The effect of obstructive sleep apnea syndrome and snoring severity to intima-media thickening of carotid artery

Predictors for carotid and femoral artery intima-media thickness in a non-diabetic sleep clinic cohort

Introduction

The impact of sleep disordered breathing (SDB) on arterial intima-media thickness (IMT), a surrogate measure for cardiovascular disease, remains uncertain, in part because of the potential for non-SDB vascular risk factor interactions. In the present study, we determined predictors for common carotid (CCA) and femoral (CFA) artery IMT in an adult, sleep clinic cohort where non-SDB vascular risk factors (particularly diabetes) were eliminated or controlled.

Methods

We recruited 296 participants for polysomnography (standard SDB severity metrics) and CCA/CFA ultrasound examinations, followed by a 12 month vascular risk factor minimisation (RFM) and continuous positive pressure (CPAP) intervention for participants with a range of SDB severity (RFM Sub-Group, n = 157; apnea hyponea index [AHI]: 14.7 (7.2–33.2), median [IQR]). Univariable and multivariable linear regression models determined independent predictors for IMT. Linear mixed effects modelling determined independent predictors for IMT change across the intervention study. P<0.05 was considered significant.

Results

Age, systolic blood pressure and waist:hip ratio were identified as non-SDB predictive factors for CCA IMT and age, weight and total cholesterol:HDL ratio for CFA IMT. No SDB severity metric emerged as an independent predictor for either CCA or CFA IMT, except in the RFM Sub-Group, where a 2-fold increase in AHI predicted a 2.4% increase in CFA IMT. Across the intervention study, CCA IMT decreased in those who lost weight, but there was no CPAP use interaction. CFA IMT, however, decreased by 12.9% (95%CI 6.8, 18.7%, p = 0.001) in those participants who both lost weight and used CPAP > = 4hours/night.

Conclusion

We conclude that SDB severity has little impact on CCA IMT values when non-SDB vascular risk factors are minimised or not present. This is the first study, however, to suggest a potential linkage between SDB severity and CFA IMT values.

Trial registration

Australian New Zealand Clinical Trials Registry, ACTRN12611000250932 and ACTRN12620000694910.

Sleep disordered breathing as a cause and consequence of stroke: A review of pathophysiological and clinical relationships

Stroke is the leading cause of death and disability globally. Sleep disordered breathing (SDB), a potentially modifiable risk factor of stroke, is highly prevalent in stroke survivors. Evidence supports a causal, bidirectional relationship between SDB and stroke. SDB may increase the risk of stroke occurrence and recurrence, and worsen stroke outcome. While SDB is associated with an increased incidence of hypertension and cardiac arrhythmias, both of which are traditional stroke risk factors, SDB is also an independent risk factor for stroke. A number of characteristics of SDB may increase stroke risk, including intermittent hypoxemia, sympathetic activation, changes in cerebral autoregulation, oxidative stress, systemic inflammation, hypercoagulability, and endothelial dysfunction. On the other hand, stroke may also cause new SDB or aggravate preexisting SDB. Continuous positive airway pressure treatment of SDB may have a beneficial role in reducing stroke risk and improving neurological outcome after stroke. The treatment should be considered as early as possible, particularly when SDB is present post-stroke. The goal of this review is to highlight the strong link between SDB and stroke and to raise awareness for practitioners to consider the possibility of SDB being present in all stroke survivors.

Snoring Sound Characteristics are Associated with Common Carotid Artery Profiles in Patients with Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) and snoring have been reported to be modifiable risk factors for thick carotid intima-media thickness (CIMT) and carotid atherosclerosis, which are closely linked to cardiovascular disease.

METHODS

This cross-sectional study prospectively recruited 70 participants with OSA and without a history of carotid artery disorder, who primarily sought surgical Intervention. OSA and snoring were assessed with the Epworth Sleepiness Scale, Snore Outcomes Survey, polysomnography, and snoring sound recording. The carotid arteries were evaluated with ultrasonography and divided into three types of carotid artery profiles (normal carotid artery, thick CIMT, or significant carotid atherosclerosis). Multivariate linear/logistic/categorical regressions were performed with the forward selection approaches/logistic least absolute shrinkage and selection operator, as appropriate.

RESULTS

Normalized snoring sound energy (301-850 Hz) was independently associated with the carotid intima-media thickness (regression coefficient [β] = 0.01, standard error [SE] = 0.004, P = 0.03; R ² = 0.067) and type of carotid profile (β = 0.40, SE = 0.09, P < 0.001; R ² = 0.156). Normalized snoring sound energy (4-300 Hz) (β = -0.10, SE = 0.04, P = 0.01) and female sex (β = 1.90, SE = 0.94, P = 0.04) were independently related to the presence of carotid stenosis (R ² = 0.159). The optimal regression model of the type of carotid artery profile included normalized snoring sound energy (301-850 Hz) (β = 0.33, SE = 0.14, P = 0.03), snoring time (β = 0.26, SE = 0.13, P = 0.047), female sex (β = 0.26, SE = 0.13, P = 0.047), and increased age (β = 0.20, SE = 0.10, P = 0.04) under the control of the Snore Outcomes Survey score, 3% oxygen desaturation index, snoring sound energy (4-1500 Hz), normalized snoring sound energy (851-1500 Hz), cigarette smoking, and hyperlipidemia (R ² = 0.427).

CONCLUSION

Our findings suggested that snoring sound characteristics are associated with carotid artery profiles among early OSA patients who cannot be noticed by ultrasound because organic changes of the carotid artery have not yet started. Future studies are warranted to verify the clinical significance of the results.

An Overview of the Role of Adipokines in Cardiometabolic Diseases

Obesity as an independent risk factor for cardiovascular diseases (CVDs) leads to an increase in morbidity, mortality, and a shortening of life span. The changes in heart structure and function as well as metabolic profile are caused by obese people, including those free of metabolic disorders. Obesity alters heart function structure and affects lipid and glucose metabolism, blood pressure, and increase inflammatory cytokines. Adipokines, specific cytokines of adipocytes, are involved in the progression of obesity and the associated co-morbidities. In the current study, we review the scientific evidence on the effects of obesity on CVDs, focusing on the changes in adipokines. Several adipokines have anti-inflammatory and cardioprotective effects comprising omentin, apelin, adiponectin, and secreted frizzled-related protein (Sfrp-5). Other adipokines have pro-inflammatory impacts on the cardiovascular system and obesity including leptin, tumor necrosis factor (TNF), retinol-binding protein4 (RBP-4), visfatin, resistin, and osteopontin. We found that obesity is associated with multiple CVDs, but can only occur in unhealthy metabolic patients. However, more studies should be designed to clarify the association between obesity, adipokine changes, and the occurrence of CVDs.

The differences of carotid atherosclerosis among non-OSAHS and OSAHS patients of different severities: a cross-sectional study

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a widely prevalent problem with many complications, such as hypertension and cerebral vascular diseases. Atherosclerosis, whose most severe outcome is ischemic stroke, is reported being affected by OSAHS. The objective of this article is to investigate the differences of carotid atherosclerosis patients with or without OSAHS by a cross-sectional research.

MATERIALS AND METHODS

Patients diagnosed with carotid atherosclerosis by ultrasonography were recruited. They were requested to fill the primary screening OSAHS questionnaire. Patients with high tendency of OSAHS underwent polysomnography (PSG) tests into OSAHS group, and patients without OSAHS were into non-OSAHS group. Blood tests and medical history were collected. Carotid atherosclerosis severity was analyzed by carotid artery intima-media thickness (IMT), carotid plaque, blood flow velocity, etc. Differences between the two groups and subgroups were analyzed.

RESULTS

A total of 242 carotid atherosclerosis patients were enrolled including 118 non-OSAHS patients (38 males and 80 females) and 124 OSAHS patients (40 mild, 32 moderate, and 52 severe). Significant differences were found in PSV-ICA and EDV-ICA on both sides (p < 0.05) but no significant differences on IMT and velocity of CCV. CA patients with OSAHS were younger than ones without OSAHS. With the severity of OSAHS increasing, the age of CA patients decreased. The more severity of OSAHS, the younger the patients were. There were no significant differences in comparing cholesterol, triglyceride, HDL, LDL, and glucose.

CONCLUSION

As far as CIMT, carotid plaque, blood flow velocity, and blood lipid are concerned, the severity of CA is not affected by the severity of OSAHS accordantly. The relationship between OSAHS and CA may not be dose dependent.

TRIAL REGISTRATION

This study has been registered on clinical trials (No. NCT03665818).

Systematic review of the different aspects of primary snoring

Primary snoring, also known as simple or non-apnoeic snoring, is regarded as the first stage of sleep disordered breathing without severe medical consequences for the snorer and co-sleeper. Although it is a highly prevalent phenomenon in the general population, our knowledge is limited because of the lack of a consensus on terminology. This systematic review of the aspects used in the definitions of simple/primary snoring was conducted to obtain an inventory of current practices and compare these definitions with the conceptual definition of the American Academy of Sleep Medicine. PubMed and Web of Science were searched from July 2016 onwards without any language limitations, and 362 references were obtained. After selection based on titles, 39 remained, among which 29 contained a definition or reference to a definition. In 69% of the studies, a cut-off <5 apnoea/Hypopnoea events per hour of sleep on the Apnoea-Hypopnoea Index was used. Despite this tendency, the cut-offs ranged from 0 to <15/h. Unfortunately, the cut-off and occasional requirements did not match the conceptual definition of the American Academy of Sleep Medicine. A consensus must be reached on an operational and clinically relevant definition based on the clear conceptual definition.

Obstructive sleep apnea causes impairment of the carotid artery in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND

Obstructive sleep apnea (OSA) prevalence is high among patients with hypertrophic cardiomyopathy (HCM). OSA can cause increase in carotid intima-media thickness (CIMT) in the general population. However, whether this phenomenon is applicable to patients with HCM is unclear.

METHODS

A total of 130 consecutive patients with a confirmed diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) at Fuwai Hospital between September 2017 and May 2018 were analyzed.

RESULTS

72 patients (55.4%) were diagnosed with OSA. Patients with OSA were older. Compared to those in patients without OSA, the left, right, and mean CIMTs were significantly increased in patients with OSA. In the multiple linear regression model, age (β = 0.341, p < 0.001), apnea-hypopnea index (AHI) (β = 0.421, p < 0.001), and fasting glucose level (β = 0.167, p < 0.03) were independently associated with mean CIMT increase (adjusted R² = 0.458, p < 0.001). In the receiver operating characteristic curve analysis, the area under the curve for CIMT was 0.813 (95% CI, 0.717-0.909, p < 0.001) with a sensitivity and specificity of 0.84 and 0.70 for unexplained syncope, respectively. In the multivariate logistic regression model, we found that the mean CIMT (OR = 10.4, 95% CI = 3.16-34.11, p < 0.001), left ventricular ejection fraction (LVEF) (OR = 0.90, 95% CI = 0.83-0.99, p = 0.03), and amaurosis (OR = 5.07, 95% CI = 1.47-17.49, p = 0.01) were independently associated with unexplained syncope occurrence.

CONCLUSIONS

In patients with HOCM, CIMT increased with OSA severity. Age, AHI, and fasting plasma glucose level were independently associated with mean CIMT increase. Moreover, amaurosis, LVEF, and higher mean CIMT were independently associated with unexplained syncope in patients with HOCM.

Arousal index as a marker of carotid artery atherosclerosis in patients with obstructive sleep apnea syndrome

PURPOSE

It was shown in a previous cohort study that men with internal carotid artery (ICA) plaque, defined as focal wall thickness of ≥ 1.5 mm, had a threefold higher risk of stroke than those without plaque. We examined the relationship between arousal indices and sleep stages in patients with obstructive sleep apnea syndrome (OSAS) and carotid atherosclerosis.

METHODS

Carotid atherosclerosis severity was evaluated using the maximal carotid wall intima-media thickness of the ICA (ICA-maxIMT) and plaque in 83 patients with OSAS.

RESULTS

The ICA-maxIMT values were positively correlated with the apnea hypopnea index (AHI) (ρ = 0.294, P = 0.007), arousal index (ρ = 0.289, P = 0.008), oxygen desaturation index (ρ = 0.298, P = 0.006), percentage of visually scored total sleep time spent in nocturnal oxygen saturation < 90% (SpO₂ < 90%) (ρ = 0.246, P = 0.025), and the percentage of visually scored total sleep time spent in non-REM sleep stage 1 (ρ = 0.326, P = 0.003) and were negatively correlated with the percentage of visually scored total sleep time spent in non-REM sleep stages 2 and 3. Arousal index, diabetes mellitus, and age were found to be independent predictors of ICA plaque presence (OR 1.052, P = 0.003; OR 8.705, P = 0.026; OR 1.064, P = 0.023, respectively).

CONCLUSIONS

Several PSG variables that are indicative of sleep fragmentation, sleep disordered breathing, and poor sleep quality correlated with the occurrence of atherosclerosis, but total arousal index was the only independent predictive factor.

The relationship between the neck circumference and the carotid intima-media thickness in Amerindians. Potential links to health risks?

The carotid intima media thickness (cIMT) is a predictor of cardiovascular events. The neck circumference (NC) has been investigated as a risk factor for increased cIMT with contradictory results. This study assessed the relationship between NC and cIMT in Atahualpa residents aged ≥40 years who had sonographic examination of carotid arteries (n = 590). We also discussed on potential pathogenetic mechanisms underlying this association. Participants belonged to the Native Ecuadorian (Amerindians) ethnic group. Non-parametric regression models were used to assess the aforementioned relationship, after adjusting for relevant confounders. The mean age of participants was 60.9 ± 12.7 years (58% women). The mean value of the cIMT was 0.85 ± 0.19 mm. The mean NC was 35.8 ± 34 cm. The NC was normally distributed, but the cIMT was not. Mean values of NC and cIMT were significantly greater in men than in women. Non-parametric models showed significant differences in median cIMT values according to quartiles of NC. Predictive cIMT margins increased by quartiles of NC, significantly among individuals in the 1st quartile as compared to the 3rd quartile. In this population of Amerindians, smaller NC is associated with lower values of cIMT. The pattern of this association is different in men than in women. Sex-related differences in cervical fat tissue distribution probably accounted for such differences.

Sleep and Migraine: Assessment and Treatment of Comorbid Sleep Disorders

The relationship of sleep and migraine is unequivocal and familiarity with the nature and magnitude of these associations may inform clinical practice. Recent prospective, longitudinal, and time-series analysis has begun to unravel the magnitude and temporal patterns of sleep and migraine. Prospective evidence has shown that sleep variables can trigger acute migraine, precede and predict new onset headache by several years, and indeed, sleep disturbance and snoring are risk factors for chronification. The presence of a sleep disorder is associated with more frequent and severe migraine and portends a poorer headache prognosis. Interestingly, the disorders linked to migraine are quite varied, including insomnia, snoring and obstructive sleep apnea, restless legs, circadian rhythm disorders, narcolepsy, and others. Insomnia is by far the most common sleep disorder in headache patients. In fact, the majority of patients with chronic migraine presenting for treatment have insomnia. Despite a rapidly expanding literature, very few controlled treatment studies have been published to guide clinical practice. This paper focuses on clinical assessment and treatment of sleep disorders. An algorithm is presented for sleep disorders management in the migraine patient, which highlights major sleep disorders and psychiatric comorbidity. Diagnostic procedures are recommended that are conducive to clinical practice. Suggested tools include the sleep history, screening mnemonics, prediction equation, and sleep diary. New developments in treatment have produced abbreviated and cost-effective therapies for insomnia and obstructive sleep apnea that may reach a larger population. Revisions in the diagnostic manuals for sleep and headache disorders enhance recognition of sleep-related headache. Recommendations include behavioral sleep regulation, shown in recent controlled trials to decrease migraine frequency, management for sleep apnea headache, cognitive behavioral therapy (CBT) for insomnia abbreviated for the physician practice setting, sleep-related headache trigger, and others. There is no empirical evidence that sleep evaluation should delay or supersede usual headache care. Rather, sleep management is complimentary to standard headache practice.

Carotid Artery Wall Thickness in Obese and Nonobese Adults With Obstructive Sleep Apnea Before and Following Positive Airway Pressure Treatment

Study objectives

Debate persists as to whether obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. The purpose of this study was to compare carotid intima-media thickness (IMT), an early sign of atherosclerosis, in obese and nonobese adults with OSA before and following positive airway pressure (PAP) treatment.

Methods

A total of 206 adults newly diagnosed with OSA with an apnea-hypopnea index (AHI) of 15-75 events/hour and 53 controls with AHI <10 were studied. Waist circumference was used to classify participants as obese and nonobese. Bilateral common carotid artery B-mode ultrasound was performed at baseline to assess IMT, arterial diameter, arterial-wall mass, and circumferential wall stress. Measurements were repeated in 118 participants with OSA who completed a 4-month PAP treatment and had an average daily use over that period of ≥4 hours/day.

Results

No significant differences in carotid IMT, diameter, or arterial-wall mass were present at baseline between participants with OSA and controls stratified by waist circumference, after adjusting for other cardiovascular risk factors. In participants with OSA, who had adequate PAP adherence over the 4-month treatment, carotid artery diameter significantly increased (mean change [95% confidence interval] = 0.13 [0.06, 0.20] mm; p = .0004), but no significant changes in carotid IMT, arterial-wall mass, and circumferential stress were observed in obese and nonobese participants.

Conclusions

Regardless of obesity status, carotid IMT is not increased in adults with moderate to severe OSA versus controls and does not change following 4 months of PAP treatment.

[Long-term effects of continuous positive airway pressure treatment on subclinical atherosclerosis in obstructive sleep apnoea syndrome]

BACKGROUND AND OBJECTIVE

Obstructive sleep apnoea (OSA) is associated with an increased risk of cardiovascular disease. Our objective was to evaluate subclinical atherosclerosis in OSA patients and the effect of continuous positive airway pressure (CPAP) treatment on carotid intima-media thickness (cIMT).

PATIENTS AND METHOD

We included 125 patients with suspected OSA. After polysomnography, 107 patients were diagnosed with OSA; 58 of these met the criteria for CPAP treatment. cIMT was measured by ultrasonography at baseline in all patients and after 2 years of follow up in 50 patients on CPAP and 35 without CPAP treatment.

RESULTS

The average cIMT was significantly thicker in OSA than in non-OSA patients (665±120 vs. 581±78μm, P=.005) and did not differ according to OSA severity. Atheromatous carotid plaque was more prevalent in OSA than non-OSA patients (48 vs. 2%, P=.004). Among OSA patients, the mean cIMT remained stable over time in the group without CPAP, whereas cIMT decreased markedly in the CPAP group (679±122 vs. 631±117μm, P<.0001).

CONCLUSIONS

Increased cIMT was associated with presence of OSA, but not with its severity. Carotid ultrasound in OSA is a reliable marker of atherosclerosis. CPAP treatment with CPAP in OSA reduces cIMT and cardiovascular risk.

Estradiol Regulates Txnip and Prevents Intermittent Hypoxia-Induced Vascular Injury

Chronic intermittent hypoxia (IH) contributes to obstructive sleep apnea (OSA)-related cardiovascular diseases through increasing oxidative stress. It has been widely recognized that estradiol decreases the risk for cardiovascular disease, but the estrogen replacement therapy is limited for its side effects. Thioredoxin (Trx) and its endogenous inhibitor, thioredoxin-interacting protein (Txnip), are associated with the protective effect of estradiol in some conditions. In this study, we aimed to explore whether estradiol could protect against IH-induced vascular injury, and the possible effect of Trx-1/Txnip in this process. Forty-eight adult female C57/BL6J mice were randomly divided into 4 groups, ovariectomy combined with IH group, sham operation combined with IH group, IH group and the control group. The mice treated with IH for 8 hrs/day, and 28 days. IH induced the injury of aorta, and ovariectomized mice were more prone to the IH-induced aortic injury, with higher level of oxidative stress. In vitro, estradiol increased Trx-1 level, but decreased the level of Txnip and oxidative stress in human umbilical vein endothelial cells (HUVECs) treated with IH for 16 hrs. Knock-down of Txnip by specific siRNA rescued oxidative stress and apoptosis. In conclusion, estradiol protects against IH-induced vascular injury, partially through the regulation of Trx-1/Txnip pathway.

Retinal Vascular Morphological Changes in Patients with Extremely Severe Obstructive Sleep Apnea Syndrome

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) has been shown to generate hypertension and endothelial dysfunction. Retinal vessel is the only vessel that can be observed directly and noninvasively; retinal vascular abnormalities can serve as a predictive marker for the occurrence, clinical course, and prognosis of cardiovascular and cerebrovascular diseases. The objective of this study was to identify the effect of OSAS severity on the morphological changes of retinal vessels.

METHODS

Adult patients complained of snoring were included in this study. The patients' general information, polysomnography, and fundus photography parameters including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole-to-venule ratio (AVR) were collected. Patients were divided into four groups according to their apnea-hypopnea index (AHI) results: Group I, AHI ≤5/h; Group II, 5/h < AHI ≤30/h; Group III, 30/h < AHI ≤60/h; and Group IV, AHI> 60/h.

RESULTS

A total of 133 patients were included in this study with 111 males (83.5%) and 22 females (16.5%). Mean age was 41.6 ± 9.9 years, and the mean body mass index was 28.1 ± 4.0 kg/m2. AHI ranged between 0 and 130.8/h with a mean of 39.1 ± 30.7/h. There were 24, 34, 35, and 40 patients in Group I, Group II, Group III, and Group IV, respectively. Significant differences were found for AHI (F = 388.368, P< 0.001), minimal pulse oxygen saturation (F = 91.902, P< 0.001), and arousal index (F = 31.014, P< 0.001) among four groups; no significant differences were found for CRAE (F = 0.460, P = 0.599) and CRVE (F = 0.404, P = 0.586) among groups; there were significant differences for AVR between Group I and Group IV (63.6 ± 5.1% vs. 67.2 ± 5.5%, P = 0.010) Group II and Group IV (64.5 ± 6.0% vs. 67.2 ± 5.5%, P = 0.030), and Group III and Group IV (64.7 ± 4.1% vs. 67.2 ± 5.5%, P = 0.043). A main group-by-AHI effect was found on the AVR: patients with higher AHI showed higher AVR results (r = 0.225, P = 0.009). Multivariate logistic regression analysis was used for multi-variable factors. A group-by-age effect was found on the AVR: younger patients showed higher AVR results (β = -0.001, P = 0.020).

CONCLUSIONS

This study indicated that increased AVR of retinal vessel can be observed in extremely severe OSAS patients. For patients with OSAS, retinal vascular abnormalities may become an early indication for further cardiovascular abnormalities.

Which Is the Ideal Marker for Early Atherosclerosis in Obstructive Sleep Apnea (OSA) - Carotid Intima-Media Thickness or Mean Platelet Volume?

BACKGROUND Obstructive sleep apnea (OSA) is known to be closely associated with cardiovascular disease. Carotid intima-media thickness (IMT) is widely used for assessment of atherosclerosis. Mean platelet volume (MPV) is a new marker associated with atherothrombosis. In this study, we aimed to detect early atherosclerosis by measuring carotid intima-media thickness and to investigate the relationship between MPV and IMT and OSA severity. MATERIAL AND METHODS The study population consisted of 158 patients who underwent polysomnography and did not have any overt cardiac disease or risk factors. Carotid IMT was measured by ultrasonography. Blood samples were taken for MPV determination. Subjects were divided into 4 groups according to OSA severity: control, mild, moderate, and severe OSA. RESULTS CONCLUSIONS OSA patients appear to have increased carotid IMT suggestive of an atherosclerotic process. Carotid IMT could be a more useful indicator than MPV in these patients. Long-term prospective studies are needed to confirm these results.

Assessment of carotid artery intima-media thickness in patients with obstructive sleep apnoea

OBJECTIVE

This study compares the carotid intima-media thickness (CIMT) in different severity of obstructive sleep apnoea (OSA) patients and assesses the role of OSA in carotid artery vasculopathy with control of multiple co-morbidities.

STUDY DESIGN

Prospective case-control study.

SETTING

Tertiary referral centre.

PARTICIPANTS

This study recruited 36 volunteers without the complaints of sleep-disordered breathing, 27 patients with mild-moderate OSA and 39 patients with severe OSA.

MAIN OUTCOME MEASURES

The CIMT was measured using a Toshiba Aplio 500 ultrasound system (Otawara, Japan) with a 5-14 MHz L probe.

RESULTS

Bilateral and mean CIMT in healthy control, mild-moderate OSA and severe OSA were 0.69 ± 0.14, 0.72 ± 0.24 and 0.94 ± 0.33, respectively (P < 0.01 in anova test). Post hoc tests show that the severe OSA group had significantly higher mean CIMT than the control and mild-moderate OSA groups (P < 0.01). With the cut-off as 1 mm, the increased risks of cardiovascular disease (CVD) for mild-moderate and severe OSA were 11% and 39%, respectively, while no patient in the healthy control group was at risk of CVD. Multivariate linear regression could not prove that OSA itself was an independent factors for increased CIMT (mild-moderate OSA β: 0, [-0.12, 0.13]; severe OSA β: 0.08, [-0.06, 0.22], both P > 0.05) after adjusting age, hypertension and body mass index.

CONCLUSION

Automated measurement of the CIMT can be a useful tool for CVD risk assessment in patients with OSA. Severity of OSA may be an intermediate factor between multiple co-morbidities and carotid atherosclerotic change.

Sleep and Breathing … and Cancer?

Sleep, like eating and breathing, is an essential part of the daily life cycle. Although the science is still emerging, sleep plays an important role in immune, cardiovascular, and neurocognitive function. Despite its great importance, nearly 40% of U.S. adults experience problems with sleep ranging from insufficient total sleep time, trouble initiating or maintaining sleep (Insomnia), circadian rhythm disorders, sleep-related movement disorders, and sleep-related breathing disorders such as obstructive sleep apnea (OSA). Herein, we discuss new evidence that suggests that sleep may also affect carcinogenesis. Specifically, we review recent epidemiologic data suggesting links between cancer and OSA. As OSA is a common, underdiagnosed, and undertreated condition, this has public health implications. Intriguing animal model data support a link between cancer and sleep/OSA, although mechanisms are not yet clear. Leaders in the fields of sleep medicine, pulmonology, and oncology recently met to review and discuss these data, as well as to outline future directions of study. We propose a multidisciplinary, three-pronged approach to studying the associations between cancer and sleep, utilizing mutually interactive epidemiologic studies, preclinical models, and early-phase clinical trials. Cancer Prev Res; 9(11); 821-7. ©2016 AACR.

The Association Between Obstructive Sleep Apnea and Carotid Intima-Media Thickness: A Systematic Review and Meta-Analysis

Obstructive sleep apnea (OSA) has been suggested as a risk factor for carotid atherosclerosis. The present meta-analysis aimed to evaluate the association between OSA and carotid intima-media thickness (CIMT). Eighteen studies comparing CIMT of patients with OSA versus non-OSA patients were included. Quantitative data synthesis was used to pool weighted standardized difference in means (SMD) of CIMT in a random-effects model. Compared to healthy controls, patients with OSA had a significantly higher CIMT (SMD: 0.881; 95% confidence interval [CI]: 0.647-1.115; P < .001). Due to the great heterogeneity, a subgroup analysis was conducted based on the study design. The pooled SMD of CIMT between patients with OSA and healthy controls were 0.810 (95% CI: 0.676-0.943; P < .001) and 1.008 (95% CI: 0.506-1.510; P < .001) in matched and unmatched group, respectively. Moreover, the correlation of apnea-hypopnea index and CIMT was moderate ( r = .389; 95% CI: 0.315-0.459; P < .001). After adjustment for several major confounders, OSA is an independent risk factor for CIMT. These findings remind clinicians to screen for cardiovascular diseases in patients with OSA.

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.

The effect of obstructive sleep apnea syndrome and hypothyroidism to intima-media thickness of carotid artery

AIM

Obstructive sleep apnea syndrome (OSAS) is a common disorder and in subjects with OSAS the prevalence of hypothyroidism is approximately 1.2-11 %. The episodes of hypoxia/reoxygenation associated with the respiratory disturbances observed in subjects with OSAS increases the risk of cardiovascular diseases. Hypothyroidism; primary or subclinical, has several effects on cardiovascular system. In our study, we investigated carotid artery intima-media thickness (IMT) which is an early sign of atherosclerosis, in OSAS subjects with hypothyroidism.

MATERIALS AND METHOD

Subjects who admitted to Kahramanmaras Necip Fazıl City State Hospital Chest Diseases out-patient clinic between May 2014 and January 2016 for snoring and had polysomnographic evaluation at the sleep laboratory were included in this study. Each subject was evaluated for serum thyroid function tests and carotid artery IMT was measured by a Doppler ultrasound.

RESULTS

Mean carotid artery IMT values in the isolated OSAS, OSAS plus hypothyroidism, and control groups were 0.67 ± 0.12, 0.8 ± 0.12, and 0.54 ± 0.08 mm, respectively; difference between groups was statistically significant (p < .05). A poXsitive correlation was found between thyroid stimulating hormone levels and IMT (r = 0.426, p = .002), while free T3 levels and IMT were negatively correlated (r = -0.463, p = .001). IMT and apnea-hypopnea index were also positively correlated (r = 0.403, p = .003).

CONCLUSION

We suggest, physicians should be alert for hypothyroidism comorbidity in OSAS, and suspected subjects with OSAS should be screened for hypothyroidism considering the potential cardiovascular complications.

Snoring as a Determinant Factor of Oxidative Stress in the Airway of Patients with Obstructive Sleep Apnea

PURPOSE

In obstructive sleep apnea-hypopnea syndrome (OSAS), airway collapses and vibrations cause local and systemic inflammatory response and oxidative stress (OS). Our objective was to determine the presence of OS in the airway of patients with OSAS compared with controls without OSAS and determine its relation to treatment with CPAP and other clinical variables.

METHOD

We performed a prospective observational case-control study with repeated measures. We recruited consecutive patients with SAHS diagnosed using complete polysomnography, and a parallel control group. We collected a sample of exhaled breath condensate (EBC) prior to nasal continuous positive airway pressure (CPAP) treatment and again after 4 months. The marker of OS used was 8-isoprostane (8-IPN). The variables analyzed were age, sex, anthropometric variables, apnea-hypopnea index (AHI), snoring, oxygenation, and polysomnographic variables.

RESULTS

The study included 20 patients and 10 controls. In cases, the initial value of 8-IPN was 6.8 (1.9), and after nasal CPAP, it was 5.3 (1.2) pg/ml (p = 0.02). In controls, the value of 8-IPN was 5.6 (1.1) pg/ml (p = 0.04 compared to initial values). 8-IPN showed significant correlation with snoring, AHI, BMI, nocturnal desaturation index, and non-REM sleep. On multivariate analysis, only snoring was a significant predictor of 8-IPN.

CONCLUSIONS

Snoring, and not OSAS severity, could be the phenomenon underlying the presence of local OS measured in the airway of patients with OSAS.

Three-year changes of prothrombotic factors in a cohort of South Africans with a high clinical suspicion of obstructive sleep apnea

A hypercoagulable state might be one important mechanism linking obstructive sleep apnea (OSA) with incident myocardial infarction and stroke. However, previous studies on prothrombotic factors in OSA are not uniform and cross-sectional. We longitudinally studied prothrombotic factors in relation to OSA risk, adjusting for baseline levels of prothrombotic factors, demographics, metabolic parameters, aspirin use, and life style factors. The Berlin Questionnaire and/or neck circumference were used to define high OSA risk in 329 South African teachers (48.0% male, 44.6% black) at baseline and at three-year follow-up. Von Willebrand factor (VWF), fibrinogen, D-dimer, plasminogen activator inhibitor-1, clot lysis time (CLT), and soluble urokinase-type plasminogen activator receptor (suPAR) were measured in plasma. At baseline 35.7% of participants had a high risk of OSA. At follow-up, persistently high OSA risk, persistently low OSA risk, OSA risk remission, and new-onset OSA risk were present in 26.1%, 53.2%, 9.4%, and 11.3% of participants, respectively. New-onset OSA risk was associated with a significant and longitudinal increase in VWF, fibrinogen, CLT, and suPAR relative to persistently low OSA risk; in VWF, fibrinogen, and suPAR relative to remitted OSA risk; and in VWF relative to persistently high OSA risk. Persistently high OSA risk was associated with an increase in CLT and suPAR relative to persistently low OSA risk and in D-dimer relative to remitted OSA risk. Remitted OSA risk was associated with D-dimer decrease relative to persistently low OSA risk. In OSA, hypercoagulability is a dynamic process with a most prominent three-year increase in individuals with new-onset OSA risk.