Gender difference in snoring and how it changes with age: systematic review and meta-regression

Management of primary snoring in adults: A scoping review examining interventions, outcomes and instruments used to assess clinical effects

While various treatment options for primary snoring are available, evidence-based recommendations to determine the optimal intervention remain unestablished. To inform future directions of research to guide clinical decision-making, this scoping review was conducted to map the existing evidence on interventions for primary snoring, the outcomes and instruments used to assess their clinical effects in adults. The feasibility of conducting further systematic reviews and comparing outcomes across these therapies using network meta-analysis was also assessed. Of the 1673 records identified, 38 interventional studies met the inclusion criteria with three-fifths of them being before-after studies. The most common reason for study exclusion was results being reported for patients with primary snoring and obstructive sleep apnoea (OSA) combined. Interventions were surgical (73 %), behavioural and the use of devices/medications. Twenty-six common outcomes were identified and categorised into six domains. Fifty-nine instruments were used to assess the outcomes and based mainly on non-validated questionnaires. Our findings indicated (1) the need for randomised controlled trials with strict discrimination between patients with primary snoring and OSA, (2) further network meta-analyses using some outcomes is feasible, and (3) a core outcome set to inform standardised reporting for future research should be developed.

The Potential Effect of Changing Patient Position on Snoring: A Systematic Review

Approximately 45% of adults snore occasionally, and 25% snore regularly, with a higher prevalence in men and an increase among postmenopausal women due to hormonal changes. Snoring is a health concern linked to vascular disease and decreased quality of life for both snorers and their bed partners. Effective snoring treatment, which aims to reduce or eliminate the sound, is challenging and depends on factors like age, comorbidities, disease severity, and anatomical features. This review aims to provide a systematic overview of the current literature on the effects of positional therapy (PT) on snoring. Various devices facilitate PT, including anti-snoring pillows and vibration alarms. PT devices maintain head and neck alignment to keep airways open, while head of bed elevation (HOBE) solutions reduce upper airway collapses by elevating the head and trunk. Studies show that PT and HOBE reduce snoring by increasing airway cross-sectional area and decreasing closing pressure. Despite their benefits, these non-surgical treatments have limitations, such as discomfort in certain sleeping positions and intolerance to prolonged head elevation. While reducing snoring intensity is critical for health reasons, further comparative studies between the different devices are needed to enhance snoring management.

Regular snoring is associated with uncontrolled hypertension

Snoring may be a risk factor for cardiovascular disease independent of other co-morbidities. However, most prior studies have relied on subjective, self-report, snoring evaluation. This study assessed snoring prevalence objectively over multiple months using in-home monitoring technology, and its association with hypertension prevalence. In this study, 12,287 participants were monitored nightly for approximately six months using under-the-mattress sensor technology to estimate the average percentage of sleep time spent snoring per night and the estimated apnea-hypopnea index (eAHI). Blood pressure cuff measurements from multiple daytime assessments were averaged to define uncontrolled hypertension based on mean systolic blood pressure≥140 mmHg and/or a mean diastolic blood pressure ≥90 mmHg. Associations between snoring and uncontrolled hypertension were examined using logistic regressions controlled for age, body mass index, sex, and eAHI. Participants were middle-aged (mean ± SD; 50 ± 12 y) and most were male (88%). There were 2467 cases (20%) with uncontrolled hypertension. Approximately 29, 14 and 7% of the study population snored for an average of >10, 20, and 30% per night, respectively. A higher proportion of time spent snoring (75th vs. 5th; 12% vs. 0.04%) was associated with a ~1.9-fold increase (OR [95%CI]; 1.87 [1.63, 2.15]) in uncontrolled hypertension independent of sleep apnea. Multi-night objective snoring assessments and repeat daytime blood pressure recordings in a large global consumer sample, indicate that snoring is common and positively associated with hypertension. These findings highlight the potential clinical utility of simple, objective, and noninvasive methods to detect snoring and its potential adverse health consequences.

Early life predictors of obstructive sleep apnoea in young adults: Insights from a longitudinal community cohort (Raine study)

OBJECTIVE

Early-life obstructive sleep apnoea (OSA) predictors are unavailable for young adults. This study identifies early-life factors predisposing young adults to OSA.

METHODS

This retrospective study included 923 young adults and their mothers from the Western Australian Pregnancy Raine Study Cohort. OSA at 22 years was determined from in-laboratory polysomnography. Logistic regression was used to identify maternal and neonatal factors associated with OSA in young adulthood.

RESULTS

OSA was observed in 20.8% (192) participants. Maternal predictors of OSA included gestational diabetes mellitus (odds ratio (OR) 9.54, 95% confidence interval (CI) 1.7, 58.5, P = 0.011), preterm delivery (OR 3.18, 95%CI 1.1,10.5, P = 0.043), preeclampsia (OR 2.95, 95%CI 1.1,8.0, P = 0.034), premature rupture of membranes (OR 2.46, 95%CI 1.2, 5.2, P = 0.015), age ≥35 years (OR 2.28, 95%CI 1.2,4.4, P = 0.011), overweight and obesity (pregnancy BMI≥25 kg/m2) (OR 2.00, 95%CI 1.2,3.2, P = 0.004), pregnancy-induced hypertension (OR 1.89, 95%CI 1.1,3.2, P = 0.019), and Chinese ethnicity (OR 2.36,95%CI 1.01,5.5, P = 0.047). Neonatal predictors included male child (OR 2.10, 95%CI 1.5,3.0, P < 0.0001), presence of meconium-stained liquor during delivery (OR 1.60, 95%CI 1.0,2.5, P = 0.044) and admission to special care nursery (OR 1.51 95%CI 1.0,2.2, P = 0.040). Higher birth lengths reduced OSA odds by 7% for each centimetre (OR 0.93, 95%CI 0.87, 0.99, P = 0.033).

CONCLUSIONS

A range of maternal and neonatal factors predict OSA in young adults, including those related to poor maternal metabolic health, high-risk pregnancy and stressful perinatal events. This information could assist in the early identification and management of at-risk individuals and indicates that better maternal health may reduce the likelihood of young adults developing OSA.

Australasian Sleep Association position statement on consensus and evidence based treatment for primary snoring

Primary snoring impacts a significant portion of the adult population and has the potential to significantly impair quality of life. The purpose of these guidelines is to provide evidence-based recommendations to assist Australasian practitioners in the management of adult patients who present with primary snoring without significant obstructive sleep apnoea. The Timetable, Methodology and Standards by which this Position Statement has been established is outlined in the Appendix S1. The main recommendations are: Weight loss, and reduced alcohol consumption should be recommended, where appropriate If clinical judgement dictates, benzodiazepine and opioid reduction or avoidance may be advised Positional therapy should be considered in supine dominant snorers In dentate patients, Mandibular advancement devices (MAD) should be recommended as a first line treatment following assessment by both an appropriate Dentist and Sleep physician Continuous positive airway pressure (CPAP) devices may be recommended in patients with primary snoring in those already committed to their use or willing to try Surgical treatment of primary snoring by an appropriately credentialled surgeon may be advised and includes nasal (adjunctive), palatal and other interventions This position statement has been designed based on the best available current evidence and our combined expert clinical experience to facilitate the management of patients who present with primary snoring. It provides clinicians with a series of both non-surgical and surgical options with the aim of achieving optimal symptom control and patient outcomes. This is the first such set of recommendations to be established within Australasia and has also been reviewed and endorsed by the Australasian Sleep Association.

Sleep Measurements in Women

Sleep in women and men have been studied in several studies with higher prevalence of sleep complaints in women compared with men. Several factors can affect sleep and could be argued to contribute to sex and gender differences in general sleep. There are no differences in guidelines when measuring sleep in women but several sleep assessment tools have been validated or compared between sexes. Because there is still a lack of knowledge on sleep measurements in women, the present review aimed to produce an overview of the current knowledge of objective and subjective sleep measurements in women.

Accuracy of a Smartphone Application Measuring Snoring in Adults-How Smart Is It Actually?

About 40% of the adult population is affected by snoring, which is closely related to obstructive sleep apnea (OSA) and can be associated with serious health implications. Commercial smartphone applications (apps) offer the possibility of monitoring snoring at home. However, the number of validation studies addressing snoring apps is limited. The purpose of the present study was to assess the accuracy of recorded snoring using the free version of the app SnoreLab (Reviva Softworks Ltd., London, UK) in comparison to a full-night polygraphic measurement (Miniscreen plus, Löwenstein Medical GmbH & Co., KG, Bad Ems, Germany). Nineteen healthy adult volunteers (4 female, 15 male, mean age: 38.9 ± 19.4 years) underwent simultaneous polygraphic and SnoreLab app measurement for one night at home. Parameters obtained by the SnoreLab app were: starting/ending time of monitoring, time in bed, duration and percent of quiet sleep, light, loud and epic snoring, total snoring time and Snore Score, a specific score obtained by the SnoreLab app. Data obtained from polygraphy were: starting/ending time of monitoring, time in bed, total snoring time, snore index (SI), snore index obstructive (SI obstructive) and apnea-hypopnea-index (AHI). For different thresholds of percentage snoring per night, accuracy, sensitivity, specificity, positive and negative predictive values were calculated. Comparison of methods was undertaken by Spearman-Rho correlations and Bland-Altman plots. The SnoreLab app provides acceptable accuracy values measuring snoring >50% per night: 94.7% accuracy, 100% sensitivity, 94.1% specificity, 66.6% positive prediction value and 100% negative prediction value. Best agreement between both methods was achieved in comparing the sum of loud and epic snoring ratios obtained by the SnoreLab app with the total snoring ratio measured by polygraphy. Obstructive events could not be detected by the SnoreLab app. Compared to polygraphy, the SnoreLab app provides acceptable accuracy values regarding the measurement of especially heavy snoring.

A finite element analysis for evaluating mandibular advancement devices

Obstructive sleep apnoea (OSA) is a disorder characterised by complete or partial occlusion of the upper airway during sleep. Muscles relax during sleeping and collapse into the airway, closing the throat and prohibiting air flowing into the lungs. Different solutions have been adopted to manage the pathology to improve the life quality of affected patients. Mandibular advancement devices (MADs) are proven to be a compliant and successful therapy in the forward repositioning of the mandible to increase the upper airway volume. However, this method has some long-term adverse events that may affect the teeth and periodontal ligaments. This paper presents a finite element model to evaluate the MADs effects (displacement and stress) on teeth and periodontal ligaments, by varying the design, the point of application of the force and the material. The modelled bodies have been reconstructed through a Reverse Engineering approach and computer-aided design tools starting from tomographic images of anatomic bodies and from laser scans of a physical MAD. The results suggest that a central connection mechanism could affect mostly the anterior teeth. In contrast, a lateral connection mechanism provides a more uniform distribution of the load on teeth.

Analyzing Neck Circumference as an Indicator of CPAP Treatment Response in Obstructive Sleep Apnea with Network Medicine

We explored the relationship between obstructive sleep apnea (OSA) patients' anthropometric measures and the CPAP treatment response. To that end, we processed three non-overlapping cohorts (D1, D2, D3) with 1046 patients from four sleep laboratories in Western Romania, including 145 subjects (D1) with one-night CPAP therapy. Using D1 data, we created a CPAP-response network of patients, and found neck circumference (NC) as the most significant qualitative indicator for apnea-hypopnea index (AHI) improvement. We also investigated a quantitative NC cutoff value for OSA screening on cohorts D2 (OSA-diagnosed) and D3 (control), using the area under the curve. As such, we confirmed the correlation between NC and AHI (ρ=0.35, p<0.001) and showed that 71% of diagnosed male subjects had bigger NC values than subjects with no OSA (area under the curve is 0.71, with 95% CI 0.63-0.79, p<0.001); the optimal NC cutoff is 41 cm, with a sensitivity of 0.8099, a specificity of 0.5185, positive predicted value (PPV) = 0.9588, negative predicted value (NPV) = 0.1647, and positive likelihood ratio (LR+) = 1.68. Our NC =41 cm threshold classified the D1 patients' CPAP responses-measured as the difference in AHI prior to and after the one-night use of CPAP-with a sensitivity of 0.913 and a specificity of 0.859.

Association between self-reported snoring and hypertension among Chinese Han population aged 30-79 in Chongqing, China

Background

We aim to explore the association between self-reported snoring and hypertension among adults aged 30–79 in Chongqing, China.

Methods

A total of 23,342 individuals aged 30–79 were included at baseline from August 2018 to January 2019, and the final sample size for the analysis was 22,423. Face-to-face interviews and physical examinations were conducted by trained investigators. Logistic regression was performed to study age-specific and gender-specific associations between snoring and hypertension.

Results

Frequent snoring was associated with the risk of hypertension for each age and gender group, and the frequency of snoring was positively correlated with the risk for hypertension. For the three age groups (< 45, 45–59, ≥ 60), compared with the non-snoring group, those who snore often had a 64.5%, 53.3%, and 24.5% increased risk of hypertension (< 45: OR = 1.65, 95%CI 1.34–2.02; 45–59: OR = 1.53, 95%CI 1.37–1.72; ≥ 60: OR = 1.25, 95%CI 1.09–1.42), respectively. For men and women, those who snore often had a 46.8% and 97.2% increased risk of hypertension, respectively, than the non-snoring group (men: OR = 1.47, 95%CI 1.33–1.63; women: OR = 1.97, 95%CI 1.75–2.23).

Conclusions

People who snore frequently should pay close attention to their blood pressure levels in order to achieve early prevention of hypertension, particularly for snorers who are female and aged under 45; importance should be attached to their blood pressure control.

Influence of age and gender on sleep bruxism and snoring in non-apneic snoring patients: A polysomnographic study

The present study aimed to assess the influence of gender and age on snoring and sleep bruxism in non-apneic snoring patients. Adult participants with clinical suspicion of snoring and with no other significant medical history were recruited. Single-night video polysomnography was performed to detect snoring and sleep bruxism. Finally, 137 snoring non-apneic participants were included. Statistical analysis of gender groups showed that the total snore index and snore train were significantly higher in men than in women. Men also presented severe bruxism, with significantly more frequent episodes and higher bruxism episodes index scores. The correlation analysis showed the presence of significant linear relationships in the supine sleep position between age and snore index, snore index in non-rapid eye movement 2 (N2) sleep stage, and snore train. The analysis of groups separated according to the criterion of third age quartile showed that the average, maximum and minimum audio volume in the non-supine sleep position was significantly higher in the older group. The analysis of groups separated according to the criterion of median age showed that the bruxism episode index and bruxism phasic episodes were significantly higher in the younger group. Thus, it can be concluded that both age and gender influence snoring and sleep bruxism. Snoring and sleep bruxism seem to be more intensive in men. Older patients seem to snore more in N2 sleep and the supine sleep position and present lower bruxism episodes, especially the phasic type. The results of the present study indicate the need for further research on this topic to establish the possible relationship between snoring and sleep bruxism.

Diagnosis and treatment of isolated snoring-open questions and areas for future research

STUDY OBJECTIVES

Snoring is a common phenomenon which is generated by vibration of soft tissue of the upper airway during sleep. Due to the high incidence of isolated snoring and the substantial burden for the patient and the bed partner, a thorough examination and appropriate therapy are required. Many recommendations for the treatment of isolated snoring are either not evidence-based or are derived from recommendations for the management of obstructive sleep apnea. Therefore, the aim of this study is the identification and description of open questions in the diagnosis and treatment of isolated snoring and the illustration of areas for further research.

METHODS

In the context of the development of the new version of the German guideline "Diagnosis and treatment of isolated snoring in adults," a multidisciplinary team of experts performed a systematic literature search on the relevant medical data and rated the current evidence regarding the key diagnostic and therapeutic measures for snoring.

RESULTS

The systematic literature review identified 2293 articles. As a major inclusion criterion, only studies on primary snoring based on objective sleep medical assessment were selected. After screening and evaluation, 33 full-text articles remained for further analysis. Based on these articles, open questions and areas for future research were identified for this review.

CONCLUSION

Several major gaps in the literature on the diagnosis and treatment of isolated snoring were identified. For the majority of diagnostic and therapeutic measures for snoring, high-level scientific evidence is still lacking.

Long-term Impact of Adenotonsillectomy on the Quality of Life of Children with Sleep-disordered breathing

Introduction  Adenotonsillectomy is the first-line treatment for obstructive sleep apnea secondary to adenotonsillar hypertrophy in children. The physical benefits of this surgery are well known as well as its impact on the quality of life (QoL), mainly according to short-term evaluations. However, the long-term effects of this surgery are still unclear.

Objective  To evaluate the long-term impact of adenotonsillectomy on the QoL of children with sleep-disordered breathing (SDB).

Method  This was a prospective non-controlled study. Children between 3 and 13 years of age with symptoms of SDB for whom adenotonsillectomy had been indicated were included. Children with comorbities were excluded. Quality of life was evaluated using the obstructive sleep apnea questionnaire (OSA-18), which was completed prior to, 10 days, 6 months, 12 months and, at least, 18 months after the procedure. For statistical analysis, p -values lower than 0.05 were defined as statistically significant.

Results  A total of 31 patients were enrolled in the study. The average age was 5.2 years, and 16 patients were male. The OSA-18 scores improved after the procedure in all domains, and this result was maintained until the last evaluation, done 22 ± 3 months after the procedure. Improvement in each domain was not superior to achieved in other domains. No correlation was found between tonsil or adenoid size and OSA-18 scores.

Conclusion  This is the largest prospective study that evaluated the long-term effects of the surgery on the QoL of children with SDB using the OSA-18. Our results show adenotonsillectomy has a positive impact in children's QoL.

A Procedure for Analyzing Mandible Roto-Translation Induced by Mandibular Advancement Devices

Background: Sleep-Related Breathing Disorders are characterized by repeated episodes of complete or partial obstruction of the upper airway during sleep. Mandibular advancement devices represent a non-invasive treatment in reducing the number of respiratory events and in decreasing symptoms. The advancement extent of these devices is responsible for the mandibular roto-translation and its effects on the temporomandibular joint. Methods: This study defined a systematic method to assess the mandible roto translation that is caused by MADs according to a scan-to-CAD approach. Starting from a closed mouth position and simulating the oral appliance at different settings it was possible to define a local reference system that is useful for the evaluation of the mandibular roto-translation. This latter was then applied to evaluate the movements of the condyle and the mandibular dental arch. Results: MAD1 resulted in a reduced mouth opening and protrusion, while MAD2 enabled a higher degree of motion of the mandible useful for patients who need an important protrusion. Conclusions: The two devices present different dynamics. Results that are achievable employing this method can be directly used by practitioners in comparing MADs, as well as by researchers in evaluating MADs effects.

Fluoride exposure and sleep patterns among older adolescents in the United States: a cross-sectional study of NHANES 2015-2016

BACKGROUND

Fluoride from environmental sources accumulates preferentially in the pineal gland which produces melatonin, the hormone that regulates the sleep-wake cycle. However, the effects of fluoride on sleep regulation remain unknown. This population-based study examined whether chronic low-level fluoride exposure is associated with sleep patterns and daytime sleepiness among older adolescents in the United States (US).

METHOD

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (2015-2016). We analyzed data from adolescents who had plasma fluoride (n = 473) and water fluoride (n = 419) measures and were not prescribed medication for sleep disorders. Relationships between fluoride exposure and self-reported sleep patterns or daytime sleepiness were examined using survey-weighted linear, binomial logistic or multinomial logistic regression after covariate adjustment. A Holm-Bonferroni correction accounted for multiple comparisons.

RESULTS

The average age of adolescents was 17 years (range = 16-19). Median (IQR) water and plasma fluoride concentrations were 0.27 (0.52) mg/L and 0.29 (0.19) μmol/L respectively. An IQR increase in water fluoride was associated with 1.97 times higher odds of reporting symptoms suggestive of sleep apnea (95% CI: 1.27, 3.05; p = 0.02), a 24 min later bedtime (B = 0.40, 95% CI: 0.10, 0.70; p = 0.05), a 26 min later morning wake time (B = 0.43, 95% CI: 0.13, 0.73; p = 0.04), and among males, a 38% reduction in the odds of reporting snoring (95% CI: 0.45, 0.87, p = 0.03).

CONCLUSIONS

Fluoride exposure may contribute to changes in sleep cycle regulation and sleep behaviors among older adolescents in the US. Additional prospective studies are warranted to examine the effects of fluoride on sleep patterns and determine critical windows of vulnerability for potential effects.

Association between snoring and heart rate variability in adolescents: effects of gender and insufficient sleep

PURPOSE

We explored the association between subjective snoring frequency and heart rate variability (HRV) in a healthy adolescent population.

METHODS

A total of 102 healthy adolescents were recruited from high schools in South Korea, and reported their sleep habits and snoring frequency. HRV was assessed to indirectly measure autonomic function. We assessed correlations between snoring frequency and HRV indices. We also investigated the effects of sex and behaviorally induced insufficient sleep syndrome (BISS) on the associations between HRV parameters and snoring frequency.

RESULTS

Overall, significant correlations were apparent between snoring frequency and HRV indices including the standard deviation of the normal-to-normal intervals (SDNN) and the low-frequency/high-frequency (LF/HF) ratio. Associations were more evident in males and those with BISS compared to females and those without BISS.

CONCLUSIONS

Our findings suggest that snoring changes autonomic nervous system (ANS) activity in adolescents; the changes are more dramatic in males and those with insufficient sleep.

The Presence of Snoring as Well as its Intensity Is Underreported by Women

STUDY OBJECTIVES

Women are underrepresented and thus sleep conditions are underdiagnosed at sleep clinics that evaluate sleep-disordered breathing. The most common sign of obstructive sleep apnea (OSA) is snoring; therefore, it is one of the main red flags for suspected OSA. The aim of this study is to determine whether self-reported snoring and snoring intensity by women and men correlates with snoring volume measured objectively during sleep laboratory study.

METHODS

Consecutive patients who were referred to a polysomnography (PSG) study in a university hospital over a 2-year period had their snoring volume quantified by means of a calibrated digital sound survey meter. Participants were given a questionnaire in which they were asked to rate the severity of their snoring. The correlation between objective snoring intensity as measured during PSG and the self-reported snoring intensity was evaluated.

RESULTS

A total of 1,913 patients were enrolled in the study. A positive correlation was found between objectively measured snoring intensity and the intensity listed by each participant in the questionnaire. Measurement of the volume of snoring revealed that women snored as loudly as men; however, 28% of the females (189/675) considered themselves to be nonsnorers compared to only 6.9% of men (P < .05). Furthermore, 36.5% of women (69/189) who reported themselves as nonsnorers turned out to have severe or very severe snoring intensity, whereas, in contrast, only 11.7% of men (10/85) of men had this discrepancy. These findings are in concordance with the finding that fewer women quantified their snoring as very severe or severe (38.4%), significantly less than men of whom 61.5% reported their snoring to be severe or very severe.

CONCLUSIONS

In a population of individuals referred to a PSG study, although no difference in snoring intensity was found between sexes, women tend to underreport the fact that they snore and to underestimate the loudness of their snoring. Improved awareness of this discrepancy may increase women's access to sleep laboratories, and improve diagnostic rates of sleep apnea in females.

Sleep Architecture in Patients With Primary Snoring and Obstructive Sleep Apnea

Introduction:

This study aimed to investigate sleep architecture in patients with primary snoring and obstructive sleep apnea.

Methods:

In this study, we analyzed polysomnographic data of 391 clients who referred to Sleep Disorders Research Center (SDRS). These people were classified into three groups based on their Apnea-Hypopnea Index (AHI) and snoring; control, Primary Snoring (PS), and Obstructive Sleep Apnea (OSA) group. Sleep architecture variables were then assessed in all groups.

Results:

The results of this study indicated a decrease in deep sleep or Slow Waves Sleep (SWS) and increase in light sleep or stage 1 of non-REM sleep (N1) in OSA patients compared with the control and PS groups. After controlling the effects of confounding factors, i.e. age and Body Mass Index (BMI) (which was performed through multiple regression analysis) significant differences were observed among the three groups with regard to N1. However, with regard to SWS, after controlling confounding variables (age and BMI), no significant difference was found among the groups.

Conclusion:

The results indicated that OSA, regardless of age and BMI, may increase light (N1) sleep possibly via a decline in blood oxygen saturation (SpO₂ ). Such increase in N1 may be responsible for brain arousal. In addition, by controlling confounding factors (age and BMI), OSA did not affect SWS in OSA patients. However, further research is necessary to determine sleep architecture in more detail in the patients with OSA.

Frequency of Loud Snoring and Metabolic Syndrome among Korean Adults: Results from the Health Examinees (HEXA) Study

Studies regarding the association between snoring and metabolic abnormalities have been inconsistent. We examine whether snoring frequency and obstructive sleep apnea markers are associated with metabolic syndrome (MetS) among Koreans aged 40-69 years. A total of 72,885 subjects (24,856 men, 48,029 women) from the Health Examinees Gem study between 2009 and 2013 were included. Snoring frequency was grouped into five categories (never, 1-3/month, 1-3/week, 4-5/week, 6+/week). Obstructive sleep apnea markers included breathing interruptions and awakenings. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated through logistic regression. Compared with non-snorers, those who snore 6+/week were associated with increased odds for MetS (OR: 2.07, 95% CI: 1.91-2.25, p-trend < 0.0001 among men; OR: 1.45, CI: 1.33-1.58, p-trend < 0.0001 among women). Snoring frequency is associated with MetS and its components in both men and women. Snoring and obstructive sleep apnea markers are important indicators of sleep quality, which may facilitate early detection of sleep disorders and further complications such as MetS.

Natural history of snoring in Hong Kong adolescents

AIM

To determine the natural history of snoring in children when they reached adolescence and the underlying risk factors for persistence of habitual snoring.

METHODS

A follow-up telephone survey was conducted to determine the natural history of snoring in children who reached adolescence. The targeted interviewees of the follow-up survey were parents of 3047 children. Adolescents who were snoring ≥6 nights a week were defined as habitual snorers. Potential risk factors for persistent and incident habitual snoring were studied, including age, gender, allergic rhinitis, asthma, body mass index (BMI), sleep duration and daytime sleepiness.

RESULTS

Of the 3047 subjects, 2005 (65.8%) were successfully interviewed by phone. The prevalence of habitual snorers was 12.7%. Ninety-one adolescents were persistent habitual snorers. Allergic rhinitis, male gender and higher BMI at follow-up were identified as significant risk factors for persistent habitual snoring. A further 163 children were identified as incident habitual snorers. The risk factors for incident habitual snoring included male gender, asthma, higher BMI at follow-up and younger age at the first survey. In the current study, the mean sleep duration was 7.6 ± 1.0 h. Overall, 90% of the current cohort slept less than the lower limit of international recommendations for sleep duration.

CONCLUSIONS

Around 40.6% of habitually snoring children continued to snore habitually as adolescents in the current study, while 9.2% of the initial non-habitual snorers became habitual snorers. Male gender and higher BMI were significant risk factors for both persistent and incident habitual snoring.

Simple snoring: not quite so simple after all?

Simple snoring (SS), in the absence of obstructive sleep apnoea (OSA), is a common problem, yet our understanding of its causes and consequences is incomplete. Our understanding is blurred by the lack of consistency in the definition of snoring, methods of assessment, and degree of concomitant complaints. Further, it remains contentious whether SS is independently associated with daytime sleepiness, or adverse health outcomes including cardiovascular disease and metabolic syndrome. Regardless of this lack of clarity, it is likely that SS exists on one end of a continuum, with OSA at its polar end. This possibility highlights the necessity of considering an otherwise 'annoying' complaint, as a serious risk factor for the development and progression of sleep apnoea, and consequent poor health outcomes. In this review, we: 1) highlight variation in prevalence estimates of snoring; 2) review the literature surrounding the distinctions between SS, upper airway resistance syndrome (UARS) and OSA; 3) present the risk factors for SS, in as far as it is distinguishable from UARS and OSA; and 4) describe common correlates of snoring, including cardiovascular disease, metabolic syndrome, and daytime sleepiness.

Self-reported habitual snoring and risk of cardiovascular disease and all-cause mortality

OBJECTIVE

Inconsistent findings have reported the association between self-reported habitual snoring and risk of cardiovascular disease (CVD) and all-cause mortality. We conducted a meta-analysis to investigate whether self-reported habitual snoring was an independent predictor for CVD and all-cause mortality using prospective observational studies.

METHODS

Electronic literature databases (PubMed, Medline, Embase, Cochrane Library, Wanfang database, and China National Knowledge Infrastructure) were searched for publications prior to September 2013. Only prospective studies evaluating baseline habitual snoring and subsequent risk of CVD and all-cause mortality were selected. Pooled adjust hazard risk (HR) and corresponding 95% confidence intervals (CI) were calculated for categorical risk estimates.

RESULTS

Eight studies with 65,037 subjects were analyzed. Pooled adjust HR was 1.26 (95% CI 0.98-1.62) for CVD, 1.15 (95% CI 1.05-1.27) for coronary heart disease (CHD), and 1.26 (95% CI 1.11-1.43) for stroke comparing habitual snoring to non-snorers. Pooled adjust HR was 0.98 (95% CI 0.78-1.23) for all-cause mortality in a random effect model comparing habitual snoring to non-snorers. Habitual snoring appeared to increase greater stroke risk among men (HR 1.54; 95% CI: 1.09-2.17) than those in women (HR 1.22; 95% CI: 1.05-1.41).

CONCLUSIONS

Self-reported habitual snoring is a mild but statistically significant risk factor for stroke and CHD, but not for CVD and all-cause mortality. However, whether the risk is attributable to obstructive sleep apnea syndrome or snoring alone remains controversial.

Self-reported snoring and carotid atherosclerosis in middle-aged and older adults: the Korean Multi-Rural Communities Cohort Study

Background

We investigated the relation of self-reported snoring with carotid intima-media thickness (IMT) and plaque in community-dwelling middle-aged and older adults.

Methods

In total, 7330 community-dwelling subjects in the Korean Multi-Rural Communities Cohort Study were included in the analysis. Common carotid artery IMT (CCA-IMT) and plaque were evaluated by high-resolution B-mode ultrasonography. Snoring status was evaluated using a structured interview.

Results

Snorers had a significantly greater average CCA-IMT than non-snorers (0.726 vs 0.713 mm; P < 0.001), after adjusting for age and gender. The odds ratios (OR) for high CCA-IMT (fifth quintile) were significantly higher for snorers than for non-snorers in multivariate-adjusted analysis (OR 1.25, 95% confidence interval [CI] 1.10–1.42). However, there was no significant relationship between snoring and carotid plaques.

Conclusions

Our data suggest that self-reported snoring is significantly associated with increased IMT, but not with the presence of plaques. These findings suggest that early screening and intervention for snoring in the general population are needed to prevent adverse cardiovascular events.