Risk factors for snoring among Japanese men and women: a community-based cross-sectional study

Snoring is associated with hypertension and diabetes mellitus among adults in north Sudan: a cross-sectional study

BACKGROUND

Different levels of association between snoring, hypertension, and diabetes mellitus (DM) are reported. There are few published studies on this topic in African countries, and no investigation was conducted in Sudan. This study aimed to assess the prevalence and factors associated with snoring and the association between snoring, hypertension, and type 2 DM (T2DM) in northern Sudan.

METHODS

A community-based cross-sectional study using a multistage sampling technique was conducted in four villages in the River Nile state of northern Sudan from July to September 2021. Sociodemographic characteristics were collected using a questionnaire. Body mass index (BMI) was measured using standard methods, and a multivariate analysis was conducted using the Statistical Package for the Social Sciences® (SPSS®) for Windows, version 22.0.

RESULTS

Of the 384 adults, 193 (50.3%) were males and 191 (49.7%) were females. Of the adults, 38 (9.9%) were underweight, 121 (31.5%) had average weight, 113 (29.4%) were overweight, and 112 (29.2%) were obese. One hundred and six (27.6%) adults were snorers. Multivariate analysis showed that increasing age (adjusted odds ratio [AOR] = 1.02, 95% confidence interval [CI] = 1.01‒1.04), increasing BMI (AOR = 1.04, 95 CI = 1.01‒1.08), obesity (AOR = 2.0, 95% CI = 1.10‒3.69), and alcohol consumption (AOR = 2.32, 95% CI = 1.14‒4.74) were positively associated with snoring. Of the 384 adults, 215 (56.0%) had hypertension. Multivariate analysis showed that increasing age (AOR = 1.04, 95% CI = 1.02‒1.06), increasing BMI (AOR = 1.08, 95% CI = 1.04‒1.13), female sex (AOR = 1.7, 95% CI = 1.08‒2.73), and snoring (AOR = 1.69, 95% CI = 1.02‒2.82) were positively associated with hypertension. One hundred and six (27.6%) adults had T2DM. Multivariate analysis showed that increasing age (AOR = 1.03, 95% CI = 1.01‒1.05) and snoring (AOR = 1.78, 95% CI = 1.09‒2.91) were associated with T2DM.

CONCLUSION

Around one-fourth of the adults in Northern Sudan are snorers. Snoring is more common among obese adults. Snoring is associated with increased odds of hypertension and T2DM. Adults who snore must pay close attention to their blood pressure and blood glucose levels to prevent hypertension and DM.

Does seasonality affect snoring? A study based on international data from the past decade

BACKGROUND

Though snoring is often regarded as a harmless condition that coincides with sound sleep, it is a sleep disorder that can be a potential indicator of more severe conditions such as sleep apnea syndrome. In the present study, we investigated the association between seasonal variations and snoring.

METHOD

Search index for snoring (SIS) data were obtained from Google Trends and Baidu Index. SIS data were collected for the USA, India, Germany, Russia, Japan, Australia, China, and Brazil from 2011 to 2020, with the periodicity of the relationship between seasonal time series data and snoring evaluated using a time series decomposition model.

RESULT

The highest average SIS growth rates from 2011 to 2020 were observed for Brazil, Japan, and Germany, with average SIS values of 94%, 68%, and 49%, respectively. The SIS of the USA, Russia, Japan, Brazil, Australia, Germany, and India increased by 22.3%, 12.4%, 11.9%, 35.4%, 12.3%, 28.0%, and 55.8%, respectively, in comparison with their SIS values in 2019, whereas for China, it decreased by 13.7%. Relative to countries in the southern hemisphere, those in the northern hemisphere showed comparable SIS trends, increasing from September to February and decreasing from March to August.

CONCLUSION

The SIS data showed cyclical changes over the study period. The search index for snoring increased during the cold season or the heating season, suggesting that snoring is associated with seasonal changes.

The effect of continuous positive airway pressure treatment on inflammatory parameters and periostin levels in patients with obstructive sleep apnea syndrome

BACKGROUND

The purpose of the study was to examine the effects of continuous positive airway pressure (CPAP) treatment on inflammation parameters in patients with obstructive sleep apnea syndrome (OSAS).

METHODS

Patients aged 18 to 65 years who underwent polysomnography (PSG) in the sleep clinic between January 1, 2019, and December 31, 2019, were included in the study. Patients with severe OSAS initiated treatment with CPAP. Patients and control subjects were assessed for levels of periostin, TNF-alpha, TGF-beta, and IL-6. Patients were re-evaluated 3 months later. Comparisons for the serum markers were made between controls and patients of different severity of OSAS. Comparisons of serum markers were also made between baseline and 3 month follow-up.  RESULTS: A total of 92 patients were enrolled in the study, including 25 controls (apnea-hypopnea index or AHI < 5/h), 39 patents with mild to moderate OSAS who did not receive CPAP, and 28 patients with severe OSAS receiving CPAP treatment. When all three groups were compared, levels of periostin, TNF-alpha, TGF-beta, and IL-6, as inflammatory markers, were higher in the OSAS group, though not at a statistically significant level. In patients with severe OSAS, there were statistically significant decreases in the TGF-beta 1, TNF-alpha, and IL-6 values between baseline values and the same measures taken after 3 months of CPAP treatment. Periostin values also decreased after treatment, but this decrease was not at a significant level.

CONCLUSION

Inflammatory parameters of patients with OSAS were significantly higher compared with healthy participants. Regression of inflammation was detected after CPAP treatment.

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

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

Effects of a novel oral appliance on snoring in adults: A pilot study

AbstractBackground/purpose

Oral appliances (OAs) have been recommended as alternatives for adult patients with obstructive sleep apnea who are intolerant of continuous positive airway pressure therapy. The aim of this study was to explore the effect on snoring rates among adult patients through use of a novel OA termed the Lin OA (LOA, airflow-interference-type nasal congestion relieving and snore-ceasing oral appliance).

Materials and methods

The LOA consist of two parts: dental braces and a fixed tongue compressor. The compressor lengths range from 0.5 cm to 3.5 cm across versions. Patients used the LOA during sleep and the SnoreClock smartphone application recorded their snoring rates.

Results

A total of 4920 recordings (4239 recordings from 34 men, 681 recordings from 8 women) were used for the analysis. The recordings were sorted in accordance with the applied length of the LOA tongue compressor (0.5–3.5 cm, LOA-0.5, LOA-1 and LOA-3.5), and participants not using the LOA were denoted as the LOA-0 group. The women had higher snoring rates in the LOA-0, LOA-0.5 to LOA-2 groups, but lower snoring rates in the LOA-3 group than men by the univariate analysis. The snoring rates were significantly reduced by a mean of 5.04% with every 1 cm increase in tongue compressor length. Continuous LOA use resulted in snoring rate reductions of 0.02% per day by the random intercept model of the linear regression.

Conclusion

Use of this novel LOA may significantly reduce snoring rates by 5.04% with each 1 cm increase in tongue compressor length.

Alcohol consumption and sleep quality: a community-based study

OBJECTIVE

To assess the association between total alcohol intake, specific alcoholic beverages and sleep quality in a community-based cohort.

DESIGN

A cross-sectional study.

SETTING

The Kailuan community, China.

PARTICIPANTS

Included were 11 905 participants who were free of a history of CVD, cancer, Parkinson's disease, dementia and head injury in or prior to 2012. Alcohol consumption (amount and frequency intake) and alcoholic beverage type were collected in 2006 (baseline) and 2012. Participants were grouped into non-, light- (women: 0-0·4 serving/d; men: 0-0·9 serving/d), moderate- (women: 0·5-1·0 serving/d; men: 1·0-2·0 servings/d) and heavy- (women: >1·0 servings/d; men: >2·0 servings/d) drinkers. Overall sleep quality was measured in 2012 and included four sleep parameters (insomnia, daytime sleepiness, sleep duration, snoring/obstructive sleep apnoea).

RESULTS

We observed a dose-response association between higher alcohol consumption in 2006 and worse sleep quality in 2012 (Ptrend < 0·001), after adjusting for age, sex, socio-economic status, smoking status, physical activity, obesity, plasma lipid profiles, diabetes and hypertension. A similar association was observed when alcohol consumption in 2012 was used as exposure. Alcohol was associated with higher odds of having short sleep duration (adjusted OR for heavy- v. non-drinkers = 1·31; 95 % CI: 1·09, 1·57) and snoring (adjusted OR for heavy- v. non-drinkers: 1·38; 95 % CI: 1·22, 1·57). Consumption of hard liquor, but not beer or wine, was significantly associated with poor sleep quality.

CONCLUSIONS

Higher alcohol consumption was associated with poorer sleep quality and higher odds of having snoring and short sleep duration.

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.

Insights into the aetiology of snoring from observational and genetic investigations in the UK Biobank

Although snoring is common in the general population, its aetiology has been largely understudied. Here we report a genetic study on snoring (n ~ 408,000; snorers ~ 152,000) using data from the UK Biobank. We identify 42 genome-wide significant loci, with an SNP-based heritability estimate of ~10% on the liability scale. Genetic correlations with body mass index, alcohol intake, smoking, schizophrenia, anorexia nervosa and neuroticism are observed. Gene-based associations identify 173 genes, including DLEU7, MSRB3 and POC5, highlighting genes expressed in the brain, cerebellum, lungs, blood and oesophagus. We use polygenic scores (PGS) to predict recent snoring and probable obstructive sleep apnoea (OSA) in an independent Australian sample (n ~ 8000). Mendelian randomization analyses suggest a potential causal relationship between high BMI and snoring. Altogether, our results uncover insights into the aetiology of snoring as a complex sleep-related trait and its role in health and disease beyond it being a cardinal symptom of OSA.

Snoring is common in the population and tends to be more prevalent in older and/or male individuals. Here, the authors perform GWAS for habitual snoring, identify 41 genomic loci and explore potential causal relationships with anthropometric and cardiometabolic disease traits.

Relationship between Snoring and Lifestyle-related Diseases among a Japanese Occupational Population

Objective Snoring is a common physical condition in active workers. However, the link between snoring and health problems is poorly understood. Therefore, the prevalence of snoring in Japanese workers and the relationships between snoring and lifestyle-related diseases were investigated. Methods This was a retrospective, single-center, cross-sectional study. The results of a single year's medical examinations were investigated for 25,141 Japanese active office workers 20 to 59 years old. The presence and duration of snoring were investigated using a personal computer at a medical interview before the medical checkup. The snoring frequency was investigated for each gender. In addition, the relationships between snoring and hypertension, diabetes, and dyslipidemia were also analyzed. Results Men (21,774) were a mean 46±6 years old with a snoring prevalence of 43%. Women (3,367) were a mean 46±6 years old with a snoring prevalence of 20%. In men, snoring was an independent comorbid factor of hypertension and dyslipidemia. In particular, a long snoring vintage (multiple years) was an independent comorbid factor for hypertension [odds ratio (OR), 1.14; 95% confidence interval (CI), 1.05-1.24; p=0.002; and OR, 1.20; 95% CI, 1.07-1.34; p=0.001]. In women, snoring was not an independent comorbid factor for lifestyle-related diseases when adjusted for the age and body mass index. Conclusion Snoring was shown to be a frequent pathophysiology in active workers. It was a health indicator for active workers, and especially in men, intervention for snoring may reduce the risk of developing lifestyle-related diseases.

Analysis of the sleep period and the amount of habitual snoring in individuals with sleep bruxism

Background

The literature does not report any association between habitual snoring and sleep bruxism, but these situations can be a reason for frequent complaints of individuals, impairing the quality of life. This study was performed to investigate the sleep period and amount of habitual snoring in individuals with sleep bruxism observing expiratory, inspiratory, and mixed snoring.

Material and Methods

A total of 90 individuals were screened and divided into the following groups: with sleep bruxism (n=45) and those without sleep bruxism (n=45). Single night sleep polysomnography was performed to diagnose sleep bruxism, quantify habitual snoring and sleep period. The results were tabulated and submitted to a Multivariate analysis of variance (MANOVA) to compare the means of the two independent groups, considering the affected diagnosis of sleep bruxism, snoring (independent variables) and age as covariate. For the post hoc, was used correcting for multiple comparisons (Bonferroni test, P <.05).

Results

There was statistically significant difference among the groups ( p =.001) in the sleep period, in that individuals with sleep bruxism slept for a longer duration (with sleep bruxism group: 460 minutes and without sleep bruxism group: 401 minutes). There were no statistically significant differences among the groups for the number of inspiratory, expiratory and mixed snores, but was observed greater amount of snoring in the with sleep bruxism group.

Conclusions

The main finding of this study is that individuals with sleep bruxism slept longer than the control group. It may also be suggested that individuals with sleep bruxism tended to increase the amount of habitual snoring during sleep.

Key words:Bruxism, adult, sleep disordered breathing, polysomnography.

Relationship between sleep characteristics and measures of body size and composition in a nationally-representative sample

BACKGROUND

Short sleep has been linked to obesity. However, sleep is a multidimensional behavior that cannot be characterized solely by sleep duration. There is limited study that comprehensively examined different sleep characteristics in relation to obesity.

METHODS

We examined various aspects of sleep in relation to adiposity in 2005-2006 NHANES participants who were 18 or older and free of cardiovascular disease, cancer, emphysema, chronic bronchitis and depression (N = 3995). Sleep characteristics were self-reported, and included duration, overall quality, onset latency, fragmentation, daytime sleepiness, snoring, and sleep disorders. Body measurements included weight, height, waist circumference, and dual-energy X-ray absorptiometry measured fat mass.

RESULTS

Snoring was associated with higher BMI (adjusted difference in kg/m² comparing snoring for 5+ nights/week with no snoring (95 % confidence interval), 1.85 (0.88, 2.83)), larger waist circumference (cm, 4.52 (2.29, 6.75)), higher percentage of body fat (%, 1.61 (0.84, 2.38)), and higher android/gynoid ratio (0.03 (0.01, 0.06)). The associations were independent of sleep duration and sleep quality, and cannot be explained by the existence of sleep disorders such as sleep apnea. Poor sleep quality (two or more problematic sleep conditions) and short sleep duration (<6 h) were also associated with higher measures of body size and fat composition, although the effects were attenuated after snoring was adjusted.

CONCLUSION

In a nationally representative sample of healthy US adults, snoring, short sleep, and poor sleep quality were associated with higher adiposity.

Impact of gender and sleep position on relationships between anthropometric parameters and obstructive sleep apnea syndrome

OBJECTIVE

Considering the mechanisms by which obesity affects obstructive sleep apnea syndrome (OSAS) and the differences of fat distribution depending on gender, associations between anthropometric parameters, and OSAS may differ depending on gender or sleep position. We analyzed the impact of gender and sleep position on the relationship between fat distribution and development of OSAS.

METHODS

One thousand thirty-two consecutive subjects were analyzed. Recorded anthropometric measurements and overnight polysomnographic data of the subjects were reviewed retrospectively. The presence of OSAS was defined by the respiratory disturbance index (RDI) ≥5 with documented symptoms of excessive daytime sleepiness.

RESULTS

Eight hundred fifty-eight males and 174 females were included. Male subjects had significantly higher body mass index (BMI), larger waist circumference (WC), and lower percent of overall body fat (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). The severity of OSAS was significantly higher in male subjects (RDI 26.9 ± 22.4 in males vs. 10.2 ± 13.8 in females, P < 0.0001). In male subjects, BMI, WC, and overall body fat were significantly associated with severity of OSAS and had larger impacts on supine RDI than lateral RDI. Overall body fat was not associated with severity of OSAS in female subjects, and there were no significant differences of the associations between all anthropometric parameters and RDIs depending on sleep position.

CONCLUSIONS

Evaluation of the correlation of anthropometric data with severity of OSAS should consider sleep position as well as gender.

Obstructive sleep apnea is a common disorder in the population-a review on the epidemiology of sleep apnea

The prevalence of obstructive sleep apnea (OSA) defined at an apnea-hypopnea index (AHI) ≥5 was a mean of 22% (range, 9-37%) in men and 17% (range, 4-50%) in women in eleven published epidemiological studies published between 1993 and 2013. OSA with excessive daytime sleepiness occurred in 6% (range, 3-18%) of men and in 4% (range, 1-17%) of women. The prevalence increased with time and OSA was reported in 37% of men and in 50% of women in studies from 2008 and 2013 respectively. OSA is more prevalent in men than in women and increases with age and obesity. Smoking and alcohol consumption are also suggested as risk factors, but the results are conflicting. Excessive daytime sleepiness is suggested as the most important symptom of OSA, but only a fraction of subjects with AHI >5 report daytime sleepiness and one study did not find any relationship between daytime sleepiness and sleep apnea in women. Stroke and hypertension and coronary artery disease are associated with sleep apnea. Cross-sectional studies indicate an association between OSA and diabetes mellitus. Patients younger than 70 years run an increased risk of early death if they suffer from OSA. It is concluded that OSA is highly prevalent in the population. It is related to age and obesity. Only a part of subjects with OSA in the population have symptoms of daytime sleepiness. The prevalence of OSA has increased in epidemiological studies over time. Differences and the increase in prevalence of sleep apnea are probably due to different diagnostic equipment, definitions, study design and characteristics of included subjects including effects of the obesity epidemic. Cardiovascular disease, especially stroke is related to OSA, and subjects under the age of 70 run an increased risk of early death if they suffer from OSA.

Relationship between Neck Length, Sleep, and Cardiovascular Risk Factors

BACKGROUND

Neck circumference, as a predicator of obesity, is a well-known risk factor for obstructive sleep apnea and cardiovascular diseases. However, little research exists on neck length associated with these factors. This study explored the association of neck length with sleep and cardiovascular risk factors by measuring midline neck length (MNL) and lateral neck length (LNL).

METHODS

We examined 240 patients aged 30 to 75 years who visited a health check-up center between January 2012 and July 2012. Patients with depressive disorder or sleep disturbance were excluded from this study. MNL from the upper margin of the hyoid bone to the jugular notch and LNL from the mandibular angle to the mid-portion of the ipsilateral clavicle were measured twice and were adjusted by height to determine their relationship with sleep and cardiovascular disease risk factors.

RESULTS

Habitual snorers had shorter LNL height ratios (P = 0.011), MNL height ratios in men (P = 0.062), and MNL height ratios in women (P = 0.052). Those snoring bad enough to annoy others had shorter MNL height ratios in men (P = 0.083) and women (P = 0.035). Men with objective sleep apnea had longer distances from the mandible to the hyoid bone to the mandible (P = 0.057). Men with metabolic syndrome had significantly shorter LNL height ratios (P = 0.021), and women with diabetes, hyperlipidemia, and metabolic syndrome had shorter MNL height ratios (P < 0.05).

CONCLUSION

This study shows that a short neck by measuring the MNL is probably associated with snoring. In addition, MNL is related to cardiovascular disease risk factors in women.

Sex-specific characteristics of anthropometry in patients with obstructive sleep apnea: neck circumference and waist-hip ratio

OBJECTIVE

This study aimed to investigate the sex-specific effects of anthropometric profiles on the occurrence and severity of obstructive sleep apnea (OSA).

METHODS

We evaluated 151 patients with suspected OSA undergoing polysomnography and anthropometric measurements such as body mass index (BMI), neck and waist circumference (NC and WC), and waist-hip ratio (WHR).

RESULTS

In men, NC (P = .006), WC (P = .035), and WHR (P = .003) were significantly increased in OSA and all were significantly correlated with apnea hypopnea index (AHI). However, in female OSA patients, BMI (P = .05), WC (P = .008), and WHR (P = .001) were elevated, but only WHR was significantly correlated with AHI. Correlation analyses showed significant correlations between NC and other anthropometric indexes in men but not in women. The receiver operating characteristic curves revealed that NC and WHR in men, and WHR in women, were significant in both model I (AHI > or = 5) and model 2 (AHI > or = 15).

CONCLUSION

Waist-hip ratio is the most reliable correlate of OSA in both sexes. Neck circumference is an independent risk factor for male, but not for female, OSA patients. These different aspects of obesity may contribute to the pathogenesis of OSA and provide helpful guidance in the screening of OSA.

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 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.

Clinical and polysomnographic features of patients with multiple system atrophy in Southwest China

PURPOSE

The association between clinical features and polysomnographic variables of Chinese patients with multiple-system atrophy (MSA) remains largely unknown.

METHODS

This study assessed 30 patients with MSA from Southwest China using the Unified Multiple-System Atrophy Rating Scale (UMSARS). Each patient also underwent video-polysomnography. Twenty age and gender matched healthy volunteers were performed video-polysomnography as control group.

RESULTS

Of the 30 patients, 23 (76.7 %) were classified as having MSA-C and seven (23.3 %) were diagnosed with MSA-P. The mean age of the patients at disease onset was 53.2 ± 8.5 years, and the mean duration of their disease was 3.6 ± 2.8 years. Twenty-one patients complained of sleep disorders. The mean scores of UMSARS-I, UMSARS-II, and UMSARS-IV of patients with MSA-P were significantly higher than those of patients with MSA-C. Polysomnography revealed that 29 patients had sleep architecture alteration. A longer duration of stage N1 sleep, a shorter REM sleep, as well as decreased sleep efficiency and total sleep time (TST) were detected. Twenty-one patients had obstructive sleep apnea. Patients with MSA-C demonstrated longer sleep onset latencies compared with patients with MSA-P. TST was negatively correlated with MSA duration, whereas sleep latency was positively correlated with MSA duration. Moreover, TST, and mean SaO2 were negatively correlated with motor disability.

CONCLUSIONS

Various sleep disorders are common in Chinese MSA patients. Sleep architecture and sleep-associated breathing disorders are predominant polysomnographic findings. Sleep quantity was reduced with disease progression.

Prevalence of obstructive sleep apnea in Asian adults: a systematic review of the literature

Background

Obstructive sleep apnea (OSA) is a common disease, affecting approximately 2% of women and 4% of men residing in Western communities. No systematically reviewed data are available about the prevalence of this disease in Asia, the most heavily populated continent.

Methods

PubMed/Medline, Scopus and Google Scholar were searched for articles published from 1993 to May 2012 that reported the prevalence of OSA diagnosed via sleep monitoring and the prevalence of patients at risk for OSA as assessed by symptomatology and/or sleep questionnaires. We have also searched abstract database of major pulmonary and sleep scientific societies for relevant abstracts presented from 2010 to 2012. The following inclusion criteria were used: articles published in English, age ≥ 18 years, ≥ 100 participants in studies using sleep monitoring for the diagnosis of OSA, ≥ 300 participants in studies using questionnaires to detect patients at high risk for OSA. Exclusion criteria: duplicate publications, studies reporting the prevalence of central sleep apnea only, hospital based studies as well as studies assessing OSA prevalence among patients with resistant arterial hypertension, chronic kidney disease, heart failure and in patients with concomitant neurological disease.

Results

Twenty four articles were found to meet the inclusion criteria, covering 47,957 subjects (26,042 men and 21,915 women) and four relevant abstracts were noted. OSA prevalence ranged from 3.7% to 97.3%. Male gender, older age, a higher BMI and waist to hip ratio, greater neck circumference, arterial hypertension, smoking, snoring and daytime sleepiness were associated with OSA. Sample size, difference between the populations studied and the fact that some works included patients with a high pre-test probability of OSA explain the difference in prevalence rates.

Conclusion

This systematic review highlights the lack of data regarding the prevalence of OSA in Asians. Only a few studies provide an approximate estimate of the OSA burden in some Asian communities.

Association between PM₁₀ exposure and sleep of Egyptian school children

PURPOSE

This study aims to investigate the potential association between exposure to particulate matter with an aerodynamic diameter <10 μm (PM10) and sleep disturbances among Egyptian school children.

METHODS

In this cross-sectional study, parents of school children from four elementary schools in areas with different PM10 exposures filled out the Sleep Disturbance Scale for Children questionnaire in Arabic. Air pollution data were obtained from the Egyptian Environmental Affairs Agency.

RESULTS

The sample consisted of 276 children, 121 (44 %) of them were boys with a mean age of 9.26 ± 1.96 years. Disorders of initiating and maintaining sleep (DIMS), disorders of excessive somnolence, and the total score were reported in the clinical range (T score > 70) in 19.9, 24.3, and 24.3 % of the sample, respectively. A generalized additive model with adjustment for potential confounding factors was used to examine the association between PM10 exposure and sleep disturbances. There were statistically significant associations between PM10 exposure and DIMS and sleep hyperhidrosis (P < 0.05).

CONCLUSIONS

Air pollution exposure has a negative impact on children's sleep with significant association between exposure to PM10 and sleep disturbances.

Self-reported snoring frequency and incidence of cardiovascular disease: the Circulatory Risk in Communities Study (CIRCS)

Background

Although associations between snoring and cardiovascular disease have been reported in several prospective studies, there is limited evidence from Asian populations. The objective of this study was to determine if there is an association between self-reported snoring frequency and the incidence of cardiovascular disease in Japanese.

Methods

The subjects were 2350 men and 4163 women aged 40 to 69 years who lived in 3 communities in Japan. All subjects were participants in the Circulatory Risk in Communities Study (CIRCS) and were followed for 6 years. Incidence of cardiovascular disease during the follow-up period comprised events of myocardial infarction, angina pectoris, sudden cardiac death and stroke.

Results

During the 6-year follow-up period, 97 participants (56 men and 41 women) had cardiovascular events. After adjustment for potential confounding factors, self-reported snoring frequency was associated with an increased risk of cardiovascular events among women but not men. The hazard ratios (95% CI) for cardiovascular events were 0.9 (0.4–2.0) for sometimes snoring and 2.5 (1.0–6.1) for everyday snoring in women and 0.7 (0.3–1.3) and 1.0 (0.5–2.1), respectively, in men. Further adjustment for body mass index attenuated the association in women; the respective hazard ratios for cardiovascular events were 0.9 (0.4–1.9) and 2.1 (0.9–5.4).

Conclusions

Self-reported habitual snoring was associated with increased risk of cardiovascular events among Japanese women. Overweight may partly mediate this association.

Pathogenesis of cognitive dysfunction in patients with obstructive sleep apnea: a hypothesis with emphasis on the nucleus tractus solitarius

OSA is characterized by the quintessential triad of intermittent apnea, hypoxia, and hypoxemia due to pharyngeal collapse. This paper highlights the upstream mechanisms that may trigger cognitive decline in OSA. Three interrelated steps underpin cognitive dysfunction in OSA patients. First, several risk factors upregulate peripheral inflammation; these crucial factors promote neuroinflammation, cerebrovascular endothelial dysfunction, and oxidative stress in OSA. Secondly, the neuroinflammation exerts negative impact globally on the CNS, and thirdly, important foci in the neocortex and brainstem are rendered inflamed and dysfunctional. A strong link is known to exist between neuroinflammation and neurodegeneration. A unique perspective delineated here underscores the importance of dysfunctional brainstem nuclei in etiopathogenesis of cognitive decline in OSA patients. Nucleus tractus solitarius (NTS) is the central integration hub for afferents from upper airway (somatosensory/gustatory), respiratory, gastrointestinal, cardiovascular (baroreceptor and chemoreceptor) and other systems. The NTS has an essential role in sympathetic and parasympathetic systems also; it projects to most key brain regions and modulates numerous physiological functions. Inflamed and dysfunctional NTS and other key brainstem nuclei may play a pivotal role in triggering memory and cognitive dysfunction in OSA. Attenuation of upstream factors and amelioration of the NTS dysfunction remain important challenges.

Dysfunctional nucleus tractus solitarius: its crucial role in promoting neuropathogenetic cascade of Alzheimer's dementia--a novel hypothesis

The pathophysiological mechanism(s) underlying Alzheimer's disease (AD) still remain unclear, and no disease-modifying or prophylactic therapies are currently available. Unraveling the fundamental neuropathogenesis of AD is an important challenge. Several studies on AD have suggested lesions in a number of CNS areas including the basal forebrain, hippocampus, entorhinal cortex, amygdale/insula, and the locus coeruleus. However, plausible unifying studies on the upstream factors that involve these heterogeneous regions and herald the onset of AD pathogenesis are not available. The current article presents a novel nucleus tractus solitarius (NTS) vector hypothesis that underpins several disparate biological mechanisms and neural circuits, and identifies relevant hallmarks of major presumptive causative factor(s) linked to the NTS, in older/aging individuals. Aging, obesity, infection, sleep apnea, smoking, neuropsychological states, and hypothermia-all activate inflammatory cytokines and oxidative stress. The synergistic impact of systemic proinflammatory mediators activates microglia and promotes neuroinflammation. Acutely, the innate immune response is protective defending against pathogens/toxins; however, when chronic, it causes neuroinflammation and neuronal dysfunction, particularly in brainstem and neocortex. The NTS in the brainstem is an essential multiple signaling hub, and an extremely important central integration site of baroreceptor, chemoreceptor, and a multitude of sensory afferents from gustatory, gastrointestinal, cardiac, pulmonary, and upper airway systems. Owing to persistent neuroinflammation, the dysfunctional NTS exerts deleterious impact on nucleus ambiguus, dorsal motor nucleus of vagus, hypoglossal, parabrachial, locus coeruleus and many key nuclei in the brainstem, and the hippocampus, entorhinal cortex, prefrontal cortex, amygdala, insula, and basal forebrain in the neocortex. The neuronal and synaptic dysfunction emanating from the inflamed NTS may affect its interconnected pathways impacting almost the entire CNS--which is already primed by neuroinflammation, thus promoting cognitive and neuropsychiatric symptoms. The upstream factors discussed here may underpin the neuropathopgenesis of AD. AD pathology is multifactorial; the current perspective underscores the value of attenuating disparate upstream factors--in conjunction with anticholinesterase, anti-inflammatory, immunosuppressive, and anti-oxidant pharmacotherapy. Amelioration of the NTS pathology may be of central importance in countering the neuropathological cascade of AD. The NTS, therefore, may be a potential target of novel therapeutic strategies.