Validation of Watch-PAT-200 against polysomnography during pregnancy

A Position Modification Device for the Prevention of Supine Sleep During Pregnancy: A Randomised Crossover Trial

OBJECTIVE

To assess the effectiveness and acceptability of a pillow-like position modification device to reduce supine sleep during late pregnancy, and to determine the impacts on the severity of sleep-disordered breathing (SDB) and foetal well-being.

DESIGN

Randomised cross-over study.

SETTING AND POPULATION

Individuals in the third trimester of pregnancy receiving antenatal care at a tertiary maternity hospital in Australia.

METHODS

Participants used their own pillow for a control week and an intervention pillow for a week overnight, in randomised order. Sleep position and total sleep time for each night of both weeks were objectively monitored, with a sleep study and foetal heart rate monitoring performed on the last night of each week.

MAIN OUTCOME MEASURES

Primary outcome = percentage of sleep time in the supine position; secondary outcomes = apnoea-hypopnoea index, foetal heart rate decelerations and birthweight centile.

RESULTS

Forty-one individuals were randomised with data collected on 35 participants over 469 nights. There was no difference in percentage of total sleep time in the supine position overnight between the control or intervention pillow week (13.0% [6.1, 25.5] vs. 16.0% [5.6, 27.2], p = 0.81 with a mean difference of 2.5% [95% CI] = -0.7, 5.6, p = 0.12), and no difference in the severity of SDB or foetal heart rate decelerations across weeks. However, increased supine sleep was significantly related to a higher apnoea-hypopnoea index (rs = 0.37, p = 0.003), lower birthweight (rs = -0.45, p = 0.007) and lower birthweight centile (rs = -0.45, p = 0.006). The proportion of supine sleep each night of the week varied widely both within and across participants, despite awareness of side-sleeping recommendations.

CONCLUSIONS

We found no evidence to suggest that the adoption of a pillow designed to discourage supine sleep was effective in late pregnancy, with women spending an average of 1 h per night supine. Alternative devices should be investigated, incorporating lessons learnt from this study to inform trials of supine sleep minimisation in pregnancy.

TRIAL REGISTRATION

Clinical Trial: (Australia New Zealand Clinical Trials Registry): ACTRN12620000371998.

Enhancing artificial intelligence-driven sleep apnea diagnosis: The critical importance of input signal proficiency with a focus on mandibular jaw movements

PURPOSE

This review aims to highlight the pivotal role of the mandibular jaw movement (MJM) signal in advancing artificial intelligence (AI)-powered technologies for diagnosing obstructive sleep apnea (OSA).

METHODS

A scoping review was conducted to evaluate various aspects of the MJM signal and their contribution to improving signal proficiency for users.

RESULTS

The comprehensive literature analysis is structured into four key sections, each addressing factors essential to signal proficiency. These factors include (1) the comprehensiveness of research, development, and application of MJM-based technology; (2) the physiological significance of the MJM signal for various clinical tasks; (3) the technical transparency; and (4) the interpretability of the MJM signal. Comparisons with the photoplethysmography (PPG) signal are made where applicable.

CONCLUSIONS

Proficiency in biosignal interpretation is essential for the success of AI-driven diagnostic tools and for maximizing the clinical benefits through enhanced physiological insight. Through rigorous research ensuring an enhanced understanding of the signal and its extensive validation, the MJM signal sets a new benchmark for the development of AI-driven diagnostic solutions in OSA diagnosis.

[Obstructive apnea hypopnea syndrome in pregnancy]

Obstructive sleep apnea hypopnea syndrome (OSA) in pregnant women is an under-diagnosed but common condition, due to the numerous physiological changes favoring upper airway collapse. Risk factors such as significant weight gain during the 1st trimester, maternal age and parity should be systematically investigated. Diagnosis is made by sleep recording. OSA can lead to maternal and fetal complications (gestational diabetes, eclampsia, intrauterine growth restriction, prematurity…) during pregnancy, delivery and the post-partum period. It is therefore essential to treat apneic patients as early as possible in pregnancy. Treatment includes hygienic and dietary measures, as well as continuous positive airway pressure (CPAP). Systematic post-partum follow-up with polygraphic monitoring should be proposed.

Obstructive sleep apnea in pregnancy: A review of the literature from the obstetrics practitioner's view and a proposed clinical approach

Obstructive sleep apnea (OSA) is a frequent condition during pregnancy and its occurrence is increased in obese women. There are growing concerns about both pre-existing OSA and the development of gestational OSA and their effect on maternal pregnancy outcomes, fetal development, and even early childhood. A strong body of research has revealed maternal complications of OSA, but far fewer studies explore its impact on the developing fetus, highlighting an important area of future research. As evidence in both areas mounts about the negative reproductive impact of OSA, studies have emerged that explore the limitations of current diagnostic criteria and screening tools for this disorder in pregnancy which, in turn, limit the practitioner's ability to appropriately refer patients for OSA diagnosis and treatment. This expert review summarizes the current data regarding OSA screening tools in pregnancy, the limitations of these tools, and available OSA treatments and their efficacies. Our objective is to develop recommendations for how to best screen and manage OSA in pregnancy. We conclude that improved understanding of available tools and treatments will allow the obstetric practitioner to better counsel patients and help mitigate the deleterious effects of OSA on mother and fetus. We herein propose a clinical approach for the screening and management of OSA in pregnancy.

Screening Tools for Obstructive Sleep Apnea in Pregnant Women: An Extended and Updated Systematic Review and Meta-analysis

The prevalence of obstructive sleep apnea syndrome (OSA) increases in women during pregnancy and negatively affects maternal and fetal outcomes. The updated systematic review and meta-analysis aimed to evaluate the validity of the Berlin, STOP-Bang, and Epworth sleepiness scale (ESS) questionnaires in detecting OSA in pregnant women. PubMed, Embase, and Web of Science were searched systematically up to March 2022. After eligible studies inclusion, two independent reviewers extracted demographic and clinical data. Bivariate random effects models were used to estimate the pooled accuracy measures including sensitivity and specificity, positive (PPV) and negative predictive values (NPVs), diagnostic odds ratio (DOR), and receiver operating characteristic curve (ROC) curve. We included 8 studies including 710 pregnant women with suspected OSA. The performance values of Berlin, STOP-Bang, and ESS questionnaires were as follows: the pooled sensitivity were 61% (95% confidence interval (CI): 40%-80%), 59% (95% CI: 49%-69%), and 29%, (95% CI: 10%-60%); pooled specificity were 61% (95% CI: 42%-78%), 80% (95% CI: 55%-93%), and 80% (95% CI: 50%-94%); pooled PPVs were 60% (95% CI: 0.49-0.72), 73% (95% CI: 61%-85%), and 59% (95% CI: 31%-87%); pooled NPVs were 60% (95% CI: 0.49-0.71), 65% (95% CI: 54%-76%), and 53% (95% CI: 41%-64%); and pooled DORs were 3 (95% CI: 1-5), 6 (95% CI: 2-19), and 2 (95% CI: 1-3), respectively. It seems that the Berlin, STOP-Bang, and ESS questionnaires had poor to moderate sensitivity and specificity in pregnancy, with the ESS showing the worst characteristics. Further studies are required to evaluate the performance of alternative screening methods for OSA in pregnancy.

Validation of self-applied unattended polysomnography using Somte V2 PSG (Somte) for diagnosis of obstructive sleep apnoea (OSA) in pregnant women in early to mid-gestation

PURPOSE

Polysomnography (PSG) may be completed in the home environment (unattended), and when self-applied, allow the collection of data with minimal healthcare worker intervention. Self-applied, unattended PSG in the home environment using Somte PSG V2 (Somte) has not been validated in pregnant women in early to mid-gestation. We undertook a study to evaluate the accuracy of Somte compared to attended PSG. The agreement between apnoea hypopnea index (AHI) and respiratory disturbance index (RDI) scores in Somte and PSG in early to mid-gestation were assessed.

METHODS

Pregnant women (≤ 24 weeks gestation) were scheduled for PSG and Somte within a 7-day window, in any order. Somte were self-applied and completed in the home. Somte were scored blinded to PSG result. AHI was the primary outcome of interest, though an AHI ≥ 5 or RDI ≥ 5 on PSG was considered diagnostic of Obstructive Sleep Apnoea (OSA). AHI, RDI, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) was calculated and receiver operating characteristic (ROC) curves were produced. Bland-Altman plots were used to determine agreement. Technical issues occurring during tests were explored.

RESULTS

Twenty-four participants successfully completed both tests between March 2021 and January 2023. PSG were completed at around 14.1 weeks' gestation (IQR 13.4, 15.7). The time interval between Somte and PSG was a median of 4 days (IQR 2, 7 (range 1-12)). Five (20.8%) women had OSA on PSG at AHI ≥ 5 and 10 (41.6%) women had OSA on PSG at RDI ≥ 5. Somte and PSG did not differ in the measurement of AHI ((1.8, 1.6, p = 0.09) or RDI (3.3, 3.5), p = 0.73). At AHI ≥ 5, diagnostic test accuracy (area under the ROC curve) of Somte was 0.94, sensitivity 80.0%, specificity 94.7%, PPV and NPV were 80.0% and 94.7% respectively. At RDI ≥ 5, diagnostic test accuracy (area under the ROC curve) was 0.95, sensitivity 60.0%, specificity 93.0% and PPV and NPV were 85.7% and 76.4% respectively. The confidence limits of Bland-Altman plots were 6.37 to - 8.89 at cut off AHI ≥ 5 and 8.89 to - 10.43 at cut off RDI ≥ 5. Somte failed to start in four tests. Technical issues were reported in both Somte (n = 13, 54.2%) and PSG (n = 6, 25.0%).

CONCLUSION

Self-applied, unattended Somte may provide an acceptable substitute to attended PSG in the identification of OSA in pregnant women in early to mid-gestation in this small sample but may fail to detect cases of OSA, particularly when using RDI as the diagnostic marker.

Validation of the Apnealink Air for diagnosis of obstructive sleep apnoea (OSA) in pregnant women in early-mid gestation

PURPOSE

The detection of obstructive sleep apnoea (OSA) in pregnant women in early-mid gestation is logistically difficult. Accurate alternates to polysomnography (PSG) in early pregnancy are not well identified. We compared the agreement between Apnealink Air (AL) and existing screening questionnaires to PSG in pregnant women ≤ 24-week gestation.

METHODS

Pregnant women (≤ 24-week gestation) underwent AL at home plus attended PSG in any order, completed within 7 days where practicable. AL was manually scored (AL(M)) and automatically scored (AL(A)). An apnoea-hypopnea index (AHI) ≥ 5 was considered diagnostic of OSA and an AHI ≥ 15 considered at least moderate OSA. Diagnostic analysis was undertaken (sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)) by generating receiver operating characteristic (ROC) curves and an area under the curve (AUC) (95% CI). Bland-Altman plots were used to plot agreement. Screening questionnaires (Epworth sleepiness score (ESS), STOP-BANG, calculated pregnancy-specific screening tool) were compared to PSG.

RESULTS

A total of 49 participants successfully completed both tests at around 14-weeks gestation (IQR 12.9, 17.1). The time interval between AL and PSG was a median of 2 days (IQR 1, 5 (range 1-11)). A total of 14 (29%) participants had OSA. The median AHI of AL(A) (3.1(IQR 0.85,4.6)) and AL(M) (IQR2.4(0.65,4.8)) did not differ from PSG (1.7(IQR1.0,6.1)). AL(A) and AL(M) compared to PSG demonstrated diagnostic test accuracy (area under curve (ROC)) of 0.94(95% CI 0.87-1.0) and 0.92(95% CI 0.85-1.0) respectively. Apnealink Air outperformed screening questionnaires tested.

CONCLUSION

The findings suggest that Apnealink may provide a substitute to attended PSG identification of OSA in pregnant women in early-mid gestation using both manual and auto-scoring methods.

Application of portable sleep monitoring devices in pregnancy: a comprehensive review

Objective.The physiological, hormonal and biomechanical changes during pregnancy may trigger sleep disordered breathing (SDB) in pregnant women. Pregnancy-related sleep disorders may associate with adverse fetal and maternal outcomes including gestational diabetes, preeclampsia, preterm birth and gestational hypertension. Most of the screening and diagnostic studies that explore SDB during pregnancy were based on questionnaires which are inherently limited in providing definitive conclusions. The current gold standard in diagnostics is overnight polysomnography (PSG) involving the comprehensive measurements of physiological changes during sleep. However, applying the overnight laboratory PSG on pregnant women is not practical due to a number of challenges such as patient inconvenience, unnatural sleep dynamics, and expenses due to highly trained personnel and technology. Parallel to the progress in wearable sensors and portable electronics, home sleep monitoring devices became indispensable tools to record the sleep signals of pregnant women at her own sleep environment. This article reviews the application of portable sleep monitoring devices in pregnancy with particular emphasis on estimating the perinatal outcomes.Approach.The advantages and disadvantages of home based sleep monitoring systems compared to subjective sleep questionnaires and overnight PSG for pregnant women were evaluated.Main Results.An overview on the efficiency of the application of home sleep monitoring in terms of accuracy and specificity were presented for particular fetal and maternal outcomes.Significance.Based on our review, more homogenous and comparable research is needed to produce conclusive results with home based sleep monitoring systems to study the epidemiology of SDB in pregnancy and its impact on maternal and neonatal health.

Tandem Mass Tag-Labeled Quantitative Proteome Analyses Identify C1R and A2M as Novel Serum Biomarkers in Pregnant Women with Obstructive Sleep Apnea

The aim of this study was to identify serum diagnostic biomarkers associated with the severity of obstructive sleep apnea (OSA) during pregnancy. Differentially expressed proteins (DEPs) were identified in the control (C), mild (O), and moderate (MO) OSA groups (n = 3 in each group). Bioinformatics analysis was conducted to identify the underlying functions, pathways, and networks of the proteins. Receiver operating characteristic curves were used to assess the diagnostic value of the identified DEPs. The enzyme-linked immunoassay was performed to detect serum levels of the complement C1r subcomponent (C1R) and alpha-2-macroglobulin (A2M) in 79 pregnant women with OSA (mild OSA [n = 32]; moderate OSA [n = 29], and severe OSA [n = 18]) and 65 healthy pregnant women without OSA. Pearson's correlation analysis was conducted to analyze the correlation between C1R and A2M levels and OSA clinicopathological factors. In total, 141 DEPs, 29 DEPs, and 103 DEPs were identified in the three groups (i.e., the mild OSA vs control group, the moderate OSA vs mild apnea group, and the moderate OSA vs control group, respectively). C1R and A2M were identified as continuously up-regulated proteins, and the levels of C1R and A2M were associated with OSA severity. C1R and A2M were found to be correlated with body mass index, systolic blood pressure, apnea-hypopnea index, oxygen desaturation index, time with saturation below 90%, and lowest SaO2. Adverse maternal and neonatal outcomes were observed in pregnant women with OSA. C1R and A2M have been identified as diagnostic biomarkers and are associated with the severity of OSA during pregnancy.

Longitudinally assessed maternal sleep position, measures of breathing during sleep, and fetal growth in high-risk pregnancies

STUDY OBJECTIVES

Subjective recall of supine sleep during pregnancy has been linked to increased risk of stillbirth, but longitudinal, objective data are lacking. We aimed to examine how sleep position and breathing parameters change throughout pregnancy, and investigated associations between maternal supine sleep, assessed objectively in early and late gestation, and fetal growth velocity in high-risk women.

METHODS

Women with singleton pregnancies and body mass index (BMI) ≥27 kg/m2 underwent level-III sleep apnea testing. Sleep position was assessed by accelerometry. We derived percentiles of estimated fetal weight and birthweight using FetalGPSR software, then calculated growth velocity as change in percentile/week between the second-trimester anatomy scan and birth.

RESULTS

In total, 446 women were included, with N = 126 in the longitudinal sleep pattern analysis and N = 83 in the fetal growth analysis. Sleep-onset position and predominant sleep position were significantly correlated in both early (p = 0.001) and late (p < 0.01) pregnancy. However, supine going-to-bed position predicted predominant supine sleep in only 47% of women. Between early and late pregnancy there was a reduction in predominant supine sleepers (51.6% to 30.2%). Percent of sleep spent supine and oxygen desaturation index, in the third trimester, were significantly associated after BMI adjustment (B = 0.018, p = 0.04). Models did not suggest significant effects of early or late pregnancy supine sleep on growth velocity (p > 0.05).

CONCLUSIONS

Going-to-bed position predicts predominant supine sleep in less than half of women with overweight and obesity. Time spent supine throughout pregnancy correlates with measures of sleep-disordered breathing. Maternal sleep position patterns did not affect fetal growth velocity in this high-risk population, but the study was not powered to detect differences.

Eye-mask and earplugs compared with sleep advice leaflet to improve night sleep duration in pregnancy: a randomized controlled trial

STUDY OBJECTIVES

To evaluate at-home use of eye-mask and earplugs (EMEP) versus sleep hygiene advice leaflet (AL) on actigraphy-derived night sleep duration in sleep-deprived pregnant women.

METHODS

A randomized controlled trial was conducted in the antenatal clinic of University Malaya Medical Centre from June 2021 to June 2022. Women at 34-36 weeks gestation with self-reported night sleep duration ≤6 hours were recruited. Participants wore an actigraphy device at night for seven consecutive nights (Observation/Baseline week). Only women whose actigraphy-derived night sleep duration was confirmed to be ≤360 minutes were randomized to use EMEP or AL. Actigraphy was continued for another week (Intervention week). Primary outcome was change in actigraphy-derived night sleep duration from observation to intervention week across trial arms. Secondary outcomes include participants' sleep quality, labor, and neonatal outcome. Comparisons were by Student t-test, Mann-Whitney U test, and chi-square test.

RESULTS

A total of 210 women were randomized: 105 each to EMEP and AL. The increase in night sleep duration over baseline was significantly longer with both EMEP (mean ± SD) 23 ± 41 minutes, p < .001, and AL 10 ± 35 minutes, p = .007. Night sleep duration was longer by 12.9 (95% CI = 2.2 to 23.7) minutes, p = .019 with EMEP over AL. Sleep quality (Global Pittsburgh Sleep Quality Index score) was significantly improved with EMEP (mean ± SD) -2.0 ± 2.5, p < .001, but not with AL -0.3 ± 2.2, p = .246. Labor and neonatal outcomes were not significantly different.

CONCLUSION

EMEP significantly lengthened night sleep duration in sleep-deprived women in late pregnancy and is superior to AL.

CLINICAL TRIAL INFORMATION

"Use of eye masks and earplugs compared with standard advice to improve sleep in pregnancy". https://doi.org/10.1186/ISRCTN19061849. Registered with ISRCTN on 07 May 2021, trial identification number: ISRCTN19061849.

Don't hold PAT: watch for and correct oximetry artifact

This study evaluated the accuracy of the algorithmic oxygen saturation (SpO2) nadir detection of WatchPAT (Zoll/Itamar, Caesarea, Israel) compared with visual inspection in a real-world setting. SpO2 tracings for 209 consecutive adult WatchPAT recordings were reviewed for SpO2 artifact, with erroneous SpO2 data removed manually. Error rates for SpO2 minima were determined across all studies, and relationships between correct and erroneous studies examined. The overall error rate for SpO2 nadir was 22.5%. Erroneous studies had overall less time spent at SpO2 ≤ 88%, higher true SpO2 nadir, lower mean body mass index, and greater artifact time; however, these variables were not associated with the magnitude of discrepancy between manual and algorithmically derived SpO2 minima. These data demonstrate that SpO2 nadir determined by WatchPAT algorithms should not be considered universally accurate. Like other home sleep apnea tests, visual inspection and manual correction of the study data are often required to derive accurate clinical results.

CITATION

Plante DT, Rumble ME. Don't hold PAT: watch for and correct oximetry artifact. J Clin Sleep Med. 2023;19(12):2113-2116.

Home monitoring for clinically suspected obstructive sleep apnea in pregnancy

STUDY OBJECTIVES

To determine if a home sleep apnea test (HSAT) using a type III portable monitor (PM), Nox-T3 (Nox Medical, Inc., Reykjavik, Iceland), detects obstructive sleep apnea in pregnant women.

METHODS

Ninety-two pregnant women (34.5 ± 4.3 years; gestational age 25.4 ± 8.9 weeks; body mass index 29.9 ± 4.7 kg/m2) with suspected obstructive sleep apnea underwent HSAT with the Nox-T3 PM followed by overnight polysomnography (PSG) and PM recording simultaneously in the laboratory within 1 week. PMs were scored automatically and manually using a 3% criteria and compared with PSGs scored by following guidelines.

RESULTS

Apnea-hypopnea indexes were 8.56 ± 10.42, 8.19 ± 13.79, and 8.71 ± 14.19 events/h on HSAT, in-laboratory PM recording, and PSG (P = .955), respectively. Bland-Altman analysis of the apnea-hypopnea index on PSG vs HSAT showed a mean difference (95% confidence interval) of -0.15 (-1.83, 1.53); limits of agreement (± 2 SD) were -16.26 to 16.56 events/h. Based on a threshold apnea-hypopnea index ≥ 5 events/h, HSAT had 91% sensitivity, 85% specificity, 84% positive-predictive value, and 92% negative-predictive value compared with PSG. When comparing the simultaneous recordings, closer agreement was observed. Automated vs manual analysis of PM showed no significant difference.

CONCLUSIONS

A type III PM had an acceptable failure rate and high diagnostic performance operating as a reasonable alternative for in-laboratory PSG in pregnant women.

CITATION

Wang J, Zhang C, Xu L, et al. Home monitoring for clinically suspected obstructive sleep apnea in pregnancy. J Clin Sleep Med. 2023;19(11):1951-1960.

Society of Anesthesia and Sleep Medicine and the Society for Obstetric Anesthesia and Perinatology Consensus Guideline on the Screening, Diagnosis, and Treatment of Obstructive Sleep Apnea in Pregnancy

The Society of Anesthesia and Sleep Medicine and the Society for Obstetric Anesthesia and Perinatology tasked an expert group to review existing evidence and to generate recommendations on the screening, diagnosis, and treatment of patients with obstructive sleep apnea during pregnancy. These recommendations are based on a systematic review of the available scientific evidence and expert opinion when scientific evidence is lacking. This guideline may not be appropriate for all clinical situations and patients, and physicians must decide whether these recommendations are appropriate for their patients on an individual basis. We recognize that not all pregnant people may identify as women. However, data on non-cisgendered pregnant patients are lacking, and many published studies use gender-binary terms; therefore, depending on the study referenced, we may refer to pregnant individuals as women. This guideline may inform the creation of clinical protocols by individual institutions that consider the unique considerations of their patient populations and the available resources.

Fascia Ecosystem: A Step Forward in Sleep Engineering and Research

Millions suffer from sleep disorders, and sleep clinics and research institutions seek improved sleep study methods. This paper proposes the Fascia Ecosystem for Sleep Engineering to improve traditional sleep studies. The Fascia Sleep Mask is more comfortable and accessible than overnight stays at a sleep center, and the Fascia Portal and Fascia Hub allow for home-based sleep studies with real-time intervention and data analysis capabilities.A study of 10 sleep experts found that the Fascia Portal is easy to access, navigate, and use, with 44.4% finding it very easy to access, 33.3% very easy to navigate, and 60% very easy to get used to. Most experts found the Fascia Portal reliable and easy to use.Moreover, the study analyzed physiological signals during various states of sleep and wakefulness in two subjects. The results demonstrated that the Fascia dataset captured higher amplitude spindles in N2 sleep (72.20 V and 109.87 V in frontal and parietal regions, respectively) and higher peak-to-peak amplitude slow waves in N3 sleep (93.51 V) compared to benchmark datasets. Fascia produced stronger and more consistent EOG signals during REM sleep, indicating its potential to improve sleep disorder diagnosis and treatment by providing a deeper understanding of sleep patterns.

Effects of posture changes on dynamic cerebral autoregulation during early pregnancy in women with obesity and/or sleep apnea

The incidence of syncope during orthostasis increases in early human pregnancy, which may be associated with cerebral blood flow (CBF) dysregulation in the upright posture. In addition, obesity and/or sleep apnea per se may influence CBF regulation due to their detrimental impacts on cerebrovascular function. However, it is unknown whether early pregnant women with obesity and/or sleep apnea could have impaired CBF regulation in the supine position and whether this impairment would be further exacerbated in the upright posture. Dynamic cerebral autoregulation (CA) was evaluated using transfer function analysis in 33 women during early pregnancy (13 with obesity, 8 with sleep apnea, 12 with normal weight) and 15 age-matched nonpregnant women during supine rest. Pregnant women also underwent a graded head-up tilt (30° and 60° for 6 min each). We found that pregnant women with obesity or sleep apnea had a higher transfer function low-frequency gain compared with nonpregnant women in the supine position (P = 0.026 and 0.009, respectively) but not normal-weight pregnant women (P = 0.945). Conversely, the transfer function low-frequency phase in all pregnancy groups decreased during head-up tilt (P = 0.001), but the phase was not different among pregnant groups (P = 0.180). These results suggest that both obesity and sleep apnea may have a detrimental effect on dynamic CA in the supine position during early pregnancy. CBF may be more vulnerable to spontaneous blood pressure fluctuations in early pregnant women during orthostatic stress compared with supine rest due to less efficient dynamic CA, regardless of obesity and/or sleep apnea.

The Utility of Home Sleep Apnea Testing in the Advanced Heart Failure Populations

Untreated sleep disorders form a risk of coronary artery disease, hypertension, obesity, and diabetes mellitus. Access to polysomnography is limited, especially during the COVID-19 pandemic, with home sleep apnea testing (HSAT) being a potentially viable alternative. We describe an HSAT protocol in patients with advanced heart failure (HF). In a single-center, observational analysis between 2019 and 2021 in patients with advanced HF and heart transplant (HT), 135 screened positive on the STOP-Bang sleep survey and underwent a validated HSAT (WatchPAT, ZOLL-Itamar). HSAT was successful in 123 patients (97.6%), of whom 112 (91.1%; 84 HF and 28 HT) tested positive for sleep apnea. A total of 91% of sleep apnea cases were obstructive, and 63% were moderate to severe. Multivariable linear regression showed that the apnea hypopnea index was 34% lower in the HT group than in the HF group (p = 0.046) after adjusting for gender, and that this effect persisted in White patients but not among African-Americans. Patient characteristics were similar between groups, with coronary artery disease, diabetes mellitus, and hypertension as the most prevalent co-morbidities. In conclusion, sleep apnea remains prevalent in patients with HF with a high co-morbidity burden. HSAT is a feasible and effective tool for screening and diagnosis in this population.

Obstructive Sleep Apnea Among Gravidas With Chronic Hypertension Compared to Matched Controls: A Prospective Cohort Study

BACKGROUND

Previous studies of obstructive sleep apnea (OSA) risk in gravidas with chronic hypertension (cHTN) did not control for obesity as a risk factor for OSA. We therefore performed this study to evaluate whether OSA is more prevalent among gravidas with cHTN compared to normotensive gravidas matched for body mass index (BMI) and gestational age (primary outcome). We also assessed whether OSA is more severe when comorbid with cHTN in pregnancy (secondary outcome).

METHODS

This was a single-center, prospective cohort study. Adult gravidas at 10-20 weeks of gestation, with and without cHTN, were enrolled and BMI matched. All subjects answered OSA screening questionnaires and underwent a home sleep test when they were between 10 and 20 weeks of gestation. Pregnancy outcomes were followed for all subjects. We performed univariable and multivariable logistic regression to model the relationship between cHTN status and OSA.

RESULTS

A total of 100 pregnant subjects (50 with cHTN and 50 normotensive) completed a home sleep test of 2 hours or more. There were no differences in demographic variables between the 2 groups, except that gravidas with cHTN were significantly older than normotensive subjects (mean ± standard deviation [SD] 34 ± 4 vs 30 ± 6 years; P < .001). OSA was more prevalent (64% vs 38%; P = .009; odds ratio [95% confidence interval (CI)] 2.90 [1.30-6.65]; P = .01) and more severe in gravidas with cHTN (moderate or severe OSA 59% vs 21%; P = .009). After controlling for age, we found no overall association between cHTN on OSA risk (adjusted odds ratio [95% CI] 2.22 [0.92-5.40]; P = .076). However, among gravidas older than 25 years of age, cHTN was associated with higher odds of OSA (adjusted odds ratio [95% CI], 2.64 [1.06-6.71], P = .038).

CONCLUSIONS

cHTN and age are important risk factors for OSA in gravidas. Gravidas with cHTN should be screened for OSA in early pregnancy. Future studies may validate screening tools that include cHTN and age, and investigate the role of OSA therapy in blood pressure control.

Interaction between alcohol consumption and use of peripheral arterial tone home sleep apnea tests for sleep apnea evaluation

OBJECTIVE/BACKGROUND

Home sleep apnea tests utilizing peripheral arterial tone (PAT HSAT) detect sleep disordered breathing by measuring various physiologic measures including changes in arterial volume in the finger. Validation tests comparing PAT HSAT to simultaneous polysomnography (PSG) have demonstrated a high correlation. Alcohol increases peripheral vasodilation, which may alter arterial tone in the finger. Validation studies have not evaluated for an interaction between alcohol consumption and PAT HSAT measures.

PATIENTS/METHODS

We describe an in-depth evaluation of a 53-year-old man who consumes alcohol on nightly basis. He underwent a series of 5 diagnostic studies under different conditions: three PAT HSATs (two nights with and another without alcohol) and two polysomnograms (one night with and another without alcohol).

RESULTS

Obstructive sleep apnea (OSA) was found on both polysomnograms but only on the PAT HSAT without alcohol, raising the possibility of two false negative PAT HSAT results after alcohol consumption.

CONCLUSIONS

This report demonstrates the need for further investigations into the performance of PAT HSATs with and without alcohol. In the meantime we recommend that testing be done without alcohol and over the course of multiple nights.

Portable Sleep Study Device Versus Polysomnography: A Meta-analysis

OBJECTIVE

To provide an updated comparison of apnea-hypopnea index (AHI), oxygen desaturation index (ODI), respiratory disturbance index (RDI), oxygen saturation (O₂ sat), and lowest oxyhemoglobin saturation (LSAT) measured by portable sleep study devices (PSSDs) compared to polysomnography (PSG).

DATA SOURCES

Primary studies were identified through PubMed, Scopus, CINAHL, and Cochrane.

REVIEW METHODS

A systematic review was performed by searching databases from inception through August 2021. Only studies examining simultaneous monitoring of a PSSD and PSG were included.  Respiratory indices AHI, ODI, RDI, O₂ sat, and LSAT was collected Meta-correlations and meta-regressions were conducted to compare sleep variable measurements between PSSD and PSG.

RESULTS

A total of 24 studies (N = 1644 patients) were included. The mean age was 49.5 ± 12.0 (range = 13-92), mean body mass index (BMI) was 30.4 ± 5.7 (range = 17-87), and 69.4% were male. Meta-correlation showed significant associations between PSSD and PSG for AHI (n = 655, r = .888; p < .001), ODI (n = 241, r = .942; p < .001), RDI (n = 313, r = .832; p < .001), O₂ sat (n = 171, r = .858; p < .001), and LSAT (n = 197, r = .930; p < .001). Meta-regressions indicated significant predictive correlations for AHI (n = 655; r = .96; p < .001), ODI (n = 740; r = .75; p = .031), RDI (n = 197; r = .99; p = .005), and LSAT (n = 197; r = .85; p = .030), but not for O₂ sat (n = 171; r = .31; p = .692).

CONCLUSIONS

Respiratory indices correlate strongly between PSSD and PSG, which is further supported by meta-regressions results. PSSD might be a valuable cost and time-saving OSA screening tool.

Portable evaluation of obstructive sleep apnea in adults: A systematic review

Obstructive sleep apnea (OSA) is a significant healthcare burden affecting approximately one billion people worldwide. The prevalence of OSA is rising with the ongoing obesity epidemic, a key risk factor for its development. While in-laboratory polysomnography (PSG) is the gold standard for diagnosing OSA, it has significant drawbacks that prevent widespread use. Portable devices with different levels of monitoring are available to allow remote assessment for OSA. To better inform clinical practice and research, this comprehensive systematic review evaluated diagnostic performances, study cost and patients' experience of different levels of portable sleep studies (type 2, 3, and 4), as well as wearable devices and non-contact systems, in adults. Despite varying study designs and devices used, portable diagnostic tests are found to be sufficient for initial screening of patients at risk of OSA. Future studies are needed to evaluate cost effectiveness with the incorporation of portable diagnostic tests into the diagnostic pathway for OSA, as well as their application in patients with chronic respiratory diseases and other comorbidities that may affect test performance.

ERS technical standards for using type III devices (limited channel studies) in the diagnosis of sleep disordered breathing in adults and children

For more than three decades, type III devices have been used in the diagnosis of sleep disordered breathing in supervised as well as unsupervised settings. They have satisfactory positive and negative predictive values for detecting obstructive and central sleep apnoea in populations with moderately high pre-test probability of symptoms associated with these events. However, standardisation of commercially available type III devices has never been undertaken and the technical specifications can vary widely. None have been subjected to the same rigorous processes as most other diagnostic modalities in the medical field. Although type III devices do not include acquisition of electroencephalographic signals overnight, the minimum number of physical sensors required to allow for respiratory event scoring using standards outlined by the American Academy of Sleep Medicine remains debatable. This technical standard summarises data on type III studies published since 2007 from multiple perspectives in both adult and paediatric sleep practice. Most importantly, it aims to provide a framework for considering current type III device limitations in the diagnosis of sleep disordered breathing while raising research- and practice-related questions aimed at improving our use of these devices in the present and future.

Eye Masks and Earplugs to Improve Night Sleep Duration in Nulliparas: A Randomized Trial

Background Women experience significant sleep disruption throughout pregnancy. Lack of sleep during the last month of pregnancy is associated with longer labor, a higher rate of Cesarean births, gestational diabetes, hypertension, and preterm birth. Eye-mask and earplugs through sensory deprivation increase sleep duration and quality in patients in the intensive care environment but their impact at home or during pregnancy is not known. We sought to evaluate eye-mask and earplugs compared to sham/placebo headbands on night sleep duration in pregnancy. Materials and methods A randomized trial was performed in a university hospital in Malaysia. Nulliparas between 34 and 36 weeks of gestation with self-reported night sleep of fewer than six hours were randomized to the use of eye-mask and earplugs or "sham" headbands during night sleep (both introduced as sleep aids). Night sleep duration was measured through a wrist actigraphy monitor during non-intervention week one and intervention week two with the allocated sleep aid. Results Data from 56 participants were analyzed on an intention-to-treat basis. Mean night sleep duration increased in intervention week two compared to non-intervention week one in both trial arms, which were 279 ± 19 vs. 304 ± 19 minutes (mean increase of 25 minutes) p = <0.001 and 286 ± 21 vs. 302 ± 22 minutes (mean increase of 16 minutes) p = <0.001 for eye-masks-earplugs and headband respectively. However, the mean increase in night sleep duration across trial arms (p=0.13) was not significant. A higher proportion of participants in the eye-masks and earplugs arm had their night sleep duration increased by at least 30 minutes, 13/29 (45%) vs. 5/26 (19%), relative risk (RR) 2.3 (95% CI 1.0-5.6) p = 0.04, more likely to agree that they slept better 19/29 (66%) vs. 7/27 (26%), RR 2.2 (95% CI 1.1-4.6) p = 0.03, expressed higher satisfaction score with their sleep aid 7 (7.0-7.5) vs. 6 (5-7), p = 0.003 and had lower induction of labor rates 4/29 (14%) vs. 12/27 (44%), RR 0.3 (95%CI 0.1-0.8) p = 0.02. Conclusion Eye masks and earplugs use in nulliparas with short night sleep duration in late pregnancy, lengthen their night sleep duration over baseline. Sleep is reportedly better and maternal satisfaction is higher with eye masks and earplugs use.

Performance comparison of peripheral arterial tonometry-based testing and polysomnography to diagnose obstructive sleep apnea in military personnel

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is increasingly common among military personnel, but diagnostic capabilities are challenged by limited capability for polysomnography (PSG). We sought to evaluate the diagnostic properties of peripheral arterial tonometry (PAT)-based home sleep apnea testing (HSAT) to accurately identify and classify OSA among active-duty military personnel.

METHODS

This study was a retrospective review of all patients suspected of having OSA who completed an initial PAT-based HSAT followed by confirmatory PSG within 120 days. The diagnostic properties of a PAT-based, HSAT-derived apnea-hypopnea index (AHI) vs a PSG-derived AHI were assessed.

RESULTS

Two hundred eight matched pairs of asynchronous studies were analyzed. The prevalence of OSA was 63.5%. PAT-based HSAT overdiagnosed 27.4% of patients with OSA and underdiagnosed 46.6% of patients with OSA. The majority (n = 116, 55.8%) of patients changed OSA severity classification (absent, mild, moderate, severe) after PSG. OSA severity classification concordance between PAT-based HSAT and PSG was observed in 53.4%, 40.5%, 28.6%, and 40.0% of patients with absent, mild, moderate, and severe OSA, respectively. Receiver operating characteristic curve analysis showed an area under the curve of 0.715 and a proposed PAT-based, HSAT-derived AHI cutoff score for OSA diagnosis of 9.0 events/h. This PAT-based, HSAT-derived AHI provided a 52% sensitivity, 83% specificity, 84% positive predictive value, and 50% negative predictive value. Bland-Altman plots showed an unacceptable degree of agreement between PAT-based, HSAT-derived AHI and AHI.

CONCLUSIONS

There is significant discordance between PAT-based HSAT and PSG among active-duty military personnel evaluated for OSA. PAT-based HSAT may have limited utility for diagnosing OSA and grading severity in this unique patient population.

CITATION

O'Reilly BM, Wang Q, Collen J, Matsangas P, Colombo CJ, Mysliwiec V. Performance comparison of peripheral arterial tonometry-based testing and polysomnography to diagnose obstructive sleep apnea in military personnel. J Clin Sleep Med. 2022;18(6):1523-1530.

Effect of Different Maxillary Oral Appliance Designs on Respiratory Variables during Sleep

This study aimed to analyze the efficacy of maxillary oral appliance (MOA) designs on respiratory variables during sleep. At baseline, 23 participants underwent a sleep test with a portable device for two nights and were categorized as participants with mild obstructive sleep apnea (mild-OSA) (n = 13) and without OSA (w/o-OSA) (n = 10). Three types of MOAs, standard-OA (S-OA), palatal covering-OA (PC-OA), and vertically increasing-OA (VI-OA), were each worn for three nights, and sleep tests with each MOA were performed with a portable device for two nights. Based on the average of the respiratory event index (REI) values for the two nights for each MOA, w/o-OSA participants with an REI ≥ 5.0 were defined as the exacerbation group and those with an REI < 5.0 as the non-exacerbation group. In mild-OSA participants, an REI ≥ 15.0 or REI ≥ baseline REI × 1.5 were defined as the exacerbation group and those with an REI < 15.0 and REI < baseline REI × 1.5 were defined as the non-exacerbation group. The percentage of the exacerbation and non-exacerbation groups with MOA was evaluated in the w/o-OSA and mild-OSA participants. The maxillary and mandibular dental-arch dimension was compared by dentition model analysis. The exacerbation group in w/o-OSA participants (n = 10) comprised 10.0% participants (n = 1) with S-OA, 40.0% (n = 4) with PC-OA, and 30.0% (n = 3) with VI-OA. The exacerbation group in the mild-OSA participants (n = 13) comprised 15.4% subjects (n = 2) with S-OA, 23.1% (n = 3) with PC-OA, and 23.1% (n = 3) in VI-OA. In the model analysis for w/o-OSA, the posterior dental arch width was significantly greater in the exacerbation group than in the non-exacerbation group wearing S-OA (p < 0.05). In addition, the ratio of the maxillary to mandibular dental arch width (anterior dental arch width) was significantly greater in the exacerbation group than in the non-exacerbation group for both PC-OA and VI-OA (p < 0.05). In mild-OSA, the maxillary and mandibular dental arch lengths and the ratio of maxillary to mandibular dental arch width (posterior dental arch width) were significantly smaller in the exacerbation group than in the non-exacerbation group for S-OA (p < 0.05). This study confirmed that wearing an MOA by w/o-OSA and mild-OSA participants may increase the REI during sleep and that PC-OA and VI-OA may increase the REI more than S-OA. The maxillary and mandibular dental-arch dimensions may affect the REI when using an MOA.

A randomized controlled trial of sleep study surveillance with targeted autoregulated positive airway pressure therapy for obstructive sleep apnea in pregnancy

BACKGROUND

Obstructive sleep apnea is associated with adverse pregnancy outcomes. The impact therapy for obstructive sleep apnea has on these pregnancy outcomes remains under investigated.

OBJECTIVE

This study aimed to determine the effects of targeted autoregulated positive airway pressure in women at risk of obstructive sleep apnea on adverse pregnancy outcomes, cost, and natural history of obstructive sleep apnea.

STUDY DESIGN

Pregnant women at high risk of obstructive sleep apnea were randomized to either a sleep study screening group receiving autoregulated positive airway therapy or a group not screened for obstructive sleep apnea receiving standard obstetrical care (control). Women in the sleep study-screened group received a sleep study at 2 periods during pregnancy, early (6-16 weeks of gestation) and late (27-33 weeks of gestation), with initiation of autoregulated positive airway therapy if their Apnea Hypopnea Index indicated ≥5 events per hour. Women of both groups had a sleep study 3 months after delivery. The primary outcome was effect on adverse pregnancy outcomes, a composite of hypertension, preterm birth, low birthweight, stillbirth, and diabetes mellitus. The secondary outcomes included obstructive sleep apnea severity and hospital costs.

RESULTS

Among 193 women randomized (100 in the sleep study-screened group and 93 in the control group; 6 lost to follow-up), there was no significant difference in composite adverse pregnancy outcomes (46.4% screened vs 43.3% control; P=.77), hypertension (23.7% screened vs 32.0% control; P=.25), preterm birth (13.4% screened vs 10.0% control; P=.5), low birthweight (5.2% screened vs 6.7% control; P=.76), stillbirth (1% screened vs 0% control; P=1), gestational diabetes (19.6% screened vs 13.3% control; P=.33), or mean cost ($12,185 screened vs $12,607 control). The Apnea Hypopnea Index increased throughout pregnancy, peaking at 3 months after delivery (P<.001). There were 24 subjects (25.8%) who had a new diagnosis of obstructive sleep apnea, with 6 in whom autoregulated positive airway was prescribed. The autoregulated positive airway compliance rates were poor with usage rates ranging from 2% (1 of 64 days) to 43% (6 of 14 days).

CONCLUSION

Targeted autoregulated positive airway therapy for obstructive sleep apnea did not decrease composite adverse pregnancy outcomes or hospital costs in the sleep study-screened high-risk pregnancy group compared with the group that received no obstructive sleep apnea screening. However, a small sample size, low autoregulated positive airway prescription rates, and poor compliance resulted in difficulty in drawing a definitive conclusion. The prevalence and severity of obstructive sleep apnea worsened throughout pregnancy, with the highest rates detected in the postpartum period. Large, multicenter clinical trials that are adequately powered are needed.

Correlations between home sleep apnea tests and polysomnography outcomes do not fully reflect the diagnostic accuracy of these tests

STUDY OBJECTIVES

The clinical performance of home sleep apnea tests (HSATs) can be described by their (diagnostic) accuracy, defined as the percentage agreement with the obstructive sleep apnea severity category (normal, mild, moderate, and severe) based on polysomnography. Rather than reporting on accuracy, there has been a strong reliance in the literature to report correlation coefficients between the apnea-hypopnea index of HSATs and polysomnography to support claims of diagnostic performance. This is surprising, as it has been well described that correlation coefficients are inadequate to evaluate equivalence between 2 parameters. The aim of this study was to systematically investigate the magnitude of the discrepancies between correlation coefficients and diagnostic accuracy reported in or retrievable from HSAT validation studies.

METHODS

We compared the discrepancy between accuracy and apnea-hypopnea index correlation coefficients of all validation papers that met the inclusion criteria. A total of 20 papers were retained, representing a participant pool of 1,652.

RESULTS

The weighted average apnea-hypopnea index correlation across all 20 papers was 0.82 and the weighted average accuracy was 0.61, highlighting a discrepancy of 0.21 and an overall misdiagnosis rate of 39%.

CONCLUSIONS

The results of our study confirm the need for increased scientific rigor in selecting primary performance endpoints to support clinical performance claims of HSATs.

CITATION

Massie F, Van Pee B, Bergmann J. Correlations between home sleep apnea tests and polysomnography outcomes do not fully reflect the diagnostic accuracy of these tests. J Clin Sleep Med. 2022;18(3):871-876.

Sleep Disturbance in Pregnancy

Sleep is vital to life, even when women enter into pregnancy state. Good sleep is important for a healthy pregnancy. Sleep disturbances are common during pregnancy and can be due to the change of pregnancy itself or the results of sleep disorders. There is growing evidence linking sleep disturbances with adverse maternal and fetal outcomes. Differentiation of sleep disorders in order to provide appropriate treatment as well as promoting good sleep for pregnant women is important. A multidisciplinary team to provide sleep care during antenatal period may be needed.

High prevalence of obstructive sleep apnea in pregnant women with class III obesity: a prospective cohort study

STUDY OBJECTIVES

To determine the prevalence of obstructive sleep apnea (OSA) in a cohort of women with class III obesity, and a comparator lean group, in the second and third trimesters of pregnancy. Secondary objectives were to compare characteristics of women with obesity with and without OSA and to assess factors that were predictive of OSA.

METHODS

We performed a prospective cohort study involving 33 women with class III obesity (mean body mass index 43.5 ± 3.9 kg/m2) and 39 lean women (body mass index 22.0 ± 1.7 kg/m2) with singleton pregnancies. Participants completed 2 level 3 sleep studies between 12-22 weeks and 32-38 weeks gestation. OSA was defined as a respiratory event index ≥ 5 events/h (≥ 3% desaturation criteria). Levels of interleukin-6, glucose, and C-peptide were quantified in maternal blood. Logistic regression analysis was performed to determine predictors of OSA.

RESULTS

OSA was identified in 12 (37.5%) and 14 (50.0%) women with obesity and in 1 (2.6%) and 3 (9.1%) lean women in the second and third trimesters, respectively. Women with obesity with OSA were older than those with no OSA but otherwise had similar characteristics. In unadjusted analysis of women with obesity, increased age, body mass index, homeostatic model assessment of insulin resistance, and history of nonsmoking were associated with increased odds of OSA. In multivariable analysis, only increased age remained significantly associated with OSA.

CONCLUSIONS

OSA is highly prevalent in pregnant women with class III obesity. Further research is required to establish effective management strategies for the growing number of women in this high-risk group.

CITATION

Johns EC, Hill EA, Williams S, et al. High prevalence of obstructive sleep apnea in pregnant women with class III obesity: a prospective cohort study. J Clin Sleep Med. 2022;18(2):423-432.

The cardiovascular, metabolic, fetal and neonatal effects of CPAP use in pregnant women: a systematic review

Continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA), but its outcomes for the pregnant are still undefined. This study aims to review current CPAP intervention during pregnancy, discuss published trials, and propose relevant issues that have yet to be addressed satisfactorily about the cardiovascular, metabolic, fetal, and neonatal effects of CPAP treatment during gestation. Two authors independently conducted a systematic review until March 28th, 2021 on PubMed, BVS, and Cochrane Library, using PRISMA guidelines, and risk of bias. Discrepancies were reconciled by a third reviewer. Of 59 identified citations, eight original trials have submitted a total of 90 pregnant women to polysomnography and CPAP therapy. Four studies performed in samples with hypertension or preeclampsia presented blood pressure decrease or maintained the antihypertensive drug dose in the CPAP group. After CPAP utilization, one trial registered cardiac output and stroke volume increase with heart rate and peripheral vascular resistance decrease, which were correlated with birth weight increment. Others documented a higher Apgar in the CPAP group and more fetal movements during CPAP use. There was a reduction in serum uric acid and tumor necrosis factor-alpha in the CPAP groups whose blood pressure decreased. However, two weeks of CPAP use in women with gestational diabetes and OSA did not improve glucose levels but raised the insulin secretion in those adherents to CPAP. Despite these positive results without adverse effects, randomized controlled trials with standardized follow-up in larger populations are required to determine CPAP therapy recommendations in pregnancy.

Sleep position, patient comfort, and technical performance with two established procedures for home sleep testing

Purpose

In patients with a high pre-test probability of suffering from obstructive sleep apnea (OSA), (cardio)-respiratory polygraphy (RP; level 3) is commonly used for home sleep testing (HST); however, testing based on peripheral arterial tonometry (PAT) is increasingly recognized as an alternative method. The aim of the study was to compare sleep position, patients’ comfort, and technical failure rates of HST with RP and PAT in patients with suspected OSA.

Methods

Sleep position, patients’ comfort, and technical failure rates of RP and PAT were compared in 56 patients receiving two nights of HST with either RP or PAT in a randomized fashion.

Results

Time in supine position with PAT was significantly lower (173.7±88 min) compared to RP (181.7±103.7 min; p < 0.001), although the absolute mean difference was not clinically significant. Patients reported to sleep better, feeling less disturbed when falling asleep, losing less sensors, and fewer nightly awakenings with PAT, but experienced more pain at the side of the finger probe. Forty-five out of 56 patients (80%) rated PAT as being the superior sleep test and 49 out of 56 (88%) would prefer PAT for further investigations (p<0.001). PAT testing was associated with less technical failures.

Conclusion

The results demonstrate that HST with PAT leads to less time in supine sleep positioning, which may be clinically relevant in selected patients. Moreover, PAT is associated with less technical failures and is perceived with less discomfort during testing and a reduced number of nocturnal awakenings in patient self-reports.

A meta-analysis of diagnostic test performance of peripheral arterial tonometry studies

STUDY OBJECTIVES

The objective of this meta-analysis was to analyze agreement in apnea-hypopnea index (AHI) determination between peripheral arterial tonometry (PAT) and polysomnography (PSG) studies.

METHODS

Mean AHI bias and standard deviation (SD) extracted from Bland-Altman plots reported in studies was pooled in a meta-analysis, which was then used to calculate percentage errors of limit agreement (PE) in AHI determination by PAT using PSG AHI as the reference. Individual participant data (where reported in studies) was used to compute Cohen's kappa to assess agreement between PSG and PAT on sleep apnea severity and also for computing sensitivity and specificity of PAT at different AHI thresholds using PSG AHI as the reference.

RESULTS

From 17 studies and 1318 participants (all underwent simultaneous PSG and WatchPAT), a pooled mean AHI bias of 0.30 (standard error (SE) 0.74) and a WatchPAT AHI PE of 230% was calculated. Meta-analysis of Cohen's kappa for agreement between PSG and WatchPAT studies for classifying patients with no sleep apnea, mild, moderate or severe sleep apnea severity was 0.45 (SE 0.06), 0.29 (SE 0.05), 0.25 (SE 0.07) and 0.64 (SE 0.05), respectively. At AHI thresholds 5, 15 and 30, WatchPAT studies showed pooled sensitivities and specificities of 94.11% and 43.47%, 92.21% and 72.39% and 74.11% and 87.10%, respectively. Likelihood ratios were not significant at any AHI threshold.

CONCLUSIONS

The results of this meta-analysis suggest clinically significant discordance between WatchPAT and PSG measurements of AHI, significant sleep apnea severity misclassification by PAT studies and also poor diagnostic test performance.

Peripheral arterial tonometry-PAT technology

PAT Technology is a plethysmographic based measurement method which facilitates the accurate recording of the pulsatile volume changes of the arteries of peripheral vascular beds at the distal end of the fingers over sustained periods of time. It represents a departure from previously available plethysmographic methods, in so far as it applies a uniform pressure field which completely envelopes the measured part of a digit, including its distal-most tip. Applying near diastolic blood pressure levels of pressure within the PAT probe optimizes the dynamic range of the signal, prevents confounding veno-arteriolar reflex vasoconstriction at the measurement site, reduces respiratory and movement artifacts and thus facilitates accurate long term measurement. The vascular bed of the distal phalanx of the finger is a major site of sympathetic nervous system mediated vasoconstrictor activity, and the PAT response to sympathetic changes provides a platform for accurate and robust measurement in a number of sleep and sleep related clinical areas, foremost as a patient friendly and extensively validated home sleep testing device.

A validation study of an esophageal probe-based polygraph against polysomnography in obstructive sleep apnea

STUDY OBJECTIVES

The aim of this study was to validate the automatically scored results of an esophageal probe-based polygraph system (ApneaGraph® Spiro) against manually scored polysomnography (Nox A1, PSG) results. We compared the apnea-hypopnea index, oxygen saturation index, and respiratory disturbance index of the devices.

METHODS

Consenting patients, referred for obstructive sleep apnea workup, were tested simultaneously with the ApneaGraph® Spiro and Nox A1® polysomnograph. Each participant made one set of simultaneous registrations for one night. PSG results were scored independently. Apnea-hypopnea index, oxygen desaturation index, and respiratory disturbance index were compared using Pearson's correlation and scatter plots. Sensitivity, specificity, and positive likelihood ratio of all indices at 5, 15, and 30 were calculated.

RESULTS

A total of 83 participants had successful registrations. The apnea-hypopnea index showed sensitivity of 0.83, specificity of 0.95, and a positive likelihood ratio of 5.11 at an index cutoff of 15. At a cutoff of 30, the positive likelihood ratio rose to 31.43. The respiratory disturbance index showed high sensitivity (> 0.9) at all cutoffs, but specificity was below 0.5 at all cutoffs. Scatterplots revealed overestimation in mild OSA and underestimation in severe OSA for all three indices.

CONCLUSIONS

The ApneaGraph® Spiro performed acceptably when OSA was defined by an AHI of 15. The equipment overestimated mild OSA and underestimated severe OSA, compared to the PSG.

A comparison of automated and manual sleep staging and respiratory event recognition in a portable sleep diagnostic device with in-lab sleep study

STUDY OBJECTIVES

The objectives were to develop and validate an algorithm for editing WatchPAT scoring and assess the accuracy in an unselected clinical population as well as age and sex substrata.

METHODS

Two hundred sixty-two participants were enrolled to undergo WatchPAT simultaneously with in-lab polysomnography (PSG) recordings for developing (n = 30), optimizing (n = 62), and validating (n = 170) an algorithm to review and edit respiratory events and sleep architecture of WatchPAT recordings, which was based on visual inspection of WatchPAT signals. Apnea-hypopnea index (AHI) and sleep indices were compared with PSG-derived and automated WatchPAT indices.

RESULTS

Although estimation of total sleep time (TST) was comparable between automated and manual algorithm, estimation of rapid eye movement (REM) sleep time was markedly improved with manual editing from 0.48, 23.0 min (-43.9 to 89.8) to 0.64, 18.3 min (-32.6 to 69.1) (correlation with PSG, mean difference [reference range] from PSG, respectively). Manual scoring also improved correlation and agreement with PSG AHI from 0.65, 2.5 events/h (-24.0 to 28.9) to 0.81, -4.5 events/h (-22.5 to 13.6) as well as concordance for categorical agreement of sleep-disordered breathing severity and concordance for detecting severe REM-related sleep-disordered breathing. Interscorer reliabilities were excellent for TST and AHI, while good for REM sleep time. The automated algorithm performed better in younger than in older patients, while performed similarly between men and women with respect to concordance statistics. The manual algorithm markedly improved concordances more in older patients and women than in their counterparts.

CONCLUSIONS

Our manual editing algorithm improves correlation and agreement with PSG-derived sleep and breathing indices. Sex and age influence the accuracy of automated analysis and the performance of manual editing on AHI concordance.

Performance of peripheral arterial tonometry-based testing for the diagnosis of obstructive sleep apnea in a large sleep clinic cohort

STUDY OBJECTIVES

Peripheral arterial tonometry (PAT)-based technology represents a validated portable monitoring modality for the diagnosis of OSA. We assessed the diagnostic accuracy of PAT-based technology in a large point-of-care cohort of patients studied with concurrent polysomnography (PSG).

METHODS

During study enrollment, all participants suspected to have OSA and tested by in-laboratory PSG underwent concurrent PAT device recordings.

RESULTS

Five hundred concomitant PSG and WatchPat tests were analyzed. Median (interquartile range) PSG AHI was 18 (8-37) events/h and PAT AHI_3% was 25 (12-46) events/h. Average bias was + 4 events/h. Diagnostic concordance was found in 42%, 41%, and 83% of mild, moderate, and severe OSA, respectively (accuracy = 53%). Among patients with PAT diagnoses of moderate or severe OSA, 5% did not have OSA and 19% had mild OSA; in those with mild OSA, PSG showed moderate or severe disease in 20% and no OSA in 30% of patients (accuracy = 69%). On average, using a 3% desaturation threshold, WatchPat overestimated disease prevalence and severity (mean + 4 events/h) and the 4% threshold underestimated disease prevalence and severity by -6 events/h.

CONCLUSIONS

Although there was an overall tendency to overestimate the severity of OSA, a significant percentage of patients had clinically relevant misclassifications. As such, we recommend that patients without OSA or with mild disease assessed by PAT undergo repeat in-laboratory PSG. Optimized clinical pathways are urgently needed to minimize therapeutic decisions instituted in the presence of diagnostic uncertainty.

Prediction Models of Obstructive Sleep Apnea in Pregnancy: A Systematic Review and Meta-Analysis of Model Performance

BACKGROUND

Gestational obstructive sleep apnea (OSA) is associated with adverse maternal and fetal outcomes. Timely diagnosis and treatment are crucial to improve pregnancy outcomes. Conventional OSA screening questionnaires are less accurate, and various prediction models have been studied specifically during pregnancy.

METHODS

A systematic review and meta-analysis were performed for multivariable prediction models of both development and validation involving diagnosis of OSA during pregnancy.

RESULTS

Of 1262 articles, only 6 studies (3713 participants) met the inclusion criteria and were included for review. All studies showed high risk of bias for the construct of models. The pooled C-statistics (95%CI) for development prediction models was 0.817 (0.783, 0850), I² = 97.81 and 0.855 (0.822, 0.887), I² = 98.06 for the first and second-third trimesters, respectively. Only multivariable apnea prediction (MVAP), and Facco models were externally validated with pooled C-statistics (95%CI) of 0.743 (0.688, 0.798), I² = 95.84, and 0.791 (0.767, 0.815), I² = 77.34, respectively. The most common predictors in the models were body mass index, age, and snoring, none included hypersomnolence.

CONCLUSIONS

Prediction models for gestational OSA showed good performance during early and late trimesters. A high level of heterogeneity and few external validations were found indicating limitation for generalizability and the need for further studies.

Fetal Heart Rate Decelerations in Women with Sleep-Disordered Breathing

Emerging literature has shown that women with sleep-disordered breathing (SDB) have increased risk for gestational hypertension/preeclampsia and gestational diabetes. Case reports suggest an association between maternal apnea and fetal heart rate deceleration but data are lacking on how maternal sleep impacts fetal health. Since decelerations may be associated with adverse outcomes, we sought to determine whether fetal heart rate decelerations were associated with SDB. A cohort study of third trimester pregnant women with a singleton fetus was conducted. Participants underwent a home sleep test with continuous portable electronic fetal monitoring. SDB was defined as a respiratory disturbance index (RDI)≥10 events/hour. The temporality between a respiratory event and fetal heart rate decelerations was determined to be present if a deceleration occurred < 30 s after a respiratory event. Forty women were included with mean (±SD) age, BMI, and gestational age of 32.0±5.5 years, 37.1±8.0 kg/m², and 34.6±2.4 weeks respectively. Overall, n=23 (57.5%) women had SDB. Thirty-seven late decelerations were observed in 18 women; of these, 84% were temporally associated with a respiratory event. Nine of the 18 women (50%) had SDB. Ten prolonged decelerations were observed in 6 women of which nine (90%) were temporally associated with a respiratory event. Five of the six women (83%) had an RDI≥10. These initial data suggest that, in this population, the majority of both late and prolonged fetal heart rate decelerations occur with a maternal respiratory event. Since respiratory events are characteristic of maternal SDB, this raises the possibility that SDB may influence fetal well-being.

Usefulness of sleep events detection using a wrist worn peripheral arterial tone signal device (WatchPAT™) in a population at low risk of obstructive sleep apnea

Due to the high prevalence of obstructive sleep apnea (OSA), it is recommended to use in-laboratory polysomnography (PSG) or a home sleep apnea test (HSAT) in uncomplicated adult subjects at high risk of OSA. The aims of the present study were to compare a HSAT device, a wrist worn peripheral arterial tone signal device (WatchPAT™-200 [WP]) with PSG and respiratory polygraphy (RP) in a low-risk population of OSA. A total of 47 adult subjects at low risk of OSA were simultaneously examined with the three different approaches in a single night. The sleep studies were scored independently and in a blinded fashion, then the results and the parameters (Respiratory Disturbance Index, apnea-hypopnea index [AHI] and oxygen desaturation index of 3%) were compared with several statistical analyses. The agreement between the sleep tools and correlation for the assessed parameters were analysed and compared with Bland and Altman plots and Pearson's coefficient (WP versus PSG, r = 0.86). For the severity of OSA ranked according to PSG, the Cohen's k was 0.60 and 0.82 for WP and RP, respectively. Specificity was higher for RP compared to WP for identifying the presence of OSA (AHIPSG cut-off ≥5 events/hr: 0.85 versus 0.73), while was quite similar in identifying patients who were more likely to be treated (AHIPSG cut-off ≥15 events/hr: 0.94 versus 0.96). Assessing the costs and the simplicity of the examination, the results of our present study demonstrate the usefulness of WP compared to PSG, especially in screening and follow-up for the ability to exclude subjects from treatment with continuous positive airway pressure (AHI <15 events/hr) in a population with a low pre-test risk of moderate-to-severe OSA.

Association Between Sleep Characteristics and Asthma Control in Middle-Aged and Older Adults: A Prospective Cohort Study

Background

Nocturnal asthma symptoms are a well-known feature of sleep disturbance. However, there are few reports on the association between sleep-related characteristics and asthma exacerbation. The aim of the current prospective observational study was to explore the factors while sleeping associated with future asthma exacerbation.

Materials and Methods

At baseline, adult asthmatics underwent home sleep monitoring by a Watch-PAT instrument and then they were prospectively followed-up for the occurrence of exacerbations. The number of asthma exacerbation was observed over a period of one year, and multivariable analyses of the factors associated with asthma exacerbation were performed.

Results

A total of 62 asthmatic subjects were enrolled (mean age 62.1 years), 59 of whom were finally included in the prospective observational study. Obstructive sleep apnea (defined by an apnea-hypopnea index based on peripheral arterial tone more than 5 times/hour) were observed in 81% of the subjects. During the one-year monitoring period, 14 of the 59 subjects (24%) used occasional systemic corticosteroids for their exacerbation asthma (worsened group) while the other 45 subjects did not experience asthma exacerbation (stable group). A comparison of the baseline clinical characteristics and sleep-related data between the two groups, mean forced expiratory volume one second percent (FEV₁/FVC), mean baseline Asthma Control Test (ACT) score, median pAHI value, and median oxygen desaturation index value were significantly lower in the worsened group than those in the stable group. Additionally, mean prevalence of the left lateral decubitus (LLD) position in sleep monitoring were significantly higher in the worsened group than that in the stable group. Among the independent variables, baseline asthma severity, ACT score, and the LLD position showed significant associations with asthma exacerbation.

Discussion/Conclusion

The present study identified that sleeping in the LLD position was also associated with asthma exacerbation.

Metabolomic profile associated with obstructive sleep apnoea severity in obese pregnant women with gestational diabetes mellitus: A pilot study

Obstructive sleep apnoea (OSA) is prevalent in obese women with gestational diabetes mellitus (GDM). The present pilot study explored associations between OSA severity and metabolites in women with GDM. A total of 81 obese women with diet-controlled GDM had OSA assessment (median gestational age [GA] 29 weeks). The metabolic profile was assayed from fasting serum samples via liquid chromatography-mass spectrometry (LC-MS) using an untargeted approach. Metabolites were extracted and subjected to an Agilent 1,290 UPLC coupled to an Agilent 6,545 quadrupole time-of-flight (Q-TOF) MS. Data were acquired using electrospray ionisation in positive and negative ion modes. The raw LC-MS data were processed using the OpenMS toolkit to detect and quantify features, and these features were annotated using the Human Metabolite Database. The feature data were compared with OSA status, apnea-hypopnea index (AHI), body mass index (BMI) and GA using "limma" in R. Correlation analyses of the continuous covariates were performed using Kendall's Tau test. The p values were adjusted for multiple testing using the Benjamini-Hochberg false discovery rate correction. A total of 42 women (51.8%) had OSA, with a median AHI of 9.1 events/hr. There were no significant differences in metabolomics profiles between those with and without OSA. However, differential analyses modelling in GA and BMI found 12 features that significantly associated with the AHI. These features could be annotated to oestradiols, lysophospholipids, and fatty acids, with higher levels related to higher AHI. Metabolites including oestradiols and phospholipids may be involved in pathogenesis of OSA in pregnant women with GDM. A targeted approach may help elucidate our understanding of their role in OSA in this population.

[Quantification of the loudness of snoring according to Watch-PAT-200 and its relationship with the severity of obstructive sleep apnea syndrome]

PURPOSE OF THE STUDY

Evaluate the capabilities of Watch-PAT-200 in obtaining data to determine the relationship between the loudness of snoring and the severity of obstructive sleep apnea syndrome (OSAS).

MATERIAL AND METHODS

From 2017 to 2019, 208 patients with complaints of nocturnal snoring were examined. Apnea / hypopnea indices (AHI) and respiratory distress index (RDI) were assessed. The study was carried out on a Watch-PAT-200 portable device (Itamar Medical, Israel). The average volume of snoring (dB) and the proportion (%) of sleep time with the intensity of snoring over 50.60 and 70 dB were measured. The correlation of the obtained data with the AHI and RDI indices is estimated.

RESULTS

During the study, it was found that the volume of snoring increases as the severity of OSAS increases, therefore, the volume of snoring can be an indicator of the severity of OSAS. There are ample opportunities for screening diagnostics of the loudness of snoring with the subsequent consultation of a somnologist and timely prescription of treatment. Due to the objectivity of the obtained data and ease of use, the Watch-PAT-200 device can be used in outpatient practice for screening diagnostics of snoring and OSAS in the population.

Rhythm Control in Heart Failure Patients with Atrial Fibrillation

AF and heart failure (HF) commonly coexist. Left atrial ablation is an effective treatment to maintain sinus rhythm (SR) in patients with AF. Recent evidence suggests that the use of ablation for AF in patients with HF is associated with an improved left ventricular ejection fraction and lower death and HF hospitalisation rates. We performed a systematic search of world literature to analyse the association in more detail and to assess the utility of AF ablation as a non-pharmacological tool in the treatment of patients with concomitant HF.

Improving the performance of peripheral arterial tonometry-based testing for the diagnosis of obstructive sleep apnea

Outside sleep laboratory settings, peripheral arterial tonometry (PAT, eg, WatchPat) represents a validated modality for diagnosing obstructive sleep apnea (OSA). We have shown before that the accuracy of home sleep apnea testing by WatchPat 200 devices in diagnosing OSA is suboptimal (50%-70%). In order to improve its diagnostic performance, we built several models that predict the main functional parameter of polysomnography (PSG), Apnea Hypopnea Index (AHI). Participants were recruited in our Sleep Center and underwent concurrent in-laboratory PSG and PAT recordings. Statistical models were then developed to predict AHI by using robust functional parameters from PAT-based testing, in concert with available demographic and anthropometric data, and their performance was confirmed in a random validation subgroup of the cohort. Five hundred synchronous PSG and WatchPat sets were analyzed. Mean diagnostic accuracy of PAT was improved to 67%, 81% and 85% in mild, moderate-severe or no OSA, respectively, by several models that included participants' age, gender, neck circumference, body mass index and the number of 4% desaturations/hour. WatchPat had an overall accuracy of 85.7% and a positive predictive value of 87.3% in diagnosing OSA (by predicted AHI above 5). In this large cohort of patients with high pretest probability of OSA, we built several models based on 4% oxygen desaturations, neck circumference, body mass index and several other variables. These simple models can be used at the point-of-care, in order to improve the diagnostic accuracy of the PAT-based testing, thus ameliorating the high rates of misclassification for OSA presence or disease severity.

Mild maternal sleep-disordered breathing during pregnancy and offspring growth and adiposity in the first 3 years of life

Sleep-disordered breathing (SDB) during pregnancy has been linked to adverse fetal outcomes. Since the intrauterine milieu plays a critical role in childhood growth, we explored the interactions between maternal SDB and offspring growth and adiposity patterns during infancy. Fifty-eight healthy women with uncomplicated pregnancies underwent an objective sleep study and laboratory evaluation during the third trimester, their offspring underwent a 3-year growth surveillance. The 14 (24.1%) women with SDB had a higher body mass index (BMI) (P = 0.003), elevated C-reactive protein levels (P = 0.003), and decreased HDL-cholesterol levels (P = 0.009) than the women without SDB. A general linear model evaluated the interactions between maternal SDB and offspring growth and adiposity measurements after controlling for gestational age and maternal and paternal BMIs. The offspring of mothers with SDB had a significantly smaller head circumference at birth (P = 0.004), with a distinctive pattern of catchup growth by the end of the first year of life (P = 0.018). Their growth pattern was distinguished by compromised birth weight-to-length, rapid catch-up growth, and an increase in both weight-to-length and triceps thickness by the age of three (P < 0.001 and P = 0.001, respectively). Our findings suggest that maternal SDB during pregnancy affects head circumference growth and adiposity acquisition from birth through infancy.