Objective Obstructive Sleep Apnea Research Articles

Assessment of Impact of Dietary Patterns on Obstructive Sleep Apnea Patients.

Objective  Obstructive sleep apnea syndrome (OSAS) is characterized by episodic cessations of breathing due to upper airway obstruction during sleep, which may cause disturbances in dietary patterns resulting from appetite-related hormonal changes. The aim of the present study was to investigate the relationship between OSAS and nutritional and dietary patterns. Materials and Methods  A total of 20 female and 53 male OSAS patients aged > 30 years were enrolled. Demographic data, as well as data on smoking and alcohol habits, were noted, anthropometric measures were made, and a questionnaire regarding chronic diseases including OSAS and four questionnaires on recent food intake frequency and content of nutrition were filled out. The content of nutrition was noted under seven categories: meat, legumes, milk and dairy products, fruits and vegetables, bread and cereals, fat and carbohydrates, and beverages. Results  The severity of OSAS (assessed by the apnea-hypopnea index. AHI) was positively correlated with the body mass index (BMI), the circumferences of the waist, chest, and buttocks, and, in males, with the circumference of the neck as well. There was no correlation between the AHI and nutritional habits in terms of the frequency of meals or snacks, the scores on the Snoring, Tiredness, Observed Apnea, and High Blood Pressure-Body Mass Index, Age, Neck Circumference, and Gender (STOP-BANG) Questionnaire and the corresponding macro- and micronutrients. Worsening apnea scores led to increased intake of macronutrients of carbohydrate and protein and micronutrients of niacin and pyridoxine ( p  < 0.05), and decreased intake of fat ( p  < 0.05). Conclusion  The present study demonstrated an association between OSAS severity and recent food intake, manifested in increased intake of carbohydrates, niacin, and pyridoxine, and decreased fat intake.

Are there any differences at gray matter sites between severe obstructive sleep apnea patients and healthy controls?

ObjectivesObstructive sleep apnea (OSA) is a disease that may cause many medical conditions. Neurocognitive disorders may be triggered by OSA. In recent studies, selectively decreased gray matter tissue was observed in patients with OSA. We aimed to determine if there was a substantial difference in patients with extreme OSA by comparing the microstructural changes in different gray matter sub-areas with healthy controls using diffusion-weighted imaging methods. MethodsWe studied 15 diagnosed severe OSA subjects before any treatment and 32 healthy control subjects. High resolution Magnetic Resonance Imaging (MRI) T1 and T2-weighted scans were visually examined to assess any major brain lesions. ResultsThere were no statistically significant differences of age and gender between the groups.The left and right globus pallidus, putamen and thalamus values did not differ significantly between OSA and control subjects. Right putamen values was negatively correlated with Apnea Hypopnea Index (AHI), supine AHI and non-REM AHI in OSA subjects, but no correlations appeared with left putamen values. The other gray matter parameters did not show any correlations with PSG parameters. AHI, Supine AHI, Non-Supine AHI, REM and NON-REM AHI values was not show any correlation with Right and Left Putamen volume sizes. ConclusionsWe made a morphological comparison of various gray matter areas of OSA patients and healthy volunteers in our study. We observed a significant decrease in right putamen gray matter volumes in patients with higher AHI values. Decreased cognitive functions are found in patients with OSA. In order to demonstrate this cognitive loss in patients with morphologically there is a need for further prospective studies with larger sample sizes.

Obstructive Sleep Apnea Plasma-Derived Exosomes Mediate Cognitive Impairment Through Hippocampal Neuronal Cell Pyroptosis

ObjectiveObstructive sleep apnea (OSA) is associated with impaired cognitive function. Exosomes are secreted by most cells and play a role in OSA-associated cognitive impairment (CI). The aim of this study was to investigate whether OSA plasma-derived exosomes cause CI through hippocampal neuronal cell pyroptosis, and to identify exosomal miRNAs in OSA plasma-derived. Materials and MethodsPlasma-derived exosomes were isolated from patients with severe OSA and healthy comparisons. Daytime sleepiness and cognitive function were assessed using the Epworth Sleepiness Scale (ESS) and the Beijing version of the Montreal Cognitive Assessment Scale (MoCA). Exosomes were coincubated with mouse hippocampal neurons (HT22) cells to evaluate the effect of exosomes on pyroptosis and inflammation of HT22 cells. Meanwhile, exosomes were injected into C57BL/6 male mice via caudal vein, and then morris water maze was used to evaluate the spatial learning and memory ability of the mice, so as to observe the effects of exosomes on the cognitive function of the mice. Western blot and qRT-PCR were used to detect the expressions of Gasdermin D (GSDMD) and Caspase-1 to evaluate the pyroptosis level. The expression of IL-1β, IL-6, IL-18 and TNF-α was detected by qRT-PCR to assess the level of inflammation. Correlations of GSDMD and Caspase-1 expression with clinical parameters were evaluated using Spearman's rank correlation analysis. In addition, plasma exosome miRNAs profile was identified, followed by Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. ResultsCompared to healthy comparisons, body mass index (BMI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and ESS scores were increased in patients with severe OSA, while lowest oxygen saturation during sleep (LSaO2), mean oxygen saturation during sleep (MSaO2) and MoCA scores were decreased. Compared to the PBS group (NC) and the healthy comparison plasma-derived exosomes (NC-EXOS), the levels of GSDMD and Caspase-1 and IL-1β, IL-6, IL-18 and TNF-α were increased significantly in the severe OSA plasma-derived exosomes (OSA-EXOS) coincubated with HT22 cells. Compared to the NC and NC-EXOS groups, the learning and memory ability of mice injected with OSA-EXOS was decreased, and the expression of GSDMD and Caspase-1 in hippocampus were significantly increased, along with the levels of IL-1β, IL-6, IL-18 and TNF-α. Spearman correlation analysis found that clinical AHI in HCs and severe OSA patients was positively correlated with GSDMD and Caspase-1 in HT22 cells from NC-EXOS and OSA-EXOS groups, while negatively correlated with clinical MoCA. At the same time, clinical MoCA in HCs and severe OSA patients was negatively correlated with GSDMD and Caspase-1 in HT22 cells from NC-EXOS and OSA-EXOS groups. A unique exosomal miRNAs profile was identified in OSA-EXOS group compared to the NC-EXOS group, in which 28 miRNAs were regulated and several KEGG and GO pathways were identified. ConclusionsThe results of this study show a hypothesis that plasma-derived exosomes from severe OSA patients promote pyroptosis and increased expression of inflammatory factors in vivo and in vitro, and lead to impaired cognitive function in mice, suggesting that OSA-EXOS can mediate CI through pyroptosis of hippocampal neurons. In addition, exosome cargo from OSA-EXOS showed a unique miRNAs profile compared to NC-EXOS, suggesting that plasma exosome associated miRNAs may reflect the differential profile of OSA related diseases, such as CI.

Sleep Apnea Among Gulf War Veterans: An Examination of VA Utilization Rates, Treatment Initiation, and Health Outcomes

ABSTRACT Objectives Obstructive sleep apnea (OSA) among veterans is frequently underdiagnosed and undertreated. The present study sought to: 1) characterize the prevalence and rate of treatment of OSA among VA users and non-users and 2) examine the associations between diagnosed or probable OSA and key physical and mental health outcomes. Methods Gulf-War I-era Veterans were recruited as part of a national survey assessing mental and physical health concerns, healthcare needs, and healthcare utilization. OSA diagnoses were self-reported while sleep apnea risk was assessed via the STOP-Bang. Veterans also completed questionnaires assessing overall health, pain, depression, PTSD, and psychosocial functioning. Results 1,153 veterans were included in the present analyses (Mean age = 58.81; 21.84% female). Compared to non-VA healthcare users, veterans receiving care at the VA were more likely to have been diagnosed with OSA (p < .001) and report receiving treatment for OSA (p = .005). Compared to veterans at low risk for OSA, veterans at elevated risk reported higher levels of pain (p = .001), depression (p = .02), and poorer psychosocial functioning (p < .001). Conclusions OSA diagnoses appear to be more common among VA healthcare users. Findings suggest that OSA remains underdiagnosed and associated with important physical and mental health consequences. Additional screening for OSA, especially among non-VA clinics, is warranted.

The role of the tongue in post-stroke dysphagia and obstructive sleep apnea: Correlation with sonography measurement

ObjectiveObstructive sleep apnea (OSA) is a common risk factor for stroke, and dysphagia and pneumonia are both well-known complications of stroke. The development of these conditions is related to the oropharyngeal structures. We investigated whether specific structural features of the tongue may lead to the development of these complications. MethodsPatients with ischemic stroke who required admission and community-dwelling elderly controls were enrolled. The participants underwent tongue measurements by received hand-held ultrasound, and received questionnaires to evaluate sleep quality and daytime sleepiness. The patient group also underwent objective sleep measurement by actigraphy and the 3-Step Swallowing Test (3-SSS). Sleep parameters and outcomes were analyzed. ResultsPatient with ischemic stroke had significantly thicker tongue than controls (6.53 cm v. 6.05 cm, p = 0.002). Multiple logistic regression analysis revealed that the anatomical parameters of the tongue in patients with stroke were significantly correlated with parameters of OSA, and the thickness of the tongue was positively correlated with the development of OSA (p = 0.024) and pneumonia (p = 0.048). ConclusionsA thicker-than average tongue may be a risk factor for OSA and pneumonia in patient with stroke. Hand-held ultrasound can be used to identify these anatomical features. Further studies are warranted to clarify the role of the tongue in these post-stroke complications.

The mediating role of coping styles in illness perception and self-management in patients with obstructive sleep apnea

Study objectivesObstructive sleep apnea (OSA) has become a chronic disease that threatens human health. Self-management in patients with OSA can influence their quality of life, and illness perception and coping styles are relevant facilitators of self-management, but this specific relationship has not been adequately studied. The purpose of this study was to investigate the current status and relationship between illness perception, coping styles, and self-management behaviors in patients with OSA, and how coping styles mediate this relationship. MethodsThis is a cross-sectional study. Conducted between September 2022 and March 2023, the study involved patients aged ≥18 years old in two hospitals who were diagnosed with OSA. The survey was conducted using the demographic characteristics questionnaire, the Brief Illness Perception Questionnaire, the Simple Coping Style Questionnaire, and the Self-management Behavior Questionnaire of patients with obstructive sleep apnea. Spearman’s correlation analysis was used for correlation analysis and multiple linear regression and structural equation models were used for mediation effect testing. ResultsThere were 282 valid questionnaires, with a 94 % valid response rate. Higher levels of self-management behaviors were associated with low negative illness perceptions, high positive coping, and low negative coping. The study also demonstrated that the mediating effect accounted for 25.65 % (−0.049/−0.191) of the overall effect. ConclusionIllness perceptions in OSA patients were negatively related to positive coping styles, positively related to negative coping styles, and negatively related to self-management. This study suggests that coping styles of OSA patients mediate illness perception and self-management.

Circadian blood pressure dysregulation in children with obstructive sleep apnea.

Obstructive sleep apnea (OSA) adversely affects normal blood pressure (BP) and may disrupt circadian BP patterns. We sought to examine 24-hour circadian BP rhythms in children with OSA and healthy controls. Children 5-14 years with OSA and healthy controls underwent 24-hour BP monitoring and actigraphy to quantify sleep. Shape invariant statistical models compared circadian BP patterns (e.g. times of BP peaks, time arrived at peak BP velocity [TAPV]) in the OSA and control groups. The analytic sample included 219 children (mild OSA: n = 52; moderate-to-severe OSA (MS-OSA): n = 50; controls: n = 117). In the morning, the MS-OSA group had earlier TAPV for DBP than controls (51 minutes, p < 0.001). TAPV in the evening was earlier for the MS-OSA group than controls (SBP: 95 minutes, p < 0.001; DBP: 28 minutes, p = 0.028). At mid-day, SBP and DBP velocity nadirs were earlier for the MS-OSA group than controls (SBP: 57 minutes, p < 0.001; DBP: 38 minutes, p < 0.01). The MS-OSA group reached most BP values significantly earlier than controls; the largest differences were 118 minutes (SBP) and 43 minutes (DBP) (p < 0.001). SBP and DBP were elevated in the MS-OSA group (hours 18-21 and 7--12, respectively, p < 0.01) compared to controls. The MS-OSA group was prone to "non-dipping" compared to controls (SBP: odds ratio [OR] = 2.16, 95% CI: 1.09, 4.29; DBP: OR = 3.45, 95% CI: 1.21, 10.23). Children with MS-OSA had changes in circadian BP patterns, namely earlier TAPV and BP peaks and nadirs than controls. Circadian disturbances in BP rhythms may be key to mapping the natural history of BP dysregulation in children with OSA.

Renal sympathetic denervation ameliorates the activated inflammatory response through JAK-STAT pathway in a chronic obstructive sleep apnea animal model

ObjectivesObstructive sleep apnea (OSA) is known to increase the risk of cardiovascular disease and inflammation plays a significant role in this process. Renal denervation (RDN) is a novel approach aimed at reducing sympathetic nervous system activity. The role of RDN in the inflammatory response to chronic OSA (COSA) is currently unclear. The main objective was to study inflammatory mechanisms in the rabbit heart with COSA and the effects of RDN. MethodsEighteen rabbits were randomized into three groups: sham control, COSA, and COSA-RDN. COSA and COSA-RDN groups received liquid silicone injections, while the sham control group received normal saline. We performed combined surgical and chemical RDN through bilateral retroperitoneal flank incisions in the COSA-RDN group after silicone injections. The inflammatory mechanisms were assessed through immunoblotting, real-time PCR, and ELISA after the experiment. ResultsH&E staining showed immune cell infiltration in COSA, which decreased after RDN treatment. The level of α7nAChR was significantly reduced in COSA compared to the sham control but was restored to a similar level in the COSA-RDN group. Furthermore, the expressions of p-JAK2 and p-STAT3 were significantly reduced in COSA but showed an up-regulation following RDN treatment. Similarly, levels of the inflammatory markers IL-6, IL-1β and TNF-α were markedly increased in COSA but decreased after RDN therapy. We observed NF-κB activation in the COSA rabbit model, which decreased after RDN treatment, as evidenced by decreased NF-κB expression. ConclusionsOur study suggests that RDN treatment may prevent COSA-associated heart inflammation via the JAK2-STAT3 signaling pathway.

Obstructive sleep apnea during rapid eye movement sleep and cognitive performance in adults

Study objectivesObstructive sleep apnea (OSA) during rapid eye movement (REM) sleep is often characterized with more frequent and lengthy breathing events and greater oxygen desaturation than during other sleep stages. Current evidence suggests an association between OSA and cognitive decline, however whether OSA during REM sleep plays a vital role in this link is understudied. MethodsA cross-sectional sample of 728 men and women (aged 59.1 ± 11.3 years) underwent a full night polysomnography for determining apnea-hypopnea index (AHI) and sleep stages. Trail Making Test (TMT) part A and B were conducted during the following day for assessing participants' cognitive function. Linear regression analyses were performed to test the possible association between AHI and AHI during REM sleep with TMT-A and B results. Similar analyses were carried out in a subsample involving participants aged ≥60 years with ≥30 min of REM sleep (n = 356). ResultsDespite a slight difference in TMT-B between participants with and without OSA (AHI ≥5 vs AHI <5, β-coefficient: 4.83, 95 % CI: [-9.44, −0.22], P = 0.040), no other association between AHI or REM-AHI and TMT results were found in the full sample. In older participants (aged ≥60 years), a REM-AHI ≥5 events/hour was associated with longer time taken to finish TMT-A (vs REM-AHI <5 events/hour, 3.93, [0.96, 6.90], P = 0.010). There was no association between REM-AHI and time taken to finish TMT-B in older participants. ConclusionsThe results indicate that OSA during REM sleep may be of particular concern for attention-related cognitive function in older adults.

Using entropy of snoring, respiratory effort and electrocardiography signals during sleep for OSA detection and severity classification

Study objectivesObstructive sleep apnea (OSA) is a very prevalent disease and its diagnosis is based on polysomnography (PSG). We investigated whether snoring-sound-, very low frequency electrocardiogram (ECG-VLF)- and thoraco-abdominal effort- PSG signal entropy values could be used as surrogate markers for detection of OSA and OSA severity classification. MethodsThe raw data of the snoring-, ECG- and abdominal and thoracic excursion signal recordings of two consecutive full-night PSGs of 86 consecutive patients (22 female, 53.74 ± 12.4 years) were analyzed retrospectively. Four epochs (30 s each, manually scored according to the American Academy of Sleep Medicine standard) of each sleep stage (N1, N2, N3, REM, awake) were used as the ground truth. Sampling entropy (SampEn) of all the above signals was calculated and group comparisons between the OSA severity groups were performed. In total, (86x4x5 = )1720 epochs/group/night were included in the training set as an input for a support vector machine (SVM) algorithm to classify the OSA severity classes. Analyses were performed for first- and second-night PSG recordings separately. ResultsTwenty-seven patients had mild (RDI = ≥ 5/h but <15/h), 21 patients moderate (RDI ≥15/h but <30/h) and 23 patients severe OSA (RDI ≥30/h). Fifteen patients had an RDI <5/h and were therefore considered non-OSA. Using SE on the above three PSG signal data and using a SVM pipeline, it was possible to distinguish between the four OSA severity classes. The best metric was snoring signal-SE. The area-under-the-curve (AUC) calculations showed reproducible significant results for both nights of PSG. The second night data were even more significant, with non-OSA (R) vs. light OSA (L) 0.61, R vs. moderate (M) 0.68, R vs. heavy OSA (H) 0.84, L vs. M 0.63, M vs. H 0.65 and L vs. H 0.82. The results were not confounded by age or gender. ConclusionsSampEn of either snoring-, very low ECG-frequencies- or thoraco-abdominal effort signals alone may be used as a surrogate marker to diagnose OSA and even predict OSA severity. More specifically, in this exploratory study snoring signal SampEn showed the greatest predictive accuracy for OSA among the three signals. Second night data showed even more accurate results for all three parameters than first-night recordings. Therefore, technologies using only parts of the PSG signal, e.g. sound-recording devices, may be used for OSA screening and OSA severity group classification.

The Cervical Fat Tissue Volume is a Predictor for Moderate to Severe OSA.

Objective  Obstructive sleep apnea (OSA) is a disorder characterized by recurrent pharyngeal obstruction during sleep, in which upper airway anatomy plays a key role in its pathogenesis. The aim of this study was to describe whether the quantification of cervical fat tissue volume (CFTV) obtained by Computed Tomography (CT)cephalometry is related to the severity of OSA. Methods  Retrospective study between 2018 and 2020 in those patients > 18 years old, with diagnosis of OSA who performed a volumetric cephalometric imaging. Three-dimensional reconstruction of the images was performed and CFTV was measured. Results  91 patients were included in this study of which: without OSA (n: 7), mild (n: 19), moderate (n: 39) and severe OSA (n: 26). We observed a progressive increase of CFTV related to OSA severity has been observed (without OSA: 58.9 ml (47.9-87.5), mild: 59.1ml (48.4-78.3), moderate: 71 ml (42.6-127.1) and severe OSA 103.6 ml (81-153); p < 0.01); nevertheless, no differences were found in the airway volume and neck area. It was showed a significant correlation between CFTV and OSA indicators: AHI, ODI and T90 (Sp r: 0.48; 0.38 and 0.36; p < 0.01 respectively). CFTV cut-off value to discriminate AHI >15 ev/h with best sensitivity-specificity relationship was 64.1 ml with an area under the curve of 0.6 ± 0.06. Multivariate analysis showed that CFTV is a predictor for moderate to severe OSA (OR:3.05, IC95%: 1.14-8.17). Conclusion  Cervical fat quantification by CT cephalometry correlates with OSA severity in adults. Fat volume > 64.1 ml increased more than three times the risk of OSA moderate to severe.

STOP-Bang and Smartwatch’s Two-Step Approach for Obstructive Sleep Apnea Screening

Background and Objectives Obstructive sleep apnea (OSA) is associated with various health risks, including hypertension, cerebrovascular disease, myocardial infarction, diabetes, cognitive impairment, and all-cause mortality. While overnight polysomnography (PSG) is the gold standard for diagnosing OSA, it is costly and time-consuming. The STOP-Bang questionnaire is a convenient tool for OSA screening, but its high sensitivity comes at the expense of low specificity. The purpose of this study was to investigate the usefulness of combining the STOP-Bang questionnaire and a smartwatch capable of measuring oxygen saturation in screening for OSA.Subjects and Method Of the patients scheduled for PSG due to OSA, 109 patients voluntarily participated in the study by filling out a STOP-Bang questionnaire during their first visit and wearing a smartwatch during PSG.Results There were 80 males and 29 females, with the patients’ mean age of 45±13.3 years. Based on the apnea-hypopnea index (AHI), 19 patients (17.4%) were normal, 28 (25.7%) had mild OSA, 23 (21.1%) had moderate OSA, and 39 (35.8%) had severe OSA. When using the AHI threshold of AHI ≥15/h, the STOP-Bang alone showed sensitivity of 85.5% and specificity of 61.7%. Combining the STOP-Bang questionnaire with a smartwatch resulted in a slight decrease in sensitivity and a significant increase in specificity, yielding the values of 80.5% and 84.4%, respectively.Conclusion A two-step approach using the STOP-Bang and a smartwatch was implemented to enhance the diagnostic accuracy of screening OSA.

Effect of nocturia in patients with different severity of obstructive sleep apnea on polysomnography: A retrospective observational study

ObjectiveObstructive sleep apnea (OSA) is one of the etiologies of nocturia. We analyzed polysomnography (PSG) results to determine correlated factors related to nocturia in OSA patients with different severity. MethodsPatients with suspected OSA were examined using PSG. They were divided into two groups based on the presence of nocturia. Nocturia was defined as a patient who needed to void at least once. Apnea–hypopnea index (AHI) was employed to classify patients according to degrees of severity: AHI<5, 5≤AHI<15, 15≤AHI<30, and AHI≥30, defined as normal, mild OSA, moderate OSA, and severe OSA, respectively. Demographic variables, PSG parameters, IPSSs, and quality of life scores due to urinary symptoms were analyzed. ResultsIn total 140 patients, 114 patients had OSA (48 had mild OSA; 34 had moderate OSA; and 32 had severe OSA) and 107 patients had nocturia. IPSS was significantly higher in nocturia patients in all groups except the group of severe OSA patients. With the increasing severity of OSA, more correlated factors related to nocturia were determined. In mild OSA patients, nocturia related to increased age (p=0.025), minimum arterial blood oxygenation saturation (p=0.046), and decreased AHI of non-rapid eye movement (p=0.047), AHI of total sleep time (p=0.010), and desaturation index (P=0.012). In moderate OSA patients, nocturia related to increased age (p<0.001), awake time (p=0.025), stage 1 sleep (p=0.033), and sleep latency (p=0.033), and decreased height (p=0.044), weight (p=0.025), and sleep efficiency (p=0.003). In severe OSA patients, nocturia related to increased weight (p=0.011), body mass index (p=0.009), awake time (p=0.008), stage 1 sleep (p=0.040), arousal number (p=0.030), arousal index (p=0.013), PLM number (p=0.013), and PLM index (p=0.004), and decreased baseline arterial blood oxygenation saturation (p=0.046). ConclusionOur study revealed that there were more correlated factors related to nocturia with increasing severity of OSA. This study helps in clinical education and treatment for OSA patients with different severity.

Is Obstructive Sleep Apnea a Risk Factor for Severe COVID-19?

Background and Objective Obstructive sleep apnea (OSA) is a breathing disorder during sleep with an obstruction of the upper airway. Previous studies showed OSA as a risk factor for severe COVID-19. It is crucial to determine the risk factors for the severity of COVID-19 infection. We aim to clarify the relationship between COVID-19 severity, and OSA and its degree.Methods Our case-control study included subjects diagnosed with OSA with polysomnography between January 2018 and November 2021, and a control group with a history of COVID-19 infection and without OSA diagnosis. The demographic data, comorbidities, apnea–hypopnea index, and oxygen desaturation index were recorded.Results A total of 217 patients were included in our study. The degree of OSA was a risk factor in the OSA group (p &lt; 0.05); on the other hand, the diagnosis of OSA by itself was not a risk factor. The apnea–hypopnea index and oxygen desaturation index were not related to the severity of COVID-19 infection (p &gt; 0.05). Diabetes mellitus was associated with increased hospitalization in inpatient clinics (p &lt; 0.05) and intensive care unit (ICU) (p &lt; 0.05). Chronic obstructive pulmonary disease was a risk factor for admission to the ICU (p &lt; 0.05).Conclusions Our results showed that moderate-to-severe OSA patients are a vulnerable population to severe COVID-19 infection, although diagnosis of OSA by itself was not a risk factor.

Characteristics of Patients With Severe Obstructive Sleep Apnea Who Maintain Slow-Wave Sleep

Background and Objectives Obstructive sleep apnea (OSA) is a complex sleep-related respiratory disorder with various pathophysiology and clinical manifestations. Diagnosis and treatment considering only the number of respiratory events, such as sleep duration, may have limitations. The purpose of this study is to analyze the clinical and polysomnography (PSG) characteristics of patients with severe OSA in whom slow wave sleep (SWS) was well-maintained.Subjects and Method This study retrospectively analyzed 203 patients who underwent PSG due to suspected OSA. Severe OSA patients were classified into a SWS maintained group (SWS≥15%) and a SWS reduced group (SWS&lt;15%), and their clinical records, PSG results, and heart rate variability (HRV) were compared.Results The SWS maintained group (n=27), compared to the SWS reduced group (n=58), had a significantly longer total sleep time (&lt;i&gt;p&lt;/i&gt;=0.027) and lower wake after sleep onset (&lt;i&gt;p&lt;/i&gt;=0.001), rapid eye movoement (REM) latency (&lt;i&gt;p&lt;/i&gt;=0.007), non-supine apnea-hypopnea index (AHI, &lt;i&gt;p&lt;/i&gt;=0.006), non-REM AHI (&lt;i&gt;p&lt;/i&gt;&lt;0.001), arousal index (&lt;i&gt;p&lt;/i&gt;&lt;0.001) and Epworth Sleepiness Scale (&lt;i&gt;p&lt;/i&gt;=0.048). In addition, the SWS maintained group had a significantly low value in very low frequency in HRV than that of the SWS reduced group (&lt;i&gt;p&lt;/i&gt;=0.046).Conclusion The SWS maintained group in the severe OSA showed better PSG and HRV results and reduced daytime sleepiness than those of the SWS reduced group.

Alterations of brain gray matter volume in children with obstructive sleep apnea.

Obstructive sleep apnea (OSA) seriously affects the children's cognitive functions, but the neuroimaging mechanism of cognitive impairment is still unclear. The purpose of our study was to explore the difference in brain local gray matter volume (GMV) between children with OSA and non-OSA, and the correlation between the difference regions of brain gray matter volume and cognitive, the severity of OSA. Eighty-three children aged 8-13 years were recruited in our study, 52 children were diagnosed as OSA by polysomnography, and 31 as the non-OSA. All the subjects were underwent high-resolution 3-dimensional T1-weighted magnetic resonance images. The voxel-based morphometry (VBM) was be used to analyse the local GMV. The Das-Naglieri cognitive assessment system (DN: CAS) was used to assess the subjects' cognitive. The difference of local GMV between the two groups was analyzed by two-sample T-test. The PSG variables and the scores of DN: CAS between the OSA group and non-OSA group were compared by independent samples t-tests. Pearson correlation was used to calculate the association between the difference areas of gray matter volumes in brain and DN: CAS scores, obstructive apnea/hypopnea index (OAHI, an index of the severity of OSA). The gray matter volume of the right Middle Frontal Gyrus (MFG_R) in OSA children were larger than the non-OSA children, and the OSA children had lower scores of the Word Series in DN: CAS. There was negative correlation between the scores of Expressive Attention in DN: CAS and the gray matter volume of the right middle frontal gyrus, and it was no significantly correlation between OAHI and the gray matter volume of the right middle frontal gyrus. Our results suggest that the development of gray matter volume in frontal cortex, which associated with attention, were sensitive to the effects of OSA, provides neuroimaging evidence for cognitive impairment in children with OSA.

Effects of Continuous Positive Airway Pressure on White Matter Microstructure in Patients With Obstructive Sleep Apnea

Background and Objective Obstructive sleep apnea (OSA) has significant effects on quality of life and may lead to cognitive impairments. Continuous positive airway pressure (CPAP) is the standard treatment for OSA and has been shown to improve sleep disturbances and daytime dysfunction. In this study, we aimed to assess the effects of CPAP on white matter (WM) integrity using longitudinal diffusion tensor imaging (DTI) tests.Methods Twenty-two male patients with moderate to severe OSA were recruited, and thepatients underwent DTI scanning before and 6–44 months after CPAP treatment. Sixteen male patients with untreated OSA who were not compliant with CPAP were included as a reference group. We compared the functional anisotropy (FA) values between baseline and follow-up magnetic resonance imaging in both the CPAP and untreated groups using tract-specific statistical analysis (TSSA) method.Results The TSSA analysis showed that FA values in the middle part of the right corticospinal tract were increased after treatment in the CPAP group. In the untreated group, no significant change in FA value was observed between baseline and follow-up. In the CPAP group, the post-treatment FA value in the anterior part of the right anterior thalamic radiation was significantly correlated with the duration of CPAP therapy, after controlling for age, body mass index, and baseline FA value.Conclusions Our study suggests that long-term CPAP treatment could gradually reverse OSA-induced injury to the WM microstructure, particularly WM associated with the motor and limbic systems. The study findings provide new insights into the mechanisms of cognitive improvement after CPAP treatment in patients with OSA.

Estimates of 10-year risk of cardiovascular death and adherence to cardiovascular risk factor management in Danish patients investigated for obstructive sleep apnea

ObjectiveObstructive sleep apnea (OSA) increases the risk of cardiovascular disease (CVD) in both morbidity and mortality. We used the risk chart of Systemic Coronary Risk Evaluation (SCORE) from European Society of Cardiology (ESC) to determine the 10-year risk of cardiovascular death, and adherence to cardiovascular risk factor management in Danish patients investigated for obstructive sleep apnea. Research design and methodsIn a prospective cohort study, 303 patients with mild, moderate and severe OSA were investigated for cardiovascular risk factors before initiating CPAP therapy. Primary outcome was estimates of 10-year risk of cardiovascular death assessed from the ESC risk chart SCORE based on sex, age, smoking status, systolic blood pressure and s-total cholesterol. Furthermore we analyzed treatment indication with statins in patients with mild (apnea-hypopnea index, AHI <15), moderate (AHI 15–29.9) and severe OSA (AHI ≥30). ResultsPatients with mild OSA predominately had low or moderate 10-year risk of CVD (low risk 55.4%, moderate risk 30.8%) while patients with moderate and severe OSA were more likely to have high or very high risk of 10-year CVD (p = 0.001). The large majority of included OSA patients had dyslipidemia, 235 (77.6%) and of those, only 27.4% were treated with cholesterol lowering drugs while additional 27.7% were eligible for oral statin supplement as risk-estimated by the ESC SCORE. In multiple regression analysis among statin naive patients, AHI was positively associated with statin eligibility when adjusted for age and sex. ConclusionPatients with moderate and severe OSA had an elevated 10-year risk of fatal CVD and were undertreated with CVD risk lowering agents such as statins.

Relationship of obstructive sleep apnea with periodontal condition and its local and systemic risk factors

ObjectiveObstructive sleep apnea (OSA) and periodontitis share risk factors, such as age, obesity, stress, and cardiovascular events, which have a bidirectional cause-effect relationship through systemic inflammation. Our objective was to determine the relationship between OSA and the periodontal condition and its associated local and systemic risk factors.Material and methodsThis was an observational case-control study involving 60 patients. Local oral risk factors and the systemic condition of each patient were evaluated. All patients underwent polysomnography for the diagnosis of OSA. Chi-squared, one-way ANOVA, and Bonferroni’s tests were performed.ResultsA higher percentage of patients with periodontitis had severe OSA (66.66%); however, no statistically significant association was found between the two pathologies (p = 0.290). In terms of systemic risk factors, an association was found between arterial hypertension and severe OSA (p = 0.038), and in terms of local factors, an association was found between the use of removable prostheses and severe OSA (p = 0.0273).ConclusionIn the general population, patients with periodontitis showed a higher prevalence of severe OSA. Obesity and hypothyroidism were the most prevalent systemic findings in patients with OSA and periodontitis. Arterial hypertension and osteoarthritis were found to be associated with severe OSA. The local risk factors associated with periodontitis and severe OSA were removable partial dentures and misfit resins.Clinical relevanceTo study the factors that can facilitate the progression of OSA and periodontitis, physicians and dentists should be advised to provide comprehensive care for patients with both pathologies.

The protective role of Nrf2 on cognitive impairment in chronic intermittent hypoxia and sleep fragmentation mice

ObjectiveObstructive Sleep Apnea Hypopnea Syndrome (OSAHS) is a sleep respiratory disease associated with cognitive impairment, The nuclear factor erythroid 2 related factor 2 (Nrf2) plays a neuroprotective role. This study was designed to investigate the mechanism of Nrf2 protecting neural cells from endoplasmic reticulum stress (ERS), induced by chronic intermittent hypoxia (CIH) and sleep fragmentation (SF) which caused cognitive impairment in mice. MethodsEstablishment of CIH and SF mice to simulate OSAHS mouse model. An eight-arm maze behavior test measured the cognitive function of mice, and Nissl staining and TUNEL staining were used to detect pathological changes in hippocampal neurons. The expression of ERS and Nrf2 and its downstream related mRNAs and proteins were detected by qRT-PCR and Western blotting. ResultsCIH and SF lead to cognitive impairment in mice, and Sulforaphane (SFN, Nrf2 agonist) plays a protective role, while Nrf2-KO aggravates the cognitive impairment. CIH and SF reduced the number of Nissl bodies in neurons and induced apoptosis. The mRNA levels of BiP, CHOP, Nrf2, GCLC and Prdx1 in CIH, SF and CIH + SF groups were increased (p = 0.001), whereas the mRNA levels of BiP and CHOP in the CIH + SF + SFN group were decreased (p = 0.02) while those of Nrf2 and Prdx1 were increased (p = 0.005). The CIH + SF + Nrf2-KO group, the mRNA levels of CHOP were increased (p = 0.001) while Nrf2, GCLC and Prdx1 were decreased (p = 0.001). The protein levels of CHOP and active Caspase-12 in CIH, SF, CIH + SF and CIH + SF + Nrf2-KO groups were increased (p = 0.03), while those of Prdx1 and Nrf2 were increased (p = 0.03) in the CIH + SF + SFN group, while decreased (p = 0.02) in the Nrf2-KO group. ConclusionsChronic intermittent hypoxia(CIH) and sleep fragmentation(SF) could aggravate the inflammatory response of nerve cells through endoplasmic reticulum stress, leading to apoptosis of nerve cells, and causing cognitive impairment in mice.Nrf2 alleviates cognitive impairment induced by chronic intermittent hypoxia and sleep fragmentation by modulating endoplasmic reticulum stress. Activation of Nrf2 protects cognitive impairment through the Nrf2-Prdx1 signaling pathway.