Polysomnographic Characteristics Research Articles

Clinical and Polysomnographic Characteristics of Patients Complaining of Excessive Daytime Sleepiness and/or Insomnia

Objectives: This study aimed to investigate group differences in demographic, clinical, and polysomnographic characteristics based on the presence or absence of excessive daytime sleepiness (EDS) and insomnia symptoms.Methods: In this retrospective study, patients were divided into five groups based on their Epworth Sleepiness Scale and Insomnia Severity Index scores. The participants’ demographics, sleep-related symptoms, questionnaires, and polysomnography findings were used in the analysis.Results: The study found that patients in the group with EDS were younger, were mostly males, and had higher body mass index (BMI) than other groups. They also reported obstructive sleep apnea symptoms. The patients in the group with both EDS and insomnia were younger and had a higher BMI than other groups. They reported higher levels of fatigue and depression, as well as insomnia, rapid eye movement sleep behavior disorder and restless legs syndrome symptoms. The patients in the group with only insomnia had a higher proportion of females, were older, and had a lower BMI than other groups. Most characteristics of the patients in the threshold insomnia group were similar to those of the patients in the EDS-insomnia group. The normal group had a higher proportion of males and a higher prevalence of obstructive sleep apnea; however, they reported lower sleep-related symptoms. Furthermore, the polysomnography showed differences among the five groups in total sleep time, sleep latency, sleep efficiency, total arousal index, and spontaneous arousal. Total apnea-hypopnea index was significantly lower in the insomnia group than that in other groups.Conclusions: This study demonstrated the clinical and polysomnographic characteristics of the five groups through self-reported questionnaires. The findings provided evidence to help assess patients’ sleep problems and the possibility of sleep disorders.

Sleep and cardiometabolic comorbidities in the obstructive sleep apnoea-COPD overlap syndrome: data from the European Sleep Apnoea Database.

The impact of obstructive sleep apnoea (OSA)-COPD overlap syndrome (OVS) on sleep quality and cardiovascular outcomes has not been fully explored. We aimed to compare clinical and polysomnographic characteristics of patients with OVS versus patients with OSA, and to explore pathophysiological links between OVS and comorbidities. This cross-sectional analysis initially included data from 5600 patients with OSA and lung function in the European Sleep Apnoea Database. Two subgroups of patients with OSA (n=1018) or OVS (n=509) were matched (2:1) based on sex, age, body mass index and apnoea-hypopnea index at baseline. After matching, patients with OVS had more severe hypoxia, lower sleep efficiency and presented with higher prevalences of arterial hypertension, ischaemic heart disease and heart failure compared with patients with OSA. OVS was associated with a significant decrease in sleep efficiency (mean difference (β) -3.0%, 95% CI -4.7 to -1.3) and in nocturnal mean peripheral oxyhaemoglobin saturation (SpO2) (β -1.1%, 95% CI -1.5 to -0.7). Further analysis revealed that a decrease in forced expiratory volume in 1 s and arterial oxygen tension was related to a decrease in sleep efficiency and in mean nocturnal SpO2. A COPD diagnosis increased the odds of having heart failure by 1.75 (95% CI 1.15-2.67) and systemic hypertension by 1.36 (95% CI 1.07-1.73). Nocturnal hypoxia was strongly associated with comorbidities; the mean nocturnal SpO2 and T90 (increase in time below SpO2 of 90%) were associated with increased odds of systemic hypertension, diabetes and heart failure but the oxygen desaturation index was only related to hypertension and diabetes. Patients with OVS presented with more sleep-related hypoxia, a reduced sleep quality and a higher risk for heart failure and hypertension.

Features of Obstructive Sleep Apnea in Children with and without Comorbidities.

To compare the clinical and polysomnographic features of obstructive sleep apnea (OSA) in children with adenotonsillar hypertrophy (Group A) and comorbidities (Group B). A five-year prospective study using nocturnal polysomnography before and after treatment. We included 168 patients: 121 in Group A and 47 in Group B, with differences in age (6.5 ± 3 vs. 8.6 ± 4 years; p < 0.001), body mass index (BMI) (18 ± 4 vs. 20 ± 7 kg/m2; p < 0.05), neck circumference (28 ± 4 vs. 30 ± 5 cm; p < 0.05), and obesity (17% vs. 30%; p < 0.05). Group B patients were more likely to have facial anomalies (p < 0.001), macroglossia (p < 0.01), dolichocephaly (p < 0.01), micrognathia (p < 0.001), and prognathism (p < 0.05). Adenotonsillectomy was performed in 103 Group A patients (85%) and 28 Group B patients (60%) (p < 0.001). In B, 13 children (28%) received treatment with continuous positive airway pressure (CPAP) and 2 (4%) with bilevel positive airway pressure (BiPAP), compared with 7 in Group A (6%) (p < 0.001). Maxillofacial surgery was more common in Group B (p < 0.01). Clinical and polysomnography parameters improved significantly in both groups after therapeutic intervention, though Group A showed better results. Obesity and facial anomalies are more frequent in childhood OSA patients with comorbidities, who often require combination therapy, such as ventilation and surgery.

Polysomnographic Assessment of Sleep Disturbances in Cancer Development: A Historical Multicenter Clinical Cohort Study

Many cellular processes are controlled by sleep. Therefore, alterations in sleep might be expected to stress biological systems that could influence malignancy risk. What is the association between polysomnographic measures of sleep disturbances and incident cancer, and what is the validity of cluster analysis in identifying polysomnography phenotypes? We conducted a retrospective multicenter cohort study using linked clinical and provincial health administrative data on consecutive adults free of cancer at baseline with polysomnography data collected between 1994 and 2017 in four academic hospitals in Ontario, Canada. Cancer status was derived from registry records. Polysomnography phenotypes were identified by k-means cluster analysis. A combination of validation statistics and distinguishing polysomnographic features was used to select clusters. Cox cause-specific regressions were used to assess the relationship between identified clusters and incident cancer. Among 29,907 individuals, 2,514 (8.4%) received a diagnosis of cancer over a median of 8.0 years (interquartile range, 4.2-13.5 years). Five clusters were identified: mild (mildly abnormal polysomnography findings), poor sleep, severe OSA or sleep fragmentation, severe desaturations, and periodic limb movements of sleep (PLMS). The associations between cancer and all clusters compared with the mild cluster were significant while controlling for clinic and year of polysomnography. When additionally controlling for age and sex, the effect remained significant only for PLMS (adjusted hazard ratio [aHR], 1.26; 95%CI, 1.06-1.50) and severe desaturations (aHR, 1.32; 95%CI, 1.04-1.66). Further controlling for confounders, the effect remained significant for PLMS, but was attenuated for severe desaturations. In a large cohort, we confirmed the importance of polysomnographic phenotypes and highlighted the role that PLMS and oxygenation desaturation may play in cancer. Using this study's findings, we also developed an Excel (Microsoft) spreadsheet (polysomnography cluster classifier) that can be used to validate the identified clusters on new data or to identify which cluster a patient belongs to. ClinicalTrials.gov; Nos.: NCT03383354 and NCT03834792; URL: www. gov.

Pediatric Obstructive Sleep Apnea and Sickle Cell Disease: Demographic and Polysomnographic Features.

Obstructive sleep apnea (OSA) is prevalent in children with sickle cell disease (SCD). We compared the demographic, clinical, and polysomnographic characteristics of children with and without SCD. This retrospective chart review included children with SCD (n=89) and without SCD (n=192) ages 1-18 years referred for polysomnography (PSG) for OSA. Children with SCD were predominantly African American when compared to the non-SCD group (95% vs. 28%, p < 0.001). The non-SCD group had a higher BMI z-score (1.3 vs. 0.1, p < 0.001) and a higher percentage of patients classified as obese (52% vs. 13%, p < 0.001). In children with SCD, 43% had severe OSA and 5.6% had no OSA. In the non-SCD group, 67% had severe OSA and 4.7% had no OSA. The SCD compared to the non-SCD group had a lower mean apnea-hypopnea index (AHI) (13.6 vs. 22.4, p=0.006) but a higher percent sleep time below 90% oxygen saturation (10.5% vs. 3.5%, p < 0.001). Predicted probability for severe OSA in children with SCD decreased with increasing age (OR=0.81, 95% CI: 0.70-0.93). Children with SCD referred for PSG are at risk for severe OSA. Compared with the non-SCD group, most children were African American with lower rates of obesity and lower AHIs but longer periods of nocturnal hypoxemia. Likelihood for severe OSA decreased with increasing age for the SCD group. 3, retrospective comparative study Laryngoscope, 133:1766-1772, 2023.

Clinical phenotypes of obstructive sleep apnea: a cluster analysis based on sleep perception and sleep quality

PurposeTo determine obstructive sleep apnea (OSA) phenotypes using cluster analysis including variables of sleep perception and sleep quality and to further explore factors correlated with poor sleep quality in different clusters.MethodsThis retrospective study included patients with OSA undergoing polysomnography (PSG) between December 2020 and April 2022. Two-step cluster analysis was performed to detect distinct clusters using sleep perception variables including discrepancy in total sleep time (TST), sleep onset latency (SOL), and wakefulness after sleep onset (WASO); objective TST, SOL, and WASO; and sleep quality. One-way analysis of variance or chi-squared tests were used to compare clinical and PSG characteristics between clusters. Binary logistic regression analyses were used to explore factors correlated with poor sleep quality.ResultsA total of 1118 patients were included (81.6% men) with mean age ± SD 43.3 ± 13.1 years, Epworth sleepiness score, 5.7 ± 4.4, and insomnia severity index 3.0 ± 2.4. Five distinct OSA clusters were identified: cluster 1 (n = 254), underestimated TST; cluster 2 (n = 158), overestimated TST; cluster 3 (n = 169), overestimated SOL; cluster 4 (n = 155), normal sleep discrepancy and poor sleep quality; and cluster 5 (n = 382), normal sleep discrepancy and good sleep quality. Patients in cluster 2 were older, more commonly had hypertension, and had the lowest apnea–hypopnea index and oxygen desaturation index. Age and sleep efficiency were correlated with poor sleep quality in clusters 1, 2, and 5, and also AHI in cluster 2.ConclusionSubgroups of patients with OSA have different patterns of sleep perception and quality that may help us to further understand the characteristics of sleep perception in OSA and provide clues for personalized treatment.

Polysomnographic characteristics and treatment modalities in a referred population of children with trisomy 21.

Children with Trisomy 21 (T21) are at an increased risk of sleep-disordered breathing (SDB), which can impact daily functioning and cause other health complications. Accordingly, it is imperative to diagnose and treat SDB in this population. Current guidelines recommend screening polysomnogram by age 4 or sooner if clinically indicated. There are limited published studies describing characteristics of SDB in children with T21, particularly in infants and young children. The objective of this study is to characterize SDB and treatment modalities in infants and young children with T21. This is a retrospective review of a cohort of children (≤60 months of age) with T21 who completed a polysomnogram (PSG) between 2015 and 2020 at a pediatric referral center. Demographic information, relevant medical history, polysomnography parameters, and treatment details of these children were collected from EMR. Descriptive and comparative statistics were calculated for the cohort; additional subgroup analysis was completed by age 0-35 months and 36-60 months. Most of the cohort met criteria for sleep apnea (84.1%), and airway surgery was the most common treatment modality (71.4%). The mean AHI was high (21.4 events/hour) with a trend towards hypoventilation (mean EtCO2 = 55.9 mmHg; mean percentage of TST with EtCO2 > 50 mmHg 20.8%). Mean arousal index was elevated (32 events/hour). There were no significant differences in SDB by age when we compared children 0-35 months and 36-60 months. This cohort of referred children with T21 showed high prevalence of SDB with a trend towards hypoventilation and disrupted sleep quality with no significant differences by age. These data highlight the importance of maintaining a high index of suspicion for SDB in young patients with T21 and obtaining PSG testing to characterize sleep and breathing.

The prevalence of rapid eye movement-related obstructive sleep apnea in a sample of Saudi population.

This study aimed to estimate the prevalence of rapid eye movement-related obstructive sleep apnea (REMrOSA) using common definitions. This was a retrospective cohort study that used three sets of criteria to identify patients with REMrOSA. These criteria were defined as strict, intermediate, and lenient depending on the apnea-hypopnea index (AHI), AHI during REM sleep/(AHI during non-REM sleep [NREM-AHI]), NREM-AHI and REM duration. The study included 609 patients with OSA and full sleep study. The prevalence of REMrOSA was 26%, 33%, and 52% using the strict, intermediate, and lenient criteria, respectively. There were no differences in the patients' general and demographic characteristics between the different groups of the three definitions. REMrOSA patients were more likely to be younger females than non-REMrOSA (NREMrOSA) patients. Comorbidities were more frequent in the REMrOSA group compared to NREMrOSA when using strict and intermediate definitions. In contrast, AHI, mean O2 saturation, and time spent <90% O2 saturation were significantly worse during NREMrOSA compared to REMrOSA, regardless of the criteria used. Our study reported higher AHI, lower mean oxygen saturation, lower minimum oxygen saturation, and longer time of desaturation during REMrOSA when lenient definition was used compared to when strict and intermediate definitions were used. REMrOSA is a common condition with a prevalence ranging between 26% and 52% depending on what definition is applied. Although OSA tends to be more severe with lenient definition, however, the clinical and polysomnographic features were similar among REMrOSA groups regardless of the definition used.

Obstructive sleep apnea in aboriginal Australians: polysomnographic outcomes and symptom perception post-continuous positive airway pressure implementation.

Obstructive sleep apnea (OSA) is reported to be highly prevalent among Aboriginal Australians. However, no studies have assessed the implementation and efficacy of continuous positive airway pressure (CPAP) therapy in this population. Hence, we compared the clinical, self-reported perception of sleep quality and polysomnographic (PSG) characteristics among Aboriginal patients with OSA. Adult Aboriginal Australians who underwent both diagnostic (Type 1 and 2) and in-lab CPAP implementation studies were included. Total of 149 patients were identified (46% female, median age 49 years, body mass index 35 kg/m2). The OSA severity was 6% mild, 26% moderate, and 68% severe on the diagnostic PSG. On application of CPAP, there were significant improvements in; total arousal index (diagnostic 29 to 17/h on CPAP), total apnea-hypopnea index (AHI) (diagnostic 48 to 9/h on CPAP), non-rapid eye movement AHI (diagnostic 47 to 8/h on CPAP), rapid eye movement (REM) AHI (diagnostic 56 to 8/h on CPAP) and oxygen saturation (SpO2) nadir (diagnostic 77% to 85% on CPAP) (p < 0.001 for each). Following a single night of CPAP, 54% of patients reported sleeping "better than normal" compared to 12% following the diagnostic study (p = 0.003). In multivariate regression models, males had a significantly lesser change in REM AHI than females (5.7 events/hour less change (IQR 0.4, 11.1), p = 0.029). There is substantial improvement in several sleep-related domains on the application of CPAP among Aboriginal patients with a good initial acceptance of treatment. Whether the positive impact observed in this study translates to better sleep health outcomes with long-term adherence to CPAP therapy is yet to be assessed.

Relationship between slow-wave sleep and serum γ-glutamine transaminase in non-obese men with obstructive sleep apnea-hypopnea syndrome.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a disease characterized with intermittent hypoxia and sleep fragmentation. Obesity and gender are major risk factors for the onset of OSAHS. Previous studies on obese men with OSAHS have been performed, while few studies on non-obese men with OSAHS have been carried out. The purpose of this study was to explore the clinical characteristics of polysomnography and blood biochemical indexes in non-obese men with OSAHS and to identify the possible influencing factors. This retrospective study included patients with OSAHS who underwent polysomnography in our hospital. General clinical data such as overnight polysomnography and biochemical indicators were recorded. The patients were divided into two groups according to the apnea-hypopnea index (AHI): mildtomoderate OSAHS and severe OSAHS. The differences in biochemical parameters such as the levels of γ-glutamine transaminase (GGT), triglyceride (TG), glucose (GLU), and sleep structure parameters such as N1, N2, slow-wave sleep (SWS), and rapid eye movement (REM) sleep were compared and analyzed. Spearman correlation analysis and logistic regression were used to identify the risk factors of non-obese men with OSAHS. ROC curves were used to evaluate the predictive ability of SWS and GGT on disease severity. Of 94 non-obese men with OSAHS, 49 had mild to moderate OSAHS and 45 had severe OSAHS.Our data suggested that the levels of low oxygen saturation (L-SaO2), mean oxygen saturation (M-SaO2), SWS, and GGT were significantly changed in the mildtomoderate OSAHS group compared with the severe group (p < 0.05). For patients with OSAHS, the proportion of SWS in the group withsevere OSAHS was higher than that in the mildtomoderate group (p < 0.05), and the serum GGT enzyme levels were significantly elevated in the severe group compared to the mildtomoderate group (p < 0.05). Using logistic regression analyses, our data revealed that both SWS and GGT enzyme levels were independent risk factors for AHI (p < 0.05). In addition, the results of correlation analysis indicated that SWS was related to triglyceride (TG), total cholesterol (TC), apolipoprotein E (APOE), and triglyceride glucose (TyG) index (p < 0.05); GGT was related to TG, TC, APOE, and TyG index (p < 0.05). Furthermore, SWS was independently associated with GGT (p < 0.05). The area under the ROC curve plotted with the combined coefficient of SWS and serum GGT was 0.728, which was predictive of the disease severity. These results suggest that SWS and GGT are independent associated factors of the severity of the disease. However, TyG index was not an independent associated factor of the severity of disease in non-obese men with OSAHS. In addition, SWS and GGT were negatively correlated. SWS combined with serum GGT may be predictive of the severity of the disease. This study may have added to our understanding of the pathogenesis of OSAHS innon-obese men.

Effects of severe obstructive sleep apnea on functional prognosis in the acute phase of ischemic stroke and quantitative electroencephalographic markers

ObjectiveTo investigate the effect of severe obstructive sleep apnea (OSA) on functional prognosis in the acute phase and quantitative electroencephalography (EEG) markers during sleep in ischemic stroke patients. MethodsThis study included 125 mild-to-moderate acute ischemic stroke patients with OSA who underwent polysomnography (PSG) within one week of stroke onset between January 2015 and June 2020. Patients were grouped according to their apnea-hypopnea index (</≥ 30/h). Poor functional prognosis was defined as modified Rankin Scale score ≥3. The EEG recorded by PSG was extracted during different sleep stages for power spectrum analysis. The delta/alpha power ratio (DAR), (delta + theta)/(alpha + beta) ratio (the slowing ratio, TSR), and the relative power (RP) of each frequency band were calculated. Differences in clinical, PSG, and quantitative EEG characteristics were compared between the groups. Additionally, we explored predictors of poor functional prognosis. ResultsPatients with severe OSA had a higher proportion of hypertension, lower relative power of high-frequency bands, and higher delta RP, TSR, and DAR (p < 0.05). Severe OSA was associated with a 3.6-fold increase in risk of poor prognosis (p < 0.05). Increased delta RP and TSR, as well as decreased alpha, beta, and sigma RP, may be independent predictors of a poor functional prognosis. ConclusionsSevere OSA is an independent risk factor for a poor functional prognosis in patients with acute ischemic stroke, and quantitative EEG during sleep showed a significant slow wave enhancement, suggesting more severe brain dysfunction. The treatment of severe OSA may improve functional prognosis.

Home continuous positive airway pressure therapy in infants: a single-center experience.

There are limited data on indications and outcomes of home continuous positive airway pressure (CPAP) therapy in the first year of life. We aimed to analyze the clinical, demographic, and polysomnographic characteristics of a cohort of children initiated on home CPAP for treatment of sleep-disordered breathing and as respiratory support in the first year of life. Children started on CPAP in the first year of life at the Queensland Children's Hospital were retrospectively evaluated for clinical and demographic parameters, underlying diagnoses, respiratory support, airway surgical intervention, and polysomnography results at baseline and on CPAP. Twenty-nine infants (median age [interquartile range] at CPAP initiation, 182 days [126-265.5 days]) were included. The underlying etiology included Trisomy 21 (n = 6), craniofacial syndromes (n = 5), hypotonia (n = 8; 5 with noncraniofacial syndrome), airway malacia (n = 5), skeletal dysplasia (n = 2), nonsyndromic upper airway obstruction (n = 2), and chronic neonatal lung disease (n = 1). The median (interquartile range) obstructive apnea-hypopnea index was 14 events/h (6.2-31 events/h) at CPAP initiation, which improved on CPAP to 3.4 events/h (1.4-6.4 events/h). The median (interquartile range) transcutaneous CO2 max remained unchanged on CPAP (56.6 mm Hg [49-66.5 mm Hg] pre-CPAP vs 54.9 mm Hg [47-62 mm Hg] on CPAP). Fifteen children needed surgical airway intervention (11 pre-CPAP and 4 post-CPAP). CPAP therapy could be successfully stopped in 9 children, 2 children needed tracheostomy, and 1 child died during the follow-up period. Home CPAP as respiratory support is an effective long-term therapy in infancy, and these patients can be weaned from CPAP therapy even if it was initiated early. Prospective studies with predefined criteria for CPAP initiation and cessation would help ascertain long-term outcomes in this poorly researched group. Joshi SS, Sivapalan D, Leclerc M-J, Kapur N. Home continuous positive airway pressure therapy in infants: a single-center experience. J Clin Sleep Med. 2023;19(3):473-477.

What are the sleep characteristics among early kidney transplant recipients? An objective and subjective measurement from China.

To evaluate the sleep quality by self-reported questionnaires and polysomnography (PSG) among early kidney transplant recipients (KTRs) and to further explore their correlation. This was a prospective and cross-sectional analysis of the sleep characteristics among early kidney transplant recipients through an objective and subjective measurement. Patients with end stage renal disease on the transplant waiting list and after kidney transplantation were from a major organ transplantation center in Southern China (n = 83). Objective outcomes: PSG, noise and light. Subjective outcomes: demographic and clinical questionnaires, self-reported pain and Richards Campbell sleep questionnaire (RCSQ). After agreement with the informed consent, participants first completed demographic and clinical questionnaires, then worn the PSG within 5-10 days after kidney transplantation. Both noise, light and self-reported pain were monitored during sleep. After completion of PSG, the RCSQs were filled out next morning. A total of 298 patients were recruited and 83 participants were finally analyzed. The total RCSQ mean score was 51.0±18.9mm. The prevalence of poor sleep quality among early KTRs was 45.1%. Most of PSG characteristics were significantly correlated with their corresponding RCSQ items. And the total RCSQ scores were significantly correlated with the number of awakenings, the N2 percentage and the total sleep time (r = 0.79, 0.47 and 0.40, P<0.05) respectively. Noise was a statistically significant factor affecting the subjective sleep quality. The sleep quality in early KTRs measured by both PSG and RCSQ exhibits consistency with each other. Sleep disruption always remains a substantial problem and is affected by self-reported noise among early KTRs. The RCSQ is easily applicable and interpretable so that it can be used for future daily clinical practice.

Sleep polysomnography in patients with heart failure

Objectives: To describe the characteristics of polysomnography of sleep apnea syndrome in heart failure patients at Bach Mai Hospital.Subjects and Methods: A cross-sectional study on 63 patients diagnosed with heart failure with echocardiography and sleep polysomnography, and consented to participate in the study.Results and conclusions: The study on 63 heart failure patients with sleep apnea included 54 (85.7%) male patients and 9 (14.3%) female patients. The average age of the study subjects was 69.57 ± 13.08 years old. ProBNP levels, ejection fraction, systolic and diastolic volume and diameter of the ventricles in the heart failure subgroups were significantly different with p &lt; 0.05. Pulmonary arterial pressure in the heart failure subgroups was not statistically significant with p &gt; 0.05. The average total sleep time was 334.8 ± 119.8 minutes. The longest recorded REM period was 54 minutes. The achieved sleep efficiency is 64.70 ±27.43%. The difference between HI and AHI in heart failure subgroups was not statistically significant with p &gt; 0.05. The rate of severity of sleep apnea at different levels of heart failure according to EF classification was not statistically significant with p &gt; 0.05.

P095 Clinical and polysomnographic characteristics of Indigenous and non-Indigenous children undergoing adenotonsillectomy with clinically suspected sleep disorders at the Top End Northern Territory of Australia

Abstract Sleep apnoea and poor sleep quality are growing public health issues which may begin in childhood and progress to significant lifelong morbidity. Literature regarding the prevalence of surgery for obstructive sleep apnoea (OSA) among Indigenous Australian children however is sparse. Children and polysomnographic (PSG) characteristics among children undergoing adenotonsillectomy (AT) for clinically suspected sleep-disordered breathing were assessed in this retrospective study. Paediatric patients Indigenous and non-Indigenous children referred for a diagnostic (PSG) via ENT service at the Top End Northern Territory of Australia for a sleep study between 2016 and 2020 were included. Of the 375 patients referred through an ENT service for a diagnostic PSG, 115 were identified to have undergone an AT and were included. The majority of patients were male (58%) and non-Indigenous (88%), in the normal weight category (64%) with a median age of 4.1 years. The median reported PDSS was 12, and snoring was reported in 77% of patients, with witnessed apnoeas in 31% and excessive daytime sleepiness in 23%. Most patients were identified to have OSA on PSG (65%, median AHI 1.6, 64% mild, 12% moderate, 23% severe). Median sleep efficiency was 85%, with a total sleep time of 520 minutes and WASO of 74 minutes. Total average SpO2 was a median of 93.5% and SpO2 Nadir 85%. We discuss how our findings can translate to future service planning and delivery whilst respecting cultural safety and indigenous group engagement.

O008 The effect of flow limited breathing and endotypes on night to night variability of sleep apnoea severity

Abstract Background Obstructive sleep apnoea (OSA) is a condition involving repetitive collapse of the upper airway during sleep. The diagnosis and characterisation of OSA is based primarily off the apnoea-hypopnoea index (AHI) in a single-night sleep study. Recent data have demonstrated night to night variability (NNV) in OSA severity. Knowledge of which patients have more variable OSA would improve long-term risk stratification and management. However, patient and polysomnographic characteristics associated with high NNV have not been completely explored. This study aims to determine whether the pattern of flow limited breathing (FLB) and underlying endotypes of patients with OSA are predictive of those with high NNV in OSA severity. Methods 71 patients with OSA were identified from the placebo arm of randomized controlled trials testing novel OSA interventions. Each patient had undergone two sleep studies. Patient characteristics, medical history and data from both sleep studies were accessed. Sleep data were processed using established algorithms to quantify the degree of FLB as well as OSA endotypes. Differences between each night were analysed for agreement, and for change in the severity of OSA. Progress to date Ethics approval has been obtained and data has been processed for statistical analysis. Intended outcome and impact It is expected that NNV will be high in those with mild to moderate OSA, and the pattern of FLB and endotypes across multiple nights will help predict those with more variable compared to stable disease.

Low Arousal Threshold Estimation Predicts Failure of Mandibular Advancement Devices in Obstructive Sleep Apnea Syndrome.

Introduction: The treatment of choice for obstructive sleep apnea syndrome (OSAS) is continuous positive airway pressure (CPAP). However, CPAP is usually poorly tolerated and mandibular advancement devices (MADs) are an alternative innovative therapeutic approach. Uncertainty still remains as to the most suitable candidates for MAD. Herein, it is hypothesized that the presence of low arousal threshold (low ArTH) could be predictive of MAD treatment failure. Methods: A total of 32 consecutive patients, with OSAS of any severity, who preferred an alternate therapy to CPAP, were treated with a tailored MAD aimed at obtaining 50% of their maximal mandibular advancement. Treatment response after 6 months of therapy was defined as AHI < 5 events per hour or a reduction of AHI ≥ 50% from baseline. Low ArTH was predicted based on the following polysomnography features, as previously shown by Edwards et al.: an AHI of 82.5% and a hypopnea fraction of total respiratory events of >58.3%. Results: There were 25 (78.1%) responders (p-value < 0.01) at 6 months. Thirteen patients (40.6%) in the non-severe group reached AHI lower than 5 events per hour. MAD treatment significantly reduced the median AHI in all patients from a median value of 22.5 to 6.5 (74.7% of reduction, p-value < 0.001). The mandibular advancement device reduced AHI, whatever the disease severity. A significant higher reduction of Delta AHI, after 6 months of treatment, was found for patients without low ArTH. Conclusions: Low ArTH at baseline was associated with a poorer response to MAD treatment and a lower AHI reduction at 6 months. A non-invasive assessment of Low ArTH can be performed through the Edwards’ score, which could help to identify an endotype with a lower predicted response to oral appliances in a clinical setting.

Lighter sleep is associated with higher enlarged perivascular spaces burden in middle-aged and elderly individuals

BackgroundWhile healthy sleep is suggested to promote glymphatic clearance in the brain, poorer sleep may be associated with higher enlarged perivascular spaces (ePVS) burden, potentially representing impaired perivascular drainage. This study aims to evaluate the association between ePVS burden and polysomnographic sleep characteristics in a large community-based sample. Methods552 dementia and stroke-free Framingham Heart Study participants (age: 58.6 ± 8.9 years; 50.4% men) underwent a full-night in-home polysomnography. Three years later on average, participants underwent a brain MRI. ePVS were rated in the basal ganglia and centrum semiovale, and dichotomized as low burden (<20 counts, grades 1 and 2) or high burden (>20 counts, grades 3 and 4). Logistic regression analyses relating sleep variables to subsequent ePVS burden were used, adjusted for age, sex, time interval between polysomnography and MRI, ApoE ε4 allele carrier status, hypertension, and smoking. ResultsLonger N1 sleep and shorter N3 sleep duration were associated with higher ePVS burden in the centrum semiovale. When stratifying these associations by subpopulations, longer N1 sleep duration with ePVS burden was observed especially in older individuals and hypertensive participants. Associations between ePVS burden and other sleep characteristics such as total sleep time and REM sleep duration varied according to ApoE ε4 allele carrier status. ConclusionsLighter sleep, as characterized by longer N1 sleep and shorter slow-wave sleep, is associated with higher ePVS burden. These findings suggest that sleep architecture may be involved in glymphatic clearance and cerebral small vessel disease, which could be an important biological link between sleep and dementia risk.

Rapid Eye Movement Sleep during Early Life: A Comprehensive Narrative Review.

The ontogenetic sleep hypothesis suggested that rapid eye movement (REM) sleep is ontogenetically primitive. Namely, REM sleep plays an imperative role in the maturation of the central nervous system. In coincidence with a rapidly developing brain during the early period of life, a remarkably large amount of REM sleep has been identified in numerous behavioral and polysomnographic studies across species. The abundant REM sleep appears to serve to optimize a cerebral state suitable for homeostasis and inherent neuronal activities favorable to brain maturation, ranging from neuronal differentiation, migration, and myelination to synaptic formation and elimination. Progressively more studies in Mammalia have provided the underlying mechanisms involved in some REM sleep-related disorders (e.g., narcolepsy, autism, attention deficit hyperactivity disorder (ADHD)). We summarize the remarkable alterations of polysomnographic, behavioral, and physiological characteristics in humans and Mammalia. Through a comprehensive review, we offer a hybrid of animal and human findings, demonstrating that early-life REM sleep disturbances constitute a common feature of many neurodevelopmental disorders. Our review may assist and promote investigations of the underlying mechanisms, functions, and neurodevelopmental diseases involved in REM sleep during early life.

Comorbidities in Clinical and Polysomnographic Features of Obstructive Sleep Apnea: A Single Tertiary Care Center Experience

BackgroundResearch on obstructive sleep apnea (OSA) is inadequate in Saudi Arabia, particularly among patients with comorbidities. This study investigates comorbidities in patients with different severity of apnea based on the Apnea–Hypopnea Index (AHI).MethodsThe retrospective charts review that included a cohort of 4391 patients who underwent polysomnography (PSG) between 2003 and 2019. The AHI is classified into four ordinal groups: normal, mild, moderate, and severe. Ordinal logistic regression was used to model proportional odds of a higher AHI category.ResultsGender was distributed equally in the study sample. The average age was 49.6 ± 14.8 years and the average AHI was 16.1 ± 22 per hour. Hypertension (43.2%) and diabetes mellitus (37.3%) were the most common comorbidities: Mild OSA 28.9%, Moderate OSA 15.6%, and severe 16.4%. The severity of apnea increased with age and BMI classes. The prevalence of hypertension increased with the severity of apnea: 42.9% in mild, 47.4% in moderate, and 54.6% in severe AHI. The prevalence of coronary artery disease (CAD), congestive heart failure (CHF), and diabetes mellitus (DM) increased with the severity of apnea. Comorbidities was more among OSA patients with excessive sleepiness. After adjustment for age and gender, greater proportional odds of severe AHI were observed in males (aOR = 1.8), 30–59 years (aOR = 2.064), 60 years or above (aOR = 2.873), obese class II (aOR = 2.016), obese class III (aOR = 2.527), and in patients with hypertension (aOR = 1.272).ConclusionHypertension and obesity were highly prevalent in the study cohort and were associated with greater proportional odds of severe AHI.