Untreated Obstructive Sleep Apnea Patients Research Articles

Globus sensation in obstructive sleep apnea patients; A cross-sectional study of 120 patients.

Globus pharyngeus (GP) is a common complaint in many disciplines, especially otolaryngology. Pharyngeal symptoms and abnormalities, including GP, are frequent in obstructive sleep apnea (OSA) patients. This study aims to investigate globus sensation in non-operated OSA patients. After translation and validation, the Laryngopharyngeal Measure of Perceived Sensation (LUMP) was administered to 120 untreated OSA patients. All patients underwent polysomnography and thorough physical examination. The association between LUMP scores and OSA measures was evaluated. LUMP score had a significant correlation with the Epworth Sleepiness Scale (ESS) (Spearman's ρ = 0.269, p = 0.004), and BMI (Spearman's ρ = 0.249, p = 0.007), the anatomical position of the tongue (ρ = -0.191, p = 0.04) and the Friedman grade of tonsils (ρ = 0.241, p = 0.01). It correlated with SpO2 nadir, though it did not reach statistical significance. The results of our study depict a relationship between a self-report measure of globus sensation and daytime sleepiness, BMI and tonsil size. In the absence of a direct relationship between OSA severity parameters and GP, we hypothesize a role for shared comorbidities and anatomical phenotypes. The increased frequency of GP in OSA patients should be considered when evaluating the complications of surgical interventions in these patients.

Cognitive complaints in patients with untreated obstructive sleep apnea versus patients with neurological and respiratory diseases: prevalence, severity and risk factors

PurposeLittle is known about cognitive complaints (self-reported problems in cognitive functioning) in patients with Obstructive Sleep Apnea (OSA). We compared the prevalence and severity of cognitive complaints in patients with untreated OSA to patients with neurological and respiratory diseases. We also studied risk factors for cognitive complaints across these diseases, including OSA.MethodsWe used a convenience sample to compare untreated OSA patients (N = 86) to patients with stroke (N = 166), primary brain tumor (N = 197) and chronic obstructive pulmonary disease (COPD, N = 204) on cognitive complaints (Cognitive Failure Questionnaire, CFQ), anxiety and depression (Hospital Anxiety and Depression Scale, HADS) and cognitive impairments using neuropsychological tests. We combined all patient groups (OSA, stroke, brain tumor and COPD) and studied potential risk factors (demographic variables, anxiety, depression and cognitive impairments) for cognitive complaints across all patient groups using regression analysis.ResultsThe prevalence of cognitive complaints was higher in OSA patients and complaints of forgetfulness and distractibility were more severe compared to stroke and primary brain tumor patients, but similar to or lower than COPD patients. Regression analysis for the combined sample of all patient groups showed that cognitive complaints were most strongly associated with symptoms of anxiety and depression.ConclusionA high rate of OSA reported clinically significant cognitive complaints, comparable to other respiratory and neurological patients. Symptoms of anxiety and depression are important risk factors for cognitive complaints in patients with various neurological and respiratory diseases. Future studies should examine the relation between anxiety, depression and cognitive complaints in patients with OSA.

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

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

Predicting the impact of CPAP on brain health: A study using the sleep EEG-derived brain age index.

This longitudinal study investigated potential positive impact of CPAP treatment on brain health in individuals with obstructive sleep Apnea (OSA). To allow this, we aimed to employ sleep electroencephalogram (EEG)-derived brain age index (BAI) to quantify CPAP's impact on brain health and identify individually varying CPAP effects on brain aging using machine learning approaches. We retrospectively analyzed CPAP-treated (n = 98) and untreated OSA patients (n = 88) with a minimum 12-month follow-up of polysomnography. BAI was calculated by subtracting chronological age from the predicted brain age. To investigate BAI changes before and after CPAP treatment, we compared annual ΔBAI between CPAP-treated and untreated OSA patients. To identify individually varying CPAP effectiveness and factors influencing CPAP effectiveness, machine learning approaches were employed to predict which patient displayed positive outcomes (negative annual ΔBAI) based on their baseline clinical features. CPAP-treated group showed lower annual ΔBAI than untreated (-0.6 ± 2.7 vs. 0.3 ± 2.6 years, p < 0.05). This BAI reduction with CPAP was reproduced independently in the Apnea, Bariatric surgery, and CPAP study cohort. Patients with more severe OSA at baseline displayed more positive annual ΔBAI (=accelerated brain aging) when untreated and displayed more negative annual ΔBAI (=decelerated brain aging) when CPAP-treated. Machine learning models achieved high accuracy (up to 86%) in predicting CPAP outcomes. CPAP treatment can alleviate brain aging in OSA, especially in severe cases. Sleep EEG-derived BAI has potential to assess CPAP's impact on brain health. The study provides insights into CPAP's effects and underscores BAI-based predictive modeling's utility in OSA management.

Daytime sleepiness and vigilance in untreated obstructive sleep apnea patients - the preliminary results from Vietnam

Daytime sleepiness and vigilance in untreated obstructive sleep apnea patients - the preliminary results from Vietnam

O011 Exploring Nocturnal Blood Pressure Surges Relationships with Brain Health and Cognitive Function.

Abstract Introduction Cerebral small vessel disease is a possible mechanism to explain the link between long-term incompletely treated obstructive sleep apnoea (OSA) and dementia. Recent evidence suggests nocturnal blood pressure (BP) surges triggered by OSA-related sympathetic hyperactivity could play a critical role. However, this remains to be determined as they often occur concurrently with desaturation events. Methods During an in-lab polysomnography study of 7 controls [AHI≤5] and 20 untreated OSA patients [AHI&amp;gt;5] aged 45-65 years the frequency of blood pressure surges (&amp;gt;10% systolic ↑BP) in the presence or not of desaturation events (↓SpO2&amp;gt;3%) were quantified with a SOMNOtouch™ NIBP device. Cerebral perfusion was assessed with pCASL MRI and brain lesions with anatomical MRI scans. The global deficit score was determined for cognitive function assessment. Inflammation was quantified with blood hs-CRP. Results After controlling for age, BMI, gender, blood glucose and cholesterol, higher AHI was associated with more frequent BP surges (r=0.52, P=0.03), BP surges occurring with desaturation events (r=0.87, P&amp;lt;0.001), but not with BP surges without oxygen desaturation (P = 0.11). Concurrent BP surges and oxygen desaturation was associated with increased hs-CRP (r=0.55, P=0.02). Frequency of BP surges was not related to cerebral perfusion, brain lesions or the global deficit score. Conclusions Recording nocturnal blood pressure surges during polysomnography may provide insight into the cardiovascular burden associated with OSA. Interestingly, an inflammatory response is associated with BP surges only during desaturations, i.e. during respiratory events. Further work is needed to assess the utility of BP surges in predicting longer-term cognitive deficits.

A Narrative Review on Obstructive Sleep Apnea in China: A Sleeping Giant in Disease Pathology

We review the aspects of obstructive sleep apnea (OSA), which is the most common respiratory disorder of sleep in China. Approximately 176 million people in China have apnea/hypopnea index ≥5/h, ranking first among the ten countries with the highest prevalence rates. Two-thirds of patients do not receive treatment at all or withdraw after only brief treatment in a survey nested in two centers in China. Drowsiness and progressive cognitive impairment related to OSA decrease work performance and add to workplace errors and accidents. Many patients with OSA remain undiagnosed. Untreated OSA increases the risk of developing cardiovascular diseases and metabolic diseases. Undiagnosed and untreated OSA patients place a great burden on healthcare costs and services, and thus enormous economic burdens across most countries across the world, due to the global epidemic of obesity, an important contributor to OSA. Continuous positive airway pressure is the first-line treatment for OSA in China; however, adherence levels are poor. Effective and less labor-intensive methods that improve adherence need to be further investigated. Traditional Chinese medicine and acupuncture are promising treatments but with unproven efficacy.

Validating Discriminative Signatures for Obstructive Sleep Apnea in Exhaled Breath.

Rapid and reliable tools for the diagnosis and monitoring of obstructive sleep apnea (OSA) are currently lacking. Prior studies using a chemical analysis of exhaled breath have suggested the existence of an OSA-specific metabolic signature. Here, we validated this diagnostic approach and the proposed marker compounds, as well as their potential to reliably diagnose OSA. In this cross-sectional observational study, exhaled breath was analyzed using secondary electrospray ionization high-resolution mass spectrometry. The study cohort included untreated OSA patients, OSA patients treated with continuous positive airway pressure and healthy subjects. The robustness of previously reported OSA markers was validated based on detectability, significant differences between groups (Mann–Whitney U test) and classification performance. The breath analysis of 118 participants resulted in 42 previously reported markers that could be confirmed in this independent validation cohort. Nine markers were significantly increased in untreated OSA compared to treated OSA, with a subset of them being consistent with a previous validation study. An OSA prediction based on the confirmed OSA signature performed with an AUC of 0.80 (accuracy 77%, sensitivity 73% and specificity 80%). As several breath markers were clearly found to be repeatable and robust in this independent validation study, these results underscore the clinical potential of breath analysis for OSA diagnostics and monitoring.

Hypoxic Regulation of the Large-Conductance, Calcium and Voltage-Activated Potassium Channel, BK

Hypoxia is a condition characterized by a reduction of cellular oxygen levels derived from alterations in oxygen balance. Hypoxic events trigger changes in cell-signaling cascades, oxidative stress, activation of pro-inflammatory molecules, and growth factors, influencing the activity of various ion channel families and leading to diverse cardiovascular diseases such as myocardial infarction, ischemic stroke, and hypertension. The large-conductance, calcium and voltage-activated potassium channel (BK) has a central role in the mechanism of oxygen (O2) sensing and its activity has been related to the hypoxic response. BK channels are ubiquitously expressed, and they are composed by the pore-forming α subunit and the regulatory subunits β (β1–β4), γ (γ1–γ4), and LINGO1. The modification of biophysical properties of BK channels by β subunits underly a myriad of physiological function of these proteins. Hypoxia induces tissue-specific modifications of BK channel α and β subunits expression. Moreover, hypoxia modifies channel activation kinetics and voltage and/or calcium dependence. The reported effects on the BK channel properties are associated with events such as the increase of reactive oxygen species (ROS) production, increases of intracellular Calcium ([Ca2+]i), the regulation by Hypoxia-inducible factor 1α (HIF-1α), and the interaction with hemeproteins. Bronchial asthma, chronic obstructive pulmonary diseases (COPD), and obstructive sleep apnea (OSA), among others, can provoke hypoxia. Untreated OSA patients showed a decrease in BK-β1 subunit mRNA levels and high arterial tension. Treatment with continuous positive airway pressure (CPAP) upregulated β1 subunit mRNA level, decreased arterial pressures, and improved endothelial function coupled with a reduction in morbidity and mortality associated with OSA. These reports suggest that the BK channel has a role in the response involved in hypoxia-associated hypertension derived from OSA. Thus, this review aims to describe the mechanisms involved in the BK channel activation after a hypoxic stimulus and their relationship with disorders like OSA. A deep understanding of the molecular mechanism involved in hypoxic response may help in the therapeutic approaches to treat the pathological processes associated with diseases involving cellular hypoxia.

The role of education in cognitive functions among middle-age and older patients with untreated obstructive sleep apnea.

ObjectiveThe goal of the current study was to examine the interaction between educational level and obstructive sleep apnea (OSA), one of the most under diagnosed sleep disorders, on cognitive functions such as verbal fluency, psychomotor vigilance, executive functions, visuospatial ability, and attention span.Material and MethodsOne hundred and nine participants (47 controls and 62 untreated OSA patients) participated in the study and completed the Wisconsin Card Sorting Test, WAIS-III digit span and block design, semantic and phonemic fluency tests, and a psychomotor vigilance task. Subjective sleep and health measures were assessed.ResultsIn semantic fluency and visuospatial ability tasks, patients with higher education performed better than patients with lower education and controls with lower education. This difference in moderation effects was not observed for vigilance, phonemic fluency, attention span, or executive functions although education was a significant predictor for all cognitive tasks.ConclusionHigher education may have contributed to cognitive reserve in OSA patients (but not for controls) as reflected in better semantic fluency and visuospatial ability. This benefit of higher education contributing to larger cognitive reserve in patients with OSA helped buffer the deficits for some cognitive functions but not for others. This may indicate that this buffer is not limitless because when the cognitive demand gets higher the educational buffer no longer works.

Inspiratory Muscle Training for Obstructive Sleep Apnea: Protocol Development and Feasibility of Home Practice by Sedentary Adults

Background: Inspiratory muscle training (IMT) may improve respiratory and cardiovascular functions in obstructive sleep apnea (OSA) and is a potential alternative or adjunct treatment to continuous positive airway pressure (CPAP). IMT protocols were originally designed for athletes, however, we found some OSA patients could not perform the exercise, so we aimed for a more OSA-friendly protocol. Our feasibility criteria included (1) participants successfully managing the technique at home; (2) participants completing daily practice sessions and recording data logs; and (3) capturing performance plateaus to determine an optimal length of the intervention.Methods: Five sedentary OSA patients participated in this feasibility study (three men, mean age = 61.6 years, SD = 10.2). Using a digital POWERbreathe K4 or K5 device, participants performed 30 daily inhalations against a resistance set at a percentage of maximum, recalculated weekly. Participants were willing to perform one but not two daily practice sessions. Intervention parameters from common IMT protocols were adapted according to ability and subjective feedback. Some were unable to perform the typically used 75% of maximum inspiratory resistance so we lowered the target to 65%. The technique required some practice; therefore, we introduced a practice week with a 50% target. After an initial 8 weeks, the intervention was open-ended and training continued until all participants demonstrated at least one plateau of inspiratory strength (2 weeks without strength gain). Weekly email and phone reminders ensured that participants completed all daily sessions and logged data in their online surveys. Weekly measures of inspiratory resistance, strength, volume, and flow were recorded.Results: Participants successfully completed the practice and subsequent 65% IMT resistance targets daily for 13 weeks. Inspiratory strength gains showed plateaus in all subjects by the end of 10 weeks of training, suggesting 12 weeks plus practice would be sufficient to achieve and capture maximum gains. Participants reported no adverse effects.Conclusion: We developed and tested a 13-week IMT protocol in a small group of sedentary, untreated OSA patients. Relative to other IMT protocols, we successfully implemented reduced performance requirements, a practice week, and an extended timeframe. This feasibility study provides the basis for a protocol for clinical trials on IMT in OSA.

Opioids and obstructive sleep apnea.

Freire C, Sennes LU, Polotsky VY. Opioids and obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):647-652.

Heterogeneity of Melanoma Cell Responses to Sleep Apnea-Derived Plasma Exosomes and to Intermittent Hypoxia.

Simple SummaryObstructive sleep apnea has been implicated in deleterious effects on cancer incidence and outcomes. Among the cancers identified as affected by sleep apnea, melanoma has consistently emerged as particularly susceptible. Furthermore, evidence suggests that exosomes, microparticles that originate from all cells and contain a variety of biologically active molecules such as microRNAs, can modify cancer cell properties. Here, we examined whether exosomes from sleep apnea patients can alter melanoma cell properties, and whether such effects were attributable to selected microRNA candidates, and affected melanoma cells harboring different mutations differently. In these experiments, the divergent responses of three melanoma cell lines to exosomes from sleep apnea patients before and after treatment indicated that STK11 gene mutations in melanoma cells make them particularly responsive to sleep apnea by altering cellular metabolism, and that specific microRNAs appear to underlie such effects.Obstructive sleep apnea (OSA) is associated with increased cutaneous melanoma incidence and adverse outcomes. Exosomes are secreted by most cells, and play a role in OSA-associated tumor progression and metastasis. We aimed to study the effects of plasma exosomes from OSA patients before and after adherent treatment with continuous positive airway pressure (CPAP) on melanoma cells lines, and also to identify exosomal miRNAs from melanoma cells exposed to intermittent hypoxia (IH) or normoxia. Plasma-derived exosomes were isolated from moderate-to-severe OSA patients before (V1) and after (V2) adherent CPAP treatment for one year. Exosomes were co-incubated with three3 different melanoma cell lines (CRL 1424; CRL 1619; CRL 1675) that are characterized by genotypes involving different mutations in BRAF, STK11, CDKN2A, and PTEN genes to assess the effect of exosomes on cell proliferation and migration, as well as on pAMK activity in the presence or absence of a chemical activator. Subsequently, CRL-1424 and CRL-1675 cells were exposed to intermittent hypoxia (IH) and normoxia, and exosomal miRNAs were identified followed by GO and KEG pathways and gene networks. The exosomes from these IH-exposed melanoma cells were also administered to THP1 macrophages to examine changes in M1 and M2 polarity markers. Plasma exosomes from V1 increased CRL-1424 melanoma cell proliferation and migration compared to V2, but not the other two cell lines. Exposure to CRL-1424 exosomes reduced pAMPK/tAMPK in V1 compared to V2, and treatment with AMPK activator reversed the effects. Unique exosomal miRNAs profiles were identified for CRL-1424 and CRL-1675 in IH compared to normoxia, with six miRNAs being regulated and several KEGG pathways were identified. Two M1 markers (CXCL10 and IL6) were significantly increased in monocytes when treated with exosomes from IH-exposed CRL-1424 and CRL-1625 cells. Our findings suggest that exosomes from untreated OSA patients increase CRL-1424 melanoma malignant properties, an effect that is not observed in two other melanoma cell lines. Exosomal cargo from CRL-1424 cells showed a unique miRNA signature compared to CRL-1675 cells after IH exposures, suggesting that melanoma cells are differentially susceptible to IH, even if they retain similar effects on immune cell polarity. It is postulated that mutations in STK-11 gene encoding for the serine/threonine kinase family that acts as a tumor suppressor may underlie susceptibility to IH-induced metabolic dysfunction, as illustrated by CRL-1424 cells.

Submental ultrasound for assessment of difficult mask ventilation in patients with obstructive sleep apnoea posted for surgery under general anaesthesia. A prospective observational study

Background and aimsUndiagnosed obstructive sleep apnoea (OSA) is commonly encountered in the perioperative setting. The ASA Task Force recognizes OSA as an important risk factor for difficult mask ventilation or intubation, or both. Thus effective mask ventilation plays a pivotal role in safe airway management of these patients. Pre-operative submental ultrasonography (USG) could be an adjunct to conventional anthropometric parameters for prediction of difficult mask ventilation (DMV). The aim of this study is to evaluate the accuracy of USG screening parameters in predicting DMV in patients presenting with undiagnosed OSA in the perioperative period. MethodsThis prospective observational study was conducted in patients undergoing elective surgery in a tertiary care hospital of south India. The study population consisted of undiagnosed and untreated OSA patients with STOP-BANG scores>3 on pre-operative screening. Submental USG was performed to record three parameters; the distance between the lingual arteries (DLA), hyo-mental distance (HMD) and tongue base thickness (TBT). The degree of difficult mask ventilation was recorded by Han's scale. ResultsThe incidence of DMV was 14.96%. The mean of all the three USG parameters (DLA, HMD and TBT) increased according to the DMV level. Logistic regression analysis demonstrated DLA above 30.78 mm was the single most important predictor of DMV (odds ratio 0.030, 95% CI, 0.871–0.990). ConclusionSubmental USG of the airway is a useful diagnostic tool for predicting DMV in OSA patients. DLA is the most sensitive and specific sonographic parameter for screening of difficult mask ventilation in these patients.

Neuropsychological and socio–cognitive deficits in patients with obstructive sleep apnea

ABSTRACT Introduction: Patients with obstructive sleep apnea (OSA) suffer from several neurocognitive deficits. We investigated the cognitive and socio-cognitive profiles of patients with severe OSA, controlling for potentially relevant mediating variables (i.e. age, body-mass index, cognitive reserve and depression). Moreover, we studied the neuropsychological profile of a high-risk OSA phenotype characterized by severe OSA and severe nocturnal hypoxemia. Method: We assessed 29 previously untreated severe OSA patients with a mean age of 55.6 (± 9.9 years) and a mean apnea-hypopnea index (AHI) of 53.1 (± 17.4). A control group of 34 healthy participants was also enrolled. Participants completed an extensive neuropsychological battery that included social cognition, a relatively new investigation area among OSA patients. Data analysis: Data were analyzed with a Bayesian approach. Specifically, Bayesian ANCOVA was used to investigate whether the grouping variable could predict test performance. Age, body-mass index, cognitive reserve and state of depression were added as covariates to the null model to weight the effects of these potential confounding factors. Three groups were analyzed: healthy controls (H), OSA with severe apnea and severe nocturnal oxygen desaturation (D+), and OSA with severe apnea non-desaturators (D−). Performances on the various neuropsychological tests were treated as the dependent variables. Results: The results indicate that non-verbal reasoning, the theory of mind skills, and mental shifting ability were impaired in OSA patients. Patients with severe nocturnal hypoxemia underperformed compared to patients with the same severity of apnea but non-desaturators. Additionally, we observed a trend toward a worse performance among OSA desaturator patients in the following abilities: constructional ability, short term verbal memory, phonological fluency, and the ability to inhibit automatic and dominant responses. Conclusion: The data suggest a key role of hypoxemia in affecting cognitive functioning in OSA patients. Executive functions and the concomitant involvement of social cognition are particularly affected.

159 The Role of Education on the Association between OSA and Cognitive Functions in Middle-age and Older Adults

Abstract Introduction A weak relation between an increase in education and improved health knowledge was observed among those who attended college, but not among those whose highest educational level attainment was high school (Altindag, Cannonier, &amp; Mocan, 2014). Alachantis and colleagues (2005) had applied cognitive reserve theory (Stern, 2002) to help explain why OSA patients with higher intelligence scores perform well on cognitive tasks. The resource substitution theory (RST; Ross &amp; Mirowsky, 2006) posits that higher education compensates for background disadvantages rather than magnifying background advantages. The goals of the current study were to examine the interaction between educational level and obstructive sleep apnea (OSA) on cognitive functions such as verbal fluency, psychomotor vigilance, executive functions, visuospatial ability, and attention span and to determine whether the results would support the RST. Methods One hundred and nine participants (47 ApneaLinkTM -screened controls and 62 untreated OSA patients) participated in the study and completed the Wisconsin Card Sorting Test, WAIS-III digit span and block design, semantic and phonemic fluency tests, and a psychomotor vigilance task. Subjective sleep (PSQI and ESS) and health measures (depression, anxiety, mood disturbance, diabetes, hypertension) were assessed. A hierarchical regression was conducted to test for the additional variance explained by the interaction term even after accounting for the covariates. Results In semantic fluency and visuospatial ability tasks, patients with higher education performed better than patients with high school or less education. This moderation effect of education was not observed for the control group. A significant interaction effect was not observed for vigilance, phonemic fluency, attention span, or executive functions although education was a significant predictor for all cognitive tasks. Conclusion The resource substitution theory was supported as the benefit of education seemed more crucial for OSA patients than for controls, specifically in semantic fluency and visuospatial ability. This benefit of higher education contributing to larger cognitive reserves in patients with OSA helped buffer some cognitive deficits but not for others, but this buffer no longer works when the cognitive demand gets larger. Support (if any) A grant from the Center for Integrative Research on Cognitive Neural Science, Southern Illinois University Carbondale was received.

Patients with Obstructive Sleep Apnea Have Altered Levels of Four Cytokines Associated with Cardiovascular and Kidney Disease, but Near Normal Levels with Airways Therapy.

IntroductionObstructive sleep apnea (OSA) results in chronic intermittent hypoxia leading to systemic inflammation, increases in pro-inflammatory cytokines TNF-Alpha and IL-6, and increased risk for a number of life threatening medical disorders such as cardiovascular and kidney disease.MethodsA BioPlex Array was used to examined the serum levels of four cytokines also expressed in endothelial cells and/or macrophages and associated with cardiovascular and kidney disease risk.ResultsRelative to untreated OSA patients, airways treated OSA patients had a 5.4-fold higher median level of MMP2 (p = 9.1x10−11), a 1.4-fold higher level of TWEAK (p = 1.8x10−7), a 1.7-fold higher level of CD163 (p = 1.4x10−6), but a 2.0-fold lower level of MMP3 (p = 7.9x10−7). Airway treatment resulted in levels more similar to or indistinguishable from control subjects. Both t-SNE or UMAP analysis of the global structure of these multi-dimensional data revealed two data clusters, one populated primarily with data for controls and most airways treated OSA patients and a second populated primarily with data for OSA patients.DiscussionWe discuss a concept in which the aberrant levels of these cytokines in untreated OSA patients may represent a chronic response after years of experiencing intermittent nightly hypoxia, which attenuated the acute response to hypoxia. A balanced therapeutic correction of the aberrant levels of these cytokines may limit the progression of CVD and kidney disease in OSA patients.

Long-term continuous positive airway pressure treatment ameliorates biological clock disruptions in obstructive sleep apnea.

BackgroundObstructive Sleep Apnea (OSA) is a highly prevalent and underdiagnosed sleep disorder. Recent studies suggest that OSA might disrupt the biological clock, potentially causing or worsening OSA-associated comorbidities. However, the effect of OSA treatment on clock disruption is not fully understood.MethodsThe impact of OSA and short- (four months) and long-term (two years) OSA treatment, with Continuous Positive Airway Pressure (CPAP), on the biological clock was investigated at four time points within 24 h, in OSA patients relative to controls subjects (no OSA) of the same sex and age group, in a case-control study. Plasma melatonin and cortisol, body temperature and the expression levels and rhythmicity of eleven clock genes in peripheral blood mononuclear cells (PBMCs) were assessed. Additional computational tools were used for a detailed data analysis.FindingsOSA impacts on clock outputs and on the expression of several clock genes in PBMCs. Neither short- nor long-term treatment fully reverted OSA-induced alterations in the expression of clock genes. However, long-term treatment was able to re-establish levels of plasma melatonin and cortisol and body temperature. Machine learning methods could discriminate controls from untreated OSA patients. Following long-term treatment, the distinction between controls and patients disappeared, suggesting a closer similarity of the phenotypes.InterpretationOSA alters biological clock-related characteristics that differentially respond to short- and long-term CPAP treatment. Long-term CPAP was more efficient in counteracting OSA impact on the clock, but the obtained results suggest that it is not fully effective. A better understanding of the impact of OSA and OSA treatment on the clock may open new avenues to OSA diagnosis, monitoring and treatment.

Sleep spindle activity correlates with implicit statistical learning consolidation in untreated obstructive sleep apnea patients

Objective/BackgroundThe aim of this study was to examine the relationship between overnight consolidation of implicit statistical learning with spindle frequency EEG activity and slow frequency delta power during non-rapid eye movement (NREM) sleep in obstructive sleep apnea (OSA). Patients/MethodsForty-seven OSA participants completed the experiment. Prior to sleep, participants performed a reaction time cover task containing hidden patterns of pictures, about which participants were not informed. After the familiarisation phase, participants underwent overnight polysomnography. 24 h after the familiarisation phase, participants performed a test phase to assess their learning of the hidden patterns, expressed as a percentage of the number of correctly identified patterns. Spindle frequency activity (SFA) and delta power (0.5–4.5 Hz), were quantified from NREM electroencephalography. Associations between statistical learning and sleep EEG, and OSA severity measures were examined. ResultsSFA in NREM sleep in frontal and central brain regions was positively correlated with statistical learning scores (r = 0.41 to 0.31, p = 0.006 to 0.044). In multiple regression, greater SFA and longer sleep onset latency were significant predictors of better statistical learning performance. Delta power and OSA severity were not significantly correlated with statistical learning. ConclusionsThese findings suggest spindle activity may serve as a marker of statistical learning capability in OSA. This work provides novel insight into how altered sleep physiology relates to consolidation of implicitly learnt information in patients with moderate to severe OSA.

CPAP Is Not Needed in Every Sleep Apnea Patient Awaiting Bariatric Surgery.

Obstructive sleep apnea (OSA) patients are at high risk of postoperative complications following bariatric surgery. The aim of our study was to compare peri- and postoperative outcomes in OSA patients awaiting laparoscopic bariatric surgery who were prescribed CPAP treatment or not before surgery using nocturnal home oximetry and capillary blood gas measurements. Data on 1094 eligible patients were analyzed. In accordance with our algorithm, those with ODI < 25/h and pCO2 < 45mmHg (358 mild/moderate apnea and 447 non-apneic) underwent surgery without previous treatment, whereas those with an ODI ≥ 25/h (n = 289) were prescribed CPAP. We compared peri- and postoperative outcomes in treated and untreated patients. Treated patients were significantly older with a higher body mass index and a higher percentage of men than non-apneic and untreated OSA. Hypertension and diabetes were significantly more prevalent in the treated and untreated OSA patients than in the non-apneic. Regarding the occurrence of cardiopulmonary complications, the incidence of cardiac arrhythmia was higher in the treated patients than in the non-apneic and the untreated OSA (2.4%; 0.6 and 0.5%, p = 0.03). The slightly longer length of hospital stay seen in treated patients compared to those of other groups (2.8 ± 1.7; 2.6 ± 2.1 and 2.6 ± 1.8days, p = 0.03) was no longer observed after adjusting for age and BMI. There is no risk increase for complications following bariatric surgery in untreated patients presenting mild/moderate OSA identified by a noninvasive screening algorithm.