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

Relationship of aberrant internal carotid artery with pharyngeal wall in obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is a common clinical condition in which the upper airway partially or completely narrows or collapses during sleep. The objective of our research was to examine the relation between the abnormal internal carotid artery (ICA) and the pharyngeal wall among individuals suffering from OSA, and to compare it to a group of control subjects.

METHODS

In this retrospective study, the closest distances of the ICA to the pharyngeal walls and midlines were measured on CT images and compared between groups.

RESULTS

The closest distance of the ICA to the right pharyngeal wall was 3.8 ± 2.4 mm and the closest distance to the left pharyngeal wall was 4.1 ± 2.3 mm in patients with OSA, which was significantly less than the controls (respectively, 4.4 ± 1.6 mm and 14.4 ± 1.7 mm) (p < 0.001). The closest distances of the ICA to the right and left pharyngeal walls (p = 0.001) and to the right and left midline (p = 0.00002) were significantly lower in patients with moderate to severe OSA compared to mild patients according to apnea / hypopnea index (AHI). In the retroglossal bifurcation of the common carotid artery (CCA), the closest distances of the ICA to the right (p = 0.027) and left pharyngeal walls (p = 0.018) and to the right (p = 0.01) and left midline (p = 0.012) were significantly lower than the retroepiglottic bifurcation of the CCA.

CONCLUSION

We observed that the distance of the aberrant ICA to the pharyngeal wall is less in individuals with OSA than in individuals without OSA, the distance of the aberrant ICA to the pharyngeal wall decreased as the severity of AHI increased.

Positive correlation between snoring and dyslipidemia in adults: results from NHANES

BACKGROUND

A few studies have shown that snoring, in certain populations, is associated with dyslipidemia. However, there are currently no large-scale national studies available that explore this association. Thus, for further clarification, studies using a large sample of the general population need to be conducted. This study aimed to explore this association using the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

A cross-sectional survey was conducted using data from the NHANES database; 2005 to 2008 and 2015 to 2018 datasets were used (weighted to be representative of United States adults aged ≥ 20 years). Information on snoring status, lipid levels, and confounding factors were included. Logistic regression of the generalized linear model was used to analyze the relationship between snoring and dyslipidemia, and hierarchical analysis, interaction analysis, and sensitivity analysis were used to explore the stability of the results.

RESULTS

Data from 28,687 participants were analyzed, and 67% of the participants had some degree of snoring. The fully adjusted multivariate logistic regression results demonstrated that snoring frequency was significantly positively associated with dyslipidemia (P < 0.001 for linear trend). Adjusted odds ratios (aORs) of dyslipidemia among those who snored rarely, occasionally, and frequently were 1.1 (95% confidence interval [CI], 1.02-1.18), 1.23 (95% CI, 1.10-1.38), and 1.43 (95% CI, 1.29-1.58), respectively, compared with that among those who never snored. In addition, age and snoring frequency showed a correlation (P = 0.02). Sensitivity analysis demonstrated that frequent snoring was significantly associated with lipid levels (all P ≤ 0.01 for linear trend), including increased low-density lipoprotein cholesterol (LDL-C) (β = 0.09 mmol/L; 95% CI, 0.02-0.16), triglyceride (TG) (β = 0.18 mmol/L; 95% CI, 0.10-0.26), total cholesterol (TC) (β = 0.11 mmol/L; 95% CI, 0.05-0.16), and decreased high-density lipoprotein cholesterol (HDL-C) (β=-0.04 mmol/L; 95% CI, -0.06--0.03).

CONCLUSIONS

A statistically significant positive association was identified between sleep snoring and dyslipidemia. It was suggested that sleep snoring interventions may reduce the risk of dyslipidemia.

Carotid Ultrasound Screening Programs in Rural Communities: A Systematic Review

Carotid atherosclerosis assessments inform about stroke and cardiovascular risk. It is known that stroke and cardiovascular disease (CVD) prevalence is higher in rural communities than in urban communities. We aimed to conduct a systematic review of rural carotid ultrasound screening programs to define carotid atherosclerosis using traditional and emerging imaging biomarkers, prevalence, and risk factors. We searched Ovid/MEDLINE, Ovid/EMBASE, SCOPUS and CINAHL from inception to 3 April 2020 for rural population studies that utilized carotid ultrasound screening for adults ≥40 years of age and free of known cerebrovascular disease. Studies were included if participants received a bilateral ultrasound scanning of the carotid arteries and reported at least one marker of carotid atherosclerosis pathology. A random effect meta-analyses calculated the estimated prevalence of carotid plaque. In total, 22/3461 articles that met all of the inclusion criteria were included. Studies reported increased intima media thickness (IMT), carotid plaque presence and carotid artery stenosis. There were no studies reporting on novel imaging markers, such as carotid stiffness, carotid plaque morphology or neovascularization. The overall random effect pooled prevalence of carotid plaque was 34.1% (95% CI, 33.6–35.0); the prevalence of increased IMT was 11.2–41.5%, and the prevalence of carotid artery stenosis was 0.4–16.0%. There is an absence of data necessary to understand the carotid atherosclerosis prevalence across global rural populations. Represented studies have focused on East Asian countries where a high burden of rural carotid artery disease has been reported. There is no rural evidence to guide the use of novel ultrasound carotid biomarkers such as stiffness or neovascularization.

Snoring frequency and risk of type 2 diabetes mellitus: a prospective cohort study

OBJECTIVE

To evaluate the association between snoring frequency and type 2 diabetes mellitus (T2DM) according to age and gender in Chinese population.

DESIGN

A cohort study was performed in Suzhou site of the China Kadoorie Biobank. Residents who didn't suffer from T2DM at baseline survey (2004-2008) and in half a year after baseline were enrolled in this study and followed cause-specific morbidity until 31 December 2013. All participants were requested to complete a detailed questionnaire and undergo anthropometric measurements. Cox regression models were used to estimate HRs and 95% CIs for the snoring and T2DM association.

SETTING

Wuzhong district, Suzhou, China.

PARTICIPANTS

A total of 49 453 participants (men: 41.8%; mean age: 51.14±10.28 years) were enrolled in this study.

OUTCOME MEASURES

T2DM cases were defined as International Classification of Diseases 10th Revision code of E11 and were identified through disease registries and health insurance databases.

RESULTS

During a media of 7.18 years follow-up, 1120 T2DM cases were identified. Higher T2DM incidence was observed in participants with frequent and occasional snoring compared with those without (4.80 and 2.87 vs 2.39 per 1000 person-years). The multivariable-adjusted model found snoring was independently associated with T2DM (HR 1.28, 95% CI 1.20 to 1.38), both in men (HR 1.25, 95% CI 1.10 to 1.41) and women (HR 1.28, 95% CI 1.17 to 1.39). Moreover, a significant multiplicative interaction effect between snoring and age was detected on T2DM risk (p=0.015).

CONCLUSIONS

Snoring was independently associated with an increased risk of T2DM in Chinese population, both in men and women. Meanwhile, there was an interaction effect between snoring and age on T2DM risk.

Snoring severity is associated with carotid vascular remodeling in young adults with overweight and obesity

BACKGROUND

Snoring is often used as a surrogate measure for obstructive sleep apnea (OSA), a sleep disorder associated with cardiovascular disease (CVD) risk. Whether snoring is linked to CVD independent of OSA remains unclear. We aimed to explore the snoring and subclinical CVD association in adults with and without OSA.

METHODS

We conducted a cross-sectional study in 122 overweight/obese participants (24% male; mean age 40.1 years) attending the 24-month follow-up visit of a lifestyle intervention. Using home-based objective measures of sleep-disordered breathing, we stratified participants into 3 snoring/OSA categories using the snoring index (SI), a measure of snoring vibration, and oxygen desaturation index (ODI): (1) OSA (ODI ≥ 5), (2) non-OSA heavy snorer (ODI <5, above-median SI), and (3) non-OSA low snorer (ODI <5, below-median SI). Vascular measures including pulse wave velocity ([PWV]; carotid-femoral [cf], femoral-ankle [fa], brachial-ankle [ba]), carotid intima-media thickness (IMT), and carotid interadventitial diameter (IAD) were compared across snoring/OSA categories. Linear regressions assessed the association between snoring and subclinical CVD independent of traditional CVD risk factors.

RESULTS

Compared to non-OSA low snorers, common carotid IMT and IAD were higher in non-OSA heavy snorers, and faPWV, IMT, and IAD were higher among those with OSA. The difference between non-OSA heavy snorers and low snorers persisted after adjusting for age, race, sex, blood pressure, body mass index, lipids, and insulin resistance (P < .05 for IMT and IAD).

CONCLUSIONS

In overweight/obese young to middle-aged adults, objectively measured snoring was related to vascular remodeling in those without OSA. Snoring may contribute to CVD risk but warrants further examination in larger prospective cohorts.

Comparison of carotid plaque burden among healthy middle-aged men living in the US, Japan, and South Korea

BACKGROUND

Carotid plaque has emerged as a marker of coronary heart disease (CHD) risk. Comparison of carotid plaque burden between different race/ethnic groups may provide a relative estimate of their future CHD risk.

METHODS

We conducted a population-based study among apparently healthy middle-aged men aged 40-49 years (ERA JUMP study (n = 924)) and recruited 310 Whites in Pittsburgh, US, 313 Japanese in Otsu, Japan, and 301 Koreans in Ansan, South Korea. The number of carotid plaque and CHD risk factors was assessed using a standardized protocol across all centers. The burden of carotid plaque was compared between race/ethnic groups after adjustment for age and BMI, and after multivariable adjustment for other CHD risk factors using marginalized zero-inflated Poisson regression models. Cross-sectional associations of risk factors with plaque were examined.

RESULTS

Whites (22.8%) had more than four-fold higher prevalence (p < 0.01) of carotid plaque than Japanese men (4.8%) while the prevalence among Koreans was 10.6%. These differences remained significant after adjustment for age, BMI as well as other risk factors - incidence density ratio (95% confidence interval) for plaque was 0.13 (0.07, 0.24) for Japanese and 0.32 (0.18, 0.58) for Koreans as compared to Whites. Age, hypertension and diabetes were the only risk factors significantly associated with presence of carotid plaque in the overall population.

CONCLUSION

Whites have significantly higher carotid plaque burden than men in Japan and Korea. Lower carotid plaque burden among Japanese and Koreans is independent of traditional CVD risk factors.

Numerical study of dynamic glottis and tidal breathing on respiratory sounds in a human upper airway model

BACKGROUND

Human snores are caused by vibrating anatomical structures in the upper airway. The glottis is a highly variable structure and a critical organ regulating inhaled flows. However, the effects of the glottis motion on airflow and breathing sound are not well understood, while static glottises have been implemented in most previous in silico studies. The objective of this study is to develop a computational acoustic model of human airways with a dynamic glottis and quantify the effects of glottis motion and tidal breathing on airflow and sound generation.

METHODS

Large eddy simulation and FW-H models were adopted to compute airflows and respiratory sounds in an image-based mouth-lung model. User-defined functions were developed that governed the glottis kinematics. Varying breathing scenarios (static vs. dynamic glottis; constant vs. sinusoidal inhalations) were simulated to understand the effects of glottis motion and inhalation pattern on sound generation. Pressure distributions were measured in airway casts with different glottal openings for model validation purpose.

RESULTS

Significant flow fluctuations were predicted in the upper airways at peak inhalation rates or during glottal constriction. The inhalation speed through the glottis was the predominating factor in the sound generation while the transient effects were less important. For all frequencies considered (20-2500 Hz), the static glottis substantially underestimated the intensity of the generated sounds, which was most pronounced in the range of 100-500 Hz. Adopting an equivalent steady flow rather than a tidal breathing further underestimated the sound intensity. An increase of 25 dB in average was observed for the life condition (sine-dynamic) compared to the idealized condition (constant-rigid) for the broadband frequencies, with the largest increase of approximately 40 dB at the frequency around 250 Hz.

CONCLUSION

Results show that a severely narrowing glottis during inhalation, as well as flow fluctuations in the downstream trachea, can generate audible sound levels.

A Gender-Specific Association between Self-Reported Snoring and Hemoglobin A1c Levels in a General Population without Type 2 Diabetes Mellitus

PURPOSE

We explored whether a gender difference was evident in terms of the associations of snoring with hemoglobin A1c (HbA1c) and homeostatic model assessment-insulin resistance (HOMA-IR) levels in a healthy population without type 2 diabetes mellitus (DM).

MATERIALS AND METHODS

We analyzed 2706 males and 4080 females who participated in the baseline survey of the Namwon Study. In terms of self-reported snoring frequency, participants were classified as non-snorers or occasional (1-3 days/week), frequent (4-6 days/week), or constant (7 days/week) snorers. Participants with DM, defined as a fasting blood glucose level ≥126 mg/dL and/or use of insulin or hypoglycemic medication, were excluded from the analysis.

RESULTS

In females, the fully adjusted mean (95% confidence interval) HbA1c levels in non-snorers and in occasional, frequent, and constant snorers were 5.53% (5.47-5.59%), 5.53% (5.47-5.59%), 5.57% (5.49-5.64%), and 5.57% (5.51-5.64%), respectively, reflecting a dose-response relationship (p trend=0.004). Compared with female non-snorers, the risk of an elevated HbA1c level (top quintile, ≥5.9%) in constant snorers remained significant (odds ratio 1.30, 95% confidence interval 1.02-1.66) after full adjustment. In addition, in females, a significant linear trend in HbA1c level odds ratio by increased snoring frequency was apparent (p trend=0.019 in model 3). In contrast, no significant association between snoring frequency and HbA1c level was identified in males. No significant association between snoring frequency and HOMA-IR was detected in either gender.

CONCLUSION

We discovered a gender-specific association between snoring and HbA1c level in a healthy, community-dwelling population free of DM.

The Frequency and Energy of Snoring Sounds Are Associated with Common Carotid Artery Intima-Media Thickness in Obstructive Sleep Apnea Patients

Obstructive sleep apnea (OSA) is a known risk factor for atherosclerosis. We investigated the association of common carotid artery intima-media thickness (CCA-IMT) with snoring sounds in OSA patients. A total of 30 newly diagnosed OSA patients with no history of cardiovascular diseases were prospectively enrolled for measuring mean CCA-IMT with B-mode ultrasonography, body mass index, metabolic syndrome, 10-year cardiovascular disease risk score, high-sensitivity C-reactive protein, and homocysteine. Good-quality signals of full-night snoring sounds in an ordinary sleep condition obtained from 15 participants were further acoustically analyzed (Included group). All variables of interest were not significantly different (all p > 0.05) between the included and non-included groups except for diastolic blood pressure (p = 0.037). In the included group, CCA-IMT was significantly correlated with snoring sound energies of 0–20 Hz (r = 0.608, p = 0.036) and 652–1500 Hz (r = 0.632, p = 0.027) and was not significantly associated with that of 20–652 Hz (r = 0.366, p = 0.242) after adjustment for age and sex. Our findings suggest that underlying snoring sounds may cause carotid wall thickening and support the large-scale evaluation of snoring sound characters as markers of surveillance and for risk stratification at diagnosis.

Association between self-reported snoring and arterial stiffness: data from the Brisighella Heart Study

The correlation of both obstructive sleep apnoea syndrome (OSAS) and snoring with cardiovascular risk is well known, but its investigation is complex and not suitable for studying large cohorts of subjects. Thus, we prospectively evaluated 1476 non-pharmacologically treated subjects selected from the last survey of the Brisighella Heart Study. Snoring and sleep apnoea were investigated asking the subjects if they were aware of snoring during the night, and if this was associated with episodes of apnoea. A full set of clinical and laboratory parameters were evaluated, while augmentation index (AIx), and pulse wave velocity (PWV) were recorded with the Vicorder(®) apparatus. A logistic regression analysis identifies as main independent predictors of AIx age (OR 1.058, 95% CI 1.043-1.065, p < 0.001), Body Mass Index (OR 1.046, 95% CI 1.014-1.079, p = 0.005), and apolipoprotein B (OR 1.014, 95% CI 1.004-1.023, p = 0.001). The main independent predictors of PWV are snoring (OR 1.215, 95% CI 1.083-1.390, p < 0.001), and snoring with apnoea (OR 1.351, 95% CI 1.135-1.598, p = 0.014), age (OR 1.078, 95% CI 1.052-1.089, p < 0.001), serum uric acid [SUA] (OR 1.093, 95% CI 1.026-1.151, p < 0.001) and mean arterial pressure (OR 1.042, 95% CI 1.024-1.056, p < 0.001). In conclusion, in our cohort of overall healthy subjects, self-reported snoring and sleep apnoea are independently associated with a higher PVW, and AIx is statistically significantly higher in snorers with or without sleep apnoea than in non-snorers. Body Mass Index and apolipoprotein B are associated with AIx, while SUA and mean arterial pressure are related to PWV.

The relationship between snoring and left ventricular hypertrophy of China: a cross-sectional study

BACKGROUND

Population-based investigations studying the association between snoring and left ventricular hypertrophy (LVH) are lacking. Therefore, our study aims to investigate whether snoring is significantly associated with LVH, and to make clear the effect of varying degrees of snoring intensity on LVH.

METHODS

A total of 10,139 participants were involved in this cross-sectional study. Snoring status and snoring intensity were evaluated by a structured questionnaire. LVH was defined as left ventricular mass index ≥ 51 g/m(2.7) for both men and women.

RESULTS

The total prevalence of LVH was 10.0%. the prevalence increased significantly in snorers according to snoring intensity, including low (10.3%), normal (13.1%), strong (14.7%) and very strong (16.7%). After adjustment for age, race, gender, educational status, physical activity, annual income, current smoking status, current drinking status, sleep duration, hypertension, body mass index, waist circumference, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, total cholesterol and fasting plasma glucose, snoring (OR, 1.371; 95% CI, 1.147-1.637, P < 0.001) was significantly associated with LVH. In addition, among the four kinds of intensity of snoring, normal (OR, 1.436; 95% CI, 1.126-1.832, P = 0.004), strong (OR, 1.462; 95% CI, 1.124-1.902, P < 0.001) and very strong (OR, 1.813; 95% CI, 1.273-2.684, P < 0.001), rather than low (OR, 1.094; 95% CI, 0.834-1.434, P = 0.518) were significantly associated with LVH.

CONCLUSIONS

Snoring is independently associated with LVH. What's more, with the rise in snoring intensity, snoring will exert an increasing effect on LVH.