Severe Sleep Apnea Research Articles

Impact of continuous positive airway pressure for severe sleep apnea on very late recurrence in patients receiving catheter ablation of atrial fibrillation

Abstract Background Sleep apnea (SA) represents a risk for arrhythmia recurrence following catheter ablation (CA) of atrial fibrillation (AF). Continuous positive airway pressure therapy (CPAP) is the established standard treatment for moderate to severe SA. While CPAP exhibits promise in reducing AF recurrences post-CA, the evidence is not entirely consistent. The impact of CPAP for severe SA on very late recurrence post-CA of AF has not been elucidated. Methods This study employed a retrospective, single-center, observational design. Data were derived from SA screening tests routinely performed in patients scheduled for CA of AF in our facility. We defined severe SA as an apnea-hypopnea index (AHI)≥30 by a home sleep apnea test or polysomnography. After excluding patients already diagnosed with sleep apnea before CA, we enrolled 466 consecutive severe SA patients. We divided them into two groups according to whether they had more than 1-year usage of continuous positive airway pressure after CA (CPAP group) or not (non-CPAP group). CPAP usage was monitored through telemonitoring and regular follow-up visits at our outpatient clinic every three months. Very late AF recurrence was defined as AF recurrence more than 1-year after the index CA. Results The age was 65±10 years, 17.4% were females, and 60.3% had non-paroxysmal AF. The mean AHI was 38.0±15.2. The CPAP group included 33.7% (n=157) and non-CPAP group 66.3% (n=309). The AF recurrence rates within 1-year post-CA were similar between the two groups (CPAP group vs. non-CPAP group, 16.6% vs. 16.2%, log-rank p=0.91). However, the very late AF recurrence rate was lower in the CPAP group than non-CPAP group (CPAP group vs. non-CPAP group, 7.6% vs. 21.6%, log-rank p=0.0002). Conclusion Among the untreated severe sleep apnea patients at the time of the catheter ablation of AF, CPAP treatment during 1-year post-CA was associated with fewer AF recurrences beyond 1-year post-CA.KM curve according to CPAP group

Pulsed-field ablation of atrial fibrillation in patients with multiple cardiovascular comorbidities: acute safety and efficacy from a large nationwide multicenter experience

Abstract Background Patients with multiple cardiovascular (CV) comorbidities are increasing users of health care globally. The decision to perform ablation of atrial fibrillation (AF) may be challenging in this population, due to the difficulty in evaluating their life expectancy and the associated procedural risk. In addition, no data have been reported on the efficiency, effectiveness, and safety outcomes for non-thermal ablation, such as electroporation with pulsed-field ablation (PFA). Purpose To evaluate procedural workflow and safety for AF ablation in these patients through a novel PFA technology (Farapulse) in a large, nationwide clinical practice. Methods Consecutive patients who had undergone PFA of AF from 10 Italian centers were included. Patients were stratified according to the numbers of several comorbidities, assigning 1 point each, including: advanced age (≥80 years), LVEF≤35%, structural heart disease, coronary artery disease, chronic kidney disease, chronic obstructive pulmonary disease, previous stroke/TIA, hyperthyroidism, cancer history, cancer ongoing, severe sleep apnea, diabetes, hypertension, dyslipidemia. Results We included 634 patients (age 62±9 years, 73% male, 67% paroxysmal AF, 88% de novo ablation procedure, LVEF 57±8%). Two-hundred-nine (33%) patients had no risk-factors, 179 (28.2%) patients had at least 1, 137 (21.6%) two, 63 (9.9%) patients 3 risk-factors and 46 (7.3%) patients more than 4 comorbidities. Patients with accumulated risk factors (≥4) had a higher percentage of long-standing AF (17.4% vs 5.4%, p=0.005) and more often underwent de novo ablation procedure (93.5% vs 81.3%, p=0.04). In these cases, operators decided to adopt more frequently, albeit not significantly, advanced diagnostic such as 3D mapping system (30.4% vs 21.9%, p=0.20) or intracardiac echocardiography (41.3% vs 29.8%, p=0.13), a general anesthesia sedation strategy (41.3% vs 32.1%, p=0.88) and a more extensive lesion set beyond PVI (i.e. left atrial posterior wall area, 32.6% vs 23.1%, p=0.15). Procedures in which patients with accumulated risk factors are involved required longer support (preparation plus skin-to-skin) time (90[65-120] min vs 72[60-100] min, p=0.02) and skin-to-skin time (70[60-100] min vs 60[55-85] min, p=0.03) compared to patients with <4 risk factors, whereas time to PVI (19[14-25] min vs 20[14-25] min, p=0.81) and total number of PFA deliveries to achieve PVI (32[32-38] vs 32[32-36], p=0.55) were similar. PVI was achieved in all patients. No major procedure-related adverse events were reported. Conclusion In this preliminary experience, the use of Farapulse PFA system for AF ablation in patients with accumulated risk factors was safe and effective and resulted in similar and fast time to PVI.

Hypoxic indices for obstructive sleep apnoea severity and cardiovascular disease risk prediction: A comparison and application in a community population.

The apnoea-hypopnoea index (AHI) and oxygen desaturation index (ODI) encounter challenges in capturing the intricate relationship between obstructive sleep apnoea (OSA) and cardiovascular disease (CVD) risks. Although novel hypoxic indices have been proposed to tackle these limitations, there remains a gap in comprehensive validation and comparisons across a unified dataset. Samples were derived from the Sleep Heart Health Study (SHHS), involving 4485 participants aged over 40 years after data quality screening. The study compared several key indices, including AHI, ODI, the reconstructed hypoxic burden (rHB), the percentage of sleep time with the duration of respiratory events causing desaturation (pRED_3p) and the sleep breathing impairment index (SBII), in relation to CVD mortality and morbidity risks. Adjusted Cox proportional models were employed to calculate hazard ratios (HRs) for each index, and comparisons were performed. SBII and pRED_3p exhibited significant correlations with both CVD mortality and morbidity, with SBII showing the highest adjusted HR (95% confidence interval) for mortality (2.04 [1.25, 3.34]) and pRED_3p for morbidity (1.43 [1.09-1.88]). In contrast, rHB was only significant in predicting CVD mortality (1.63 [1.05-2.53]), while AHI and ODI did not show significant correlations with CVD outcomes. The adjusted models based on SBII and pRED_3p exhibited optimal performance in the CVD mortality and morbidity datasets, respectively. This study identified the optimal indices for OSA-related CVD risks prediction, SBII for mortality and pRED_3p for morbidity. The open-source online platform provides the computation of the indices.

The use of preoperative continuous positive airway pressure in patients with obstructive sleep apnea following total knee arthroplasty: a propensity score matched analysis.

Patients with sleep apnea, affecting up to 1 in 4 older men in the United States, may be at increased risk of postoperative complications after total knee arthroplasty (TKA), including increased thromboembolic and cerebrovascular events, as well as respiratory, cardiac, and digestive complications. However, the extent to which the use of CPAP in patients with sleep apnea has been studied in TKA is limited. A national, all-payer database was queried to identify all patients who underwent a primary TKA between 2010 and 2021. Patients who had any history of sleep apnea were identified and then stratified based on the use of CPAP. A propensity score match analysis was conducted to limit the influence of confounders. Medical complications, such as cardiac arrest, stroke, pulmonary embolism, transfusion, venous thromboembolism, and wound complications, were collected at 90-days, 1-year, and 2-years. The bivariate analysis showed inferior outcomes for sleep apnea with CPAP use compared to sleep apnea with no CPAP use, in terms of length of stay (5.9 vs. 5.2, p < 0.001), PJI (1.31% vs. 1.14%, p < 0.001), stroke (0.97% vs. 0.82%, p < 0.001), VTE (1.04% vs. 0.82, p < 0.001), and all other complications at 90-days (p < 0.001) except cardiac arrest (0.14% vs. 0.11%, p = 0.052), and aseptic revision (0.40% vs. 0.39%, p = 0.832), PJI (1.81% vs. 1.55%, p < 0.001) and aseptic revision (1.25% vs. 1.06%, p < 0.001) at 1-year, and PJI (2.07 vs. 1.77, p < 0.001) and aseptic revision (1.98 vs. 1.17, p < 0.001) at 2-years. Patients with sleep apnea have increased postoperative complications after undergoing TKA in comparison to patients without sleep apnea. More severe sleep apnea, represented by CPAP usage in this study led to worse postoperative outcomes but further analysis is required signify the role of CPAP in this patient population. Patients with sleep apnea should be treated as a high-risk group.

Screening for treatment-required sleep apnoea in patients with spinal cord injury within one year after injury in a rehabilitation setting.

The current study aims to assess the efficacy of the Stop-Bang Questionnaire (SBQ) in screening treatment-required sleep apnoea following Spinal Cord Injury (SCI). Additionally, we explore the performance of combined questionnaires and pulse oximetry to determine the most cost-effective method. The study employs a cross-sectional observational design. All patients admitted to in-hospital rehabilitation at the Spinal Cord Injury Centre of Western Denmark from September 2022 to February 2023 were continuously enrolled. Participating patients underwent SBQ screening, a standard sleep questionnaire, and cardiorespiratory monitoring, followed by an individual consultation with a physician. During the study period, 35 SCI patients were admitted, with 24 providing informed consent. Among the 24 included patients, there was a 75% prevalence of mild to severe sleep apnoea, and 46% had treatment-required sleep apnoea. The SBQ missed only one patient with treatment-required sleep apnoea but misclassified eight patients. Combining SBQ with the pulse oximetry demonstrated the best performance in identifying patients with sleep apnoea. The study indicates that SBQ alone is insufficient for screening treatment-required sleep apnoea. Exploratory analysis suggests that combining SBQ with a simple pulse oximetry measurement might enhance accuracy.

Respiration-triggered olfactory stimulation reduces obstructive sleep apnea severity: A prospective pilot study.

Obstructive sleep apnea is a prevalent sleep-disordered breathing condition characterized by repetitive reduction in breathing during sleep. The current care standard for obstructive sleep apnea is continuous positive air pressure devices, often suffering from low tolerance due to limited adherence. Capitalizing on the unique neurocircuitry of olfactory perception and its retained function during sleep, we conducted a pilot study to test transient, respiration-based olfactory stimulation as a treatment for obstructive sleep apnea markers. Thirty-two patients with obstructive sleep apnea (apnea-hypopnea index ≥ 15 events per hr) underwent two polysomnography sessions, "Odour" and "Control", in random order. In "Odour" nights, patients were presented with transient respiratory-based olfactory stimulation delivered via a computer-controlled commercial olfactometer (Scentific). The olfactometer, equipped with a wireless monitoring, analysed respiratory patterns and presented odour upon detection of respiratory events. No odours were presented in "Control" nights. Following exclusions, 17 patients entered the analysis (four women, 47.4 (10.5) years, body mass index: 29.4 (6.3) kg m-2). We observed that olfactory stimulation during sleep reduced the apnea-hypopnea index ("Odour": 17.2 (20.9), "Control": 28.2 (18.6), z = -3.337, p = 0.000846, BF10 [Bayesian Factor 10]= 57.9), reflecting an average decrease of 31.3% in the number of events. Relatedly, stimulation reduced the oxygen desaturation index by 26.9% ("Odour": 12.5 (15.8), "Control": 25.7 (25.9), z = -3.337, p = 0.000846, BF10 = 9.522). This effect was not linked to the severity of baseline obstructive sleep apnea markers (ρ = -0.042, p = 0.87). Olfactory stimulation did not arouse from sleep or affect sleep structure, measured as time per sleep stage (F1,16 = 0.088, p = 0.77). In conclusion, olfactory stimulation during sleep was effective in reducing the severity of obstructive sleep apnea markers without inducing arousals, and may provide a novel treatment for obstructive sleep apnea, prompting continued research.

Sleep apnea-related hypoxic burden as a predictor of pregnancy and neonatal outcome

Study objectivesTo determine the clinical impact of sleep apnea-related hypoxic burden in pregnant women and neonates. MethodsThis is a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) study. Hypoxia burden was calculated from the home sleep apnea test (HSAT) and defined as the total area under respiratory events. Logistic regression analysis assessed the relationship between hypoxia burden and pregnancy/neonatal outcomes. ResultsA total of 3006 subjects in the early term, and 2326 subjects in the middle term of pregnancy, had HSAT. A hypoxic burden greater than 6.8%min was present in 1740 at early term and associated with a higher risk of preeclampsia (odds ratio 1.297, 95 % confidence interval 1.032–1.630, p: 0.026) after adjusted by obstructive sleep apnea (OSA) severity. In the middle term, 1058 subjects had a hypoxia burden more than 11.8%min, which was a predictor for higher incidence of gestational diabetes (OR 1.795, 95 % CI 1.097–2.938, p: 0.020) and an Apgar <7 at 1 min (OR 1.446, 95 % CI 1.079–1.939, p: 0.012) after adjusted by obstructive sleep apnea (OSA) severity. After adjusted by oxygenation disturbance index, HB was not related with Apgar <7 at 1 min (p:0.565). ConclusionsThe hypoxic burden is an independent predictor for preeclampsia and gestational diabetes and an Apgar <7 at 1 min.

The study of the relationship between moderate to severe sleep obstructive apnea and cognitive impairment, anxiety, and depression.

The present study endeavored to investigate the interconnection between obstructive sleep apnea (OSA) and cognitive function, alongside the manifestations of depression and anxiety. Simultaneously, an analysis was conducted to discern the factors exerting influence upon cognitive function. A cohort of 102 patients, who had undergone polysomnography (PSG) at Binhu Hospital, Anhui Medical University, between January 2022 and June 2023, was encompassed in the study. Employing the PSG findings, these individuals were classified into two distinct categories: the grouping consisted of those with either negligible or mild OSA, and the other comprised individuals with moderate to severe OSA. Utilizing the Montreal Cognitive Assessment (MoCA-Beijing), Stroop Color and Word Test (SCWT), Digit Span Test (DST), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS), scores were recorded and analysed for each of the respective assessments. Additionally, discrepancies and associations between these groups were also scrutinized. The group exhibiting moderate to severe OSA demonstrated significantly elevated measurements in parameters such as neck circumference, BMI, completion times for SCWT-A, B, C, Sleep Inefficiency Index (SIE), SAS, and SDS, in comparison to the No or Mild OSA group. Furthermore, the moderate-severe OSA group manifested notably diminished MoCA scores in areas of visual-spatial and executive function, memory, language, abstraction, delayed recall, orientation, total MoCA score, lowest oxygen saturation (LSaO2), average oxygen saturation, Digit Span Test-backward(DST-b), and Digit Span Test-forward(DST-f), as contrasted with the no-mild OSA group. These inter-group disparities exhibited statistical significance (p < 0.05). The MoCA total score portrayed inverse correlations with age, Apnea-Hypopnea Index (AHI), BMI, SIE, SAS, SDS, CT90%, AHT90%, and Hypoxic Apnea Duration (HAD) (ranging from -0.380 to -0.481, p < 0.05). Conversely, it displayed positive correlations with DST-f, DST-b, LSaO2, and average oxygen saturation (ranging from 0.414 to 0.744, p < 0.05). Neck circumference, AHI, and SAS were autonomously linked to MoCA scores (OR = 1.401, 1.028, 1.070, p < 0.05), while AHI exhibited an independent correlation with SDS and SAS scores (OR = 1.001, p = 0.003). Patients grappling with moderate to severe OSA frequently reveal cognitive impairment and concomitant emotional predicaments encompassing depression and anxiety. These manifestations share an intimate association with AHI, LSaO2, and average oxygen saturation. Notably, anxiety, when coupled with OSA, emerges as an autonomous influential element impinging upon cognitive impairment.

Older adults at greater risk for Alzheimer’s disease show stronger associations between sleep apnea severity in REM sleep and verbal memory

BackgroundObstructive sleep apnea (OSA) increases risk for cognitive decline and Alzheimer’s disease (AD). While the underlying mechanisms remain unclear, hypoxemia during OSA has been implicated in cognitive impairment. OSA during rapid eye movement (REM) sleep is usually more severe than in non-rapid eye movement (NREM) sleep, but the relative effect of oxyhemoglobin desaturation during REM versus NREM sleep on memory is not completely characterized. Here, we examined the impact of OSA, as well as the moderating effects of AD risk factors, on verbal memory in a sample of middle-aged and older adults with heightened AD risk.MethodsEighty-one adults (mean age:61.7 ± 6.0 years, 62% females, 32% apolipoprotein E ε4 allele (APOE4) carriers, and 70% with parental history of AD) underwent clinical polysomnography including assessment of OSA. OSA features were derived in total, NREM, and REM sleep. REM-NREM ratios of OSA features were also calculated. Verbal memory was assessed with the Rey Auditory Verbal Learning Test (RAVLT). Multiple regression models evaluated the relationships between OSA features and RAVLT scores while adjusting for sex, age, time between assessments, education years, body mass index (BMI), and APOE4 status or parental history of AD. The significant main effects of OSA features on RAVLT performance and the moderating effects of AD risk factors (i.e., sex, age, APOE4 status, and parental history of AD) were examined.ResultsApnea–hypopnea index (AHI), respiratory disturbance index (RDI), and oxyhemoglobin desaturation index (ODI) during REM sleep were negatively associated with RAVLT total learning and long-delay recall. Further, greater REM-NREM ratios of AHI, RDI, and ODI (i.e., more events in REM than NREM) were related to worse total learning and recall. We found specifically that the negative association between REM ODI and total learning was driven by adults 60 + years old. In addition, the negative relationships between REM-NREM ODI ratio and total learning, and REM-NREM RDI ratio and long-delay recall were driven by APOE4 carriers.ConclusionGreater OSA severity, particularly during REM sleep, negatively affects verbal memory, especially for people with greater AD risk. These findings underscore the potential importance of proactive screening and treatment of REM OSA even if overall AHI appears low.

ASSOCIATION OF SEVERE SLEEP APNOEA IN PRIMARY ALDOSTERONISM

Objective: It is well known that sleep apnoea and primary aldosteronism are related. However, it is unclear whether aldosterone excess contributes to the severity of sleep apnoea. We investigated factors correlated with sleep apnoea in patients with primary aldosteronism: the endocrine system, including aldosterone, cardiac function, renal function, and blood pressure. Design and method: We performed a 3% oxygen saturation index with a pulse oximeter in 50 patients (54% male, 49 ± 7.3 years) diagnosed with primary aldosteronism scheduled for adrenal vein sampling in 2017-2020. 3% oxygen saturation index results were classified as mild (less than 5), moderate (5-15), or severe(15 and above) sleep apnoea. In addition, we compared aldosterone (radioimmunoassay), renin activity, aldosterone/renin activity, brain natriuretic peptide, estimated glomerular filtration rate and blood pressure at the initial visit in the severe group and other groups. Results: The severe group did not have higher aldosterone than the mild (192.7 ± 114.7 vs 238.9 ± 128.8 pg/mL, P=0.640) and moderate (192.7 ± 114.7 vs 187.5 ± 85.5 pg/mL, P=0.995) groups, and the same results were obtained for renin activity and aldosterone/renin activity. In other parameters, estimated glomerular filtration rate was not significantly different between groups, but systolic blood pressure at the initial visit in the severe group was significantly higher than in the mild (175.3±25.7 vs 144.8±18.7 mmHg, P=0.003) and moderate (175.3±25.7 vs 143.0±18.5 mmHg, P=0.003) groups. Similarly, brain natriuretic peptide in the severe group was significantly higher than in the mild (53.5±90.0 vs 12.7±8.3 pg/mL, P=0.020) and moderate (53.5±90.0 vs 10.7±11.2, P=0.014) groups. Conclusions: Our results showed that aldosterone excess did not contribute to the severity of sleep apnoea. However, severe sleep apnoea was significantly associated with elevated systolic blood pressure and brain natriuretic peptide.

Correlation of diffusion tensor tractography with obstructive sleep apnea severity.

Using correlation tractography, this study aimed to find statistically significant correlations between white matter (WM) tracts in participants with obstructive sleep apnea (OSA) and OSA severity. We hypothesized that changes in certain WM tracts could be related to OSA severity. We enrolled 40 participants with OSA who underwent diffusion tensor imaging (DTI) using a 3.0 Tesla MRI scanner. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and quantitative anisotropy (QA)-values were used in the connectometry analysis. The apnea-hypopnea index (AHI) is a representative measure of the severity of OSA. Diffusion MRI connectometry that was used to derive correlational tractography revealed changes in the values of FA, MD, AD, RD, and QA when correlated with the AHI. A false-discovery rate threshold of 0.05 was used to select tracts to conduct multiple corrections. Connectometry analysis revealed that the AHI in participants with OSA was negatively correlated with FA values in WM tracts that included the cingulum, corpus callosum, cerebellum, inferior longitudinal fasciculus, fornices, thalamic radiations, inferior fronto-occipital fasciculus, superior and posterior corticostriatal tracts, medial lemnisci, and arcuate fasciculus. However, there were no statistically significant results in the WM tracts, in which FA values were positively correlated with the AHI. In addition, connectometry analysis did not reveal statistically significant results in WM tracts, in which MD, AD, RD, and QA values were positively or negatively correlated with the AHI. Several WM tract changes were correlated with OSA severity. However, WM changes in OSA likely involve tissue edema and not neuronal changes, such as axonal loss. Connectometry analyses are valuable tools for detecting WM changes in sleep disorders.

Chronic intermittent hypoxia alters CD8+ expression in the bone marrow of C57BL/6 mice

Cytotoxic CD8+ cells are critical in anticancer immune response and have become prevalent in immunotherapies over the past decade. Anti-LAG3/anti-PD1 combined immunotherapies increase the number of CD8+ cells. Moderate to severe sleep apnea increases the risk of cancer-related mortality. Chronic intermittent hypoxia, a feature of sleep apnea, decreases the percentage of perforin-expressing CD8+ cells, impairing cytotoxicity. Our objective is to determine the distribution of Prf1(perforin), LAG3(lymphocyte-activation gene 3), and PDCD1(programmed cell death 1) in C57BL/6 mice exposed to chronic intermittent hypoxia (CIH). We hypothesize that Prf1, PDCD1, and LAG3 will be expressed on three discrete clusters with a higher expression of LAG3 and PDCD1 and lower expression of Prf1 between C57BL/6 mice exposed to chronic intermittent hypoxia and normoxia. Bone marrow from the femur of C57BL/6 mice exposed to chronic intermittent hypoxia or normoxia was harvested. Bone marrow mononuclear cells were isolated, RNA was extracted, and single-cell RNA sequencing was performed. Loupe browser was used to re-cluster and quantify expression for genes of interest. Prf1 and PDCD1 are expressed in CD3+CD8−CD4− cluster and LAG3 is expressed in CD3−CD8+CD4+ cluster. LAG3 and Prf1 are present among the top ten genes, while PDCD1 is not in those clusters. Further analysis of the top ten genes of CD3+CD8−CD4− has demonstrated they are a group of natural killer cells. Contradictory to our expectation, Prf1 and PDCD1 are present in CD3+CD8−CD4− cluster while LAG3 is present in CD3−CD8+CD4+ cluster. Further analysis is necessary to determine the underlying mechanisms causing these changes. 5R01CA244271-02. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Severity of sleep apnea as a prognostic factor for mortality in patients with multiple system atrophy

BackgroundWe determined whether the severity of sleep apnea increases the risk of mortality in patients with multiple system atrophy (MSA) with and without stridor.MethodsThis retrospective study included patients who underwent polysomnography within one year after diagnosis of probable MSA. Stridor, sleep apnea, and arousal from sleep were determined using full-night polysomnography. Disease severity was measured using the Unified MSA Rating Scale (UMSARS). Survival data were collected and analyzed using Cox regression analysis. ResultsSixty-four patients with MSA were included. During a median follow-up of 34.5 months, 49 (76.6 %) patients died. Stridor was present in 56.3 % of patients. Patients with stridor had more severe sleep apnea and shorter sleep time than those without, but the hazard ratio (HR) for death did not differ between patients with and without stridor. Among patients without stridor, apnea-hypopnea index ≥30/h (HR, 6.850; 95 % confidence interval [CI], 1.983–23.664; p = 0.002) and a score of UMSARS I + II (HR, 1.080; 95 % CI, 1.040–1.121; p < 0.001) were independently associated with death. In contrast, among patients with stridor, frequent arousals from sleep (HR, 0.254; 95 % CI, 0.089–0.729; p = 0.011) were a significant factor associated with longer survival, while MSA-cerebellar type tended to be associated with poor survival (HR, 2.195; 95 % CI, 0.941–5.120; p = 0.069). ConclusionThe severity of sleep apnea might be a significant predictor of shorter survival in MSA patients without stridor, whereas frequent arousals from sleep might be a significant predictor for longer survival in MSA patients with stridor.

Prediction of Treatment Response and Effect on Clinical Manifestations for Normal Pressure Hydrocephalus of Sleep Related Breathing Disorders

Objectives: Sleep disorders and normal pressure hydrocephalus (NPH) are increasingly important issues observed in neurological disorders. However, the correlation between these diseases has not been sufficiently studied. Thus, we discuss the correlation between sleep disorders and the clinical features of NPH. Methods: Overall, 40 patients with idiopathic NPH were included in the study. To evaluate the sleep disorders and psychiatric problems, surveys were administered, including the 36-Item Short Form Survey, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), Berlin Questionnaire, STOP-Bang Questionnaire, Hospital Anxiety and Depression Scale (HADS), Morningness-Eveningness Questionnaire, and the REM Sleep Behavior Disorder Screening Questionnaire. To evaluate the severity of dementia and ataxia, all of the patients completed the Korean mini-mental state examination; Korea frontal assessment battery score, amd unified Parkinson’s disease rating scale-motor scores before and after cerebrospinal fluid (CSF) drainage. The Pearson’s chi-square test, independent Student’s t-test, Mann–Whitney U test, and linear regression analysis were used to analyze the relationship between sleep disorders and symptom improvement after CSF drainage. Results: Of the 40 patients, 21 patients had poor sleep quality (PSQI&gt;5), 8 patients had insomnia (ISI≥8), 11 patients had daytime sleepiness (ESS≥11), 9 (STOP-Bang≥3) to 13 (Berlin≥2 categories) patients had sleep apnea, 13 patients were anxious (HAS≥8), and 27 patients were depressed (HDS≥8). A linear regression analysis showed that sleep apnea was significantly correlated with cognitive function, and insomnia was correlated with cognitive, motor, and frontal lobe functions. Additionally, patients with severe sleep apnea demonstrated a greater recovery of cognitive function after CSF drainage. Conclusions: Obstructive sleep apnea (OSA) is closely related to the clinical symptoms and treatment effectiveness of NPH. The diagnosis and proper treatment of OSA is expected to improve the prognosis of patients with NPH.

3D analysis of upper airway morphology related to obstructive sleep apnea severity

BackgroundObstructive sleep apnea (OSA) is the most common sleep-related breathing disorder characterized by repetitive collapse of the upper airway during sleep. However, little evidence is available on the differences between the sub-regions of the upper airway morphology and OSA severity. Since orthodontists frequently perform cone beam computed tomography (CBCT) in the neck area, we aimed to investigate the relationship and the differences between upper airway morphology and OSA severity using CBCT. Materials and methodsThe medical records, CBCT imaging of 21 OSA patients diagnosed by polysomnography, and the apnea-hypopnea index (AHI) results were included to classify OSA severity as mild, moderate, or severe. The minimum cross-sectional areas (MCA) and volumes of the upper pharyngeal airway boundaries in four sub-regions: nasopharynx, retropalatal, retroglossal, and hypopharynx were measured. Dolphin Imaging software was used for upper airway segmentation. The correlation coefficient (r), one-way ANOVA, and the least significant difference post hoc multiple comparison test were applied to fulfill the objectives. ResultsA statistically significant relationship was found between the MCA of the nasopharynx and the AHI (r = −0.473, P < 0.05). Furthermore, a difference was found between mild and moderate and moderate and severe OSA severity in the MCA results of the retroglossal region (P < 0.05). However, no relationship was found between the upper airway volume and OSA severity. ConclusionsMCA was moderately negatively correlated to AHI only in the nasopharynx subregion. Moderate OSA presented significantly less MCA than mild and severe OSA only in the oropharynx and retroglossal subregions.

In-Laboratory Polysomnography Worsens Obstructive Sleep Apnea by Changing Body Position Compared to Home Testing.

(1) Background: Home sleep apnea testing, known as polysomnography type 3 (PSG3), underestimates respiratory events in comparison with in-laboratory polysomnography type 1 (PSG1). Without head electrodes for scoring sleep and arousal, in a home environment, patients feel unfettered and move their bodies more naturally. Adopting a natural position may decrease obstructive sleep apnea (OSA) severity in PSG3, independently of missing hypopneas associated with arousals. (2) Methods: Patients with suspected OSA performed PSG1 and PSG3 in a randomized sequence. We performed an additional analysis, called reduced polysomnography, in which we blindly reassessed all PSG1 tests to remove electroencephalographic electrodes, electrooculogram, and surface electromyography data to estimate the impact of not scoring sleep and arousal-based hypopneas on the test results. A difference of 15 or more in the apnea-hypopnea index (AHI) between tests was deemed clinically relevant. We compared the group of patients with and without clinically relevant differences between lab and home tests (3) Results: As expected, by not scoring sleep, there was a decrease in OSA severity in the lab test, similar to the home test results. The group of patients with clinically relevant differences between lab and home tests presented more severe OSA in the lab compared to the other group (mean AHI, 42.5 vs. 20.2 events/h, p = 0.002), and this difference disappeared in the home test. There was no difference between groups in the shift of OSA severity by abolishing sleep scoring in the lab. However, by comparing lab and home tests, there were greater variations in supine AHI and time spent in the supine position in the group with a clinically relevant difference, either with or without scoring sleep, showing an impact of the site of the test on body position during sleep. These variations presented as a marked increase or decrease in supine outcomes according to the site of the test, with no particular trend. (4) Conclusions: In-lab polysomnography may artificially increase OSA severity in a subset of patients by inducing marked changes in body position compared to home tests. The location of the sleep test seems to interfere with the evaluation of patients with more 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.

Effect of obesity on sleep apnea pathogenesis differs in women versus men: multiple mediation analyses in the retrospective SNOOzzzE cohort.

There are multiple mechanisms underlying obstructive sleep apnea (OSA) development. However, how classic OSA risk factors such as body mass index (BMI) and sex portend to OSA development has not been fully described. Thus we sought to evaluate how obesity leads to OSA and assess how these mechanisms differ between men and women. The San Diego Multi-Outcome OSA Endophenotype (SNOOzzzE) cohort includes 3,319 consecutive adults who underwent a clinical in-laboratory polysomnography at the University of California, San Diego, sleep clinic between January 2017 and December 2019. Using routine polysomnography signals, we determined OSA endotypes. We then performed mediation analyses stratified by sex to determine how BMI influenced the apnea-hypopnea index (AHI) using OSA pathophysiological traits as mediators, adjusting for age, race, and ethnicity. We included 2,146 patients of whom 919 (43%) were women and 1,227 (57%) were obese [body mass index (BMI) > 30 kg/m2]. BMI was significantly associated with AHI in both women and men. In men, the adjusted effect of BMI on AHI was partially mediated by a reduction in upper airway stiffness (βstandardized = 0.124), a reduction in circulatory delay (βstandardized = 0.063), and an increase in arousal threshold (βstandardized = 0.029; Pboot-strapped,all < 0.05). In women, the adjusted effect of BMI on AHI was partially mediated by a reduction in upper airway stiffness (βstandardized = 0.05) and circulatory delay (βstandardized = 0.037; Pboot-strapped,all < 0.05). BMI-related OSA pathogenesis differs by sex. An increase in upper airway collapsibility is consistent with prior studies. A reduction in circulatory delay may lead to shorter and thus more events per hour (higher AHI), while the relationship between arousal threshold and OSA is likely complex.NEW & NOTEWORTHY Our data provide important insights into obesity-related obstructive sleep apnea (OSA) pathogenesis, thereby validating, and extending, prior research findings. This is the largest sample size study to examine the relationships between obesity and gender on OSA pathogenesis. The influence of obesity on sleep apnea severity is mediated by different mechanistic traits (endotypes).

A gated recurrent unit model based on ultrasound images of dynamic tongue movement for determining the severity of obstructive sleep apnea

Obstructive sleep apnea (OSA) presents as a respiratory disorder characterized by recurrent upper pharyngeal airway collapse during sleep. Dynamic tongue movement (DTM) analysis emerges as a promising avenue for elucidating the pathophysiological underpinnings of OSA, thereby facilitating its diagnosis. Recent endeavors have utilized artificial intelligence techniques to categorize OSA severity leveraging electrocardiography and blood oxygen saturation data. Nonetheless, the integration of ultrasound (US) imaging of the tongue remains largely untapped in the development of machine learning models aimed at determining the severity of OSA. This study endeavors to bridge this gap by capturing US images of DTM dynamics during wakefulness, encompassing transitions from normal breathing (NB) to the performance of the Müller maneuver (MM) in a cohort of 53 patients. Leveraging the modified optical flow method (MOFM), the trajectories of patients’ DTM were tracked, facililtating the extraction of 27 parameters vital for model training. These parameters encompassed nine-point lateral movement, nine-point axial movement, and nine-point total displacement of the tongue, resulting in a dataset of 186,030 samples. The gated recurrent unit (GRU) method, renowned for its efficacy in motion tracking, was employed for model development in this study. Validation of the developed model was conducted via stratified k-fold cross-validation (SCV). The systems’ overall performance in classifying OSA severity, as quantified by mean accuracy (MA), yielded a value of 43.49%. This pilot investigation marks an exploratory endeavor into the utilization of artificial intelligence for the classification of OSA severity based on US images and dynamic movement patterns. This novel model holds potential to assist clinicians in categorizing OSA severity and guiding the selection of pertinent treatment modalities tailored to the individual needs of patients afflicted with OSA.

Obstructive sleep apnea severity, circulating biomarkers, and cancer risk.

To determine whether obstructive sleep apnea (OSA) severity and/or biomarkers of inflammation/angiogenesis are associated with incident cancer in this clinical cohort. Consenting adult patients at the University of British Columbia Hospital between 2003 and 2014 completed a questionnaire about their medical history and sleep habits prior to undergoing a polysomnogram. Blood samples were collected the morning after polysomnography and processed for biomarkers of inflammation and angiogenesis. The clinical, polysomnography, and biomarker data were linked to the British Columbia Cancer Registry to ascertain incident cancer diagnoses. Cox proportional hazard regression was used to assess the association between OSA severity and biomarker concentrations with cancer risk. A total of 1,990 patients were included in the analysis with a mean follow-up time of 12.8 years; 181 of them (9.1%) developed cancer after polysomnography. OSA severity was significantly associated with cancer risk after controlling for relevant covariates (hazard ratio = 1.08 per 10 events/h apnea-hypopnea index increase, confidence interval = 1.02-1.15, P = .015). In an exploratory analysis, 2 biomarkers were significantly associated with an increased cancer risk after controlling for relevant covariates (hazard ratio per interquartile range pg/mL increase of endostatin = 1.45, confidence interval = 1.12-1.87, P = .01 and hazard ratio for interquartile range pg/mL increase of vascular cell adhesion molecule-1 = 1.48, confidence interval = 1.04-2.11, P = .03, respectively). OSA severity was an independent risk factor for cancer. Furthermore, 2 circulating markers were significantly associated with cancer risk. If these preliminary findings can be reproduced in other cohorts, biomarkers could potentially be used to prognosticate patients with OSA with respect to cancer risk. Hirsch Allen AJ, Kendzerska T, Bhatti P, etal. Obstructive sleep apnea severity, circulating biomarkers, and cancer risk. J Clin Sleep Med. 2024;20(9):1415-1422.