of delivery. We examined the association of snoring frequency, a key SDB marker, and snoring intensity, a correlate of SDB severity, with time-to-delivery among a cohort of pregnant women.

METHODS

In this prospective cohort study, 1483 third trimester pregnant women were recruited from the University of Michigan prenatal clinics. Women completed a questionnaire about their sleep, and demographic and pregnancy information was abstracted from medical charts. After exclusion of those with hypertension or diabetes, 954 women were classified into two groups by their snoring onset timing, chronic or pregnancy-onset. Within each of these groups, women were divided into four groups based on their snoring frequency and intensity: non-snorers; infrequent-quiet; frequent-quiet; or frequent-loud snorers. Cox proportional hazard regression models were used to investigate the association between snoring frequency and intensity and time-to-delivery, adjusting for maternal characteristics.

RESULTS

Chronic snoring was reported by half of the pregnant women, and of those, 7% were frequent-loud snorers. Deliveries before 38 weeks' gestation are completed occurred among 25% of women with chronic, frequent-loud snoring. Compared with pre-pregnancy non-snorers, women with chronic frequent-loud snoring had an increased hazard ratio for delivery (adjusted hazard ratio 1.60, 95% confidence interval 1.04, 2.45).

CONCLUSIONS

Snoring frequency and intensity is associated with time-to-delivery in women absent of hypertension or diabetes. Frequent-loud snoring may have a clinical utility to identify otherwise low-risk women who are likely to deliver earlier.

Predictors of Sleep Apnea in the Canadian Population

Older age, obesity, hypertension, snoring, and excessive daytime sleepiness have been associated with sleep apnea. The objective of this study was to determine the prevalence (crude and adjusted), as well as the risk factors, of sleep apnea in the adult Canadian population. Data from the 2009 Sleep Apnea Rapid Response (SARR) questionnaire were used to identify the risk factors, and all sleep-related questions in the SARR questionnaire were used. The outcome variable of interest was health professional-diagnosed sleep apnea. Covariates of interest were demographic variables, population characteristics, respiratory and cardiovascular diseases, and enabling resources. The multiple logistic regression model adjusted for the clustering effect was used to analyze the data. Sleep apnea was diagnosed in 858,913 adults (3.4% of the population), and more men (65.4%) than women (34.6%) were diagnosed with sleep apnea. Multivariable logistic regression analysis indicated that age (45 and older), loud snoring, sudden awakening with gasping/choking (rare/sometimes and once or more a week), and nodding off/falling asleep in driving in the past 12 months were significantly associated with diagnosed sleep apnea. Predictive probability demonstrated that in overweight and obese persons, ≥15 minutes of daily exercise significantly decreased the risk of diagnosed sleep apnea. The conclusion of this study is that in the Canadian population, sleep apnea is associated with older age, loud snoring, and sleeping problems. The protective effect of exercise warrants further investigation.