Obstructive Sleep Apnea Hypopnea Research Articles

A Pilot Study on the Relationship between Obstructive Sleep Apnoea-Hypopnea Syndrome, Neurodevelopment, and Ricketts' Cephalometry.

Background: The aim of this research is to achieve the early detection of facial characteristics in patients diagnosed with neurodevelopmental deficits and obstructive sleep apnoea-hypopnea syndrome (OSAHS) through the analysis of the VERT index and Ricketts' cephalometry to minimise the neurocognitive morbidity associated with these disorders. Methods: This clinical study was conducted on 44 patients aged 4 to 15 years. Participants completed an initial questionnaire about sleep disturbances, followed by a polysomnography, a radiographic study, and an oral examination. Results: The maximum variability in the data was obtained in the mandibular plane angle, where we observed that the measurement was higher in patients diagnosed with OSAHS. The relative and normalised indices of facial depth and the mandibular plane showed variations between patients with a clinical picture compatible with OSAHS and the control group without pathology. Conclusions: Our findings indicate that Ricketts' VERT index by itself is unable to provide evidence of a diagnosis compatible with OSAHS in patients with early neurodevelopmental deficits, but, after analysing the results obtained, we observed that for the cephalometric measurements of the mandibular plane angle and facial depth relative to the patient's age, there are sufficiently strong variations for creating a solid method of differential diagnosis, thus preventing complications at the neurocognitive level.

Detection and Classification of Obstructive Sleep Apnea Using Audio Spectrogram Analysis

Sleep disorders are steadily increasing in the population and can significantly affect daily life. Low-cost and noninvasive systems that can assist the diagnostic process will become increasingly widespread in the coming years. This work aims to investigate and compare the performance of machine learning-based classifiers for the identification of obstructive sleep apnea–hypopnea (OSAH) events, including apnea/non-apnea status classification, apnea–hypopnea index (AHI) prediction, and AHI severity classification. The dataset considered contains recordings from 192 patients. It is derived from a recently released dataset which contains, amongst others, audio signals recorded with an ambient microphone placed ∼1 m above the studied subjects and apnea/hypopnea accurate events annotations performed by specialized medical doctors. We employ mel spectrogram images extracted from the environmental audio signals as input of a machine-learning-based classifier for apnea/hypopnea events classification. The proposed approach involves a stacked model which utilizes a combination of a pretrained VGG-like audio classification (VGGish) network and a bidirectional long short-term memory (bi-LSTM) network. Performance analysis was conducted using a 5-fold cross-validation approach, leaving out patients used for training and validation of the models in the testing step. Comparative evaluations with recently presented methods from the literature demonstrate the advantages of the proposed approach. The proposed architecture can be considered a useful tool for supporting OSAHS diagnoses by means of low-cost devices such as smartphones.

Positive Airway Pressure Treatment of Obstructive Sleep Apnea-Hypopnea in Hypertensive Disorders of Pregnancy: A Pilot Randomized Proof-of-Concept Clinical Trial.

Rationale: Maternal obstructive sleep apnea-hypopnea (OSAH) is associated with hypertensive disorders of pregnancy (HDP). OSAH treatment with positive airway pressure (PAP) in the general population lowers blood pressure (BP). However, there are limited data on the effects of PAP therapy in maternal OSAH. Objectives: Our primary objective was to assess the feasibility of recruitment to a pilot randomized trial and adherence to PAP therapy for OSAH in women with HDP. Secondary objectives included assessment of PAP effects on 24-h BP, arterial stiffness, and maternal and fetal outcomes. Methods: Women with singleton pregnancies at ⩾12 weeks' gestation and hypertension underwent home level 2 polysomnography; those with mild to moderate OSAH (apnea-hypopnea index ⩾ 5 events/h; women with severe OSAH with apnea-hypopnea index > 30 events/h and oxygen desaturation index > 30 were excluded) were randomized to either PAP or nasal dilator strip (NDS; control) therapy. After PAP education, adherence was monitored online with episodic phone or in-person support by research personnel. Twenty-four-hour BP and arterial stiffness were assessed at baseline and before delivery. Maternal and fetal outcomes were also recorded. Results: Of 105 potentially eligible participants, 67 agreed to undergo screening for OSAH over 38 months; 48 women meeting OSAH inclusion criteria were randomized to PAP (n = 27) or NDS (n = 21) therapy. Of these, 14 PAP (52%) and 13 NDS (62%) participants completed all predelivery measurements, with lack of completion due to urgent delivery (19% in the PAP group, 14% in the NDS group), PAP intolerance at initiation (19%), or other factors. Mean PAP use was 3.1 ± 2.5 h/night, with use ⩾4 h/night on 38.4 ± 33.7% of nights during 9.6 ± 4.0 weeks of treatment. BP was controlled within the target range in most participants. There were no differences in mean change in 24-hour BP or arterial stiffness measurements or in adverse maternal and fetal outcomes between the PAP and NDS groups in either intention-to-treat or per-protocol analyses. Conclusions: PAP adherence was suboptimal in this HDP cohort despite education and troubleshooting. Further work is required to identify optimal OSAH treatment strategies during pregnancy. Clinical trial registered with www.clinicaltrials.gov (NCT03309826).

The influence of mouth opening on pharyngeal pressure loss and its underlying mechanism: A computational fluid dynamic analysis.

Objective: During inspiration, mechanical energy generated from respiratory muscle produces a negative pressure gradient to fulfill enough pulmonary ventilation. The pressure loss, a surrogate for energy loss, is considered as the portion of negative pressure without converting into the kinetic energy of airflow. Mouth opening (MO) during sleep is a common symptom in patients with obstructive sleep apnoea-hypopnea syndrome (OSAHS). This study aimed to evaluate the effects of mouth opening on pharyngeal pressure loss using computational fluid dynamics (CFD) simulation. Methods: A total of four subjects who were morphologically distinct in the pharyngeal characteristics based on Friedman tongue position (FTP) grades were selected. Upper airway computed tomography (CT) scan was performed under two conditions: Mouth closing (MC) and mouth opening, in order to reconstruct the upper airway models. computational fluid dynamics was used to simulate the flow on the two different occasions: Mouth closing and mouth opening. Results: The pharyngeal jet was the typical aerodynamic feature and its formation and development were different from mouth closing to mouth opening in subjects with different Friedman tongue position grades. For FTP I with mouth closing, a pharyngeal jet gradually formed with proximity to the velopharyngeal minimum area plane (planeAmin). Downstream the planeAmin, the jet impingement on the pharyngeal wall resulted in the frictional loss associated with wall shear stress (WSS). A rapid luminal expansion led to flow separation and large recirculation region, corresponding to the interior flow loss. They all contributed to the pharyngeal total pressure loss. While for FTP I with mouth opening, the improved velopharyngeal constriction led to smoother flow and a lower total pressure loss. For FTP IV, the narrower the planeAmin after mouth opening, the stronger the jet formation and its impingement on the pharyngeal wall, predicting a higher frictional loss resulted from higher WSS. Besides, a longer length of the mouth opening-associated constant constrictive segment was another important morphological factor promoting frictional loss. Conclusion: For certain OSAHS patients with higher Friedman tongue position grade, mouth opening-related stronger jet formation, more jet breakdown and stronger jet flow separation might contribute to the increased pharyngeal pressure loss. It might require compensation from more inspiratory negative static pressure that would potentially increase the severity of OSAHS.

Diurnal changes of retinal microvascular circulation and RNFL thickness measured by optical coherence tomography angiography in patients with obstructive sleep apnea-hypopnea.

PurposeTo evaluate capillaries perfusion and retinal nerve fiber layer (RNFL) thickness diurnal changes of macular/optic disc regions among participants with or without obstructive sleep apnea-hypopnea (OSA) using spectral-domain optical coherence tomography angiography (OCTA).MethodsIn this study, we enrolled a cohort of 35 participants including 14 patients with mild-to-moderate OSA, 12 patients with severe OSA, and 9 healthy individuals. All participants had Berlin questionnaire filled. At 20:00 and 6:30, right before and after the polysomnography examination, a comprehensive ocular examination was conducted. The systemic and ocular clinical characteristics were collected, and OCTA scans were performed repeatedly. Blood flow and RNFL thickness parameters were then exported using built-in software and analyzed accordingly.ResultsAfter sleep, the overall vessel density (VD) variables, especially macular and choriocapillaris VDs, were relatively comparative and stable. One exception was the RPC vessel density at the inside-disc region with a decreasing trend in the mild-to-moderate group (p=0.023). RNFL changes before and after sleep in the nasal-inferior and peripapillary region were statistically significant (p=0.003; p=0.043) among three groups. And multiple testing correction verified the significant difference in diurnal changes between the mild-to-moderate group and the control group in pairwise comparisons (p=0.006; p=0.02).ConclusionsThe changes of imperceptible blood flow and RNFL thickness overnight around optic disc areas could be observed in OSA patients. Despite physiological fluctuations, aberrant diurnal changes might be useful for identifying a decrease in micro-environmental stability associated with the development of various ocular diseases such as glaucoma. Other VD variables, especially macular and choriocapillaris VDs, are relatively stable in eyes of patients having OSA with different severity.

Effects of intermittent hypoxia with thrombin in an in vitro model of human brain endothelial cells and their impact on PAR-1/PAR-3 cleavage

Patients with obstructive sleep apnea/hypopnea (OSA) are at high risk of cerebrovascular diseases leading to cognitive impairment. The oxidative stress generated by intermittent hypoxia (IH) could lead to an increase in blood–brain barrier (BBB) permeability, an essential interface for the protection of the brain. Moreover, in patients with OSA, blood coagulation could be increased leading to cardiovascular complications. Thrombin is a factor found increased in these populations that exerts various cellular effects through activation of protease activated receptors (PARs). Thus, we have evaluated in an in vitro BBB model the association of IH with thrombin at two concentrations. We measured the apparent BBB permeability, expression of tight junctions, ROS production, HIF-1α expression, and cleavage of PAR-1/PAR-3. Pre-treatment with dabigatran was performed. IH and higher thrombin concentrations altered BBB permeability: high levels of HIF-1α expression, ROS and PAR-1 activation compared to PAR-3 in such conditions. Conversely, lower concentration of thrombin associated with IH appear to have a protective effect on BBB with a significant cleavage of PAR-3. Dabigatran reversed the deleterious effect of thrombin at high concentrations but also suppressed the beneficial effect of low dose thrombin. Therefore, thrombin and PARs represent novel attractive targets to prevent BBB opening in OSA.

Analysis of effects of laryngopharyngeal reflux disease and proton pump inhibitor treatment on Eustachian tube function in patients with obstructive sleep apnea hypopnea.

This study aims to explore the effects of laryngopharyngeal reflux disease (LPRD) and proton pump inhibitor (PPI) treatment on Eustachian tube function in patients with obstructive sleep apnea (OSA). The Eustachian tube score-7 (ETS-7) was observed before and after PPI treatment in the control group, OSA only group, and OSA + LPRD group. Age, sex, smoking history, and drinking history showed no differences among 3 groups (P > .05). The body mass index (BMI) in the control group was lower than that in other groups (P < .017). Before PPI treatment, the abnormality rate of ETS-7 in the OSA + LPRD group statistically differed from that in the control group and the OSA only group (P < .017). After PPI treatment, the abnormality rate of ETS-7 in the OSA + LPRD group exhibited no significant differences compared with that in the control group and the OSA only group (P > .017), and it declined remarkably compared with that before PPI treatment (75% vs 35%, χ2 = 13.334, P = .001). Moreover, the multivariate analysis revealed that only LPRD had an independent correlation with the abnormality of ETS-7 (OR = 1.245, 95% CI: 1.759-6.861, P = .000). In view of its high incidence in OSA patients, LPRD may be a considerable factor for the high incidence of abnormality rate of ETS-7 in OSA patients, and PPI therapy is of significant value in improving Eustachian tube function in OSA patients with LPRD.

Phenotyping OSAH patients during wakefulness.

Although currently there are simplified methods to measure the pathophysiological traits that stimulate the occurrence and maintenance of obstructive sleep apnea-hypopnea (OSAH), they remain difficult to implement in routine practice. This pilot study aimed to find a simpler daytime approach to obtain a meaningful, similar pathophysiological phenotypic profile in patients with OSAH. After obtaining diagnostic polygraphy from a group of consecutive patients with OSAH, we performed the dial-down CPAP technique during nocturnal polysomnography and used it as reference method. This allowed assessment of upper airway collapsibility, loop gain (LG), arousal threshold (AT), and upper airway muscle gain (UAG). We compared these results with a daytime protocol based on negative expiratory pressure (NEP) technique for evaluating upper airway collapsibility and UAG, on maximal voluntary apnea for LG, and on clinical predictors for AT. Of 15 patients studied, 13 patients with OSAH accurately completed the two procedures. There were strong (all r2 > 0.75) and significant (all p < 0.001) correlations for each phenotypic trait between the measurements obtained through the reference method and those achieved during wakefulness. It is possible to phenotype patients withOSAH from a pathophysiological point of view while they are awake. Using this approach, cutoff values corresponding to those usually adopted using the reference method can be identified to detect abnormal traits, achieving profiles similar to those obtained through the dial-down CPAP technique.

Chapter 9 - Multiple Sclerosis and related disorders

Multiple Sclerosis (MS) is a common neuroinflammatory disorder which is associated with disabling clinical consequences. The MS disease process may involve neural centers implicated in the control of breathing, leading to ventilatory disturbances during both wakefulness and sleep. In this chapter, a brief overview of MS disease mechanisms and clinical sequelae including sleep disorders is provided. The chapter then focuses on obstructive sleep apnea-hypopnea (OSAH) which is the most prevalent respiratory control abnormality encountered in ambulatory MS patients. The diagnosis, prevalence, and clinical consequences as well as data on effects of OSAH treatment in MS patients are discussed, including the impact on the disabling symptom of fatigue and other clinical sequelae. We also review pathophysiologic mechanisms contributing to OSAH in MS, and in turn mechanisms by which OSAH may impact on the MS disease process, resulting in a bidirectional relationship between these two conditions. We then discuss central sleep apnea, other respiratory control disturbances, and the pathogenesis and management of respiratory muscle weakness and chronic hypoventilation in MS. We also provide a brief overview of Neuromyelitis Optica Spectrum Disorders and review current data on respiratory control disturbances and sleep-disordered breathing in that condition.

Effect of Maternal Obstructive Sleep Apnea-Hypopnea on 24-Hour Blood Pressure, Nocturnal Blood Pressure Dipping and Arterial Stiffness in Hypertensive Disorders of Pregnancy.

Rationale: Maternal obstructive sleep apnea-hypopnea (OSAH) is associated with hypertensive disorders of pregnancy (HDP). Attenuation of the normal nocturnal blood pressure (BP) decline (non-dipping) is associated with adverse pregnancy outcomes. OSAH is associated with nocturnal non-dipping in the general population, but this has not been studied in pregnancy. We therefore analyzed baseline data from an ongoing RCT (NCT03309826) assessing the impact of OSAH treatment on HDP outcomes, to evaluate the relationship of OSAH to 24-h BP profile, in particular nocturnal BP dipping, and measures of arterial stiffness.Methods: Women with a singleton pregnancy and HDP underwent level II polysomnography. Patients with OSAH (apnea-hypopnea index (AHI) ≥ 5 events/h) then underwent 24-h ambulatory BP monitoring and arterial stiffness measurements (applanation tonometry, SphygmoCor). Positive dipping was defined as nocturnal systolic blood pressure (SBP) dip ≥ 10%. The relationships between measures of OSAH severity, measures of BP and arterial stiffness were evaluated using linear regression analyses.Results: We studied 51 HDP participants (36.5 ± 4.9 years, BMI 36.9 ± 8.6 kg/m2) with OSAH with mean AHI 27.7 ± 26.4 events/h at 25.0 ± 4.9 weeks’ gestation. We found no significant relationships between AHI or other OSA severity measures and mean 24-h BP values, although BP was generally well-controlled. Most women were SBP non-dippers (78.4%). AHI showed a significant inverse correlation with % SBP dipping following adjustment for age, BMI, parity, gestational age, and BP medications (β = −0.11, p = 0.02). Significant inverse correlations were also observed between AHI and DBP (β = −0.16, p = 0.01) and MAP (β = −0.13, p = 0.02) % dipping. Oxygen desaturation index and sleep time below SaO2 90% were also inversely correlated with % dipping. Moreover, a significant positive correlation was observed between carotid-femoral pulse wave velocity (cfPWV) and REM AHI (β = 0.02, p = 0.04) in unadjusted but not adjusted analysis.Conclusion: Blood pressure non-dipping was observed in a majority of women with HDP and OSAH. There were significant inverse relationships between OSAH severity measures and nocturnal % dipping. Increased arterial stiffness was associated with increasing severity of OSAH during REM sleep in unadjusted although not adjusted analysis. These findings suggest that OSAH may represent a therapeutic target to improve BP profile and vascular risk in HDP.

Effect of continuous positive airway pressure treatment of obstructive sleep apnea-hypopnea in multiple sclerosis: A randomized, double-blind, placebo-controlled trial (SAMS-PAP study)

Objective: The aim of this study was to evaluate the effect of continuous positive airway pressure (CPAP) treatment on the Fatigue Severity Scale (FSS, preplanned primary outcome), another fatigue measure, sleep quality, somnolence, pain, disability, and quality of life in multiple sclerosis (MS) patients with obstructive sleep apnea-hypopnea (OSAH). Methods: In a randomized, double-blind trial (NCT01746342), MS patients with fatigue, poor subjective sleep quality, and OSAH (apnea-hypopnea index of ⩾ 15 events per hour/sleep), but without severe OSAH (apnea-hypopnea index > 30, and 4% oxygen desaturation index > 15 events/hour or severe somnolence), were randomized to fixed CPAP or sham CPAP for 6 months. Outcome assessments were performed at 3 and 6 months. Results: Of 49 randomized patients, 34 completed the protocol. Among completers, FSS did not improve with CPAP compared to sham at 6 months. FSS tended to improve (p = 0.09), and sleepiness (Epworth Sleepiness Scale) improved significantly (p = 0.03) at 3 months with CPAP compared to sham, but there were no other improvements with CPAP at either study evaluation. Conclusion: In non-severe OSAH patients, CPAP did not significantly improve the primary outcome of FSS change at 6 months. In secondary analyses, we found a trend to improved FSS, and a significant reduction in somnolence with CPAP at 3 months.

Intermittent hypoxia-induced downregulation of microRNA-320b promotes lung cancer tumorigenesis by increasing CDT1 via USP37

Obstructive sleep apnea-hypopnea (OSAH) is correlated with an increased incidence of lung cancer. In our study, we explored the functional roles of microRNAs (miRNAs) in lung cancer patients that were complicated with OSAH involving the deubiquitination enzyme. The miR-320b expression pattern in lung cancer tissues and cells was determined. The interactions between ubiquitin-specific peptidase 37 (USP37) and miR-320b were evaluated by a dual-luciferase reporter gene assay, whereas USP37 and Cdc10-dependent transcript 1 (CDT1) was assessed by co-immunoprecipitation and immunofluorescence. After the induction of intermittent hypoxia (IH), a gain-of function approach was performed to investigate roles of miR-320b, USP37, and CDT1 in lung cancer cell proliferation and invasion. In addition, nude mouse xenograft models were used to study their effects on tumor growth in vivo. miR-320b was poorly expressed in lung cancer patients with OSAH. IH treatment downregulated the expression of miR-320b but promoted the proliferation and invasion capabilities of lung cancer cells, both of which were suppressed by the overexpression of miR-320b through decreasing USP37. USP37 interacted with and deubiquitinated CDT1 to protect it from proteasomal degradation. Our study uncovered that IH-induced downregulation of miR-320b promoted the tumorigenesis of lung cancer by the USP37-mediated deubiquitination of CDT1.

Prothrombotic Factors in Obstructive Sleep Apnea: A Systematic Review With Meta-Analysis.

Previous studies revealed that the prothrombotic factors in patients with obstructive sleep apnea (OSA) remain controversial. The aim of the systematic review is to elucidate the relationship between prothrombotic factors and OSA. This systematic review was performed under the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The literature we investigated was extracted from 4 main medical databases (PubMed, Web of Science, Cochrane Library, and Chinese databases) as of February 2020. We used significant weighted mean differences (SMDs) with 95% CIs from random-effects model. A total of 15 studies comprising 2190 patients were available for the meta-analysis. The pooled results showed that the levels of fibrinogen (SMD = 0.95, 95% CI = 0.26 to 1.65, P = .000), vascular endothelial growth factor (SMD = 0.37, 95% CI = -0.90 to 1.63, P = .000), and plasminogen activator inhibitor 1 (SMD = 0.61, 95% CI = 0.29 to 0.92, P = .040) increased in patients with OSA. There were no statistical differences between groups in terms of d-dimer (P = .108) and platelet counts (P = .233). Subgroup analyses demonstrated that specimen types and age could account for the heterogeneity. This meta-analysis indicated the relationship between prothrombotic factors in OSA hypopnea. Obstructive sleep apnea-related effects may underline the importance of considering the dysfunction of the hemostatic system. The prothrombotic factors in OSA can influence making a choice of appropriate therapy.

Robotic Surgery in Obstructive Sleep Apnea-Hypopnoea Syndrome

Obstructive sleep apnoea-hypopnoea (OSAH) syndrome is a sleep disorder characterised by pauses in breathing (apnoea) or periods of reduced breathing (hypopnoea) during sleep. It results in cerebral hypoxia and a disturbed sleep pattern. The gold standard treatment for OSA is continuous positive airway pressure (CPAP). However, significant number of patients are not able to tolerate this device and approximately 50% of patients report inability to achieve long term usage to CPAP.Robotic surgery is an emerging technique for sleep surgery. TORS is an alternative treatment for OSA for patients who have failed CPAP treatment or conventional non-robotic sleep surgery. This technology is assisted by remote-controlled miniaturized surgical instruments and magnified visualization with a high-definition three-dimensional camera. Tongue base reduction (TBR) refers to the primary focus of this targeted surgery for obstructive sleep apnea (OSA).TORS approach for OSA may include 2 different surgical steps frequently combined in the same procedures according to the patient’s features: tongue base reduction and supraglottoplasty (SGP).In the light of the present results and of the literature, TORS tongue-base reduction appears to be effective. With the improved visualization and precise tissue removal provided by robotic surgery, TORS may become more widespread in the treatment of OSA in the coming years. There was an improvement in objective and subjective sleep measures. The comparison among pre-operative and post-operative parameters showed a significant decreasing in post-operative AHI, ESS and an increasing of the lowest SpO2 value.

Obstructive sleep apnea in adults with Down syndrome.

Patients with Down syndrome (DS) often have a high occurrence of obstructive sleep apnea-hypopnea (OSA) syndrome. We studied a large cohort of adults with DS attended due to clinical suspicion of OSA. A standardized questionnaire and full medical assessment were conducted, including a sleep study. One hundred and fifty-seven DS individuals were studied, with a mean ± SD age of 36 ± 10 years, 40.7% women, BMI 29.4 ± 5.6 kg/m2 . The main clinical symptom was daytime sleepiness (64.9%). A sleep study was conducted in 114 patients. All 114 DS patients were diagnosed with OSA, with a predominance of obstructive and hypopnea events, (apnea-hypopnoea index, AHI, 35.0 ± 26.6), with an oxygen desaturation index of 32.9, and a Tc90% of 24.7%. Continuous positive airway pressure (CPAP) treatment was implemented in 75 (65.8%) of subjects. Tolerance was considered good in 75% of them, with a high compliance of 79.2% >4 hr/day (mean 7.1 hr/day), resulting in a symptomatic improvement in 58.7% of them. Obstructive sleep apnea is frequently confirmed in patients with DS when it clinically suspected. Treatment with CPAP in DS is feasible, and with higher adherence than in adults with normal cognitive functioning.

Quantitative evaluation of retinal microvascular circulation in patients with obstructive sleep apnea-hypopnea using optical coherence tomography angiography.

To compare capillaries perfusion in macular areas at different layers and peripapillary region in radial peripapillary capillaries (RPC) between healthy subjects and subjects with obstructive sleep apnea-hypopnea (OSA) using spectral-domain optical coherence tomography angiography (OCTA). Totally 16 eyes with mild-to-moderate OSA, 14 eyes with severe OSA and 22 control eyes were enrolled in this study. Every subject filled out the Berlin questionnaire and received a comprehensive ocular and physical examination. The clinical characteristics were collected, OCT and OCTA scans using OCTA RT XR Avanti (AngioVue software, Optovue Inc., Fremont, CA, USA) were performed and analyzed. Compared to the control group, the severe group had significantly higher VD in parafovea and perifoveal regions (p = 0.031; p = 0.029) at the level of deep capillary plexus (DCP), whereas the mild-to-moderate group had a significantly lower VD in the peripapillary region on RPC network in disc areas (p = 0.013). Blood flow changes in macular areas might first appear at the DCP layer in OSA patients. Reduced VD in the peripapillary region at the RPC layer might be associated with OSA and cause subsequent RNFL changes.

Automatic scoring of apnea and hypopnea events using blood oxygen saturation signals

The obstructive sleep apnea-hypopnea (OSAH) syndrome is a common and frequently undiagnosed sleep disorder. It is characterized by repeated events of partial (hypopnea) or total (apnea) obstruction of the upper airway while sleeping. To quantify the severity of the pathology, the Apnea Hypopnea Index (AHI) is used. This index is defined as the average number of apnea and hypopnea events per hour of sleep. Discriminating between these two types of events is a very challenging task and in fact most traditional methods fail to do it. A reliable recognition of such events would not only allow for an accurate estimation of the AHI index, but it would also provide useful information regarding the severity of the pathology, which is very important for clinical purposes. In this work we use a method for structured dictionary learning, which is found to be suitable for automatically differentiating between apnea and hypopnea using as a unique input blood oxygen saturation signals. The method is tested for both classification of segments and OSAH screening on the Sleep Heart Health Study database. For OSAH screening, a receiver operating characteristic curve analysis shows an average area under the curve of 0.934 and diagnostic sensitivity and specificity of 89.10% and 86.70%, respectively. These results represent important improvements with respect to all state-of-the-art procedures which where used for comparison purposes. They also provide a solid support for our conclusion that the method can be used for screening OSAH syndrome more reliably and conveniently, using only a pulse oximeter.

When will we ditch the AHI?

When will we ditch the AHI?

When Traumatic Memories Affect Your Health: A Clinical Case Study

Obstructive sleep apnea hypopnea (OSA) is the most common breathing-related sleep disorder and affects more than 20% of older individuals. Furthermore, risk of OSA increases in postmenopausal women. OSA is effectively treated using continuous positive airway pressure (CPAP). However, Mary, a 74-year-old White woman with OSA, severe, refused to obtain a CPAP machine because the sound of the machine elicited memories of her late husband’s suicide. Intervention focused on reducing Mary’s fear of CPAP sounds. Treatment involved imaginal exposure, in vivo exposure, sleep hygiene strategies, and relaxation strategies. Although evidence-based treatments for OSA and trauma separately exist, there are no treatment protocols designed to address the specific combination of the conditions. Treatment gains included a reduction in trauma-related symptoms and an increase in CPAP compliance. Quantity and quality of patient’s sleep did not improve despite sleep hygiene and CPAP use. At 3-week follow-up, treatment gains and CPAP compliance were maintained.

Alternations of Circadian Clock Genes Expression and Oscillation in Obstructive Sleep Apnea.

Circadian misalignment plays an important role in disease processes and can affect disease severity, treatment outcomes, and even survivorship. In this study, we aim to investigate whether expression and daily oscillation patterns of core circadian clock genes were disturbed in patients with obstructive sleep apnea/hypopnea (OSA) syndrome. We performed real-time quantitative reverse transcriptase-polymerase chain reactions to examine the expression of the nine core circadian clock genes in leukocytes of peripheral blood collected at 12 AM, 6 AM, 12 PM, and 6 PM from 133 patients with OSA and 11 normal controls. Daily expression patterns of the nine circadian clock genes were observed in normal controls, but three of these genes (BMAL1, CLOCK, CRY2) were disrupted in patients with OSA. The expressions of eight circadian clock genes (except PER1) at midnight were significantly downregulated in patients with severe OSA. Binary logistic regression analysis selected CRY1 and PER3 as independent factors for severe OSA and showed that the combined expressions of CRY1 and PER3 enhanced the capability of predicting severe OSA (Odds ratio, 5.800; 95% CI, 1.978 to 17.004; p = 0.001). Our results show that combined expressions of CRY1 and PER3 at midnight could be a potential predictor for severe OSA.