A narrative review of the association between obstructive sleep apnea and glaucoma in adults

Background: Obstructive sleep apnea (OSA) is a sleep disorder, primarily of the upper airway, which not only has a significant impact on quality of life but is also associated with various systemic diseases. Several ophthalmological diseases are also associated with OSA, especially glaucoma. The purpose of this review is to take a closer look at the causality and mutual influence. Methods: A systematic literature search was conducted using PubMed. A total of 19 studies with 316,178 adult participants were included. Results: Eleven of the sixteen studies concentrating on the prevalence of glaucoma in patients with OSA showed an association of both entities. One paper found a higher risk for progression of glaucoma in OSA patients. Five of the sixteen included studies failed to show a correlation between OSA and glaucoma. One study out of three surveying specific ophthalmological parameters showed an influence of OSA therapy on retinal nerve fiber layer (RNFL) thinning and vision. One study showed a rise in intraocular pressure (IOP), while two other studies showed no increase under continuous positive airway pressure (CPAP). Conclusions: Our findings suggest an association between OSA and glaucoma and, especially, between OSA and thinning of RNFL. CPAP therapy appears to be also suitable for patients with comorbid glaucoma

Current treatment of comorbid insomnia and obstructive sleep apnea with CBTI and PAP-therapy : a systematic review

Insomnia and obstructive sleep apnea (OSA) are often both present in patients with sleep- disordered-breathing. The coexistence of the two disorders shows an increase in cumulative morbidity and an overall greater illness severity. There is still considerable controversy regarding management decisions in this group of patients. This systematic review focused on more recent evidence regarding treatment of patients presenting with both clinical entities of comorbid insomnia and obstructive sleep apnea in terms of their management, especially using combinations of positive airway pressure (PAP, namely aPAP, cPAP, adaptive servo-ventilation[ASV]) and CBTi as well as each one of these two modalities alone. As a conclusion it is necessary to specifically target distinct combinations of both insomnia (initial, middle, late) and OSA (mild, moderate, severe) phenotypes. The present review gives reason to assume that both CBTi and PAP-therapy are necessary. However, it appears that distinct treatment patterns may suit different COMISA phenotypes

Heart rate variability as a surrogate marker of severe chronic coronary syndrome in patients with obstructive sleep apnea

Background and Objectives: Obstructive sleep apnea (OSA) is a known risk factor for chronic coronary syndrome (CCS). CCS and OSA are separately associated with significant changes in heart rate variability (HRV). In this proof-of-concept study, we tested whether HRV values are significantly different between OSA patients with concomitant severe CCS, and OSA patients without known CCS. Material and Methods: The study comprised a retrospective assessment of the historical and raw polysomnography (PSG) data of 32 patients who presented to a tertiary university hospital with clinical complaints of OSA. A total of 16 patients (four females, mean age 62.94 ± 2.74 years, mean body mass index (BMI) 31.93 ± 1.65 kg/m2) with OSA (median apnea-hypopnea index (AHI) 39.1 (30.5–70.6)/h) and severe CCS were compared to 16 patients (four females, mean age 62.35 ± 2.06 years, mean BMI 32.19 ± 1.07 kg/m2) with OSA (median AHI 40 (30.6–44.5)/h) but without severe CCS. The short–long-term HRV (in msec) was calculated based on the data of a single-lead electrocardiogram (ECG) provided by one full-night PSG, using the standard deviation of the NN, normal-to-normal intervals (SDNN) and the heart rate variability triangular index (HRVI) methods, and compared between the two groups. Results: A significant reduction (p < 0.05) in both SDNN and HRVI was found in the OSA group with CCS compared to the OSA group without CCS. Conclusions: Severe CCS has a significant impact on short–long-term HRV in OSA patients. Further studies in OSA patients with less-severe CCS may shed more light onto the involved mechanistic processes. If confirmed in future larger studies, this physiologic metric has the potential to provide a robust surrogate marker of severe CCS in OSA patients

Intensity of respiratory cortical arousals is a distinct pathophysiologic feature and is associated with disease severity in obstructive sleep apnea patients

Background: We investigated whether the number, duration and intensity of respiratory arousals (RA) on C3-electroencephalographic (EEG) recordings correlate with polysomnography (PSG)-related disease severity in obstructive sleep apnea (OSA) patients. We also investigated if every patient might have an individual RA microstructure pattern, independent from OSA-severity. Methods: PSG recordings of 20 OSA patients (9 female; age 27–80 years) were analyzed retrospectively. Correlation coefficients were calculated between RA microstructure (duration, EEG-intensity) and RA number and respiratory disturbance index (RDI), oxygen desaturation index (ODI) and arousal index (AI). Intraclass correlations (ICC) for both RA duration and intensity were calculated. Sleep stage-specific and apnea- and hypopnea-specific analyses were also done. The probability distributions of duration and intensity were plotted, interpolated with a kernel which fits the distribution. A Bayesian posterior distribution analysis and pair-wise comparisons of each patient with all other 19 patients were performed. Results: Of the analyzed 2600 RA, strong positive correlations were found between average RA intensity and both RDI and AI. The number of PSG-recorded RA was strongly positively correlated with RDI. Significant correlations between average RA intensity in REM, NREM2 and NREM3 sleep stages and total ODI were identified. No sleep stage-specific correlations of arousal microstructure with age, sex, RDI or AI were identified. Although between-subjects ICC values were 0.7 (all p < 0.05). While apnea-related RA duration did not differ from hypopnea-related RA duration, RA intensity was significantly higher (p = 0.00135) in hypopneas than in apneas. A clear individual pattern of arousal duration for each patient was made distinct. For arousal intensity, a Gaussian distribution was identified in most patients. The Bayesian statistics regarding the arousal microstructure showed significant differences between each pair of patients. Conclusions: Each individual patient with OSA might have an individual pattern of RA intensity and duration indicating a distinct individual pathophysiological feature. Arousal intensity was significantly higher in hypopneic than in apneic events and may be related causally to the diminished (compared to apneas) respiratory distress associated with hypopneas. RA intensity in REM, NREM2 and NREM3 strongly correlated with ODI

Using entropy of snoring, respiratory effort and electrocardiography signals during sleep for OSA detection and severity classification

Study objectives Obstructive sleep apnea (OSA) is a very prevalent disease and its diagnosis is based on polysomnography (PSG). We investigated whether snoring-sound-, very low frequency electrocardiogram (ECG-VLF)- and thoraco-abdominal effort- PSG signal entropy values could be used as surrogate markers for detection of OSA and OSA severity classification. Methods The raw data of the snoring-, ECG- and abdominal and thoracic excursion signal recordings of two consecutive full-night PSGs of 86 consecutive patients (22 female, 53.74 ± 12.4 years) were analyzed retrospectively. Four epochs (30 s each, manually scored according to the American Academy of Sleep Medicine standard) of each sleep stage (N1, N2, N3, REM, awake) were used as the ground truth. Sampling entropy (SampEn) of all the above signals was calculated and group comparisons between the OSA severity groups were performed. In total, (86x4x5 = )1720 epochs/group/night were included in the training set as an input for a support vector machine (SVM) algorithm to classify the OSA severity classes. Analyses were performed for first- and second-night PSG recordings separately. Results Twenty-seven patients had mild (RDI = ≥ 5/h but <15/h), 21 patients moderate (RDI ≥15/h but <30/h) and 23 patients severe OSA (RDI ≥30/h). Fifteen patients had an RDI <5/h and were therefore considered non-OSA. Using SE on the above three PSG signal data and using a SVM pipeline, it was possible to distinguish between the four OSA severity classes. The best metric was snoring signal-SE. The area-under-the-curve (AUC) calculations showed reproducible significant results for both nights of PSG. The second night data were even more significant, with non-OSA (R) vs. light OSA (L) 0.61, R vs. moderate (M) 0.68, R vs. heavy OSA (H) 0.84, L vs. M 0.63, M vs. H 0.65 and L vs. H 0.82. The results were not confounded by age or gender. Conclusions SampEn of either snoring-, very low ECG-frequencies- or thoraco-abdominal effort signals alone may be used as a surrogate marker to diagnose OSA and even predict OSA severity. More specifically, in this exploratory study snoring signal SampEn showed the greatest predictive accuracy for OSA among the three signals. Second night data showed even more accurate results for all three parameters than first-night recordings. Therefore, technologies using only parts of the PSG signal, e.g. sound-recording devices, may be used for OSA screening and OSA severity group classification

OSA in patients with head and neck cancer is associated with cancer size and oncologic outcome

PURPOSE Obstructive sleep apnea (OSA) is associated with severe daytime sleepiness and reduced quality of life. These symptoms are also present in patients with squamous cell carcinoma of the head and neck (SCCHN) before, during and after treatment, so that comorbidity cannot be excluded. The aim was to evaluate the prevalence of OSA and its impact on the quality of life in patients with oropharyngeal, hypopharyngeal and lateral tongue SCCHN in a prospective study. METHODS We performed cardiorespiratory home sleep apnea testing and recorded sleep-related patient-reported outcomes in 33 patients with confirmed oropharyngeal, hypopharyngeal and lateral tongue SCCHN. We correlated the sleep-related variables to oncologic variables and endpoints. RESULTS Five female and 28 male patients with SCCHN (aged 46–77 years) were recruited. Thirty patients (90%) had OSA as defined by an Apnea/Hypopnea Index (AHI) > 5 /h before treatment. Evaluation after treatment, which was possible in 17 patients, showed OSA in 16 patients (94%). Radiologic primary tumor size showed significant positive correlation with AHI and apnea-index. Tumor recurrence and tumor-related mortality showed significant positive association with AHI. PSQI of these patients showed at least a moderate sleep disturbance. EORTC QLQ c30 questionnaire showed reduced values for all tested qualities, in particular for fatigue, insomnia, pain and financial distress. CONCLUSION Obstructive sleep apnea is a significant comorbidity in patients with SCCHN. Pre-interventional AHI may be correlated with the oncologic outcome. Further research is needed to further describe the course of OSA and its treatment before, during and after therapy

Automated Management of IP Networks through Policy and Mobile Agents

With the magnificent expansion of network, both in the types of network elements and the software components to manage them, driven by the increasing requirement of different services, it is getting more imperative to seek a means to deploy the network management tasks and services in a fast, ubiquitous and automated way. Mobile agent technology (MAT) provides a promising means to achieve this goal with more flexibility and automation of managing network than those traditional client/server based distributed methods, such as CORBA. Mobile agents, as an enabling technology, can easily represent one of the roles involved in the network management; therefore have great potential to be widely used in network management. This paper proposes to use Policy-based Network Management (PBNM) as an application for MAT to facilitate network management products' development. PBNM, as a newly introduced but widely welcomed technology in the Internet world, can take over the overall management of hybrid network whereas MAT enables the flexible implementation of PBNM system. On the other hand, the agents usually have intelligence, which can be well guided by established policies from PBNM, which makes MAT and PBNM perfectly matched to each other. The work presented in this paper has been developed in the framework of the Europe Union (EU) sponsored IST Project MANTRIP. A commercially oriented test-bed, which is fully based on mobile agent technology, has been set up, and a scenario for solving a practical network management challenge, i.e., inter-domain IP Virtual Private Network, is implemented on this test-bed, which predicts a very promising commercial use of mobile agent in real world. Moreover, the policy-based network management system presented in this paper also covers some of the network management issues under investigation in the EU IST CONTEXT project. This policy and MAT based network management system intends to provide a ubiquitous network management system regardless of the underlying network resources, either wired network elements as the main scope of MANTRIP project or wireless network elements as the main stream of CONTEXT project

A novel quantitative arousal-associated EEG-metric to predict severity of respiratory distress in obstructive sleep apnea patients

Respiratory arousals (RA) on polysomnography (PSG) are an important predictor of obstructive sleep apnea (OSA) disease severity. Additionally, recent reports suggest that more global indices of desaturation such as the hypoxic burden, namely the area under the curve (AUC) of the oxygen saturation (SaO2) PSG trace may better depict the desaturation burden in OSA. Here we investigated possible associations between a new metric, namely the AUC of the respiratory arousal electroencephalographic (EEG) recording, and already established parameters as the apnea/hypopnea index (AHI), arousal index and hypoxic burden in patients with OSA. In this data-driven study, polysomnographic data from 102 patients with OSAS were assessed (32 female; 70 male; mean value of age: 52 years; mean value of Body-Mass-Index-BMI: 31 kg/m2). The marked arousals from the pooled EEG signal (C3 and C4) were smoothed and the AUC was estimated. We used a support vector regressor (SVR) analysis to predict AHI, arousal index and hypoxic burden as captured by the PSG. The SVR with the arousal-AUC metric could quite reliably predict the AHI with a high correlation coefficient (0,58 in the training set, 0,65 in the testing set and 0,64 overall), as well as the hypoxic burden (0,62 in the training set, 0,58 in the testing set and 0,59 overall) and the arousal index (0,58 in the training set, 0,67 in the testing set and 0,66 overall). This novel arousal-AUC metric may predict AHI, hypoxic burden and arousal index with a quite high correlation coefficient and therefore could be used as an additional quantitative surrogate marker in the description of obstructive sleep apnea disease severity

Impact of Preoperative Daytime Sleepiness and Insomnia on Therapy Adherence and Neurostimulation Amplitude in Unilateral Hypoglossal Nerve Stimulation

Johannes Pordzik,1,&ast; Katharina Ludwig,1,&ast; Christian Ruckes,2 Haralampos Gouveris1 1Department of Otolaryngology/Head and Neck Surgery & Sleep Medicine Center, University Medical Center Mainz, Mainz, 55131, Germany; 2Interdisciplinary Center for Clinical Trials, University Medical Center Mainz, Mainz, 55131, Germany&ast;These authors contributed equally to this workCorrespondence: Haralampos Gouveris, Email [email protected]: Average adherence to hypoglossal nerve stimulation (HGNS) therapy is more than 5 h/night. Reported data on HGNS therapy adherence is often based on studies that performed in-lab titration of the neurostimulation parameters and may therefore not represent real-world therapy outcomes. Adherence to HGNS therapy is a major determinant of success of this kind of therapy. Factors with the potential to influence adherence to HGNS therapy should be further elucidated. The aims of this study were to investigate 1) details regarding therapy adherence under HGNS therapy and 2) the possible association between age, insomnia, daytime sleepiness, polysomnography (PSG)-based metrics, neurostimulation parameters and HGNS-therapy adherence.Methods: Forty-three consecutive patients with detailed information about therapy adherence time were included. About 225 ± 191 days after implantation, a PSG without any in-lab titration was performed. Adherence was assessed by interrogating the impulse generator’s data at that time. Patient-reported insomnia was assessed using the insomnia severity index (ISI) and the Epworth Sleepiness scale (ESS) was used to assess daytime sleepiness before and after HGNS treatment.Results: An increased adherence in a real-world setting with 48.72 ± 14.74 hours per week (6.96 hours per night) was found. A strong negative correlation between preoperative ESS score and adherence time (r = - 0.43; p< 0.005) was found. Neither pre-operative insomnia nor sleepiness had any impact on neurostimulation amplitude. A positive association between preoperative age and therapeutic amplitude levels could be shown.Discussion: In this cohort, average adherence was much higher than previously reported. We provide evidence that pre-operative excessive daytime sleepiness may seriously impair adherence to HGNS therapy.Keywords: obstructive sleep apnea, hypoglossal nerve stimulation, adherence, sleepiness, insomnia, positive airway pressure therap