Effect of Obstructive Sleep Apnea on Neurocognitive Performance

Circulating exosomes in pediatric obstructive sleep apnea with or without neurocognitive deficits and their effects on a 3D-blood-brain barrier spheroid model

Obstructive sleep apnea (OSA) in children is linked to cognitive impairments, potentially due to blood-brain barrier (BBB) dysfunction. Exosomes, small vesicles released by most cells, reflect cellular changes. This study examined the effects of exosomes from children with OSA, with or without cognitive deficits, on neurovascular unit (NVU) models. Twenty-six children were categorized into three groups: healthy controls (Cont, n = 6), OSA without cognitive deficits (OSA-NG, n = 10), and OSA with neurocognitive deficits (OSA-POS, n = 10). Plasma exosomes were characterized and applied to human 3D NVU spheroids for 24 h. Barrier integrity, permeability, and angiogenesis were assessed using trans-endothelial electrical resistance (TEER), tight junction integrity, and tube formation assays. Single-nucleus RNA sequencing (snRNA-seq) and bioinformatics, including CellChat analysis, identified intercellular signaling pathways. Results showed that exosomes from OSA-POS children disrupted TEER, increased permeability, and impaired ZO1 staining in spheroids, compared to the other groups. Both OSA-POS and OSA-NG exosomes increased permeability in NVU cells in monolayer and microfluidic BBB models. snRNA-seq analysis further revealed distinct cell clusters and pathways associated with the different groups. This 3D NVU spheroid model provides a robust platform to study BBB properties and the role of exosomes in OSA. These findings suggest that integrating snRNA-seq with exosome studies can uncover mechanisms underlying neurocognitive dysfunction in pediatric OSA, potentially leading to personalized therapeutic approaches.

Cardiopulmonary coupling estimated sleep quality and memory in children with obstructive sleep-disordered breathing

OBJECTIVE

To investigate the association between sleep quality/stability and memory in children with sleep-disordered breathing.

METHODS

Children aged 5-12 years with suspected sleep-disordered breathing who visited the Sleep Center of Beijing Children's Hospital, from June 2022 to March 2023 were enrolled. All patients underwent polysomnography (PSG) and cardiopulmonary coupling monitoring (CPC) analysis based on the photoplethysmogram, and memory tests (immediate and delayed recognition and recall) before sleep and after sleep, respectively. In the CPC analysis, high frequency coupling (HFC) as percentage of total sleep time is stable sleep. A sleep quality index (SQI) integrates HFC, sleep duration and sleep fragmentation. The correlation between memory function and sleep quality/stability was analyzed. Cyclic variation in heart rate was quantified as a sleep apnea indicator (SAI).

RESULTS

Patients were divided into three groups based on HFC: low (<60), moderate (60-80) and high (>80). A total of 152 children were included in the study, 100 males and 52 females, with an average age of 8.2 ± 1.7 years.HFC% was negatively correlated with AHI and OAHI (r: -0.32,p: <0.01; r: -0.31, p: <0.01), while LFC% was positively correlated with AHI and OAHI (r: 0.29, p: <0.01; r: 0.28, p: <0.01). The SQI and HFC was positively correlated with the delayed recall test score(r: 0.19, p: <0.05), and with the recognition consolidation rate (r: 0.23, p: <0.05). In contrast, LFC was negatively correlated with delayed recall test score (r:0.19, p: <0.05), delayed recognition score (r:0.15,p < 0.05), and recognition consolidation rate (r:0.21, p: <0.01). SAI was negatively correlated with Recognition consolidation rate score (r: -0.17, p: <0.05).

CONCLUSIONS

Sleep stability assessed via CPC may reflect a risk biomarker for memory function in children with OSA.

Early sleep apnea treatment in stroke (eSATIS) - a multicentre, randomised controlled, rater-blinded, clinical trial: The association of post-stroke cognition with sleep-disordered breathing and its treatment

Sleep-disordered breathing (SDB) is linked to cognitive dysfunction. Although SDB is common in stroke patients, the impact of SDB and its early treatment on cognitive functioning after stroke remains poorly investigated. Therefore, we explored the association between SDB and post-stroke cognitive functioning, including the impact of early SDB treatment with adaptive servo-ventilation (ASV) on cognitive recovery from acute event to 3 months post-stroke. We used data from two studies, which included ischaemic stroke patients (n = 131) and no-stroke controls (n = 37) without SDB (apnea-hypopnea index, AHI <5/h) and with SDB (AHI≥20/h). Cognitive functioning was assessed within 7 days and 3 months post-stroke in stroke patients, or at study inclusion in no-stroke control group, respectively. Stroke patients with SDB were randomized to ASV treatment (ASV+) or usual care (ASV-). Linear regression adjusted for main confounders assessed the impact of SDB and its treatment on cognitive recovery. The intention-to-treat analysis did not show significant associations of SDB ASV+ (n = 30) versus SDB ASV- (n = 29) with cognitive recovery. In an exploratory subanalysis, compliant SDB ASV+ (n = 14) versus SDB ASV- showed improvements with ASV in visual memory and cognitive flexibility. Combining the stroke and non-stroke datasets, SDB (n = 85) versus no-SDB (n = 83) was associated with deficits in visual memory and response inhibition independently of stroke. SDB ASV- versus no-SDB (n = 51) was associated with less improvement in visual memory. There was no substantial evidence for benefits of intention-to-treat ASV on cognitive recovery. Exploratory analysis indicated that compliant ASV treatment could benefit visual memory and cognitive flexibility, whereas untreated SDB could contribute to a poor recovery of visual memory.

Differences in time perception in patients with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a condition that occurs due to complete (apnea) and partial (hypopnea) obstruction in the upper airways during sleep. Hypoxia is one of the key factors contributing to the development of symptoms of obstructive sleep apnea and OSA-related diseases.

OBJECTIVE

The present study aimed to evaluate time perception differences between patients with OSA and healthy individuals, as well as among different OSA severity groups.

METHODS

Twenty severe OSA, twenty moderate OSA, twenty mild OSA patients, and twenty healthy volunteers without OSA were included in the study. Scales were administered to the participants. Time perception tests were administered to evaluate perceptual timing.

RESULTS

In the paced motor timing test, a difference was observed between the OSA ( +) group and the OSA (-) group. In the Time Estimation Test, a difference was observed between the OSA ( +) group and the OSA (-) group and their subgroups.

CONCLUSION

The internal clock works slower in the OSA ( +) group. When subgroups were compared based on the degree of OSA, the internal clock worked slower as we transitioned from the OSA (-) group to the severe OSA group. It is considered that as you move from the OSA (-) group to the severe OSA group, the switch between pacemaker and accumulator is disrupted due to the decrease in attention. Recurrent hypoxia observed in OSA may alter the perception of time by affecting attention.

Arousal threshold modifies the effect of CPAP on executive function among individuals with obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is associated with neurocognitive dysfunction. However, randomised trials evaluating the effects of continuous positive airway pressure (CPAP) on neurocognition in those without dementia do not show a benefit. We thus aimed to assess whether arousal threshold (ArTH) modifies the effect of CPAP on neurocognitive function.

METHODS

We performed a secondary analysis of a randomised, sham-controlled trial (Apnea Positive Pressure Long-term Efficacy Study (APPLES); ClinicalTrials.gov: NCT00051363). ArTH was estimated from polysomnography using a translatable method. Neurocognitive outcomes included the Sustained Working Memory Test-Overall Mid-Day (SWMT-OMD) score (executive function, primary outcome), with the Pathfinder Number Test total time (attention) and Buschke Selective Reminding Test sum recall (learning and memory) as secondary outcomes. Generalised linear modelling assessed whether the effect of CPAP was modified by baseline ArTH (treatment×ArTH interaction). 833 participants with OSA (apnoea-hypopnoea index ≥10 events·h-1), available ArTH and outcomes were analysed (active CPAP n=437 and sham CPAP n=396).

RESULTS

For executive function, the effect of CPAP treatment was modified by ArTH (pinteraction=0.042). Specifically, for every 1sd increase in ArTH, the SWMT-OMD score improved by 0.091 (95% CI 0.003-0.178) in active compared to sham CPAP at 6 months; at ArTH 1sd above the mean, SWMT-OMD improvements were nearly three times that in those with average ArTH (0.139 (95% CI 0.018-0.261) versus 0.053 (95% CI -0.034-0.140), respectively). No effect modification was observed for attention (p=0.311) or learning and memory (p=0.744).

CONCLUSION

In OSA, a higher ArTH is associated with greater improvements in executive function following CPAP therapy.

Exploring emotional regulation in insomnia with and without major depressive episode

Previous studies have highlighted the pivotal role of emotional regulation impairment in the progression of depressive and insomnia disorders, individually. Nevertheless, to date, no study has undertaken a direct comparison of the emotional profiles in individuals experiencing insomnia with or without major depressive episode (MDE). In this study, our objective was to closely examine multiple aspects of emotional regulation among individuals experiencing insomnia, with or without concurrent depression. This descriptive observational study involved 57 participants, comprising 27 individuals with comorbid chronic insomnia and MDE, and 30 with chronic insomnia alone. All participants completed self-questionnaires assessing aspects of emotional regulation: the Affect Intensity Measure (intensity), Affective Lability Scale (lability), Temperament Evaluation of Memphis Pisa Paris and San Diego Autoquestionnaire (temperament), Cognitive Emotion Regulation Questionnaire (cognitive strategies), and Multidimensional Assessment of Thymic States (reactivity). There were statistically significant differences between the group with insomnia with MDE and insomnia without MDE in terms of anxiety/depression lability. Discrepancies also manifested in terms of activation or inhibition in motor activity and motivation. Additionally, a noteworthy variance in cognitive strategies for emotional regulation was observed, specifically in self-blame and catastrophising. From a cognitive perspective, patients with insomnia and a MDE exhibited a greater inclination towards self-blame and catastrophising, in contrast to those with insomnia only. Behaviourally, the former group demonstrated heightened inhibition of motivation and motor activity. These findings underscore the importance of larger-scale investigations to validate these insights and pave the way for clinical prospects centred around emotional regulation, ultimately fostering personalised treatments for insomnia.

Impact of continuous positive airway pressure on cognitive functions in adult patients with obstructive sleep apnea: A systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is associated with the impairment of a range of cognitive functions. Whether treatment with continuous positive airway pressure (CPAP) improves these cognitive functions is still a matter of debate.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) that included OSA patients (apnea hypopnea index, AHI >10/h), naive to CPAP treatment, with a cognitive assessment before and after CPAP initiation. We compared CPAP versus sham-CPAP or placebo tablet or dietary rules or no treatment. This systematic review and meta-analysis were registered in PROSPERO (ID CRD42021275214).

RESULTS

Eleven RCTs encompassing 923 OSA patients were included. For most of them, CPAP initiation was ≤3 months. A significant post-treatment improvement was found for the Trail Making Test part B (TMT-B; SMD = -0.93, 95 % CI = [-1.60, -0.25], Z = -2.70, p = 0.007), but not for the other neuropsychological assessments. No global effects on other cognitive domains (information processing speed, executive functions, working memory) were found.

CONCLUSION

The significant improvement in the TMT-B supports a short-term enhancement in cognitive flexibility with CPAP treatment. Further studies that take into account OSA comorbidities, cognitive profiles, a more diverse range of cognition assessments and include long-term evaluations are needed.

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

INTRODUCTION

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.

METHODS

Sixty patients with OSA (18-65 years, 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.

RESULTS

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).

CONCLUSION

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.

Microstructural brain abnormalities and associated neurocognitive dysfunction in obstructive sleep apnea: a pilot study with diffusion kurtosis imaging

STUDY OBJECTIVES

We assessed possible brain abnormalities in adult patients with moderate and severe obstructive sleep apnea using the mean kurtosis (MK) from diffusion kurtosis imaging and analyzed the correlation between MK and cognitive function.

METHODS

A total of 30 patients with moderate or severe obstructive sleep apnea and 30 healthy controls evaluated by the Montreal Cognitive Assessment scale were enrolled. All participants underwent diffusion kurtosis imaging and 3-dimensional T1-weighted imaging on a 3.0T magnetic resonance scanner. The MK values of gray and white matter brain regions were compared. Partial correlation analysis was used to analyze the correlation between respiratory sleep parameters/cognitive score and MK values in different brain regions.

RESULTS

Compared with the healthy controls, the MK of 20 brain regions (13 after false discovery rate correction) and cognitive scores in the obstructive sleep apnea group were significantly lower. In the obstructive sleep apnea group, apnea-hypopnea index was negatively correlated with the MK in the white matter of the right occipital lobe; lowest oxygen saturation was positively correlated with the MK in the bilateral parietal, precentral, and right postcentral cortex; total score on the Montreal Cognitive Assessment scale was positively correlated with MK in the left hippocampus; language function was positively correlated with MK in the white matter of the left parietal lobe; and delayed recall was positively correlated with the MK in right insula cortex and bilateral cingulate. After false discovery rate correction, only the correlations of lowest oxygen saturation with right precentral gyrus cortex and bilateral parietal cortex were significant.

CONCLUSIONS

MK values of diffusion kurtosis imaging may provide valuable information in assessing the neurological impacts of obstructive sleep apnea.

CITATION

Zhang N, Peng K, Guo J-X, Liu Q, Xiao A-L, Jing H. Microstructural brain abnormalities and associated neurocognitive dysfunction in obstructive sleep apnea: a pilot study with diffusion kurtosis imaging. J Clin Sleep Med. 2024;20(10):1571-1578.

Differences in Positive Airway Pressure Requirements in Obstructive Sleep Apnea Between Black and White Patients

OBJECTIVE

There are disparities between Black and White patients in the utilization of positive airway pressure (PAP) alternatives for obstructive sleep apnea (OSA). Given low utilization rates among Black patients, there is limited knowledge of PAP alternative outcomes in this group. Therapeutic PAP levels are clinically accessible measures that have been shown to predict PAP alternative outcomes. Herein, we examined differences in PAP requirements between Black and White patients in a large clinical sample.

STUDY DESIGN

Cross-sectional.

SETTING

Academic sleep center.

METHODS

We included OSA patients prescribed autoadjusting PAP between January 2018 and 2020 with baseline apnea-hypopnea index (AHI) ≥ 10. Mean and 90th percentile PAP levels were compared between White and Black patients who used PAP for ≥1 hour daily using linear regression controlling for age, sex, body mass index (BMI), AHI, oxygen saturation nadir, and mask type.

RESULTS

There were 157 Black and 234 White patients who were generally obese (BMI, 37.3 ± 8.7) with severe OSA (AHI, 36.9 ± 25.6). Black patients had a 0.68 cm higher (95% confidence interval [CI]: 0.36, 1.35) mean PAP level and 0.85 cm H2O higher (95% CI: 0.36, 1.35) 90th percentile PAP level than white patients. Although statistically significant, differences were small and not clinically meaningful.

CONCLUSION

Black and White OSA patients had clinically insignificant differences in PAP requirements, suggesting comparable upper airway collapsibility. Considering the predictive value of therapeutic PAP levels, our findings suggest Black and White patients may have comparable PAP alternative responses from a collapsibility standpoint. Future studies should explore reasons for low utilization of PAP alternatives among Black patients.

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

Objective

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.

Methods

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.

Results

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).

Conclusion

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.

Correlation between cognitive impairment and serum markers in patients with obstructive sleep apnea-hypopnea syndrome

BACKGROUND

Previous studies have revealed that sleep structure and hypoxemia are two important environmental factors for cognitive impairment in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). We hypothesized that the pathophysiological mechanisms between these two factors may also be involved in cognitive impairment in patients with OSAHS. Previous studies have suggested that alterations in serum glucose and lipid metabolism, inflammatory responses, and astrocyte markers not only contribute to sleep structural disorders in OSAHS but also affect the occurrence and development of this disease. Therefore, we hypothesized that alterations in the abovementioned indicators may be involved in cognitive impairment in OSAHS. Additionally, obesity is an important risk factor for OSAHS. This study therefore aimed to explore the correlation between serum indicators and cognitive impairment in patients with OSAHS.

METHODS

Patients with OSAHS who underwent polysomnography in our hospital were recruited in this study. The overall cognitive function of patients were evaluated using the Mini mental State Examination (MMSE). Blood biochemical indicators such as glucose (GLU), triglycerides (TG), and triglyceride glucose (TyG) index were measured. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of serum glucagon-like peptide-1 receptor (GLP-1R), fibroblast growth factor 21 (FGF21), S100 calcium binding protein B (S100B), brain derived neurotrophic factor (BDNF), inflammatory factors such as C-reactive protein (CRP), tumor necrosis factor-α (TNFα), interleukin-4 (IL-4), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Spearman correlation analysis was used to determine if the indicator was related to cognitive function, and backward linear regression analysis was used to identify the main risk factors for cognitive impairment in non-obese and obese patients with OSAHS.

RESULTS

Among 34 patients, 19 were non-obese and 15 were obese. Obese patients exhibited higher AHI compared to non-obese individuals, and the difference was statistically significant (p < 0.05). In non-obese patients, Spearman correlation analysis revealed a negative correlation between serum GLU, IL-4, and MMSE scores (p < 0.05); IL-6 was positively correlated with MMSE (p < 0.05). In addition, GLU and IL-6 were independently correlated with MMSE in non-obese patients (p < 0.05). In obese patients, serum TG and TyG were positively correlated with MMSE scores (p < 0.05); age, BMI, and IL-4 were negatively correlated with MMSE scores (p < 0.05). In addition, age and IL-4 were independently correlated with MMSE in obese patients (p < 0.05).

CONCLUSIONS

Our data suggested that GLU and IL-6 were independently correlated with cognitive impairment in non-obese patients with OSAHS; age and IL-4 were independently correlated with cognitive impairment in obese patients. Early detection of this difference in heterogeneity may provide theoretical support for future investigations in prevention and treatment of cognitive impairment in patients with OSAHS.

General low alertness in people with obstructive sleep apnea

STUDY OBJECTIVES

In patients with obstructive sleep apnea (OSA), a previous study using a Go/No-Go task reported an average attention deficit. However, the temporal dynamics of such a deficit are unknown. Here, we investigated whether attention deficits in different subdomains increased as the test progressed. We also investigated the effect of target frequency and speed of stimulus presentation on performance.

METHODS

Twenty-seven untreated people with OSA and 27 age- and sex-matched controls underwent a 15-minute Go/No-Go task, divided into 6 blocks. Each block was subdivided into 3 different interstimulus intervals (1, 2, and 4 seconds). Three blocks had a low and three had a high target probability (20% and 80%, respectively). Reaction time (alertness), variability of reaction time (sustained attention), commission errors (response inhibition), and omission errors (focused attention) were measured.

RESULTS

Alertness was lower in the group with OSA compared with controls, as evidenced by a significantly higher average reaction time. This effect was seen from the start of the task and continued until the end but did not increase in test progression. The temporal pattern of intrinsic alertness deficits in patients with OSA was found to be independent of target frequency or interstimulus interval.

CONCLUSIONS

The primary attention problem in OSA is on the alertness subdomain irrespective of the number of required responses or speed of stimulus presentation. The present results support the notion that OSA is distinct from other neurological and psychiatric conditions, such as depression or chronic pain. The results also suggest significant concerns regarding daily life activities (eg, driving).

CITATION

de Souza Bezerra ML, van Duinkerken E, Simões E, Schmidt SL. General low alertness in people with obstructive sleep apnea. J Clin Sleep Med. 2024;20(5):689-698.

Airway Collapsibility during Drug-Induced Sleep Endoscopy Relates with Clinical Features of Obstructive Sleep Apnea

INTRODUCTION

Increased pharyngeal collapsibility leads to obstructive sleep apnea (OSA). Positive airway pressure titration during drug-induced sleep endoscopy (DISE-PAP) provides objective collapsibility metrics, the pharyngeal opening pressure (PhOP), and active pharyngeal critical pressure (PcritA ). We examined the interrelationships between risk factors of OSA, airway collapsibility measures, and clinical manifestations of the disease.

METHODS

This is a cross-sectional analysis of consecutive OSA patients undergoing DISE-PAP. Nasal PAP was increased stepwise until inspiratory flow limitation was abolished, signifying PhOP. PcritA was derived from the resulting titration pressure-flow relationships. Clinical data including demographics, anthropometrics, sleep studies, and patient-symptom questionnaires were obtained from the electronic medical record. Multivariate regression was used to evaluate the relationship between risk factors, airway collapsibility, and clinical data.

RESULTS

On average, the 164 patients meeting inclusion criteria were middle-aged (54.2 ± 14.7 years), overweight/obese (BMI 29.9 ± 4.5 kg/m2 ), male (72.6%), White (79.3%) and had severe OSA (AHI 32.0 ± 20.5 events/hour). Mean PhOP was 7.5 ± 3.3 cm H2 O and mean PcritA was 0.80 ± 3.70 cm H2 O. Younger age (Standardized β = -0.191, p = 0.015) and higher BMI (Standardized β = 0.176, p = 0.028) were associated with higher PhOP, but not PcritA . PhOP and PcritA were both associated with AHI, supine AHI, and SpO2 nadir. Higher PhOP was associated with higher snoring scores (Standardized β = 0.246, p = 0.008), but not other patient-reported outcomes.

CONCLUSION

Objective assessment of passive and active airway mechanics during DISE relates with clinical risk factors for OSA. Quantitative measures of collapsibility provide accessible and meaningful data, enhancing the standard sleep surgery evaluation.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1978-1985, 2024.

Boosting obstructive sleep apnea therapy by non-pharmacological approaches: A network meta-analysis

INTRODUCTION

Obstructive sleep apnea (OSA) is the most common breathing-related sleep disorder with a considerable economic burden, low diagnosis and treatment rates. Continuous positive airway pressure (CPAP/PAP) is the principal therapy for OSA treatment; nevertheless, effectiveness is often limited by suboptimal adherence. The present network meta-analysis aims to systematically summarize and quantify different interventions' effects on CPAP/PAP adherence (such as mean usage CPAP or PAP in hours per night) in OSA patients, comparing Behavioral, Educational, Supportive and Mixed interventions in Randomized Control Trials (RCT).

METHODS

We conducted a computer-based search using the electronic databases of Pubmed, Psycinfo, Scopus, Embase, Chinal and Medline until August 2022, selecting 50 RCT.

RESULTS

By means of a random effect model network meta-analysis, results suggested that the most effective treatment in improving CPAP/PAP adherence was the Supportive approach followed by Behavioral Therapy focused on OSA treatment adherence.

CONCLUSION

This network meta-analysis might encourage the most experienced clinicians and researchers in the field to collaborate and implement treatments for improving CPAP/PAP treatment adherence. Moreover, these results support the importance of multidisciplinary approaches for OSA treatment, which should be framed within a biopsychological model.

Respiratory Dysfunction in Alzheimer's Disease-Consequence or Underlying Cause? Applying Animal Models to the Study of Respiratory Malfunctions

Alzheimer's disease (AD) is a neurodegenerative brain disease that is the most common cause of dementia among the elderly. In addition to dementia, which is the loss of cognitive function, including thinking, remembering, and reasoning, and behavioral abilities, AD patients also experience respiratory disturbances. The most common respiratory problems observed in AD patients are pneumonia, shortness of breath, respiratory muscle weakness, and obstructive sleep apnea (OSA). The latter is considered an outcome of Alzheimer's disease and is suggested to be a causative factor. While this narrative review addresses the bidirectional relationship between obstructive sleep apnea and Alzheimer's disease and reports on existing studies describing the most common respiratory disorders found in patients with Alzheimer's disease, its main purpose is to review all currently available studies using animal models of Alzheimer's disease to study respiratory impairments. These studies on animal models of AD are few in number but are crucial for establishing mechanisms, causation, implementing potential therapies for respiratory disorders, and ultimately applying these findings to clinical practice. This review summarizes what is already known in the context of research on respiratory disorders in animal models, while pointing out directions for future research.

Patient-level factors associated with the self-report of trouble sleeping to healthcare providers in adults at high risk for obstructive sleep apnea

INTRODUCTION

In adults at risk for obstructive sleep apnea, it is unclear what patient-level factors and symptoms may influence communication with healthcare providers regarding sleep difficulties. This analysis examined associations between sociodemographic characteristics, comorbidities, and obstructive sleep apnea-related symptoms and whether adults at high risk for obstructive sleep apnea reported trouble sleeping to an healthcare provider.

METHODS

The sample included participants from the 2015-2018 National Health and Nutrition Examination Survey determined by a modified STOP-Bang to be at high risk for obstructive sleep apnea (n = 2009). Participants were asked if they had ever reported trouble sleeping to an healthcare provider. Self-reported comorbidities and obstructive sleep apnea-related symptoms (ie, snoring, snorting, gasping, or breathing cessation during sleep, daytime sleepiness, fatigue, insomnia, and nocturia) were assessed.

RESULTS

Half of the sample (50.8%) never reported trouble sleeping to an healthcare provider. Factors associated with an increased likelihood of reporting trouble sleeping included female sex, former smoker, and prediabetes or diabetes, obstructive lung disease, daytime sleepiness, insomnia, nocturia, and symptoms of snorting, gasping, and/or breathing cessation during sleep. Factors associated with a decreased likelihood of reporting trouble sleeping included Mexican American background or Asian race and having less than a high school education.

CONCLUSION

Differences in sex, race, education, comorbidities, and obstructive sleep apnea-related symptoms exist between adults at high risk for obstructive sleep apnea who have and have not reported trouble sleeping to an healthcare provider. It is important for healthcare providers to ask all adults about sleep problems, recognizing that men, minorities, and persons with lower educational attainment may be less likely to report trouble sleeping.

NLRP3/miR-223-3p axis attenuates neuroinflammation induced by chronic intermittent hypoxia

Obstructive sleep apnea (OSA) is mainly characterized by chronic intermittent hypoxia (CIH) with multiple brain injuries. Nucleotide oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome is considered the most important factor inducing and maintaining inflammation. However, the role of NLRP3 and its underlying mechanism in CIH-elicited neuroinflammation remains unclear. We constructed an OSA-related CIH in vivo model and assessed the rats' cognitive behavior in the Morris water maze. The combination of miR-223-3p and NLRP3 was confirmed by the TargetScan database, double luciferase reporter gene experiment, and RNA immunoprecipitation (RIP) experiment. Western blot and ELISA assay were used to analyze the effects of miR-223-3p targeting NLRP3 on the expression of pyroptotic or inflammatory factors in vivo in CIH rats. Severe cognitive impairment was observed in rats at week 6 post-treatment, with increased inflammatory factors in the blood and hippocampus, heightened NLRP3 expression, and low miR-223-3p levels. And the good binding activity of the two was confirmed by dual luciferase reporter and RIP experiments. Next, we found that silencing NLRP3 or overexpression of miR-223-3p in the CIH model could improve cognitive deficits and reduce the level of proinflammatory factors and pyroptosis factors in rats. Finally, based on silencing NLRP3 or overexpression miR-223-3p, we confirmed that there was a regulatory relationship between miR-223-3p and NLRP3. Our results suggested that the NLRP3/ miR-223-3p axis played a role in attenuating CIH-induced neuroinflammation.

Effect of tele-yoga on aerobic capacity, respiratory muscle strength, and cognitive performance in patients with obstructive sleep apnea syndrome

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) causes a decrease in aerobic capacity, respiratory muscle strength, and cognitive function, negatively affecting health-related quality of life.

OBJECTIVES

This study aimed to compare aerobic capacity, respiratory muscle strength, cognitive performance, functional capacity, sleep quality and daytime sleepiness in OSAS patients practicing and not practicing tele-yoga (TY).

METHODS

44 OSAS patients (40 M, 4F) were randomized into TY and control groups. TY group underwent live synchronous group-based TY sessions, 60 min/day, three days/week, for 12 weeks. Control group performed unsupervised thoracic expansion exercises at home 4 times daily for 12 weeks. The following were evaluated at baseline and at the end of the 6th and 12th weeks: inspiratory and expiratory respiratory muscle strength (MIP, MEP), cardiopulmonary exercise test, Corsi Block Tapping Test (CBTT) and Stroop TBAG test, six-minute walk test (6MWT), Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS).

RESULTS

TY significantly improved MIP, and exercise test parameters (VE, HRmax,%HR, heart rate recovery in the first minute and RQmax), CBTT (forward) and Stroop TBAG test scores (parts of 3,4,5) compared to the controls (p<0.05). There were no significant changes 6MWT in the TY group compared to the control group (p > 0.05). Sleep duration (min), sleep efficiency, sleep quality of PSQI and ESS score improved significantly in the TY group compared to the control group (p < 0.05).

CONCLUSION

We suggest including TY intervention as a method of exercise in addition to CPAP treatments since it improves the health-related parameters of OSAS patients.

Semantic clustering on common list-learning tasks: a systematic review of the state of the literature and recommendations for future directions

INTRODUCTION

On some list-learning tasks, such as the California Verbal Learning Test (CVLT) or Hopkins Verbal Learning Test (HVLT), examinees have the opportunity to group words based on semantically related categories (i.e., semantic clustering). Semantic clustering (SC) is often considered the most efficient organizational strategy and adopting SC is presumed to improve learning and memory. In addition, SC is conceptualized as reflecting higher-order executive functioning skills. Although SC measures have intuitive appeal, to date, there are no comprehensive reviews of the SC literature base that summarize its psychometric utility. In this systematic review, we synthesize the literature to judge the validity of SC scores.

METHOD

We conducted a systematic literature search for empirical articles reporting SC from the CVLT and HVLT. We qualitatively described the relationship of SC with other list-learning and cognitive test scores and clinical diagnoses, contrasting SC with serial clustering and total learning scores when possible.

RESULTS

SC was inversely correlated with serial clustering. Higher SC was strongly associated with better learning and memory performances. When compared with cognitive tests, SC tended to have the strongest relationships with other memory measures and modest relationships with tests of executive functioning. SC had negligible to small relationships with most other cognitive domains. Traditional memory scores yielded stronger relationships to cognitive test performances than did SC. SC across clinical groups varied widely, but clinical groups tended to use SC less often than healthy comparison groups.

CONCLUSION

Our comprehensive review of the literature revealed that SC is strongly related to measures of learning and memory on the CVLT and HVLT and is correlated with a wide range of cognitive functions. SC has been understudied in relevant populations and additional research is needed to test the degree to which it adds incremental validity beyond traditional measures of learning and memory.

Sex and age affect acute and persisting COVID-19 illness

Long COVID is associated with neurological and neuropsychiatric manifestations. We conducted an observational study on 97 patients with prior SARS-CoV-2 infection and persisting cognitive complaints that presented to the University Health Network Memory Clinic between October 2020 and December 2021. We assessed the main effects of sex, age, and their interaction on COVID-19 symptoms and outcomes. We also examined the relative contribution of demographics and acute COVID-19 presentation (assessed retrospectively) on persistent neurological symptoms and cognition. Among our cohort, males had higher hospitalization rates than females during the acute COVID-19 illness (18/35 (51%) vs. 15/62 (24%); P = .009). Abnormal scores on cognitive assessments post-COVID were associated with older age (AOR = 0.84; 95% CI 0.74-0.93) and brain fog during initial illness (AOR = 8.80; 95% CI 1.76-65.13). Female sex (ARR = 1.42; 95% CI 1.09-1.87) and acute shortness of breath (ARR = 1.41; 95% CI 1.09-1.84) were associated with a higher risk of experiencing more persistent short-term memory symptoms. Female sex was the only predictor associated with persistent executive dysfunction (ARR = 1.39; 95% CI 1.12-1.76) and neurological symptoms (ARR = 1.66; 95% CI 1.19-2.36). Sex differences were evident in presentations and cognitive outcomes in patients with long COVID.

Patient's Perception of Nasal Function and Cosmesis After Maxillomandibular Advancement for Obstructive Sleep Apnea

Background: Maxillomandibular advancement (MMA) remains one of the most effective surgeries for the treatment of obstructive sleep apnea (OSA), but it can be difficult to manage nasal and midfacial esthetics for patients requiring significant maxillary advancement. Objective: To evaluate changes in the Standardized Cosmesis and Health Nasal Outcomes Survey (SCHNOS) after the modified MMA approach. Methods: This prospective study was conducted on subjects undergoing MMA at a tertiary referral center from September 2020 to August 2021. Nasal function, cosmesis, and sleepiness were assessed perioperatively with the SCHNOS, visual analog scale for nasal function and cosmesis, and Epworth sleepiness scale (ESS). Objective polysomnography data were also investigated. Results: Thirty-one subjects met inclusion criteria. After MMA, SCHNOS-O (obstruction domain) improved from 44.38 ± 26.21 to 19.03 ± -4.75 (p < 0.001). The SCHNOS-C (cosmesis domain) improved significantly from 13.95 ± 19.32 to 5.27 ± 8.93 (p = 0.029). Specific items evaluating self-esteem, nasal straightness, and symmetry showed significant improvement (p = 0.006, 0.025, 0.044). The ESS also improved from 9.41 ± 6.11 to 3.26 ± 3.03 (p < 0.001), and it correlated with nasal obstruction scores. Conclusion: In this study, patients' perception of nasal obstruction and appearance improved after applying the nasal modifications to MMA described for OSA.

Glaucoma Is Associated with the Risk of Obstructive Sleep Apnea: A Population-Based Nationwide Cohort Study

The association between glaucoma and the risk of obstructive sleep apnea (OSA) has not been fully evaluated. Therefore, this study aimed to investigate the prospective association between glaucoma and OSA. In total, 1437 patients with glaucoma and 5748 patients without glaucoma were enrolled after 1:4 propensity score matching using a nationwide cohort sample. We investigated OSA events during a 10-year follow-up period. Survival analysis, the log-rank test, and Cox proportional hazards regression models were used to calculate the incidence, disease-free survival rate, and hazard ratio (HR). The incidence of OSA was 12,509.0 person-years among those with glaucoma. The adjusted HR for patients with glaucoma developing OSA events during the follow-up period was 1.52 (95% confidence interval [CI]: 0.64-3.621) after other covariates. In a subgroup analysis, primary angle-closure glaucoma (PACG) showed a significantly increased adjusted HR for OSA events (5.65, 95% CI: 1.65-19.41), whereas we could not find any significant association between primary open-angle glaucoma (POAG) and OSA. The adjusted HR of OSA events in POAG was considerably increased 4 years after POAG diagnosis. PACG may be associated with an increased incidence of OSA. Clinicians should pay attention to early detection of OSA in patients with PACG.

The effects of an exercise intervention on executive function among overweight adults with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is associated with poorer executive function. This study examined the effects of a comprehensive exercise intervention on executive function in overweight adults with mild and moderate-to-severe OSA.

METHODS

Participants aged between 30 and 65 years, with a body mass index (BMI) ranging from 27 to 42 kg/m^2, participated in a 6-week exercise program. Standardized polysomnographic recording methods provided total Apnea-Hypopnea Index (AHI) and level of hypoxemia. Executive function was assessed using the NIH Toolbox Flanker Inhibitory Control Test. A submaximal treadmill exercise test evaluated cardiorespiratory fitness. Participants with baseline total AHI between 5 and 14.9 events/h were classified as mild OSA and participants with baseline total AHI 15 ≥ events/h were classified as moderate-to-severe OSA.

RESULTS

Fifteen participants completed 18 exercise sessions. Significant differences between OSA categories at baseline were observed for sleep characteristics, but not for fitness or executive function. Wilcoxon Signed Rank Tests showed significant increases in median values for the Flanker Test in the moderate-to-severe category only, z = 2.429, p < .015, η² = .737.

CONCLUSION

Six weeks of exercise improved executive function in overweight individuals with moderate-to-severe OSA, but not in those with mild OSA.

Research Letter: Impact of Obstructive Sleep Apnea Disease Duration on Neuropsychological Functioning After Traumatic Brain Injury: A Veterans Affairs TBI Model Systems Study

OBJECTIVE

To examine the relationship between obstructive sleep apnea (OSA) disease duration and cognitive functioning in those with a history of traumatic brain injury (TBI). We hypothesized that longer OSA duration would predict poorer cognitive performance.

SETTING

Inpatient brain injury units at a Veterans Affairs (VA) Polytrauma Rehabilitation Center.

PARTICIPANTS

Participants in the VA TBI Model Systems multicenter longitudinal study who enrolled in a modular substudy (April 15, 2018, to January 15, 2021) examining cognition following TBI. All participants had received inpatient rehabilitation for TBI and reported a diagnosis of OSA ( n = 89, mean age = 40.8 years, 97% male, 81% White). Reported duration of OSA ranged from 2 to 7 years (mean = 4.2; SD = 3.9).

DESIGN

Retrospective analysis of prospective cohort, cross-sectional.

MAIN MEASURES

Brief Test of Adult Cognition by Telephone (BTACT).

RESULTS

Controlling for age, education, and time to follow commands, OSA disease duration was negatively associated with delayed verbal memory ( R2Δ = 0.053, F(1,84) = 5.479, P = .022). Performance in other cognitive domains was not significantly associated with OSA disease duration.

CONCLUSION

This study provides preliminary evidence that longer duration of OSA (ie, time since diagnosis) has a negative impact on verbal memory in those with a history of hospitalized TBI. This finding extends the literature (which focused on the general population) on the cognitive impact of OSA and is consistent with hypothesized mechanisms such as hippocampal damage and secondary impact of fatigue. Findings suggest that early OSA identification and treatment may be prudent for persons with TBI.

Effect of Simultaneous Multiplane Surgery on Cardiopulmonary Function in Patients with Moderate to Severe Obstructive Sleep Apnea-Hypopnea Syndrome and Its Curative Effect

Objective

To investigate the changes in cardiopulmonary function in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) by one-stage multiplane surgery.

Methods

70 patients with moderate and severe OSAHS underwent nasal in our hospital from July 2017 to February 2021, palatopharyngeal, and/or tongue operations simultaneously and were followed up for 6 months. The Epworth Sleeping Scale (ESS) scores of patients before and after surgery were compared to observe the surgical efficacy, and the changes in the cardiopulmonary function of patients before and after surgery were detected. The static and dynamic indexes of cardiopulmonary function, respiratory disturbance index (AHI), and blood oxygen saturation (SaO2) were compared before and after the operation.

Results

After surgery, all patients' indexes of static lung function were improved compared with that before surgery. After surgery, the percentage of maximal oxygen uptake peak to the predicted value, percentage of oxygen pulse to the predicted value, the ratio of oxygen uptake power, anaerobic threshold, and maximum ventilatory capacity per minute/maximum exercise volume were increased compared with that before surgery, and AHI and SaO2 were improved compared with that before surgery.

Conclusion

This study suggests that it is feasible for patients with OSAHS who are unable to tolerate or unwilling to undergo noninvasive assisted ventilation to undergo simultaneous surgery for multiplane stenosis. It can reduce clinical symptoms and improve cardiopulmonary function.

Cognition in Patients with Sleep-Disordered Breathing: Can Obstructive and Central Apneic Pauses Play a Different Role in Cognitive Impairment?

BACKGROUND

There are increasing data linking sleep apnea with cognitive impairment. We aimed to clarify the relationship between sleep-disordered breathing (SDB) and cognition. Detailed attention was assigned to the potential role of central versus obstructive apneic pauses in cognitive impairment.

METHODS

Patients with suspected SDB were prospectively enrolled, and a complex sleep study was performed that included overnight polysomnography. A revised version of Addenbrooke's Cognitive Examination (ACE-R) was used to assess cognition, evaluating overall cognition and individual subdomains.

RESULTS

A total number of 101 participants were included in the study. In multivariate binary logistic regression analysis, obstructive apnea index ([OAI], 95% CI: 1.009-1.057, p = 0.008) was the only significant contributor to the model predicting attention deficit. The proportion of N1 stage of NREM sleep was the only significant contributor to the model predicting impaired verbal fluency (95% CI: 1.004-1.081, p = 0.029). No significant differences in sleep-related indices were observed in the remaining ACE-R subdomains.

CONCLUSION

Except for verbal fluency and attention, we failed to find any significant association of sleep-related indices with the impairment in different cognitive subdomains. Our data suggest that impairment observed in verbal fluency is associated with a higher proportion of shallow NREM sleep, and attention deficit is associated with higher OAI. Obstructive respiratory episodes seem to play a more important role in cognitive impairment when compared to central ones.

Impairment of executive functions due to sleep alterations: An integrative review on the use of P300

Objective

Cognitive impairment due to sleep deprivation (SD) is an important global health concern as part of the growing rates of sleep disorders and sleep deprivation worldwide. Amongst the affected cognitive processes, the effects of SD on the executive functions (EFs) show diverse methods and inconclusive or contradictory results, highlighting the importance of further research in this field. Considering this scenario, we evaluate one of the most used methods for objectively evaluating EFs on SD: the event-related potential (ERP) P300.

Methods

Our study provides a comprehensive review on the use of P300 for evaluating executive functions in sleep alterations on subjects of all ages, as well as an analysis on the efficiency of P300 as an assessment method for executive functions compared to traditional neurocognitive batteries. We review the benefits of P300 application for multiple sleep/wake alterations, whether evoked in laboratory or as part of pre-existing sleep disorders.

Results

We assess the diverse protocols used to elicit and complement P300, the most identified alterations in amplitude and latency, and suggest new lines of study that could benefit from P300 within the field.

Conclusion

We conclude that P300 is a valuable asset for evaluating executive dysfunction under sleep deprivation both as a standalone protocol and in conjunction with subjective methods, with consistently significant results in assessing executive dysfunction in a diversity of subjects and etiologies.

Contribution of Obstructive Sleep Apnoea to Cognitive Functioning of Males With Coronary Artery Disease: A Relationship With Endocrine and Inflammatory Biomarkers

Introduction

Our exploratory study aimed to determine whether obstructive sleep apnoea (OSA) could affect cognitive functioning in males with coronary artery disease (CAD), and whether such impact could be associated with changes in thyroid hormones and inflammatory marker regulation on cognitive functioning.

Method

We evaluated different endocrine and inflammatory biomarkers, including free triiodothyronine [fT3], free tetraiodothyronine [fT4], N-terminal pro-B-type natriuretic peptide [NT-pro-BNP], and high-sensitivity C-reactive protein [hs-CRP] serum levels in 328 males (x¯ = 57 ± 10 years), undergoing cardiac rehabilitation after an acute coronary event. Participants underwent full-night polysomnography and were classified in mild/non-OSA (n = 253) and OSA (n = 75) according to an apnoea-hypopnoea index ≥ 15 event/h. Cognitive functioning testing included the Digit Span Test, Digit Symbol Test (DSST), and Trail Making Test. Analyses of variance assessed the impact of OSA on cognitive functioning and possible relationships of fT3/fT4, NT-pro-BNP and with hs-CRP on cognitive measures.

Results

Significant group (OSA, mild/non-OSA) × NT-pro-BNP (<157.0 vs. ≥157.0, ng/L) interactions were found for the DSST raw score (F_(2,324) = 3.58, p = 0.014). Decomposition of interactions showed that the DSST scores of the OSA group with NT-pro-BNP ≥ 157.0 ng/L (M = 33.2; SD = 8.1) were significantly lower, p = 0.031, than those of the mild/non-OSA with NT-pro-BNP < 157.0 ng/L (M = 37.7; SD = 8.9).

Conclusion

These findings indicate that males with OSA and clinically elevated NT-pro-BNP levels experienced inferior psychomotor performance compared to those without OSA and reduced NT-pro-BNP levels.

An Ultra-Short Measure of Excessive Daytime Sleepiness Is Related to Circadian Biological Rhythms: The French Psychometric Validation of the Barcelona Sleepiness Index

The Barcelona Sleepiness Index (BSI) is an ultra-short instrument with several advantages for assessing excessive daytime sleepiness (EDS). The present study was performed to analyze the validity of the French version of the BSI in screening for EDS. We conducted a cross-sectional study on a population of students using an online questionnaire. The French version of the BSI was developed by a rigorous forward-backward translation process. We computed the discrimination properties of the BSI to predict EDS assessed by the Epworth Sleepiness Scale (ESS), as well as correlations with other sleep measures. In total, 662 students were enrolled in the study (mean age: 20.9 years, 76.0% women). The BSI score (mean = 1.5 ± 1.0) showed a strong correlation with the ESS score (r = 0.47, p < 10−4) and acceptable discrimination of EDS assessed by ESS score ≥ 11 (AUC = 0.742) with an optimal cutoff point of 2, as in the original study. The BSI score was significantly associated with sleep deprivation and social jetlag. Therefore, the French version of the BSI is a valid ultra-short instrument for EDS screening in individuals. In addition, the BSI score may be associated with both homeostatic and circadian processes. Further studies are needed to confirm these findings in general populations and in patients with sleep disorders.

PAI-1: A Major Player in the Vascular Dysfunction in Obstructive Sleep Apnea?

Obstructive sleep apnea is a chronic and prevalent condition that is associated with endothelial dysfunction, atherosclerosis, and imposes excess overall cardiovascular risk and mortality. Despite its high prevalence and the susceptibility of CVD patients to OSA-mediated stressors, OSA is still under-recognized and untreated in cardiovascular practice. Moreover, conventional OSA treatments have yielded either controversial or disappointing results in terms of protection against CVD, prompting the need for the identification of additional mechanisms and associated adjuvant therapies. Plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of tissue-type plasminogen activator (tPA) and urinary-type plasminogen activator (uPA), is a key regulator of fibrinolysis and cell migration. Indeed, elevated PAI-1 expression is associated with major cardiovascular adverse events that have been attributed to its antifibrinolytic activity. However, extensive evidence indicates that PAI-1 can induce endothelial dysfunction and atherosclerosis through complex interactions within the vasculature in an antifibrinolytic-independent matter. Elevated PAI-1 levels have been reported in OSA patients. However, the impact of PAI-1 on OSA-induced CVD has not been addressed to date. Here, we provide a comprehensive review on the mechanisms by which OSA and its most detrimental perturbation, intermittent hypoxia (IH), can enhance the transcription of PAI-1. We also propose causal pathways by which PAI-1 can promote atherosclerosis in OSA, thereby identifying PAI-1 as a potential therapeutic target in OSA-induced CVD.

Mouth Closing to Improve the Efficacy of Mandibular Advancement Devices in Sleep Apnea

RATIONALE

Mouth breathing increases upper airway collapsibility, leading to decreased efficacy of obstructive sleep apnea (OSA) treatments. We hypothesized that the use of mandibular advancement devices (MAD) increases mouth breathing and, thus, using an adhesive mouthpiece (AMT), to prevent mouth breathing, in combination with MAD can improve the treatment efficacy.

OBJECTIVES

To evaluate the efficacy of MAD + AMT in comparison to MAD alone.

METHODS

A prospective crossover pilot study was designed to test this hypothesis. Briefly, adult participants with an apnea-hypopnea index (AHI) between 10-50 events/h at the screening visit were randomized to no treatment (baseline), MAD treatment, AMT treatment, and MAD+AMT treatment. As a primary analysis, absolute AHI was compared between MAD and MAD + AMT arms. Secondary analyses included quantifying the percent change in AHI, percentage of complete (AHI < 5 events/h) and incomplete (AHI 5 - 10 events/h) responders, and the efficacy of AMT alone in comparison with other treatment arms.

RESULTS

A total 21 of participants were included. (Baseline AHI= 24.3±9.9 event/h) The median AHI (Interquartile [IQR]) in the MAD and MAD+AMT arms were 10.5 [5.4-19.6] events/h and 5.6 [2.2-11.7] events/h (p-value= 0.02), respectively. A total of 76% of individuals achieved an AHI < 10 events/h in the MAD + AMT arm vs. 43% in the MAD arm (p-value<0.01). Finally, the observed effect was similar in moderate to severe OSA (AHI ≥15 events/h) in terms of absolute reduction and treatment responders, and AMT alone did not significantly reduce the AHI compared to baseline.

CONCLUSION

Combination of an adhesive mouthpiece and MAD is a more effective therapy than MAD alone. These findings may help improve clinical decision-making in sleep apnea.

Neurological effects of respiratory dysfunction

The respiratory and the nervous systems are closely interconnected and are maintained in a fine balance. Central mechanisms maintain strict control of ventilation due to the high metabolic demands of brain which depends on a continuous supply of oxygenated blood along with glucose. Moreover, brain perfusion is highly sensitive to changes in the partial pressures of carbon dioxide and oxygen in blood, which in turn depend on respiratory function. Ventilatory control is strictly monitored and regulated by the central nervous system through central and peripheral chemoreceptors, baroreceptors, the cardiovascular system, and the autonomic nervous system. Disruption in this delicate control of respiratory function can have subtle to devastating neurological effects as a result of ensuing hypoxia or hypercapnia. In addition, pulmonary circulation receives entire cardiac output and this may act as a conduit to transmit infections and also for metastasis of malignancies to brain resulting in neurological dysfunction. Furthermore, many neurological paraneoplastic syndromes can have underlying lung malignancies resulting in respiratory dysfunction. It is essential to understand the underlying mechanisms and the resulting manifestations in order to prevent and effectively manage the many neurological effects of respiratory dysfunction. This chapter explores the various neurological effects of respiratory dysfunction with focus on their pathophysiology, etiologies, clinical features and long-term neurological sequelae.

Effects of Obstructive Sleep Apnea and CPAP on Cognitive Function

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial upper airway obstruction during sleep. Studies indicate that OSA is an independent risk factor for cognitive decline in older patients. The purpose of this paper is to critically review the recent literature on the cognitive effects of untreated OSA and the benefits of treatment across cognitive domains.

RECENT FINDINGS

OSA's greatest impact appears to be on attention, vigilance, and information processing speed. Furthermore, the presence of OSA seems to have a significant impact on development and progression of mild cognitive impairment (MCI). Impact of OSA treatment, particularly with CPAP, appears to mitigate and slow the rate of cognitive decline and may reduce the risk of dementia. Larger properly controlled studies, of a prospective nature, are required to further elucidate the degree of treatment effect. More studies are needed on other treatments for OSA such as oral mandibular devices and hypoglossal nerve stimulation.

Self-reported view on work capacity predicts abnormal Oxford Sleep Resistance Test results in patients with obstructive sleep apnea

STUDY OBJECTIVES

The Oxford Sleep Resistance Test is an objective vigilance test based on behavior. It is a modified version of the maintenance of wakefulness test and is considered less burdensome and less expensive than the maintenance of wakefulness test. Although professional drivers with obstructive sleep apnea in Europe must be assessed for their ability to maintain adequate wakefulness on a yearly basis, Oxford Sleep Resistance Test results are usually normal in this population. In this retrospective observational study, we searched for predictive factors of abnormal Oxford Sleep Resistance Test sleep latency.

METHODS

We included 1,071 Oxford Sleep Resistance Test results of patients with obstructive sleep apnea (95% men, aged 21-74 years). Mean sleep latency < 40 minutes was considered abnormal.

RESULTS

Sleep latency was abnormal in 12.0% of tests. Participants at risk for abnormal test results self-reported as being sleepy, depressed, on sick leave, unemployed, or retired or considered themselves unable to work. In a logistic regression model, the self-reported view on work capacity was the most important predictor of abnormal Oxford Sleep Resistance Test sleep latency (odds ratio, 3.5). Ongoing sick leave was also an important predictor for abnormal test results.

CONCLUSIONS

A self-reported good ability to work predicts that a patient with sleep apnea can maintain wakefulness in a vigilance test. This may help in reducing the increasing challenge with frequent tests.

Effects of surgery for obstructive sleep apnea on cognitive function and driving performance

BACKGROUND

Obstructive sleep apnea (OSA) is associated with a significantly increased risk of motor vehicle accidents in addition to such cognitive impairments as attention and memory deficits. The aim of the study was to examine the effect of upper airway surgery for OSA on driving and cognitive function.

METHODS

Adult patients who underwent surgery for OSA at a tertiary medical center in 2016-2019 were prospectively recruited. Patients were assessed before and 3-6 months after surgery with a self-report and neurocognitive battery and a driving simulation platform.

RESULTS

The cohort included 32 patients of average age 46.9 ± 11.6 years. During the 3 years before treatment, 9 patients had been involved in road accidents and 18 were detained by police for traffic violations. After surgery, there was a significant decrease in the Epworth Sleepiness Scale (13.7 vs. 8.1, p 0.043) and a significant reduction in time to completion of the Color Trail Test (part 1: 21.4 vs 18.7 s, p = 0.049; part 2: 46.8 vs 40.5 s, p = 0.038). Improvements in divided attention and selective attention response times were noted on the advanced stages of the Useful Field of Vision Scale (p = 0.013, p = 0.054). Before surgery, patients showed a high tendency to drive over the speed limit and to cross the dividing line to the opposite lane on the simulation test. Nevertheless, all considered themselves good drivers. These tendencies decreased after treatment.

CONCLUSIONS

Surgery for OSA can significantly improve driving performance and cognitive function.

Effectiveness of Continuous Positive Airway Pressure Versus Mandibular Advancement Device in Severe Obstructive Sleep Apnea Patients With Mandibular Retrognathia: A Prospective Clinical Trial

AIM

Some obstructive sleep apnea (OSA) patients may have mandibular retrognathia (ANB > 4.7° and SNB < 76.2°). Currently, there are no studies that have compared the effectiveness of continuous positive airway pressure (CPAP) versus mandibular advancement device (MAD) in severe OSA patients with mandibular retrognathia. We explored the efficacy of CPAP versus MAD for the treatment of severe OSA patients with mandibular retrognathia.

METHODS

A total of 105 patients were enrolled. Outcomes were assessed by using polysomnography, Epworth Sleepiness Scale (ESS), Snore Scale (SS), Self-rating Anxiety Scale (SAS), and compliance, before treatment and after 6 and 12 months of treatment.

RESULTS

Continuous positive airway pressure was superior to MAD in improving polysomnographic outcomes and SS score, but reported compliance was higher on MAD. There is no significant difference between the 2 treatments in terms of ESS score and SAS score. Obstructive sleep apnea patients with mandibular retrognathia showed greater improvement than those without mandibular retrognathia in terms of apnea-hypopnea index and oxygen desaturation index after MAD.

CONCLUSION

Continuous positive airway pressure and MAD are both effective in treating severe OSA patients with mandibular retrognathia. Mandibular advancement device is a good alternative to CPAP in severe OSA patients with mandibular retrognathia. Mandibular advancement device is more effective in treating OSA patients with mandibular retrognathia than those without. Trial registration: ChiCTR2000032541.

Effect of mild obstructive sleep apnea in mountaineers during the climb to Mount Aconcagua

OBJECTIVE

to compare mountaineers with and without asymptomatic sleep apnea (OSA) before the ascent and to study high altitude-related sleep disorders, its interaction with metabolic, neuroendocrine and immunological components.

MATERIAL AND METHODS

During an expedition to Mount Aconcagua, researchers assessed the respiratory polygraphy (RP), clinical condition and inflammatory parameters, and rhythm of cortisol secretion in mountaineers sleeping at different altitude camps.

RESULTS

8 athletes (4 women), 36 years old (25-51) participated. Baseline and final BMI were; 23.6 (20.9-28.7) and 22.77 (20.9-27.7), respectively: p<0.01. 40 valid RP recordings were analyzed. At 746 m.a.s.l. (baseline), only 2 mountaineers presented mild asymptomatic OSA. The OSA group presented baseline apnea-hypopnea index (AHI) values between 5-15 events per hour, which evidence a mild respiratory sleep disorder with AHI increased by altitude depending of central apneas and hypopneas (p<0.05) as high altitude periodic breathing pattern but no increase in obstructive apneas (p<0.01). The circadian rhythm of cortisol was maintained in all cases in which they had not received treatment with dexamethasone and their values increased with the altitude reached. Increased systolic blood pressure was observed in the OSA group.

CONCLUSION

In a context of hypobaric hypoxia, individuals with pre-existing asymptomatic OSA are prone to experiencing lower oxygen saturations and clinical deterioration.