Obstructive Sleep Apnea Patients Research Articles

0544 The Impact of Telemedicine on Continuous Positive Airway Pressure Adherence in Obstructive Sleep Apnea Patients

0544 The Impact of Telemedicine on Continuous Positive Airway Pressure Adherence in Obstructive Sleep Apnea Patients

0503 The Impact of Health Disparities on Access to Care for Obstructive Sleep Apnea Patients: A Retrospective Study

0503 The Impact of Health Disparities on Access to Care for Obstructive Sleep Apnea Patients: A Retrospective Study

0538 Healthcare Resource Utilization in Treated Obstructive Sleep Apnea Patients with Comorbid Insomnia

0538 Healthcare Resource Utilization in Treated Obstructive Sleep Apnea Patients with Comorbid Insomnia

Burden of obstructive sleep apnea in patients with lung cancer and its effect on performance status.

The association between lung cancer and obstructive sleep apnea has remained a matter of debate for years. Obstructive sleep apnea is thought to increase the incidence of lung cancer due to intermittent hypoxaemia and sleep fragmentation. The aim of this study is to assess the prevalence of obstructive sleep apnea in patients with lung cancer and its effect on those patients' performance status. This is a prevalence study that was conducted at Chest Diseases Department, Alexandria Main University Hospitals. We enrolled 153 patients with lung cancer. All patients underwent cardiorespiratory monitoring using a home sleep-testing device. Performance status was assessed using Karnofsky performance status scale. The study included 120 (78.4%) males and 33 (21.6%) females newly diagnosed with lung cancer. The mean age was 59.98 ± 11.11 years. Obstructive sleep apnea (apnea-hypopnea index ≥ 5) was present in 134 (87.6%) patients. Eighty-five (63.4%) patients had mild obstructive sleep apnea, 39 (29.1%) patients had moderate obstructive sleep apnea, and 10 (7.46%) patients had severe obstructive sleep apnea. Prolonged nocturnal oxygen desaturation as demonstrated by time of oxygen saturation spent below 90% (T90%) during total sleep time > 30% was present in 25 (16.3%) patients. There was a significant difference in the median value of Karnofsky performance status scale between patients with lung cancer and associated obstructive sleep apnea and those without obstructive sleep apnea. In conclusion, obstructive sleep apnea is highly prevalent among patients with lung cancer. Performance status is worse among patients with lung cancer in the presence of obstructive sleep apnea. Screening patients with lung cancer for obstructive sleep apnea is important regardless of the presence of classical symptoms of obstructive sleep apnea.

Comorbidity of depression and anxiety with obstructive sleep apnea in a sample of Egyptian patients

Abstract Background Over the past 2 decades, sleep researchers have made significant advances in understanding sleep disorders including obstructive sleep apnea (OSA). OSA commonly coexists with psychiatric disorders encompassing mental health issues like depression, anxiety, bipolar, schizophrenia an others. This study aims to assess the comorbidity of OSA with depression and anxiety disorders among Egyptian patients. During the study, we conducted a cross-sectional study involving 92 adults diagnosed with OSA. Those patients were interviewed using a checklist to gather information regarding their chief complaints and other associated symptoms. The psychological status was assessed utilizing the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID I), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI) scoring. The severity of the breathing disorder was classified as mild, moderate, or severe based on the respiratory disturbance index (RDI), which was confirmed through overnight polysomnography. Daytime sleepiness was assessed by the Epworth Sleepiness Scale (ESS). Results The sample of patients as a whole shows that witnessed apneas represent the highest percentage (70.7%), followed by fatigue (69.6%), then non-refreshing sleep (67.4%), and snores (63.0%). The least frequent presenting symptom is frequent naps. The majority of OSA patients have a comorbid psychiatric disorder (65.0%). Among these, depressive disorders are the most prevalent (31.5%), followed by anxiety disorders (23.9%) and psychoses (6.5%). It is worth noting that 38% of OSA patients do not have any psychiatric disorders. In terms of anxiety disorders, the most common subtype observed is OCD (8.7%), followed by GAD (6.5%), panic (5%), and PTSD (3.3%). As regards depressive disorders, the predominant subtype present is depressive disorder not otherwise specified (11.9%), followed by dysthymic disorder and major depressive disorder (8.7% for each), and then bipolar disorder (depression) at 2.2%. Conclusions We conclude the following: 1. OSA patients are likely to present with comorbid depression and/or anxiety disorder(s). 2. Fatigue was found to be the most prevalent presenting symptom in OSA patients with comorbid anxiety compared to those without anxiety.

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: <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.

Correlation of Headache Frequency and Intensity with the Risk of Obstructive Sleep Apnea in Patients with Idiopathic Intracranial Hypertension (P10-12.007)

Correlation of Headache Frequency and Intensity with the Risk of Obstructive Sleep Apnea in Patients with Idiopathic Intracranial Hypertension (P10-12.007)

Predictive factors and screening strategy for obstructive sleep apnea in patients with advanced multiple sclerosis

BackgroundObstructive sleep apnea (OSA) screening questionnaires have been evaluated in Multiple Sclerosis (MS) but not yet validated in patients with advanced disease. The aim of this study is to identify OSA predictive factors in advanced MS and to discuss screening strategies. MethodsOximetry data from 125 patients were retrospectively derived from polysomnographic reports. Univariate and multivariate analysis were used to determine predictive factors for OSA. A two-level screening model was assessed combining the oxygen desaturation index (ODI) and a method of visual analysis. Resultsmultivariate analysis showed that among the clinical factors only age and snoring were associated with OSA. Usual predictive factors such as sleepiness, Body mass index (BMI) or sex were not significantly associated with increased Apnea Hypopnea Index (AHI). The ODI was highly predictive (p < 0.0001) and correctly identified 84.1 % of patients with moderate OSA and 93.8 % with severe OSA. The visual analysis model combined with the ODI did not outperform the properties of ODI used alone. ConclusionAs the usual clinical predictors are not associated with OSA in patients with advanced MS, questionnaires developed for the general population are not appropriate in these patients. Nocturnal oximetry seems a pertinent, ambulatory and accessible method for OSA screening in this population.

Excessive daytime sleepiness is associated with relative delta frequency power among patients with mild OSA.

Excessive daytime sleepiness (EDS) is a cause of low quality of life among obstructive sleep apnoea (OSA) patients. Current methods of assessing and predicting EDS are limited due to time constraints or differences in subjective experience and scoring. Electroencephalogram (EEG) power spectral densities (PSDs) have shown differences between OSA and non-OSA patients, and fatigued and non-fatigued patients. Therefore, polysomnographic EEG PSDs may be useful to assess the extent of EDS among patients with OSA. Patients presenting to Israel Loewenstein hospital reporting daytime sleepiness who recorded mild OSA on polysomnography and undertook a multiple sleep latency test. Alpha, beta, and delta relative powers were assessed between patients categorized as non-sleepy (mean sleep latency (MSL) ≥10 min) and sleepy (MSL <10 min). 139 patients (74% male) were included for analysis. 73 (53%) were categorized as sleepy (median MSL 6.5 min). There were no significant differences in demographics or polysomnographic parameters between sleepy and non-sleepy groups. In multivariate analysis, increasing relative delta frequency power was associated with increased odds of sleepiness (OR 1.025 (95% CI 1.024-1.026)), while relative alpha and beta powers were associated with decreased odds. The effect size of delta PSD on sleepiness was significantly greater than that of either alpha or beta frequencies. Delta PSD during polysomnography is significantly associated with a greater degree of objective daytime sleepiness among patients with mild OSA. Further research is needed to corroborate our findings and identify the direction of potential causal correlation between delta PSD and EDS.

T266M variants of ANGPTL4 improve lipid metabolism by modifying their binding affinity to acetyl-CoA carboxylase in obstructive sleep apnea

Background Angiopoietin-like protein 4 (ANGPTL4) is recognized as a crucial regulator in lipid metabolism. Acetyl-CoA carboxylases (ACACAs) play a role in the β-oxidation of fatty acids. Yet, the functions of ANGPTL4 and ACACA in dyslipidemia of obstructive sleep apnea (OSA) remain unclear. Methods This study included 125 male OSA subjects from the Shanghai Sleep Health Study (SSHS) who were matched for age, body mass index (BMI), and lipid profile. Serum ANGPTL4 levels were measured via ELISA. The ANGPTL4 T266M variants of 4455 subjects along with their anthropometric, fasting biochemical, and standard polysomnographic parameters were collected. Linear regression was used to analyze the associations between quantitative traits and ANGPTL4 T266M. Molecular docking and molecular dynamic simulation were employed to compare the effects of the wild-type ANGPTL4 and its T266M mutation on ACACA. Results Serum ANGPTL4 levels significantly decreased with increasing OSA severity (non-OSA: 59.6 ± 17.4 ng/mL, mild OSA: 50.0 ± 17.5 ng/mL, moderate OSA: 46.3 ± 15.5 ng/mL, severe OSA: 19.9 ± 14.3 ng/mL, respectively, p = 6.02 × 10−16). No associations were found between T266M and clinical characteristics. Molecular docking indicated that mutant ANGTPL4 T266M had stronger binding affinity for the ACACA protein, compared with wild-type ANGPTL4. In terms of protein secondary structure, mutant ANGTPL4 T266M demonstrated greater stability than wild-type ANGPTL4. Conclusions Serum ANGTPL4 levels were significantly decreased in OSA patients, particularly among individuals with severe OSA. Although functional ANGTPL4 T266M variants were not associated with lipid levels in OSA, ANGTPL4 T266M could enhance binding affinity for the ACACA protein, potentially regulating lipid metabolism.

Desmin gene expression is not ubiquitous in all upper airway myofibers and the pattern differs between healthy and sleep apnea subjects

BackgroundDesmin is a major cytoskeletal protein considered ubiquitous in mature muscle fibers. However, we earlier reported that a subgroup of muscle fibers in the soft palate of healthy subjects and obstructive sleep apnea patients (OSA) lacked immunoexpression for desmin. This raised the question of whether these fibers also lack messenger ribonucleic acid (mRNA) for desmin and can be considered a novel fiber phenotype. Moreover, some fibers in the OSA patients had an abnormal distribution and aggregates of desmin. Thus, the aim of the study was to investigate if these desmin protein abnormalities are also reflected in the expression of desmin mRNA in an upper airway muscle of healthy subjects and OSA patients.MethodsMuscle biopsies from the musculus uvulae in the soft palate were obtained from ten healthy male subjects and six male patients with OSA. Overnight sleep apnea registrations were done for all participants. Immunohistochemistry, in-situ hybridization, and reverse transcription–quantitative polymerase chain reaction (RT–qPCR) techniques were used to evaluate the presence of desmin protein and its mRNA.ResultsOur findings demonstrated that a group of muscle fibers lacked expression for desmin mRNA and desmin protein in healthy individuals and OSA patients (12.0 ± 5.6% vs. 23.1 ± 10.8%, p = 0.03). A subpopulation of these fibers displayed a weak subsarcolemmal rim of desmin accompanied by a few scattered mRNA dots in the cytoplasm. The muscles of OSA patients also differed from healthy subjects by exhibiting muscle fibers with reorganized or accumulated aggregates of desmin protein (14.5 ± 6.5%). In these abnormal fibers, the density of mRNA was generally low or concentrated in specific regions. The overall quantification of desmin mRNA by RT–qPCR was significantly upregulated in OSA patients compared to healthy subjects (p = 0.01).ConclusionsOur study shows evidence that muscle fibers in the human soft palate lack both mRNA and protein for desmin. This indicates a novel cytoskeletal structure and challenges the ubiquity of desmin in muscle fibers. Moreover, the observation of reorganized or accumulated aggregates of desmin mRNA and desmin protein in OSA patients suggests a disturbance in the transcription and translation process in the fibers of the patients.

Relationship between OSA pathophysiological phenotypes and treatment response to mandibular advancement devices: a pilot study.

We assessed whether critical pathophysiological phenotypes predict treatment response in patients with obstructive sleep apnea using a mandibular advancement device (MAD). Thirty-one patients with obstructive sleep apnea were treated with a MAD. Individuals were categorized and graded into 4 pathophysiological phenotypes based on polysomnographic features (anatomical, ventilatory control, arousal threshold, and muscle responsiveness). Morpho-anthropometric data were additionally assessed. Patients were classified as responders or nonresponders. Associations between polysomnographic phenotypes and treatment response were documented, as were morpho-anthropometric data and their impact on therapeutic success. There was a male predominance (64.5%), with a median age of 49 years (25th percentile: 40; 75th percentile: 55), body mass index = 27.4 kg/m2 (25th percentile: 26; 75th percentile: 28.8), and apnea-hypopnea index of 18.2 events/h (25th percentile: 11.7; 75th percentile: 27.6). The majority of patients treated with a MAD (58%) were good responders (68.0% mild and moderate vs 16.7% severe). Treatment response was associated with shorter intermolar and interpremolar distances in the lower arch (P = .0092 and .0129). Rapid eye movement sleep apnea-hypopnea index and MAD-related treatment response were inversely correlated (P = .0013). Favorable anatomical (P = .0339) and low muscle response (P = .0447) phenotypes were correlated with outcomes. According to our results, a favorable response occurred in a better "anatomical phenotype" and in the worse "muscular responsiveness phenotype" according to polysomnographic data. Furthermore, other favorable predictors, such as a rapid eye movement sleep apnea-hypopnea index < 16 events/h and a smaller distance between lower molars and premolars, were found. These findings indicate that clinical and polysomnographic aspects can discriminate phenotypes that may guide decisions on MAD treatment for obstructive sleep apnea. Manetta IP, Duarte BB, Nucci LB, Enes CC. Relationship between OSA pathophysiological phenotypes and treatment response to mandibular advancement devices: a pilot study. J Clin Sleep Med. 2024;20(8):1321-1330.

Attention and executive function impairments in obstructive sleep apnea are associated with decreased sleep spindles.

Sleep spindles play a key role in sleep-mediated cognitive processes. Cognitive functions are well-known to be affected in obstructive sleep apnea (OSA). Here, we analyzed attention and executive functions in patients with OSA and investigated the relationship between sleep spindles and cognitive abilities. Sixty patients with OSA (18-65years, 19 females and 41 males) and a control group (n = 41) including age-and sex-matched healthy individuals were consecutively and prospectively enrolled. All participants had a full-night polysomnography, and sleep spindles were analyzed using a semi-automated program. For the evaluation of short-term memory, attention and executive functions, Stroop test, forward and backward digit span tests were applied to all participants upon awakening following polysomnography. Scores of forward and backward digit span and Stroop tests were worse in OSA patients in compared to those in controls. Mean density of sleep spindles was decreased in OSA patients than those in controls (p = 0.044). A positive correlation was found between fast sleep spindle frequency and forward digit span (r = 2.222; p = 0.038) and backward digit span test scores (r = 2,157; p = 0.042) in OSA patients. In patients with moderate to severe OSA, sleep spindle density was positively correlated with forward (r = 2.323, p = 0.029) and backward (r = 2.500, p = 0.016) DSTs, and the duration of sleep spindles had positive correlation with backward DST (r = 2.452, p = 0.010). Our findings demonstrated that the disturbances in sleep spindle characteristics in OSA are associated with the cognitive impairments in attention, short-term memory, and executive functions, especially in patients with moderate to severe OSA.

A Prospective Study of Role of Functional MRI in Suspects of Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) syndrome, characterized by daytime impairment, affects approximately 1 in 20 adults and can lead to a range of behavioral and cardiovascular abnormalities. Understanding the underlying causes and identifying the specific obstructions within the upper airway is crucial for effective management of this condition. Sleep MRI has emerged as a valuable tool in accurately diagnosing OSA by providing detailed insights into the level, magnitude, and type of obstruction present in affected individuals. One of the key observations made through sleep MRI studies is the increased collapsibility of the velopharynx in apneic patients, particularly during sleep. This heightened collapsibility predisposes the airway to occlusion, contributing to the repetitive breathing pauses characteristic of OSA. By visualizing the dimensions and configurations of the upper airway during both wakefulness and sleep, sleep MRI enables clinicians to pinpoint structural and dynamic factors that play a role in the development and progression of OSA. Moreover, the information gleaned from sleep MRI scans can inform the development of personalized treatment strategies for OSA patients. By identifying specific anatomical abnormalities and dynamic changes in the upper airway, clinicians can tailor interventions such as continuous positive airway pressure (CPAP), oral appliances, or surgical procedures to address the underlying causes of obstruction more effectively. Sleep MRI serves as a powerful diagnostic tool in the management of OSA, offering detailed anatomical and functional insights that guide treatment planning and optimization. Its ability to uncover structural and dynamic factors contributing to airway obstruction enhances our understanding of OSA pathophysiology and facilitates targeted therapeutic interventions aimed at improving patient outcomes and quality of life.

Evaluation of daytime sleepiness and insomnia symptoms in OSA patients with a characterization of symptom-defined phenotypes and their involvement in depression comorbidity

IntroductionRecent studies have emphasized the importance of clinical manifestations, such as insomnia and sleepiness, in defining phenotypes of obstructive sleep apnea (OSA), shifting from a focus on OSA severity and sleep structure.ObjectivesThe study aimed to characterize insomnia and sleepiness associated with OSA phenotypes and assess their involvement in depression symptoms (DS) in OSA.Methods A total of 181 participants undergoing polysomnography (PSG) were asked to fill out questionnaires, including Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Back Depression Index (BDI). They were categorized into phenotypes: insomnia-sleepiness (I+S; ESS≥11; ISI≥15; n=20), sleepiness (S; ESS≥11; ISI&lt;15; n=22), insomnia (I; ESS&lt;11; ISI≥15) and asymptomatic (A; ESS&lt;11; ISI&lt;15; n=55).ResultsA linear regression model for BDI score (R2=0.357, p&lt;0.001) included ISI score and subjective to objective sleep latency ratio. ISI score was a predictive factor for mild and moderate DS (OR=1.226, p&lt;0.001 and OR=1.392, p=0.002, respectively). I and I+S phenotypes are characterized by higher BDI scores (p&lt;0.001 and p=0.015), longer subjective sleep latency (p=0.008 and p=0.041), and shorter subjective total sleep time (TST; p=0.049 and p=0.006), compared to A. Furthermore, the I and I+S groups had shorter subjective TST than S (p=0.028 and p=0.047). I and I+S had higher BDI scores than A (p&lt;0.001 and p=0.015, respectively) and S (p&lt;0.001 and p=0.017, respectively). I phenotype was associated with the risk of mild and moderate DS (OR=5.614, p&lt;0.001 and OR=9.550, p=0.008 respectively). Moreover, the I+S phenotype presented an even greater risk for mild DS (OR=10.286, p&lt;0.001).ConclusionsThe study suggests that using clinical features for OSA phenotyping holds promise for finding OSA individuals with increased risk for the occurrence of DS.Disclosure of InterestNone Declared

Assessment of the Epworth Sleepiness Scale, Pediatric Sleep Questionnaire, and Mallampati Score in Children With Obstructive Sleep Apnea: An Observational Study

Background and Objective Individuals diagnosed with obstructive sleep apnea (OSA) experience recurrent episodes of breathing cessation due to blockage of the upper airway during sleep. This study aimed to assess the Pediatric Sleep Questionnaire (PSQ) scores, Epworth Sleepiness Scale (ESS) scores, and Mallampati score in pediatric patients with OSA, compared with non-OSA.Methods An observational study was conducted on 100 pediatric female patients aged 9-13 years with retrognathic mandible. The participants were subjected to PSQ, ESS, and Mallampati score to assess the size and shape of the patient’s tongue and esophageal airway. Finally, polysomnographic examination was carried out for all the participants and they were divided into two groups: Group 1 (50 patients) who were diagnosed with OSA by polysomnography and Group 2 (50 patients) consisting of non-OSA patients. Chi-square and Mann–Whitney U test were applied to compare scores between the two groups.Results The mean PSQ, ESS, and Mallampati scores of participants were 0.78 ± 0.45, 9.86 ± 2.47, and 2.27 ± 0.98, respectively in Group 1 and 0.24 ± 0.03, 7.27 ± 2.39, and 1.32 ± 0.57, respectively in Group 2, and this difference was statistically significant (p &lt; 0.05). PSQ, ESS, and Mallampati scores had specificity of 100%, 95.5%, and 72.7%, respectively, whereas the sensitivity was 45.5%, 22.7%, and 63.6%, respectively. ESS scores ≥ 10, PSQ scores ≥ 0.3, and Mallampati scores ≥ 2 were indicative of OSA.Conclusions Patients with OSA having retrognathic mandible had higher PSQ, ESS, and Mallampati scores compared to healthy individuals without OSA. Mallampati score can be satisfactorily used for screening OSA patients.

Indications for Dental Specialists for Treating Obstructive Sleep Apnea with Mandibular Advancement Devices: A Narrative Review.

Obstructive sleep apnea (OSA) syndrome is characterized by repeated airway collapse during sleep. It determines cardiovascular, pulmonary, and neurocognitive consequences and is associated with several daytime and nighttime symptoms that influence the patient's quality of life. The contribution of the dental specialist in the clinical management of OSA patients entails participating in the screening process as diagnostic sentinels and providing adequate treatment using mandibular advancement devices (MADs). Since the treatment of OSA requires a multidisciplinary approach, including different medical specialists, dentists should have a comprehensive understanding of medical and dental factors that influence the strategy and effectiveness of OSA treatment with MAD. Such expertise is crucial in determining the appropriate treatment indications and helps clinicians establish a consolidated position within the multidisciplinary OSA team. In this regard, this review summarizes the evidence of the clinical indications for MAD treatment and provides the dental specialist with helpful information about medical, functional, and other relevant factors that should be considered during diagnosis, treatment plan, and follow-up stages. Information retrieved was organized and discussed, generating specific domains/queries oriented to the clinical management of OSA patients from the clinical perspective of dental specialists.

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.

Polysomnographic airflow shapes and site of collapse during drug-induced sleep endoscopy.

Differences in the pharyngeal site-of-collapse influences efficacy of non-CPAP therapies for obstructive sleep apnoea (OSA). Notably, complete concentric collapse at the palate (CCCp) during drug-induced sleep endoscopy (DISE) is associated with reduced efficacy of hypoglossal nerve stimulation, but CCCp is currently not recognisable using polysomnography. Here we develop a means to estimate DISE-based site-of-collapse using overnight polysomnography. 182 OSA patients provided DISE and polysomnography data. Six polysomnographic flow-shape characteristics (mean during hypopnoeas) were identified as candidate predictors of CCCp (primary outcome variable, N=44/182), including inspiratory skewness and inspiratory scoopiness. Multivariable logistic regression combined the six characteristics to predict clear presence (N=22) versus absence (N=128) of CCCp (partial collapse and concurrent tongue-base collapse excluded). Odds ratios for actual CCCp between predicted subgroups were quantified after cross-validation. Secondary analyses examined complete lateral wall, tongue-base, or epiglottis collapse. External validation was performed on a separate dataset (Ntotal=466). CCCp was characterised by greater scoopiness (β=1.5±0.6 per 2SD, multivariable estimate±se) and skewness (β=11.4±2.4) compared to non-CCCp. Odds ratio [95%CI] for CCCp in predicted positive versus negative subgroups was 5.0[1.9-13.1]. The same characteristics provided significant cross-validated prediction of lateral wall (OR=6.3[2.4-16.5]), tongue-base (3.2[1.4-7.3]), and epiglottis (4.4[1.5-12.4]) collapse. CCCp and lateral wall collapse shared similar characteristics (skewed, scoopy), diametrically opposed to tongue-base and epiglottis collapse characteristics. External validation confirmed model prediction. The current study provides a means to recognise patients with likely CCCp or other DISE-based site-of-collapse categories using routine polysomnography. Since site-of-collapse influences therapeutic responses, polysomnographic airflow shape analysis could facilitate precision site-specific OSA interventions.

Heart rate variability analysis in obstructive sleep apnea patients with daytime sleepiness.

Recent studies suggest that sleepy patients with obstructive sleep apnea (OSA) are at higher risk for incident cardiovascular disease. This study assessed cardiac autonomic function in sleepy versus non-sleepy patients with OSA using heart rate variability (HRV) analysis. We hypothesized that HRV profiles of sleepy patients would indicate higher cardiovascular risk. Electrocardiograms (ECG) derived from polysomnograms (PSG) collected by the Sydney Sleep Biobank were used to study HRV in groups of sleepy (ESS ≥ 10) and non-sleepy OSA patients (ESS < 10). HRV parameters were averaged across available ECG signals during N2 sleep. A total of 421 patients were evaluated, with a mean age of 54 (14) years, body mass index of 33 (9) kg/m2, apnea-hypopnea index of 21 (28) events/h, and 66% male. The sleepy group consisted of 119 patients and the non-sleepy group 302 patients. Sleepy patients exhibited lower HRV values for: root mean square successive difference (RMSSD, p = 0.028), total power (TP, p = 0.031), absolute low frequency (LF, p = 0.045), and high-frequency (HF, p = 0.010) power compared to non-sleepy patients. Sleepy patients with moderate-to-severe OSA exhibited lower HRV values for: (RMSSD, p = 0.045; TP, p = 0.052), absolute LF (p = 0.051), and HF power (p = 0.025). There were no differences in other time and frequency domain HRV markers. This study shows a trend toward parasympathetic withdrawal in sleepy OSA patients, particularly in moderate-to-severe cases, lending mechanistic support to the link between the sleepy phenotype and CVD risk in OSA.