The Ignored Parameter in the Diagnosis of Obstructive Sleep Apnea Syndrome: The Oxygen Desaturation Index

Changes in human sweat metabolome conditioned by severity of obstructive sleep apnea and intermittent hypoxemia

Obstructive sleep apnea (OSA) is a sleep disorder that has been associated with the incidence of other pathologies. Diagnosis is mainly based on the apnea-hypopnea index (AHI) obviating other repercussions such as intermittent hypoxemia, which has been found to be associated to cardiovascular complications. Blood-based samples and urine have been the most utilised biofluids in metabolomics studies related to OSA, while sweat could be an alternative due to its non-invasive and accessible sampling, its reduced complexity, and comparability with other biofluids. Therefore, this research aimed to evaluate metabolic overnight changes in sweat collected from patients with OSA classified according to the AHI and oxygen desaturation index (ODI), looking for potential cardiovascular repercussions. Pre- and post-sleeping sweat samples from all individuals (n = 61) were analysed by gas chromatography coupled to high-resolution mass spectrometry after appropriate sample preparation to detect as many metabolites as possible. Permanent significant alterations in the sweat were reported for pyruvate, serine, lactose, and hydroxybutyrate. The most relevant overnight metabolic alterations in sweat were reported for lactose, succinate, urea, and oxoproline, which presented significantly different effects on factors such as the AHI and ODI for OSA severity classification. Overall metabolic alterations mainly affected energy production-related processes, nitrogen metabolism, and oxidative stress. In conclusion, this research demonstrated the applicability of sweat for evaluation of OSA diagnosis and severity supported by the detected metabolic changes during sleep.

The effect of pharyngeal structures on the severity of obstructive sleep apnea

BACKGROUND/OBJECTIVE

Obstructive sleep apnea (OSA) is characterized by complete or partial cessation of breathing during sleep. The tongue is suggested as a possible anatomical site causing airway obstruction. However, the role of other pharyngeal structures in the development of OSA remains unclear. We designed a study using both the apnea-hypopnea index (AHI) and the oxygen saturation measurements to assess the severity of OSA. We aimed to identify critical anatomical structures of the upper airway that correlate with the severity of OSA and to evaluate the utility of magnetic resonance imaging (MRI) markers to detect possible OSA in patients without overt symptoms.

MATERIALS AND METHODS

The study included participants referred to the neurology outpatient clinic from the check-up unit. Participants were grouped as controls, mild, moderate, or severe OSA according to the AHI. A cranial MRI with a field of view (FOV) encompassing the upper airway structures was obtained from all participants. The areas of the tongue and the uvula were measured on the sagittal images by drawing the boundaries of the tissues manually. The posterior air space (PAS) area was evaluated from regions of interest in five parallel planes.

RESULTS

Of 105 participants, 30 were controls, 27 had mild, 25 had moderate, and 23 had severe OSA. The moderate and severe OSA groups did not differ in oxygen saturation levels during sleep. Therefore, patients with moderate and severe OSA were combined into one group (moderate/severe OSA). The area of the tongue was significantly larger in the moderate/severe OSA group compared to the control group. Both the tongue and the uvula areas showed a significant positive correlation with the AHI.

CONCLUSION

Our findings suggest that the tongue and uvula have prominent roles in the severity of OSAS. It may be useful to measure these structures with MRI to screen for at-risk individuals without overt OSA symptoms.

Comparing efficacy of the mandibular advancement device after drug-induced sleep endoscopy and continuous positive airway pressure in patients with obstructive sleep apnea

PURPOSE

The purpose of this study was to compare objective and self-reported outcomes of two treatments for managing mild, moderate, and severe obstructive sleep apnea (OSA) in adults: a mandibular advancement device (MAD) and continuous positive airway pressure (CPAP).

METHODS

Patients diagnosed with OSA by means of polysomnography (PSG) included one group treated with a custom-made, two-piece, adjustable MAD and a second group treated with CPAP for 8 weeks. Before the initiation of the treatment, all patients assigned to MAD underwent drug-induced sleep endoscopy (DISE), and all CPAP group patients underwent manual titration of CPAP after PSG. Objective (PSG) and self-reported (Epworth Sleepiness Scale [ESS] and Short Form Health Survey [SF-36]) data were used to assess outcomes. Collected data included apnea-hypopnea index (AHI), mean capillary oxygen saturation (SpO2), oxygen desaturation index (ODI), arousal index (AI), degree of daytime sleepiness, and quality of life. A PSG follow-up after 8 weeks with MAD in situ, and data from the CPAP data card were used to assess the effect of the two treatments.

RESULTS

A total of 59 patients included 30 treated with MAD and 29 treated with CPAP. Between baseline and the 8-week follow-up, the mean AHI score decreased significantly from 35.1 to 6.8 episodes/h (p < 0.001) in patients treated with MAD and from 35.2 to 3.0 episodes/h (p < 0.001) in patients treated with CPAP. The mean AHI score at the 8-week follow-up was significantly lower in CPAP group than in MAD group (p = 0.003). The two groups did not differ significantly at follow-up regarding SpO2 (p = 0.571), ODI (p = 0.273), AI (p = 0.100), ESS score (p = 0.648), and SF-36 score (p = 0.237).

CONCLUSION

In the short term, patients on CPAP attained better PSG outcomes in terms of AHI reduction. Both MAD after DISE evaluation and CPAP resulted in similar improvements in clinical symptoms and health-related quality of life, even in patients with severe OSA.

Assessment of oropharyngeal respiratory volume and sleep apnoea scores using peripheral arterial tonometry may improve diagnosis and treatment planning of combined dysgnathia therapy approaches

BACKGROUND

Increased daytime sleepiness is a frequently reported symptom in patients with pronounced dysgnathia.

OBJECTIVES

This study investigated possible correlations using home peripheral arterial tonometry (PAT) and oropharyngeal airway volume determination in patients with dysgnathia and daytime sleepiness.

METHODS

Twenty patients (13 male, median age 27.6 ± 6.8 years) with abnormal sleep history and 10 skeletal neutral configured controls (6 male, median age 29.5 ± 4.2 years) with normal sleep history were examined. Patients and controls were evaluated for apnoea-hypopnoea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index (ODI), snoring volume (dB), total sleep time (TST) and REM-percentage (REM). Airway volumetry was measured via CBCT. Individual user experience for PAT was assessed using the User Experience Questionnaire (UEQ).

RESULTS

Patients had significantly higher respiratory scores than controls. AHI increased 4.6-fold (p = .006), RDI 2.5-fold (p = .008) and ODI 6.4-fold (p < .001). Oropharyngeal volumes showed a 30% decrease (p = .003). dB, TST and REM showed no significant differences. AHI (r = -.51; p = .005), ODI (r = -.60; p < .001) and RDI (r = -.45; p = .016) correlated negatively with pharyngeal volume. Wits appraisal correlated negatively with oropharyngeal volume (r = -.47; p = .010) and positively with AHI (r = .41; p = .03) and ODI (r = .49; p = .007). dB and TST (r = -.49; p = .008) and REM and RDI (r = -.43; p = .02) correlated negatively. UEQ-KPI (2.17 ± 0.24) confirmed excellent usability of PAT.

CONCLUSION

Patients with mandibular retrognathia and abnormal sleep history showed significantly higher respiratory indices and smaller oropharyngeal volumes than neutrally configured controls. The dygnathia severity directly influenced the risk of obstructive sleep apnoea.

Relationship between ODI and sleep structure of obstructive sleep apnea and cardiac remodeling

PURPOSE

The purpose of the study was to evaluate the quantitative relationship between Oxygen Desaturation Index (ODI) and sleep structure of obstructive sleep apnea (OSA) and cardiac remodeling.

METHODS

In this study, patients were enrolled from January 2015 to October 2022, and were divided into 3 groups according to AHI: patients with AHI < 15, patients with 15 ≤ AHI < 30, and 260 patients with AHI ≥ 30. Stratified linear regression was used to analyze independent risk factors for cardiac remodeling in OSA.

RESULTS

A total of 479 patients were enrolled. We found that compared with AHI < 15 group (n = 120), the group with AHI > 30 (n = 260) had increased left atrial anteroposterior diameter, left ventricular end-diastolic internal diameter, left ventricular posterior wall thickness, right ventricular anteroposterior diameter, and interventricular septal thickness (P < 0.05). The group with 15 ≤ AHI ≤ 30 (n = 99) had increased left atrial anteroposterior diameter (P < 0.05). Multivariate linear regression revealed that N2 sleep was an independent risk factor for left ventricular posterior wall thickness, with positive correlation (p < 0.05). N3 sleep was an independent risk factor for transverse right atrial diameter and right ventricular anteroposterior diameter, with negative correlation (P < 0.05). ODI was an independent risk factor for interventricular septal thickness, with positive correlation (P < 0.05). The arousal index was an independent risk factor for increased left atrial anteroposterior diameter, with positive correlation (P < 0.05).

CONCLUSIONS

Increased ODI is an independent risk factor for interventricular septal thickness, while decreased slow wave sleep is an independent risk factor for right heart remodeling in OSA.

Distinguishing the impact of distinct obstructive sleep apnea syndrome (OSAS) and obesity related factors on human monocyte subsets

Obstructive sleep apnea syndrome (OSAS) and obesity go hand in hand in the majority of patients and both are associated with a systemic inflammation, immune disturbance and comorbidities such as cardiovascular disease. However, the unambiguous impact of OSAS and obesity on the individual inflammatory microenvironment and the immunological consequences of human monocytes has not been distinguished yet. Therefore, aim of this study was to investigate the impact of OSAS and obesity related factors on the inflammatory microenvironment by performing flow cytometric whole blood measurements of CD14/CD16 monocyte subsets in normal weight OSAS patients, patients with obesity but without OSAS, and patients with OSAS and obesity, compared to healthy donors. Moreover, explicitly OSAS and obesity related plasma levels of inflammatory mediators adiponectin, leptin, lipocalin and metalloproteinase-9 were determined and the influence of different OSAS and obesity related factors on cytokine secretion and expression of different adhesion molecules by THP-1 monocytes was analysed. Our data revealed a significant redistribution of circulating classical and intermediate monocytes in all three patient cohorts, but differential effects in terms of monocytic adhesion molecules CD11a, CD11b, CD11c, CX3CR1, CD29, CD49d, and plasma cytokine levels. These data were reflected by differential effects of OSAS and obesity related factors leptin, TNFα and hypoxia on THP-1 cytokine secretion patterns and expression of adhesion molecules CD11b and CD49d. In summary, our data revealed differential effects of OSAS and obesity, which underlines the need for a customized therapeutic regimen with respect to the individual weighting of these overlapping diseases.

Obstructive sleep apnea and temporal changes in cardiac repolarization in patients undergoing coronary artery bypass grafting

STUDY OBJECTIVES

In coronary artery bypass grafting (CABG), abnormal cardiac repolarization is associated with adverse cardiovascular events that can be measured via the QTc interval. We investigated the impact of obstructive sleep apnea on the change in repolarization after CABG and the association of change in repolarization with the occurrence of major adverse cardiac and cerebrovascular events.

METHODS

A total of 1,007 patients from 4 hospitals underwent an overnight sleep study prior to a nonemergent CABG. Electrocardiograms of 954 patients (median age: 62 years; male: 86%; mean follow-up: 2.1 years) were acquired prospectively within 48 hours before CABG (T1) and within 24 hours after CABG (T2). QTc intervals were measured using the BRAVO algorithm by Analyzing Medical Parameters for Solutions LLC. The change in T2 from T1 for QTc (ΔQTc) was derived, and Cox regression was performed.

RESULTS

Compared with those without, patients who developed major adverse cardiac and cerebrovascular events (n = 115) were older and had (1) a higher prevalence of smoking, hypertension, diabetes mellitus, and chronic kidney disease; (2) a higher apnea-hypopnea index and oxygen desaturation index; and (3) a smaller ΔQTc. Cox regression analysis demonstrated a smaller ΔQTc to be an independent risk factor for major adverse cardiac and cerebrovascular events (hazard ratio: 0.997; P = .032). In the multivariable regression model, a higher oxygen desaturation index was independently associated with a smaller ΔQTc (correlation coefficient: -0.58; P < .001).

CONCLUSIONS

A higher preoperative oxygen desaturation index was an independent predictor of a smaller ΔQTc. ΔQTc within 24 hours after CABG could be a novel predictor of occurrence of major adverse cardiac and cerebrovascular events at medium-term follow-up.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Undiagnosed Sleep Apnea and Bypass OperaTion (SABOT); URL: https://classic.clinicaltrials.gov/ct2/show/NCT02701504; Identifier: NCT02701504.

CITATION

Teo YH, Yong CL, Ou YH, et al. Obstructive sleep apnea and temporal changes in cardiac repolarization in patients undergoing coronary artery bypass grafting. J Clin Sleep Med. 2024;20(1):49-55.

A Review of Novel Oximetry Parameters for the Prediction of Cardiovascular Disease in Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a sleep disorder with repetitive collapse of the upper airway during sleep, which leads to intermittent hypoxic events overnight, adverse neurocognitive, metabolic complications, and ultimately an increased risk of cardiovascular disease (CVD). The standard diagnostic parameter for OSA, apnoea-hypopnoea index (AHI), is inadequate to predict CVD morbidity and mortality, because it focuses only on the frequency of apnoea and hypopnoea events, and fails to reveal other physiological information for the prediction of CVD events. Novel parameters have been introduced to compensate for the deficiencies of AHI. However, the calculation methods and criteria for these parameters are unclear, hindering their use in cross-study analysis and studies. This review aims to discuss novel parameters for predicting CVD events from oximetry signals and to summarise the corresponding computational methods.

Effect of Cuff Inflation on Blood Pressure, Arousals, Sleep Efficiency, and Desaturations: Sub-Analysis of the VAST Pilot Study

The influence of cuff inflations on night-time measurements during 24 h ambulatory blood pressure (BP) measurements is unknown. We investigated the potential effect of cuff inflations on sleep parameters using measurements taken simultaneously with a cuffless device using pulse-transit-time (PTT). On the first day of measurement, standard cuff-based 24 h BP and cuffless measurements were simultaneously performed on the right and left arms (CUFF/PTT-D). In this experiment, 1-2 days after the first measurement, the cuffless device was worn alone (PTT-D). Only data from the cuffless device were analyzed. The following mean sleep parameters were analyzed: mean systolic and diastolic BP, arousals, sleep efficiency, total arousals, arousal per hour, and desaturations. In total, 21 individuals were prospectively enrolled. The mean (SD) age was 47 (±15) years, and 57% were female. The mean systolic asleep BP during CUFF/PTT-D and during PTT-D were 131 (±21) and 131 (±26) mmHg, respectively. The mean diastolic asleep BP values during CUFF/PTT-D and during PTT-D were 80 (±14) and 84 (±14) mmHg, respectively (p = 0.860, p = 0.100, respectively). Systolic and diastolic asleep mean difference was 0.1 (±18.0) and -3.6 (±9.8) mmHg, respectively. There were significantly more total arousals during PTT-D (p = 0.042). There were no significant differences seen in sleep efficiency (p = 0.339) or desaturations (p = 0.896) between the two measurement periods. We could not show any significant impact from cuff inflations during sleep, as documented by PTT-D measurements.

Evaluation of a custom-made mandibular repositioning device for the treatment of obstructive sleep apnoea syndrome

Obstructive sleep apnoea (OSA) is a common, chronic condition that affects breathing during sleep. The gold standard for treatment is continuous positive airway pressure (CPAP) which is often not well-tolerated. Mandibular repositioning appliances (MRDs) are an alternative that dentists may be requested to provide.The purpose of this audit is to evaluate the effectiveness of an MRD in improving the Oxygen Desaturation Index (ODI) and Epworth Sleepiness Scale (ESS). A total of 52 patients diagnosed with OSA in an NHS hospital respiratory clinic were fitted with an MRD. Analysis of the digitally recorded oximeter signals was recorded among other treatment outcomes before and 6-8 weeks after the fit of the appliance.The meta-analysis of the audit data showed supportive evidence for MRD treatment in OSA patients. There was a statistically significant reduction in ODI and ESS. The audit population consisted of 138 patients (91 men, 47 women; mean age: 49.49 ± 11.93 years). The ODI outcomes improved significantly, from 10.68 to 6.58 (p <0.02). The ESS improved significantly from 9.46 to 6.02 (p <0.01).This audit demonstrates that MRDs are effective and should be considered as an alternative to CPAP in some specific OSA phenotypes.

An exploratory study on the association between serotonin and sleep breathing disorders

This exploratory observational study aimed to evaluate whether the blood levels of serotonin and enzymes involved in serotonin synthesis are associated with sleep breathing parameters. A total of 105 patients were included in this study, who were subjected to single-night polysomnography with simultaneous audio-video recordings. Peripheral blood samples were collected to estimate the serum levels of serotonin, tryptophan hydroxylase 1 (TPH1), and aromatic l-amino acid decarboxylase (AADC). Results showed a negative correlation between blood serotonin levels, and oxygen desaturation index (ODI) (p = 0.027), central apnea (p = 0.044) and obstructive apnea (OA) (p = 0.032) scores. Blood TPH1 levels were negatively correlated with average (p = 0.003) and minimal saturation (p = 0.035) and positively correlated with apnea-hypopnea index (p = 0.010), OA (p = 0.049), and hypopnea index (p = 0.007) scores. A tendency to sleep-disordered breathing seemed to co-occur with lower blood serotonin and higher TPH1 levels.Clinical Trial Registration : www.ClinicalTrials.gov , identifier NCT04214561.

Suspension-expansion pharyngoplasty: a modified technique for oropharyngeal collapse in obstructive sleep apnea

BACKGROUND AND PURPOSE

Lateral pharyngeal wall (LPW) collapse plays a fundamental role in the pathogenesis of obstructive sleep apnea (OSA) and might determine the severity of the disease. This study presents the suspension/expansion pharyngoplasty (SEP) for the treatment of selected cases of OSA. The procedure aimed to splint LPW collapse via supporting and lateralization of both superior constrictor muscle (SCM) and palatopharyngeal muscle (PPM) individually and in two different planes.

METHODS

Twenty-one adult patients with single-level OSA who showed a lateral pattern of collapse at the oropharyngeal region had the modified procedure (SEP). The basic steps are the individual dissection of the muscular components of the lateral pharyngeal wall: SCM which was sutured anteriorly to the anterior tonsillar pillar and the PPM which was suspended to the pterygomandibular raphe. The supra-tonsillar fat was preserved.

RESULTS

At 9-12 months, highly significant improvement was reported as regards the mean Apnea hypopnea index and the mean lowest oxygen saturation (p < 0.000). The Epworth Sleepiness Scale and VAS-snoring showed a significant (p < 0.05) reduction. The oxygen desaturation index showed significant improvement. Non-significant improvements were reported as regards the percentage of total sleep time with oxygen saturation below 90%. According to Sher criteria, successful outcomes were reported in 17 patients.

CONCLUSION

SEP could widen the pharyngeal airway and could support the collapsible lateral pharyngeal wall guarding against soft tissue collapse. In selected subjects, SEP had reported subjective and objective favorable outcomes with no significant comorbidities. The procedure could be combined with other procedures in multilevel surgery.

LEVEL OF EVIDENCE: 4

Comparative evaluation of the efficacy of customized maxillary oral appliance with mandibular advancement appliance as a treatment modality for moderate obstructive sleep apnea patients-a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is quite common among the adult population, according to recent epidemiological studies. The most frequently suggested alternate treatment for mild to moderate OSA is oral appliances (OA). The purpose of the present study was to assess as well as compare the effectiveness of custom-made maxillary oral appliances against mandibular advancement appliances in the care of individuals suffering from moderate obstructive sleep apnea.

METHODS

A prospective interventional research was carried out with 40 participants. Polysomnography (PSG) was done and the participants with an apnea-hypopnea index (AHI) >15-30 were involved in the research. Study participants were randomly split up into two test groups: group I was the "Control Group" (group treated with a mandibular advancement device (MAD), n=20), while group II was exposed to a "customized maxillary oral appliance" (CMOA, n=20). Both groups had reference measures for AHI, blood oxygen saturation (SpO2), oro-nasal airflow via respiratory disturbance index (RDI), and the Epworth Sleepiness Scale (ESS). Appliances were fabricated and delivered to the respective study group participants. PSG was again conducted after a period of 1 and 3 months of appliance delivery and re-evaluation was done for all the parameters and was compared with reference measurements. The facts were analyzed using descriptive and analytical statistical methods. The statistical program utilized in the study was "SPSS (Statistical Package for Social Sciences) Version 20.1." After 1 and 3 months, the statistical significance between the two study groups was assessed at P<0.05.

RESULTS

The analysis of mean AHI, SPO2, RDI, and ESS for both test groups manifested statistically significant measures (P<0.001). The study results revealed a statistically significant depletion in mean AHI scores, improvement in mean SPO2 scores, and reduction in mean RDI scores and ESS scores when compared with reference measurements to 1 month, 1 to 3 months, and between reference measurements and 3 months.

CONCLUSION

The CMOA was effective in managing moderate OSA and has great therapeutic potential. It can be an option for the MAD for treating patients suffering from moderate obstructive sleep apnea.

TRIAL REGISTRATION

The study was registered under Clinical Trials Registry-India and the registration number is CTRI/2020/07/026936 . Registered on 31 July 2020.

A novel OSA-related model of intermittent hypoxia in endothelial cells under flow reveals pronounced inflammatory pathway activation

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder characterized by recurrent episodes of upper airway obstruction and subsequent hypoxia. In patients with OSA, severity and number of these hypoxic events positively correlate with the extent of associated cardiovascular pathology. The molecular mechanisms underlying intermittent hypoxia (IH)-driven cardiovascular disease in OSA, however, remain poorly understood-partly due to the lack of adequate experimental models. Here, we present a novel experimental approach that utilizes primary human endothelial cells cultivated under shear stress. Oxygen partial pressure dynamics were adopted in our in vitro model according to the desaturation-reoxygenation patterns identified in polysomnographic data of severe OSA patients (n = 10, with 892 severe desaturations, SpO₂<80%). Using western blot analysis, we detected a robust activation of the two major inflammatory pathways ERK and NF-κB in endothelial cells, whereas no HIF1α and HIF2α protein stabilization was observed. In line with these findings, mRNA and protein expression of the pro-inflammatory adhesion and signaling molecule ICAM-1 and the chemokine CCL2 were significantly increased. Hence, we established a novel in vitro model for deciphering OSA-elicited effects on the vascular endothelium. First data obtained in this model point to the endothelial activation of pro-inflammatory rather than hypoxia-associated pathways in OSA. Future studies in this model might contribute to the development of targeted strategies against OSA-induced, secondary cardiovascular disease.

Lung and chest wall volume during vital capacity manoeuvre in Osteogenesis Imperfecta

Background

Although Osteogenesis Imperfecta (OI) affects the connective tissue, pulmonary function might be compromised because of thoracic deformities. OI is known to be a restrictive lung disease, but spirometry provides global measurement without localizing the site of the restriction. Opto-electronic plethysmography (OEP), is a non-invasive method able to underline altered respiratory function as well as ventilatory thoraco-abdominal paradoxes during spontaneous breathing. We aimed to reconstruct the thoraco-abdominal surface, to perform local analyses of trunk motion and to make quantitative comparison of trunk shape and respiratory kinematics according to OI severity, particularly during maximal inspiratory and expiratory expansions. This is a cross-sectional study where we have studied the thoraco-abdominal compartmental analysis in 26 adult OI patients (14 Type III) at rest and during vital capacity manoeuvre using OEP. We have also applied a new method that created realistic and accurate 3D models to perform local analyses of trunk motion and to make quantitative comparison of trunk shape and respiratory kinematics.

Results

Type III patients were characterized by lower spirometric lung volume, by lower sleep quality, by a more compressed thoracic configuration aggravated by severe scoliosis, by reduced global expansion at rest and during maximal maneuvers because of the reduced expansion of the pulmonary ribcage at rest (12% vs. 65% in healthy subjects), during maximal inspiration (37% vs. 69%) and expiration (16% vs. 68%) with local paradoxical movement occurring on the side of the ribcage region.

Conclusion

The kinematics of the trunk changed to compensate for the severe structural deformities by shifting the expansion in the abdomen both at rest and during maximal manoeuvre because of a restricted thorax. For the first time, we have quantified and localized the site of the restriction in OI patients in the lateral part of the thorax. The 3D analysis proposed seemed a promising graphical immediate new method for pathophysiology study of chest wall restriction.

Association between Patient- and Partner-Reported Sleepiness Using the Epworth Sleepiness Scale in Patients with Obstructive Sleep Apnoea

Excessive daytime sleepiness in obstructive sleep apnoea (OSA) is often measured differently by patients and their partners. This study investigated the association between patient- and partner-completed Epworth Sleepiness Scale (ESS) scores and a potential correlation with OSA severity. One hundred two participants, 51 patients and 51 partners, completed the ESS before and three months after initiating CPAP treatment. There was no significant difference when comparing patients’ and partners’ ESS scores at baseline (10.75 ± 5.29 vs. 11.47 ± 4.96, respectively) and at follow-up (6.04 ± 4.49 vs. 6.41 ± 4.60, respectively). There was a strong correlation between patients’ and partners’ ESS scores on both (baseline and follow-up) assessments (p < 0.001). There was significant improvement in patients’ and partners’ ESS scores after CPAP therapy (p < 0.001). There was no significant difference in patients’ or partners’ ESS scores between patients with mild, moderate or severe OSA. There was no significant correlation between oxygen desaturation index (ODI) and ESS score reported either by patient or by partner. In conclusion, our study revealed a strong correlation between patient- and partner-reported ESS scores. However, neither patient- nor partner-completed ESS scores were associated with OSA severity.

The Impact of Mouth-Taping in Mouth-Breathers with Mild Obstructive Sleep Apnea: A Preliminary Study

Background: Many patients with obstructive sleep apnea (OSA) are mouth-breathers. Mouth-breathing not only narrows the upper airway, consequently worsening the severity of OSA, but also it affects compliance with nasal continuous positive airway pressure (CPAP) treatment. This study aimed to investigate changes in OSA by the use of mouth tape in mouth-breathers with mild OSA. Method: Mouth-breathers with mild OSA who met inclusion criteria and tolerated the sealing of the mouth were enrolled in the study. We used 3M silicone hypoallergenic tape was used to seal the mouths of the participants during sleep. The home sleep test (HST) used in this study was ApneaLink^®. Subjects received both a baseline HST and an outcome HST to be used 1 week later while their mouths were taped. The changes between the baseline and the outcome HSTs were compared, and the factors that influenced the differences in the sleep-test parameters after the shift of the breathing route were analyzed. A “responder” was defined as a patient who experienced a reduction from the baseline snoring index of at least 50% under mouth-taping in the HST; otherwise, patients were considered as having a poor response. Results: A total of 20 patients with mild OSA were included. Following the taping of the mouth, a good response was found in 13 patients (65%). The median apnea/hypopnea index (AHI) decreased significantly, from 8.3 to 4.7 event/h (by 47%, p = 0.0002), especially in supine AHI (9.4 vs. 5.5 event/h, p = 0.0001). The median snoring index (SI) was also improved (by 47%, 303.8 vs. 121.1 event/h, p = 0.0002). Despite no significant difference in the mean saturation, improvements in the oxygen desaturation index (8.7 vs. 5.8, p = 0.0003) and the lowest saturation (82.5% vs. 87%, p = 0.049) were noted. The change in AHI was associated with baseline AHI (r = −0.52, p = 0.02), oxygen desaturation index (ODI) (r = −0.54, p = 0.01), and SI (r = −0.47, p = 0.04). The change in SI was strongly associated with baseline SI (r = −0.77, p = 0.001). Conclusions: Mouth-taping during sleep improved snoring and the severity of sleep apnea in mouth-breathers with mild OSA, with AHI and SI being reduced by about half. The higher the level of baseline AHI and SI, the greater the improvement was shown after mouth-taping. Mouth-taping could be an alternative treatment in patients with mild OSA before turning to CPAP therapy or surgical intervention.

Acute sleep loss increases CNS health biomarkers and compromises the ability to stay awake in a sex-and weight-specific manner

Night shift work impairs vigilance performance, reduces the ability to stay awake, and compromises brain health. To investigate if the magnitude of these adverse night shift work effects differs between sexes and weight groups, 47 men and women with either normal weight or obesity participated in one night of sleep and one night of total sleep loss. During the night of sleep loss, participants' subjective sleepiness, vigilance performance, and ability to stay awake during 2-min quiet wake with eyes closed were repeatedly assessed. In addition, blood was collected in the morning after sleep loss and sleep to measure central nervous system (CNS) health biomarkers. Our analysis showed that women were sleepier during the night of sleep loss (P < 0.05) and spent more time in microsleep during quiet wake testing (P < 0.05). Finally, higher blood levels of neurofilament light chain, a biomarker of axonal damage, were found among women in the morning after sleep loss (P < 0.002). Compared with normal-weight subjects, those with obesity were more prone to fall asleep during quiet wake (P < 0.05) and exhibited higher blood levels of the CNS health biomarker pTau181 following sleep loss (P = 0.001). Finally, no differences in vigilance performance were noted between the sex and weight groups. Our findings suggest that the ability to stay awake during and the CNS health biomarker response to night shift work may differ between sexes and weight groups. Follow-up studies must confirm our findings under more long-term night shift work conditions.

The effects of obstructive sleep apnea-hypopnea syndrome (OSAHS) on learn and memory function of 6-12 years old children

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep disorder causing cognitive impairments.

AIMS

We use the auditory verbal learning test (AVLT), clock drawing test (CDT), Wechsler intelligence scale for children (WISC) and Montreal cognitive assessment (MoCA) to evaluate the memory and spatial impairments of OSHAS in 6-12 years old children patients with different severity.

MATERIAL AND METHODS

A total of 137 children of snoring were enrolled following the inclusion criteria of this study. According to the apnea-hypopnea indices (AHI), they were divided into three groups. The AVLT, CDT, WISC and MoCA tests were executed by physicians. The self-rating depression scale (SDS) test was performed for depression screening.

RESULTS

Compared with the children in the primary snoring group, the other two groups had higher body mass index (BMI), longer periods of snoring and older age. The AHI, oxygen desaturation index (ODI) and 90% oxygen saturation (TS90%) showed increasing trends whereas the lowest blood oxygen saturation (LSaO₂) showed a decreasing trend. Besides, compared with the primary snoring group, the two groups had lower immediate recall scores in AVLT.

CONCLUSION

AVLT had clinical values for evaluation of impaired memory function in OSAHS children, suggesting a correlation between cognitive impairments and nocturnal hypoxia.

Association of traffic air pollution with severity of obstructive sleep apnea in urban areas of Northern Taiwan: A cross-sectional study

BACKGROUND

Although recent studies have indicated an association between obstructive sleep apnea (OSA) and air pollution, they have reported inconsistent results. Moreover, few studies investigated the effects of short-term air pollution exposure.

OBJECTIVE

To estimate the health effects of short- and long-term exposure to traffic air pollution on mild OSA in Taipei.

METHODS

We collected participants' data from Taipei Sleep Center and air pollution data from Taiwan Environmental Protection Administration. A spatiotemporal model was used to estimate the individual exposure level. Generalized linear models were used to assess the percent change of overall apnea-hypopnea index (AHI), AHI in rapid eye movement period (AHI-REM), AHI in non-REM (AHI-NREM), and oxygen desaturation index (ODI) associated with an interquartile (IQR) increase in personal pollution exposure. A generalized logistic model was used to estimate the ORs of different severities of OSA compared with the reference group.

RESULTS

In the patients with AHI of <15, both short- and long-term exposure to NO₂ were significantly associated with AHI and ODI increases: an IQR increase in 2-year mean NO₂ increased 7.3% of AHI and 8.4% of ODI; these values were the highest among all exposure windows. The effects of NO₂ on AHI increase were stronger in the men and younger patients. Moreover, the association between AHI and NO₂ in the patients with AHI of <15 was mediated by the REM stage. NO₂ exposure was associated with an increased risk of mild OSA that reached up to 24.8% per IQR increase in NO₂ averaged over 2 years. PM_2.5 exerted no effects on AHI, but an IQR increase in 1-year and 2-year mean PM_2.5 was associated with 6.8% and 8.8% increases in ODI, respectively.

CONCLUSIONS

Both short- and long-term exposure to traffic air pollution were associated with the risk of mild OSA, which was modified by REM stage.

Diagnostic value of smartphone in obstructive sleep apnea syndrome: A systematic review and meta-analysis

Objectives

To assess the diagnostic utility of smartphone-based measurement in detecting moderate to severe obstructive sleep apnea syndrome (OSAS).

Methods

Six databases were thoroughly reviewed. Random-effect models were used to estimate the summary sensitivity, specificity, negative predictive value, positive predictive value, diagnostic odds ratio, summary receiver operating characteristic curve and measured the areas under the curve. To assess the accuracy and precision, pooled mean difference and standard deviation of apnea hypopnea index (AHI) between smartphone and polysomnography (95% limits of agreement) across studies were calculated using the random-effects model. Study methodological quality was evaluated using the QUADAS-2 tool.

Results

Eleven studies were analyzed. The smartphone diagnostic odds ratio for moderate-to-severe OSAS (apnea/hypopnea index > 15) was 57.3873 (95% confidence interval [CI]: [34.7462; 94.7815]). The area under the summary receiver operating characteristic curve was 0.917. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.9064 [0.8789; 0.9282], 0.8801 [0.8227; 0.9207], 0.9049 [0.8556; 0.9386], and 0.8844 [0.8234; 0.9263], respectively. We performed subgroup analysis based on the various OSAS detection methods (motion, sound, oximetry, and combinations thereof). Although the diagnostic odds ratios, specificities, and negative predictive values varied significantly (all p < 0.05), all methods afforded good sensitivity (> 80%). The sensitivities and positive predictive values were similar for the various methods (both p > 0.05). The mean difference with standard deviation in the AHI between smartphone and polysomnography was -0.6845 ± 1.611 events/h [-3.8426; 2.4735].

Conclusions

Smartphone could be used to screen the moderate-to-severe OSAS. The mean difference between smartphones and polysomnography AHI measurements was small, though limits of agreement was wide. Therefore, clinicians should be cautious when making clinical decisions based on these devices.

Dysmetabolism and Sleep Fragmentation in Obstructive Sleep Apnea Patients Run Independently of High Caffeine Consumption

Daytime hypersomnolence, the prime feature of obstructive sleep apnea (OSA), frequently leads to high coffee consumption. Nevertheless, some clinicians ask for patients’ caffeine avoidance. Caffeinated drinks are sometimes associated with more severe OSA. However, these effects are not consensual. Here we investigated the effect of caffeine consumption on sleep architecture and apnea/hypopnea index in OSA. Also, the impact of caffeine on variables related with dysmetabolism, dyslipidemia, and sympathetic nervous system (SNS) dysfunction were investigated. A total of 65 patients diagnosed with OSA and 32 without OSA were included after given written informed consent. Polysomnographic studies were performed. Blood was collected to quantify caffeine and its metabolites in plasma and biochemical parameters. 24 h urine samples were collected for catecholamines measurement. Statistical analyses were performed by SPSS: (1) non-parametric Mann-Whitney test to compare variables between controls and OSA; (2) multivariate logistic regression testing the effect of caffeine on sets of variables in the 2 groups; and (3) Spearmans’ correlation between caffeine levels and comorbidities in patients with OSA. As expected OSA development is associated with dyslipidemia, dysmetabolism, SNS dysfunction, and sleep fragmentation. There was also a significant increase in plasma caffeine levels in the OSA group. However, the higher consumption of caffeine by OSA patients do not alter any of these associations. These results showed that there is no apparent rationale for caffeine avoidance in chronic consumers with OSA.

Nasal Symptoms in Patients with Obstructive Sleep Apnoea and Their Association with Continuous Positive Airway Pressure Usage

The role of nasal symptoms in continuous positive airway pressure (CPAP) tolerance is not completely clear. This study aimed to investigate the association between CPAP usage and nasal symptoms, either prior to, or developing during, CPAP use in patients with obstructive sleep apnoea (OSA). Two hundred thirty patients were studied and divided into high-, low-, and non-CPAP users. Nasal symptoms and related quality of life parameters were evaluated prior to CPAP initiation and after three months. We also investigated predictive factors for CPAP usage. Non-CPAP users had significantly worse baseline scores for runny nose compared with high and low users (1.34 vs. 0.68 and 0.75, respectively, p = 0.006). There were no other significant differences between the groups. Runny nose was an independent predictive factor for lower CPAP usage (p = 0.036). An evaluation after three months showed worsening in runny nose score in high-CPAP users (p = 0.025) but not in low- and non-users. There were no significant changes in other nasal symptoms. Our study demonstrates that nasal symptoms were very common in this population but rhinorrhoea was the only symptom associated with poorer CPAP adherence. Moreover, rhinorrhoea worsened after a three-month trial of high-CPAP usage.

Comparative evaluation of the efficacy of customized maxillary oral appliance with mandibular advancement appliance as a treatment modality for moderate obstructive sleep apnea patients-protocol for a randomized controlled trial

Background

Obstructive sleep apnea (OSA) is due to the obstruction of the upper airway during sleep. This condition is often associated with multiple symptoms and co-morbidities. There are many treatment options mentioned in the literature to manage OSA, among which interventional option of continuous positive airflow (CPAP) and non-interventional option, i.e., mandibular advancement device (MAD), which is an oral appliance (OA), are the most preferred ones. This study aims to evaluate the efficacy of customized maxillary oral appliances with mandibular advancement devices in moderate OSA patients.

Methods

A prospective interventional study with a randomized controlled trial will be carried out involving 40 participants (sample size), with an apnea-hypopnea index (AHI) > 15–30, recorded on polysomnography (PSG). Study participants will be randomly divided into the following treatment groups: control group or group subjected to mandibular advancement device (MAD, n=20) and second group subjected to customized maxillary oral appliance (CMOA, n=20). Baseline assessment of apnea/hypopnea index (AHI), oxygen saturation in blood, percentage of rapid eye movement, electroencephalogram, electrocardiogram, oro-nasal airflow via a pressure transducer, and Epworth Sleepiness Scale will be done. Then both study group participants will receive their respective appliances. And after one month and three months of delivery of the appliance, all the parameters, i.e., AHI, oxygen saturation in blood, percentage of rapid eye movement, electroencephalogram, electrocardiogram, oro-nasal airflow via a pressure transducer, and Epworth Sleepiness Scale will be re-evaluated and compared with the baseline measurements. Descriptive and analytical statistics will be done. SPSS (Statistical Package for Social Sciences) Version 20.1 will be used as statistical software. The statistical significance between the two groups after one month and three months will be evaluated at p< 0.05.

Discussion

We expect, customized maxillary oral appliance to be more efficient in managing moderate OSA, in comparison with MAD. If the hypothesis of the present study is confirmed, then this customized maxillary appliance will be quoted as a “gold standard” for managing moderate OSA.

Trial registration

CTRI/2020/07/026936 Registered 31 July 2020.

The Effect of Obstructive Sleep Apnea Treatment and Severity on Choroidal Thickness in Patients With Central Serous Chorioretinopathy

Purpose:

This work aimed to analyze the association of obstructive sleep apnea (OSA) with choroidal thickness (CT) in patients with central serous chorioretinopathy (CSC).

Methods:

We identified patients in the Stanford Research Repository with a diagnosis of CSC and OSA. Age- and sex-matched controls with either CSC or OSA only were also identified. CT was measured at 5 points (subfoveal, and 1500 and 3000 µm nasal and temporal) by 2 graders. In addition to OSA treatment and severity, we also investigated the association of Oxygen Desaturation Index and nocturnal oxygen saturation nadir with subfoveal CT (SFCT).

Results:

A total of 57 patients and 72 eyes met the study inclusion criteria. The mean SFCT was significantly different across the 3 groups: OSA-only was the thinnest, followed by CSC with OSA, and CSC-only was the thickest (194.2 μm, 295.1 μm, and 357.8 μm, respectively, P < .001). SFCT was thicker in CSC with OSA compared with those with only OSA ( P < .05). OSA treatment status and OSA severity did not show a significant difference in SFCT in multivariable modeling. Nocturnal oxygen saturation nadir was positively associated with SFCT, but this did not reach significance..

Conclusions:

SFCT is significantly different in patients with OSA alone, CSC with OSA, and CSC alone. While OSA treatment status did not demonstrate a significant difference in SFCT in this study, future studies should evaluate patients for OSA in patients known to have CSC and atypically thin CT to further investigate the novel metrics leveraged in this study.

PSG-Audio, a scored polysomnography dataset with simultaneous audio recordings for sleep apnea studies

The sleep apnea syndrome is a chronic condition that affects the quality of life and increases the risk of severe health conditions such as cardiovascular diseases. However, the prevalence of the syndrome in the general population is considered to be heavily underestimated due to the restricted number of people seeking diagnosis, with the leading cause for this being the inconvenience of the current reference standard for apnea diagnosis: Polysomnography. To enhance patients' awareness of the syndrome, a great endeavour is conducted in the literature. Various home-based apnea detection systems are being developed, profiting from information in a restricted set of polysomnography signals. In particular, breathing sound has been proven highly effective in detecting apneic events during sleep. The development of accurate systems requires multitudinous datasets of audio recordings and polysomnograms. In this work, we provide the first open access dataset, comprising 212 polysomnograms along with synchronized high-quality tracheal and ambient microphone recordings. We envision this dataset to be widely used for the development of home-based apnea detection techniques and frameworks.

Respiratory Event Detection during Sleep Using Electrocardiogram and Respiratory Related Signals: Using Polysomnogram and Patch-Type Wearable Device Data

This paper presents an automatic algorithm for the detection of respiratory events in patients using electrocardiogram (ECG) and respiratory signals. The proposed method was developed using data of polysomnogram (PSG) and those recorded from a patch-type device. In total, data of 1,285 subjects were used for algorithm development and evaluation. The proposed method involved respiratory event detection and apnea-hypopnea index (AHI) estimation. Handcrafted features from the ECG and respiratory signals were applied to machine learning algorithms including linear discriminant analysis, quadratic discriminant analysis, random forest, multi-layer perceptron, and the support vector machine (SVM). High performance was demonstrated when using SVM, where the overall accuracy achieved was 83% and the Cohens kappa was 0.53 for the minute-by-minute respiratory event detection. The correlation coefficient between the reference AHI obtained using the PSG and estimated AHI as per the proposed method was 0.87. Furthermore, patient classification based on an AHI cutoff of 15 showed an accuracy of 87% and a Cohens kappa of 0.72. The proposed method increases performance result, as it records the ECG and respiratory signals simultaneously. Overall, it can be used to lower the development cost of commercial software owing to the use of open datasets.

SleepPos App: An Automated Smartphone Application for Angle Based High Resolution Sleep Position Monitoring and Treatment

Poor sleep quality or disturbed sleep is associated with multiple health conditions. Sleep position affects the severity and occurrence of these complications, and positional therapy is one of the less invasive treatments to deal with them. Sleep positions can be self-reported, which is unreliable, or determined by using specific devices, such as polysomnography, polygraphy or cameras, that can be expensive and difficult to employ at home. The aim of this study is to determine how smartphones could be used to monitor and treat sleep position at home. We divided our research into three tasks: (1) develop an Android smartphone application (‘SleepPos’ app) which monitors angle-based high-resolution sleep position and allows to simultaneously apply positional treatment; (2) test the smartphone application at home coupled with a pulse oximeter; and (3) explore the potential of this tool to detect the positional occurrence of desaturation events. The results show how the ‘SleepPos’ app successfully determined the sleep position and revealed positional patterns of occurrence of desaturation events. The ‘SleepPos’ app also succeeded in applying positional therapy and preventing the subjects from sleeping in the supine sleep position. This study demonstrates how smartphones are capable of reliably monitoring high-resolution sleep position and provide useful clinical information about the positional occurrence of desaturation events.

Predictors of obstructive sleep apnea misclassification when using total bed time versus total sleep time

Obstructive sleep apnea (OSA) is a highly prevalent condition worldwide. Untreated, it is associated with multiple medical complications as well as a reduced quality of life. Home sleep apnea tests are increasingly used for its diagnosis and evaluation of severity, but using total bed time rather than total sleep time may underestimate OSA severity. We aim to uncover the extent and predictors of OSA misclassification when using total bed time. A retrospective observational study was conducted using data from the sleep laboratory of the National University Hospital, Singapore, a tertiary hospital with 1200 beds. Misclassification of OSA was defined as any OSA severity that was less severe using total bed time versus total sleep time. Logistic regression was used to identify predictors of OSA misclassification. A total of 1621 patients were studied (mean age 45.6 ± 15.9 years; 73.4% male). 300 (18.5%) patients were misclassified. Risk factors for OSA misclassification included age (OR 1.02, 95% CI 1.01–1.03, P = 0.001) and body-mass index (BMI) (OR 0.97, 95% CI 0.95–0.99, P = 0.015). Risk for misclassification was significant in patients aged ≥ 57 years old, with BMI < 32.3 kg/m². Using total bed time rather than total sleep time to quantify OSA severity was associated with a significant risk of misclassification, particularly in patients aged ≥ 57 years old, with BMI < 32.3 kg/m².

Perceptual snoring as a basis for a psychoacoustical modeling and clinical patient profiling

PURPOSE

The perceptual burden and social nuisance for mainly the co-sleeper can affect the relationship between snorer and bedpartner. Mandibular advancement devices (MAD) are commonly recommended to treat sleep-related breathing such as snoring or sleep apnea. There is no consensus about the definition of snoring particularly with MAD, which is essential for assessing the effectiveness of treatment. We aimed to stablish a notion of perceptual snoring with MAD in place.

METHODS

Sound samples, each 30 min long, were recorded during in-home, overnight, automatic mandibular repositioning titration studies in a population of 29 patients with obstructive sleep apnea syndrome (OSAS) from a clinical trial carried out to validate the MATRx plus. Three unspecialized and calibrated raters identified sound events and classified them as noise, snore, or breathing as well as providing scores for classification certainty and annoyance. Data were analyzed with respect to expiration-inspiration, duration, annoyance, and classification certainty.

RESULTS

A Fleiss' kappa (>0.80) and correlation duration of events (>0.90) between raters were observed. Prevalence of all breath sounds: snore 55.6% (N = 6398), breathing sounds 31.7% (N = 3652), and noise 9.3% (N = 1072). Inspiration occurs in 88.3% of events, 96.8% contained at least on expiration phase. Snore and breath events had similar duration, respectively 2.58s (sd 1.43) and 2.41s (sd 1.22). Annoyance is lowest for breathing events (8.00 sd 0.98) and highest for snore events (4.90 sd 1.92) on a VAS from zero to ten.

CONCLUSION

Perceptual sound events can be a basis for analysis in a psychosocial context. Perceived snoring occurs during both expiration as well as inspiration. Substantial amount of snoring remains despite repositioning of the mandible aimed at the reduction of AHI-ODI.

Walking exercise alters protein digestion, amino acid absorption, and whole body protein kinetics in older adults with and without COPD

Gut function is disturbed in older adults with COPD. As exercise is the cornerstone of pulmonary rehabilitation in COPD, knowledge of the response of the gut to aerobic exercise is of importance.

Weight Loss as the First-Line Therapy in Patients with Severe Obesity and Obstructive Sleep Apnea Syndrome: the Role of Laparoscopic Sleeve Gastrectomy

PURPOSE

The objective of this study is to investigate the effects of laparoscopic sleeve gastrectomy (LSG) on the polysomnographic parameters related to OSAS.

MATERIALS AND METHODS

We conducted this 3-year prospective cohort study in a tertiary care center between December 2016 and December 2019. In total, we enrolled 31 patients with severe obesity who underwent full-night polysomnography (PSG) before LSG. Later, the patients were re-evaluated by full-night PSG 12 months after the surgery.

RESULTS

The mean age of the patients was 44.1 ± 9.6 years. The mean body mass index (BMI) decreased significantly from a mean value of 49.8 ± 8.5 kg/m² at baseline to 33.2 ± 8.2 kg/m² and a percent BMI (%BMI) reduction of 33.8 ± 10.4% and a percent total weight loss (%TWL) of 35.4 ± 10.8% was achieved on the same day of the postsurgical PSG (p < 0.001). There was a remarkable improvement in the AHI (baseline: 36.1 ± 27.1, 12 months after the surgery: 10.3 ± 11.8; difference: 25.8 ± 22.8 events per hour) (p < 0.001). Importantly, there was a decrease in the percentage of non-rapid eye movement (NREM) 2 (p < 0.001), whereas NREM 3 and REM stages witnessed a significant increase (p = 0.001 and p < 0.001, respectively) after the surgery.

CONCLUSION

The results of this study showed that weight loss after LSG yields improvement not only in AHI but also in many polysomnographic parameters such as sleep quality and desaturation indices.

Prediction of obstructive sleep apnea: comparative performance of three screening instruments on the apnea-hypopnea index and the oxygen desaturation index

Purpose

To evaluate the performance of the NoSAS (neck, obesity, snoring, age, sex) score, the STOP-Bang (snoring, tiredness, observed apneas, blood pressure, body mass index, age, neck circumference, gender) questionnaire, and the Epworth sleepiness score (ESS) as a screening tool for obstructive sleep apnea (OSA) severity based on the apnea-hypopnea index (AHI) and the oxygen desaturation index (ODI).

Methods

Data from 235 patients who were monitored by ambulant polysomnography (PSG) were retrospectively analyzed. OSA severity was classified based on the AHI; similar classification categories were made based on the ODI. Discrimination was assessed by the area under the curve (AUC), while predictive parameters were calculated by four-grid contingency tables.

Results

The NoSAS score and the STOP-Bang questionnaire were both equally adequate screening tools for the AHI and the ODI with AUC ranging from 0.695 to 0.767 and 0.684 to 0.767, respectively. Both questionnaires perform better when used as a continuous variable. The ESS did not show adequate discrimination for screening for OSA (AUC ranging from 0.450 to 0.525). Male gender, age, and BMI proved to be the strongest individual predictors in this cohort.

Conclusion

This is the first study to evaluate the predictive performance of three different screening instruments with respect to both the AHI and the ODI. This is important, due to increasing evidence that the ODI may have a higher reproducibility in the clinical setting. The NoSAS score and the STOP-Bang questionnaire proved to be equally adequate to predict OSA severity based on both the AHI and the ODI.

Electronic supplementary material

The online version of this article (10.1007/s11325-020-02219-6) contains supplementary material, which is available to authorized users.

Clinical Characteristics and Prognosis of 244 Cardiovascular Patients Suffering From Coronavirus Disease in Wuhan, China

Background

The coronavirus disease 2019 (COVID‐19) has developed into a global outbreak. Patients with cardiovascular disease (CVD) with COVID‐19 have different clinical characteristics and prognostic outcomes. This study aimed to summarize the clinical characteristics and laboratory indicators of patients with COVID‐19 with CVD, especially the critically ill patients.

Methods and Results

This study included 244 patients diagnosed with COVID‐19 and CVD (hypertension, coronary heart disease, or heart failure). The patients were categorized into critical (n=36) and noncritical (n=208) groups according to the interim guidance of China’s National Health Commission. Clinical, laboratory, and outcome data were collected from the patients’ medical records and compared between the 2 groups. The average body mass index of patients was significantly higher in the critical group than in the noncritical group. Neutrophil/lymphocyte ratio, and C‐reactive protein, procalcitonin, and fibrinogen, and d‐dimer levels at admission were significantly increased in the critical group. The all‐cause mortality rate among cases of COVID‐19 combined with CVD was 19.26%; the proportion of coronary heart disease and heart failure was significantly higher in deceased patients than in recovered patients. High body mass index, previous history of coronary heart disease, lactic acid accumulation, and a decrease in the partial pressure of oxygen were associated with death.

Conclusions

All‐cause mortality in patients with COVID‐19 with CVD in hospitals is high. The high neutrophil/lymphocyte ratio may be a predictor of critical patients. Overweight/obesity combined with coronary heart disease, severe hypoxia, and lactic acid accumulation resulting from respiratory failure are related to poor outcomes.

Registration

URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2000029865.

Preoperative identification of children at high risk of obstructive sleep apnea

Obstructive sleep apnea is a common childhood disorder which can lead to serious health problems if left untreated. Enlarged adenoid and tonsils are the commonest causes, and adenotonsillectomy is the recommended first line of treatment. Obstructive sleep apnea poses as an anesthetic challenge, and it is a well-known risk factor for perioperative adverse events. The presence and severity of an obstructive sleep apnea diagnosis will influence anesthesia, pain management, and level of monitoring in recovery period. Preoperative obstructive sleep apnea assessment is necessary, and anesthetists are ideally placed to do so. Currently, there is no standardized approach to the best method of preoperative screening for obstructive sleep apnea. Focused history, clinical assessments, and knowledge regarding the strengths and limitations of available obstructive sleep apnea assessment tools will help recognize a child with obstructive sleep apnea in the preoperative setting.

Classification of Sleep Apnea Severity by Electrocardiogram Monitoring Using a Novel Wearable Device

Sleep apnea (SA) is a prevalent disorder diagnosed by polysomnography (PSG) based on the number of apnea–hypopnea events per hour of sleep (apnea–hypopnea index, AHI). PSG is expensive and technically complex; therefore, its use is rather limited to the initial diagnostic phase and simpler devices are required for long-term follow-up. The validity of single-parameter wearable devices for the assessment of sleep apnea severity is still debated. In this context, a wearable electrocardiogram (ECG) acquisition system (ECG belt) was developed and its suitability for the classification of sleep apnea severity was investigated using heart rate variability analysis with or without data pre-filtering. Several classification algorithms were compared and support vector machine was preferred due to its simplicity and overall performance. Whole-night ECG signals from 241 patients with a suspicion of sleep apnea were recorded using both the ECG belt and patched ECG during PSG recordings. 65% of patients had an obstructive sleep apnea and the median AHI was 21 [IQR: 7–40] h−1. The classification accuracy obtained from the ECG belt (accuracy: 72%, sensitivity: 70%, specificity: 74%) was comparable to the patched ECG (accuracy: 74%, sensitivity: 88%, specificity: 61%). The highest classification accuracy was obtained for the discrimination between individuals with no or mild SA vs. moderate to severe SA. In conclusion, the ECG belt provided signals comparable to patched ECG and could be used for the assessment of sleep apnea severity, especially during follow-up.

Does nesfatin-1 influence the hypothalamic–pituitary–gonadal axis in adult males with obstructive sleep apnoea?

There is growing evidence that obstructive sleep apnoea (OSA) influences the hypothalamic–pituitary–gonadal axis (HPG axis) in men. The aim of the study was to assess the association of nesfatin-1 with HPG axis disturbances in OSA. This is a prospective study with consecutive enrolment. It comprises 72 newly diagnosed OSA patients ((AHI: apnoea-hypopnea index) 18 subjects: 5 ≤ AHI < 15; 24: 15 ≤ AHI < 30; 30: AHI ≥ 30) and a control group composed of 19 patients (AHI < 5). All patients underwent polysomnography and fasting blood collection for nesfatin-1, testosterone, luteinising hormone (LH), high-sensitivity C-reactive protein (hsCRP), aspartate transaminase (AST), alanine aminotransferase (ALT), creatinine and glucose. Groups had similar levels of LH, nesfatin-1 and testosterone (p = 0.87; p = 0.24; p = 0.08). Nesfatin-1 was not correlated to LH (p = 0.71), testosterone (p = 0.38), AHI (p = 0.34) or the oxygen desaturation index (ODI) (p = 0.69) either in the whole group, or in sub-groups. The study did not reveal any association between the HPG axis and nesfatin-1 in OSA adult males. It is possible that nesfatin-1 is not a mediator of HPG axis disturbances in adult patients with OSA.

Do apneas and hypopneas best reflect risk for poor outcomes after stroke?

OBJECTIVE/BACKGROUND

Sleep apnea (SA) is associated with poor outcomes after stroke. The best sleep apnea-related measure to capture this relationship is currently unknown. This measure or its underlying pathophysiology could serve as a treatment target.

PATIENTS/METHODS

Within the population-based Brain Attack Surveillance in Corpus Christi (BASIC) project, the ApneaLink Plus was used to perform sleep apnea tests shortly after ischemic stroke (2010-2015). Functional and cognitive outcomes were measured via in-person interviews 90-days post-stroke. Recurrent stroke was assessed longitudinally through active and passive surveillance procedures. After standardization to allow direct comparisons, adjusted models were built for each ApneaLink Plus measure and each outcome, to assess the effect of 1 standard deviation difference in the measure.

RESULTS

Among 995 subjects, median age was 67 years (interquartile range: 59, 78) and 52% were women. The respiratory event index had the strongest relationship with functional outcome (mean difference = 0.094, 95% confidence interval (CI): 0.040, 0.147). Desaturations ≤85% were associated with worse functional outcome (mean difference = 0.016, 95% CI: 0.002, 0.030), but desaturations ≤ 90% were not. Obstructive apnea index (OAI) showed the strongest association with cognitive outcome (mean difference = -0.079, 95% CI: -0.162, 0.005), but was not significant. Oxygen desaturation index (ODI) showed the strongest association with recurrent ischemic stroke (hazard ratio = 1.338, 95% CI: 1.016, 1.759).

CONCLUSIONS

Measurements easily obtained from a commonly used home sleep apnea test predicted outcomes differentially. This suggests the possibility of different SA-associated targets (perhaps using strategies more tolerable than standard treatment) based on the outcome of interest.

Adenotonsillectomy in children with syndromic craniosynostosis: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis in children with syndromic craniosynostosis, to evaluate the effect of adenotonsillectomy for the treatment of obstructive sleep apnea (OSA).

STUDY DESIGN

A systematic review and meta-analysis.

SEARCH METHODS

Data sources: a comprehensive search of PubMed, SCOPUS, Ovid Medline, and Web of science databases was performed through June 22nd, 2018. Manual searches and subject matter expert input were also obtained. This article includes studies assessing the effectiveness of adenotonsillectomy in syndromic craniosynostosis children, in which apnea-hypopnea index (AHI) or oxygen desaturation index (ODI) was reported.

RESULTS

A total of 3 retrospective studies (24 patients) met the inclusion criteria. Pooled random effect analysis did not identify a statistically significant difference between preoperative and postoperative AHI. But there was an overall reduction of AHI of 5.00 events per hour [95% confidence interval (CI) (- 17.79, 7.79); P = 0.44]. However, the fixed effect model demonstrated a statistically significant difference between preoperative and postoperative ODI with an overall reduction of 8.5 per hour [95% CI (- 15.01, - 1.99); P = 0.01].

CONCLUSION

Adenotonsillectomy showed benefits for the treatment of OSA in syndromic craniosynostosis children, in terms of AHI and ODI. However, only ODI, but not AHI, reached statistical significance. Data were based on meta-analysis of retrospective reviews. Further studies that are conducted at multiple centers are needed to confirm the benefits of adenotonsillectomy for the treatment of OSA in syndromic craniosynostosis children.