Severe Obstructive Sleep Apnea Patients Research Articles

‘Selected’ Exosomes from Sera of Elderly Severe Obstructive Sleep Apnea Patients and Their Impact on Blood–Brain Barrier Function: A Preliminary Report

Obstructive sleep apnea syndrome (OSAS) affects a large part of the aging population. It is characterized by chronic intermittent hypoxia and associated with neurocognitive dysfunction. One hypothesis is that the blood–brain barrier (BBB) functions could be altered by exosomes. Exosomes are nanovesicles found in biological fluids. Through the study of exosomes and their content in tau and amyloid beta (Aβ), the aim of this study was to show how exosomes could be used as biomarkers of OSAS and of their cognitive disorders. Two groups of 15 volunteers from the PROOF cohort were selected: severe apnea (AHI > 30) and control (AHI < 5). After exosome isolation from blood serum, we characterized and quantified them (CD81, CD9, CD63) by western blot and ELISAs and put them 5 h in contact with an in vitro BBB model. The apparent permeability of the BBB was measured using sodium-fluorescein and TEER. Cell ELISAs were performed on tight junctions (ZO-1, claudin-5, occludin). The amount of tau and Aβ proteins found in the exosomes was quantified using ELISAs. Compared to controls, OSAS patients had a greater quantity of exosomes, tau, and Aβ proteins in their blood sera, which induced an increase in BBB permeability in the model and was reflected by a loss of tight junction’ expression. Elderly patients suffering severe OSAS released more exosomes in serum from the brain compartment than controls. Such exosomes increased BBB permeability. The impact of such alterations on the risk of developing cognitive dysfunction and/or neurodegenerative diseases is questioned.

Factors Affecting Daily Functioning in Turkish Patients with Obstructive Sleep Apnea.

Background and Objectives: This study aims to examine the factors affecting the daily functioning of patients with obstructive sleep apnea (OSA). Materials and Methods: In addition to the polysomnography records of 361 patients, participants completed the Turkish FOSQ-10 (Functional Outcomes of Sleep-10), Medical Outcome Survey Short Form-12, Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). First, the psychometrics properties of the Turkish FOSQ-10 were evaluated. Then, factors affecting daily functioning were examined through univariate and multivariate analyses. Results: Of all participants, 68.7% (n = 248) were male, and the average age was 47.94 ± 11.08. According to the OSA category, 23% (n = 83) were mild, 22.7% (n = 82) were moderate, 45.2% (n = 163) were severe, and 9.1% (n = 33) were OSA negative. The Turkish FOSQ-10 was found to be a valid and reliable scale through validity and reliability analyses. The moderate and severe OSA patients had different FOSQ-10 Total scores compared to the negative OSA group. Daily functioning was positively associated with overall quality of life while inversely associated with depression, being anxious, and daytime sleepiness in OSA patients. In a multiple regression model, BDI, mental component summary-12, physical component summary-12, and ESS scores were significantly related to the FOSQ-10 Total score in OSA patients (p < 0.05). Conclusions: The daily functioning of moderate and severe OSA patients was worse than that of the negative OSA group. Depression, quality of life, and daytime sleepiness were simultaneously important variables associated with daily functioning in OSA patients.

Assessing Cognitive Impairments in Obstructive Sleep Apnea Patients Using Montreal Cognitive Assessment (MoCA) Scores.

Obstructive Sleep Apnea (OSA) is a chronic condition associated with cognitive impairment and various comorbidities. This prospective study evaluated cognitive deficits in OSA patients and identified clinical factors affecting cognitive function. Seventy-two participants were assessed using polysomnography (PSG) and the Montreal Cognitive Assessment (MoCA). Findings revealed significantly lower MoCA scores in severe OSA patients compared to those with mild or moderate OSA. Severe OSA patients had a median MoCA score of 23.5 (20.0-25.0), indicating more significant cognitive impairment, while those with normal OSA severity had the highest median score of 28.5 (27.8-29.2). Mild and moderate OSA patients had median scores of 26.5 (21.0-28.0) and 25.0 (23.80-26.0), respectively (p < 0.008). Logistic regression showed that ex-smoking status negatively impacted MoCA scores more in the unadjusted model (p = 0.003) than in the adjusted one (p = 0.018). Forced Vital Capacity (FVC) positively correlated with MoCA scores, stronger in the unadjusted model (p < 0.001 vs. p < 0.03). Higher Oxygen Desaturation Index (ODI) correlated with higher MoCA scores while increasing Apnea-Hypopnea Index (AHI) severity correlated with lower MoCA scores in both models. A significant negative correlation was found between age and MoCA score (r = -0.473, p < 0.001), and between MoCA score and AHI (r = -0.350, p < 0.003). This study highlights the need for sensitive cognitive screening tools like MoCA inevaluating OSA patients, linking cognitive impairment closely with OSA severity and other clinical factors.

Long-term effect of obstructive sleep apnoea management on blood pressure in patients with resistant hypertension: the SARAH study.

There is a close relationship between obstructive sleep apnoea (OSA) and resistant hypertension (RH). However, studies assessing the long-term effect of diagnosing and treating OSA on blood pressure (BP) control in these patients are lacking. To address this gap, we recruited 478 RH patients from hypertension units and followed them prospectively after they were screened for OSA through a sleep study. By performing 24-h ambulatory BP monitoring (ABPM) annually, the effect of OSA management was assessed. The patients had a median (interquartile range (IQR)) age of 64.0 (57.2-69.0) years, 67% were males and most were nonsleepy, with a median (IQR) apnoea-hypopnoea index (AHI) of 15.8 (7.9-30.7) events·h-1. The median (IQR) follow-up time was 3.01 (2.93-3.12) years. At baseline, severe OSA was associated with uncontrolled BP, nocturnal hypertension and a nondipper circadian BP pattern. Moreover, these patients had higher BP values during follow-up than did patients in the other groups. However, among patients with moderate and severe OSA, the management of sleep disordered breathing, including the implementation of continuous positive airway pressure treatment, was associated with a reduction in 24-h ABPM parameters, especially night-time BP values, at the 1-year follow-up. These benefits were attenuated over time and only subjects with severe OSA maintained an ABPM night-time reduction at 3 years. Furthermore, clinical variables such as uncontrolled BP, sex and age showed a predictive value for the BP response at 1 year of follow-up. A favourable long-term decrease in BP was detected by diagnosing and treating OSA in a cohort of RH patients from hypertension units, but over time this decrease was only partially maintained in severe OSA patients.

Gefapixant as a P2X3 receptor antagonist treatment for obstructive sleep apnea: a randomized controlled trial.

Obstructive sleep apnea (OSA) is a highly prevalent disorder with serious health consequences but limited therapeutic options. For a subset of those with OSA, a key underlying mechanism is hypersensitive chemoreflex control of breathing. There is no approved therapy that targets this endotypic trait. Here we determine whether the P2X3 receptor antagonist gefapixant, which is predicted to attenuate hypersensitive carotid chemoreflexes, reduces OSA severity in patients with chemoreflex-dependent OSA. In a randomized placebo-controlled cross-over study, 24 patients with moderate-to-severe OSA (aged 39-68 years, non-CPAP users) whose disorder was partially responsive to supplemental oxygen (chemoreflex-dependent OSA) were treated with gefapixant 180 mg (or placebo) administered as tablets taken orally before bedtime for 7 days and assessed via overnight polysomnography. The primary analysis examined whether gefapixant treatment resulted in a greater reduction in the apnea-hypopnea index (AHI) from baseline than placebo. Gefapixant did not lower the AHI significantly more than placebo; the estimated ratio of the AHI on gefapixant versus placebo was 0.92 [90% CI: 0.73, 1.17]. Notably, nocturnal hypoxemia was increased (ratio of total sleep time with SpO2 <90% on gefapixant versus placebo = 2.08 [90% CI: 1.53, 2.82]), consistent with reduced chemoreflex output. Commonly reported adverse events with gefapixant included ageusia, dysgeusia, oral hypoaesthesia, nausea, somnolence, and taste disorders. Gefapixant, while generally well tolerated, did not reduce OSA severity in patients with chemoreflex-dependent OSA. P2X3 receptor antagonism is unlikely to provide an avenue for therapeutic intervention in OSA. Registry: ClinicalTrials.gov; Name: Safety and Tolerability of Gefapixant (MK-7264) in Participants With Obstructive Sleep Apnea (MK-7264-039); URL: https://clinicaltrials.gov/study/NCT03882801; Identifier: NCT03882801.

Melatonin mediates intestinal barrier dysfunction and systemic inflammation in moderate-severe OSA patients

Background Intestinal barrier dysfunction and systemic inflammation are common in obstructive sleep apnoea (OSA). We aimed to investigate the role of melatonin, an anti-inflammatory mediator, in mediating the relationships between OSA, intestinal barrier dysfunction and systemic inflammation. Methods Two hundred and thirty-five male participants who complained with sleep problems and underwent whole night polysomnography at our sleep centre between 2017 and 2018 were enrolled. Polysomnographic data, anthropometric measurements and biochemical indicators were collected. Serum melatonin, intestinal barrier function biomarker zonula occludens-1 (ZO-1) and inflammatory biomarkers C-reactive protein (CRP) with lipopolysaccharide (LPS) were detected. Spearman’s correlation analysis assessed the correlations between sleep parameters, melatonin and biomarkers (ZO-1, LPS and CRP). Mediation analysis explored the effect of OSA on intestinal barrier dysfunction and systemic inflammation in moderate-severe OSA patients. Results As OSA severity increased, serum melatonin decreased, whereas ZO-1, LPS and CRP increased. Spearman’s correlation analysis showed that serum melatonin was significantly negatively correlated with ZO-1 (r = −0.19, p < .05) and LPS (r = −0.20, p < .05) in the moderate-OSA group; serum melatonin was significantly negatively correlated with ZO-1 (r = −0.46, p < .01), LPS (r = −0.35, p < .01) and CPR (r = −0.30, p < .05) in the severe-OSA group. Mediation analyses showed melatonin explain 36.12% and 35.38% of the effect of apnoea–hypopnea index (AHI) on ZO-1 and LPS in moderate to severe OSA patients. Conclusions Our study revealed that melatonin may be involved in mediating intestinal barrier dysfunction and systemic inflammation in moderate-to-severe OSA patients.

Correlation between Heart Rate Variability and Disease Severity in Obstructive Sleep Apnea

Objective: This study aimed to investigate the variations in Heart Rate Variability (HRV) among individuals with Obstructive Sleep Apnea (OSA) and to explore the relationship between HRV, respiratory parameters, and disease severity. Methods: This prospective study included sixty participants diagnosed with OSA. Polysomnography (PSG) was utilized to assess HRV parameters, including time-domain and frequency-domain measures. Participants were categorized based on the severity of OSA, and data on hemoglobin (HGB), C-reactive protein (CRP), triglyceride (TG) levels, and nocturnal oxygen desaturation (NOD) were collected. Statistical analyses were performed to evaluate the correlations between HRV, respiratory parameters, and disease severity. Results: Among the participants, 23 (38%) had severe OSA, while 17 (28%) were habitual snorers (HS). Hemoglobin, C-reactive protein, and triglyceride levels were significantly higher in patients with severe OSA and NOD compared to HS individuals (p=0.002). Increased Epworth Sleepiness Scale (ESS) scores were associated with higher heart rates during sleep in severe OSA patients compared to HS individuals. NOD (+) patients exhibited statistically higher heart rates during sleep compared to NOD (-) patients (p=0.008). Individuals with an apnea/hypopnea index (AHI) &gt;30, NOD (+), and the lowest SpO2 percentage overnight had significantly lower HRV compared to HS and NOD (-) individuals. Conclusions: In addition to AHI, NOD and the lowest overnight SpO2 are significant markers of elevated cardiovascular risk and are useful for assessing HRV. These findings suggest that cardiovascular risks in OSA patients are heightened both during sleep and wakefulness. Therefore, individuals with severe symptoms, especially those with excessive daytime sleepiness, high levels of NOD, and low nocturnal SpO2 percentages, should be prioritized for treatment, alongside those with high levels of severe OSA.

Correlation Between Body Mass Index and Apnea-Hypopnea Index or Nadir Oxygen Saturation Levels in Patients With Obstructive Sleep Apnea.

Apnea-hypopnea index (AHI) and nadir oxygen saturation (SpO2) are the indexes used to measure the severity of obstructive sleep apnea (OSA). Obesity, measured by body mass index (BMI), is one of the main contributing factors to the onset and severity of OSA in patients. This study was conducted to find the association between BMI and OSA severity indexes, mainly AHI and nadir SpO2 levels. Polysomnography reports of patients with diagnosed OSA in a teaching hospital were retrospectively reviewed. BMI, AHI, and nadir SpO2 levels were recorded from the sleep study reports of the patients. Spearman's Rho test was applied to find the correlation between BMI and AHI/nadir Spo2 levels. A total of 167 patients were included in the study, comprising 83 males and 84 females. The Mann-Whitney U test was utilized to investigate the association between BMI and gender and age groups. The analysis revealed a significant difference in BMI between males and females, with females having a higher BMI. However, there was no significant difference in BMI among individuals in the early middle and late middle age groups. Spearman's Rho test was employed to explore the correlation between BMI and AHI/nadir SpO2 levels. The results indicated no significant correlation between BMI and AHI (p= .122) or nadir SpO2 levels (p= .239). Contrary to common belief, BMI was not linked to the severity of OSA. It implies that several other factors, independent of BMI, play a role in the disease progression and severity.

Cluster Headache Characteristics and the Severity of Obstructive Sleep Apnea: Insights from Polysomnography Analysis

Purpose: Cluster headache (CH) is characterized by circadian rhythmicity of the attacks, and it is known to respond exceptionally well to oxygen therapy. Furthermore, obstructive sleep apnea (OSA) frequently co-occurs with CH, and both conditions may be parallel outcomes of hypothalamic dysfunction rather than being causally related. The aim of this study was to analyze the association between CH characteristics and polysomnographic factors stratified by the severity of OSA in patients diagnosed with CH and OSA.Methods: We retrospectively analyzed the data of OSA patients with CH who were enrolled in the Korean Cluster Headache Registry and underwent polysomnography due to clinical suspicion of OSA. Basic demographic data, headache-related parameters, and polysomnographic parameters were analyzed according to the severity of OSA (apnea-hypopnea index: &lt;15 or ≥15 per hour).Results: Twelve CH patients with OSA were evaluated. The onset age of CH was higher (38.5 years vs. 19.0 years, p=0.010), and the maximal duration of cluster bouts was longer (156.5 days vs. 47.0 days, p=0.037) in the moderate-to-severe OSA group than in the mild OSA group. Unlike other polysomnographic parameters, the apnea-hypopnea index and respiratory arousal index during rapid eye movement (REM) sleep were comparable across different OSA severity levels.Conclusion: The onset age and duration of cluster bouts were associated with the severity of OSA in CH patients. Additionally, the relatively high susceptibility to hypoxia during REM sleep in patients with mild OSA implies that interventions may be potentially advantageous, even in CH patients with mild OSA.

Association Between Obstructive Sleep Apnea (OSA) Severity and Optimal Continuous Positive Airway Pressure (CPAP); Do Severe OSA Patients Always Need High CPAP Pressure?

Objective: Obstructive sleep apnea (OSA) is a prevalent sleep disorder associated with an increased risk of cardiovascular disease. Severity of OSA is assessed using the apnea-hypopnea index (AHI), but the optimal continuous positive airway pressure (CPAP) does not always correlate proportionally with AHI. This study aims to identify factors leading to the need for high CPAP pressure despite low AHI or vice versa.Methods: The study includes 91 patients diagnosed with OSA through polysomnography. Participants undergoing CPAP titration were categorized in three groups based on AHI (30/h) and optimal CPAP pressure (10 cm H&lt;sub&gt;2&lt;/sub&gt;O); low AHI and high CPAP pressure group (LH group), high AHI and low CPAP pressure group (HL group), direct proportion group (DP group). The Kruskal–Wallis nonparametric statistical test is used to identify significant differences between the three groups.Results: Among the subjects, 78% were male, with no significant age or BMI differences between groups. There were 36 (39.6%) subjects with mild to moderate OSA and 55 (60.4%) subjects with severe OSA. The study revealed that patients requiring high CPAP pressure despite low AHI (LH group) had lower AHI, oxygen desaturation index, and various other parameters compared to other groups as expected. However, certain factors like the percentage of hypopnea in AHI, limb movement (LM) arousal index, and spontaneous arousal index were higher in the LH group.Conclusion: Patients with mild to moderate OSA requiring high CPAP pressure are more likely associated with specific aspects such as hypopnea in AHI, LM arousal, and spontaneous arousal index, presenting unpredictable outcomes.

Obstrüktif Uyku Apnede (OUA) Ortalama Trombosit Hacmi (OTH) ve OUA'da Sürekli Pozitif Hava Yolu Basıncı (CPAP) Tedavisinin OTH Üzerine Etkisi

Aims: In this study, our objective was to evaluate mean platelet volume (MPV), an indirect marker of platelet activation, in patients with obstructive sleep apnea (OSA), and assess the effect of OSA treatment with continuous positive airway pressure (CPAP) on MPV&#x0D; Methods: In this study, records of consecutive patients who underwent polysomnographic evaluation for OSA symptoms in the Sleep Disorders Laboratory during a one-year period were reviewed retrospectively. Patients who had both complete blood count and MPV measurements were included in the study.&#x0D; Results: A total of 158 patients, including 51 females (32.3%) and 107 males (67.7%), were included in the study. The mean age of the patients was 51±13 (min-18, max-82) years. OSA was detected in 74.1% (117/158) of the patients. It was determined that as the severity of OSA increased, hemoglobin and hematocrit values increased significantly. There was no significant difference in platelet count according to the presence and severity of OSA. The MPV was significantly lower in severe OSA cases compared to those without OSA and mild OSA cases. A negative correlation was observed between MPV and the apnea-hypopnea index, desaturation index, and the amount of oxygen saturation below 90% during sleep. There was no significant difference in median erythrocyte and thrombocyte counts, hematocrit percentage and hemoglobin values before and after treatment in OSA patients who used CPAP therapy. However, a significant decrease in MPV was observed after OSA treatment compared to pre-treatment. (p=0.021).&#x0D; Conclusions: The results of the study do not support an increase in MPV and hence platelet activation in severe OSA patients compared with those without OSA. However, the results suggest that one month of CPAP treatment reduces MPV and thus platelet activation in severe OSA patients. Further controlled, prospective studies including treatment outcomes are needed on this subject.

Nocturnal gastro-oesophageal reflux and respiratory symptoms are increased in sleep apnoea: comparison with the general population

AimTo assess respiratory symptoms and nocturnal gastro-oesophageal reflux (nGER) among untreated obstructive sleep apnoea (OSA) patients, compared with the general population. Also, if nGER associates differently with respiratory symptoms among...

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.

Physical discomfort and longer sleep time important influencing factors in CPAP adherence in moderate and severe obstructive sleep apnea patients

Physical discomfort and longer sleep time important influencing factors in CPAP adherence in moderate and severe obstructive sleep apnea patients

The Epworth sleepiness scale may have more advantages than the multiple sleep latency test in assessing sleepiness in patients with obstructive sleep apnea.

This study aimed to analyze the brain function of severe obstructive sleep apnea patients with various sleepiness assessment methods and explore the brain imaging basis for the differences between these methods. This study included 30 severe obstructive sleep apnea patients and 19 healthy controls. Obstructive sleep apnea patients were divided into a subjective excessive daytime sleepiness group and a subjective non-excessive daytime sleepiness group according to the Epworth sleepiness scale. Moreover, they were divided into an objective excessive daytime sleepiness group and an objective non-excessive daytime sleepiness group according to the multiple sleep latency test. The fractional amplitude of low-frequency fluctuation was used to assess the features of brain function. Compared with healthy controls, participants in the subjective excessive daytime sleepiness group exhibited higher fractional amplitude of low-frequency fluctuation signals in the right thalamus, left cerebellar lobe 6, left putamen, and pallidum. Participants in the objective excessive daytime sleepiness group showed higher fractional amplitude of low-frequency fluctuation signals in the right thalamus and lower fractional amplitude of low-frequency fluctuation signals in the right superior frontal gyrus, the dorsolateral and superior frontal gyrus, and the medial orbital. We concluded that the thalamus may be involved in subjective and objective sleepiness regulation. Functional abnormalities in the putamen and pallidum may be involved in subjective sleepiness, whereas the frontal lobe may be involved in objective sleepiness.

The relationship between aerodynamic characteristics of the upper airway and severity of obstructive sleep apnea in adults

ABSTRACT Objective To investigate the relationship between aerodynamic characteristics of theupper airway and severity of obstructive sleep apnea (OSA)in adults. Methods Ninety-seven adult OSA patients underwent polysomnography and cone beam computedtomography (CBCT). The anatomical and aerodynamic characteristics were measuredbased on CBCT images and computational fluid dynamics modelling of the upper airway. Results Aftercontrolling for patients’ gender, age, and body mass index (BMI), the maximumvelocity during inspiration (In-Vmax) led to the largest increase in theexplanatory power of apnea-hypopnea index (AHI) variation. The In-Vmax was closely correlated with theminimum axial area, and their relationship was represented by an inverselyproportional fitted curve. Conclusions TheIn-Vmax was the most relevant to OSA severity, and it could be used to assistin recognizing severe OSA patients and as a primary variable to evaluate treatmentoutcomes of OSA. The In-Vmax was closely related to the most constricted areaof the upper airway.

Urinary metabolite signatures reflect the altered host metabolism in severe obstructive sleep apnea

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder. The onset and progression of OSA are often linked with severe cardiovascular and metabolic comorbidities. At the same time, given the increasing prevalence of OSA, novel methods to screen OSA and its follow-up are needed. Untargeted metabolic profiling of OSA patients and healthy controls was planned to capture a snapshot of urinary metabolites and potential biomarkers using the gas chromatography-mass spectrometry (GC–MS) method.Polysomnography (PSG) confirmed severe OSA patients with AHI index ≥ 30 were considered for urine sample collection. The sample size was constituted of OSA (n = 36) and healthy controls (n = 36). Metabolite extraction and derivatization were performed and metabolomic analysis was performed by using GC–MS.The obtained data set was statistically analyzed using univariate and multivariate analysis. The Orthogonal partial least-squares discriminant analysis (OPLS-DA) was performed to screen differential metabolites between OSA patients and healthy controls.The metabolomic analysis revealed a total of 142 significantly altered metabolites of interest.Biomarker analysis allows for the creation of a list of putative urinary biomarkers including GABA, malic acid, glutamic acid, epichoric acid etc., with an accuracy of 99.8 % to 100 % for OSA screening. Subsequently, pathway analysis revealed that related biochemical pathways like the tricarboxylic acid cycle (TCA), glutamate/glutamine, amino acid and fatty acid metabolism, that are significantly interlinked with these metabolic biomarkers can play a crucial role in the pathogenesis of OSA. This study paves the way to undertake mass screening in a larger population to identify specific and reliable biomarkers.

Characteristics of genioglossus neuromuscular activity in patients with obstructive sleep apnea during drug-induced sleep

Objective: To analyze genioglossus (GG) activation responses to the negative pressure of upper airway cavity during awake and different sleep stages in patients with different obstructive sleep apnea (OSA) graduation. Methods: This prospective cohort study started from August 2019 to January 2021, recruited 42 male OSA patients aged from 21 to 59 (38.77±8.42) years. After completing whole night polysomnography (PSG) and upper airway CT, each subject underwent drug-induced sleep with simultaneous monitoring of genioglossal electromyography (GGEMG) and pressure of epiglottis (Pepi). Subjects were divided into three groups of mild OSA(7 males), moderate OSA(12 males), and severe OSA(23 males). The differences in upper airway CT measurements, parameters of GGEMG and Pepi during awake and induced sleep were compared. Statistical analysis was conducted by SPSS 21.0. Results: There was no significant difference in the GGEMG parameters between the mild and moderate groups. In wakefulness, the peak phasic GGEMG of the severe group was higher than the mild group (t=1.249, P=0.025), with no statistically difference in the corresponding Pepi. In the sleep onset, the GGEMG parameters and Pepi in severe group were higher than the other two groups. Linear regression analysis of the maximum GGEMG and maximum Pepi at the end of obstructive apnea (OA) in all moderate plus severe patients (n=35) was shown nonlinear correlation (r=0.28, P=0.694). The airway length of the glossopharyngeal cavity was linearly correlated with the maximum Pepi of OA (r=0.468, R2=0.219, P=0.005). Conclusions: The individual difference of GG activation in OSA patients is related to the severity of the disease (frequency of respiratory events) and negative pressure stimulation. In moderate and severe OSA patients, GG activity is not in harmony with the corresponding negative pressure stimulation, which may be one of the mechanisms leading to the aggravation of OSA.

Triglyceride-glucose index as a predictor of obstructive sleep apnoea severity in the absence of traditional risk factors.

We evaluated the association between the triglyceride-glucose (TG) index, a marker of insulin resistance, and obstructive sleep apnoea (OSA) severity in patients without diabetes mellitus, obesity, and metabolic syndrome. This retrospective cohort study included 1,527 patients. We used univariate and multivariate analyses to identify the independent predictors associated with OSA. Most patients were males (81.5%) with a mean age of 43.9 ± 11.1 (15-90) years. Based on the apnoea-hypopnea index (AHI), 353 (23.1%) patients were included in the control group, whereas 32.4%, 23.5%, and 21% had mild, moderate, and severe OSA, respectively. The TG index values demonstrated significant associations with OSA patients compared with the control group (p = 0.001). In addition, the mean values of the oxygen desaturation index (ODI), AHI, minimum oxygen saturation, and total sleep time percentage with saturation below 90% demonstrated statistically significant differences among the TG index groups (p: 0.001; p:0.001; p:0.001; p:0.003). The optimal TG index cutoff value to predict OSA was 8.615 (AUC = 0.638, 95% CI = 0.606-0.671, p = 0.001). In multivariate logistic regression analysis, after adjusting for age, sex, and body mass index, the TG index was independently associated with OSA patients. The TG index is independently associated with increased risk for OSA. This indicates that this index, a marker for disease severity, can be used to identify severe OSA patients on waiting lists for PSG.

A Novel Clinical Tool to Detect Severe Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is a disease with high morbidity and is associated with adverse health outcomes. Screening potential severe OSA patients will improve the quality of patient management and prognosis, while the accuracy and feasibility of existing screening tools are not so satisfactory. The purpose of this study is to develop and validate a well-feasible clinical predictive model for screening potential severe OSA patients. We performed a retrospective cohort study including 1920 adults with overnight polysomnography among which 979 cases were diagnosed with severe OSA. Based on demography, symptoms, and hematological data, a multivariate logistic regression model was constructed and cross-validated and then a nomogram was developed to identify severe OSA. Moreover, we compared the performance of our model with the most commonly used screening tool, Stop-Bang Questionnaire (SBQ), among patients who completed the questionnaires. Severe OSA was associated with male, BMI≥ 28 kg/m2, high blood pressure, choke, sleepiness, apnea, white blood cell count ≥9.5×109/L, hemoglobin ≥175g/L, triglycerides ≥1.7 mmol/L. The AUC of the final model was 0.76 (95% CI: 0.74-0.78), with sensitivity and specificity under the optimal threshold selected by maximizing Youden Index of 73% and 66%. Among patients having the information of SBQ, the AUC of our model was statistically significantly greater than that of SBQ (0.78 vs 0.66, P = 0.002). Based on common clinical examination of admission, we develop a novel model and a nomogram for identifying severe OSA from inpatient with suspected OSA, which provides physicians with a visual and easy-to-use tool for screening severe OSA.