bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy and safety of Dimdazenil in adults with insomnia disorder: results from a multicenter, randomized, double-blind, placebo-controlled phase III trials
Authors: Huang Zhaoyang , Zhan Shuqin , Chen Chunyan , Zhang Ruoxi , Zhou Yanling , He Jingjing , Lin Zhaocun , Bao Cungang , Zhu Shuangpeng , Zhao Jianjun , Zhang Shengan , Jiang Yu , Wang Yuping
Published: October 2023

Study Objectives

To evaluate the efficacy and safety of Dimdazenil, a novel partial positive allosteric modulator for GABAA receptor in adults with insomnia disorder.

Methods

This was a 2-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group phase III study of Dimdazenil. The primary efficacy outcome was total sleep time (TST) analyzed by polysomnography (PSG) on day 13/14. Latency to persistent sleep (LPS), sleep efficiency (SE), and wake after sleep onset (WASO) were analyzed in the same way by polysomnography (PSG). The other secondary outcomes including the average subjective sleep latency (sSL), subjective TST (sTST), subjective SE (sSE), subjective WASO (sWASO), and subjective number of awakenings (sNAW) were analyzed from sleep diary data, and the insomnia severity index (ISI) was also assessed. Treatment-emergent adverse events (TEAEs) were monitored throughout the study.

Results

A total of 546 participants with insomnia (age ≥18 years) were randomized (2:1), received treatment with an oral dose of Dimdazenil (2.5 mg) or placebo, and analyzed. Compared to baseline and placebo, Dimdazenil demonstrated significant improvements in PSG measures, increased TST (71.09, 31.68 minutes, respectively; both p < 0.001), increased SE (13.26%, 5.55%, respectively; both < 0.001), reduced WASO (49.67, 20.16 minutes, respectively; both p < 0.001), and reduced LPS (21.65 minutes, p < 0.001; 6.46 minutes, p = 0.023). Compared to placebo, Dimdazenil also improved key self-reported measures of sTST (18.33 minutes, p < 0.001), sWASO (14.60 minutes, p < 0.001), sSL (4.23 minutes, p < 0.001), sSE (2.97%, p < 0.001), and sNAW (0.29, p < 0.001). Participants treated with Dimdazenil reported a significant improvement in ISI. Dimdazenil was well tolerated. The majority of TEAEs were mild or moderate. There were no clinically relevant treatment-related serious AEs and no deaths.

Conclusions

Dimdazenil of 2.5 mg provided significant benefit on sleep maintenance and sleep onset in individuals with insomnia disorder versus placebo, with a favorable safety profile and was well tolerated.

Clinical Trial Information

A multicenter, randomized, double-blind phase III clinical study evaluating the efficacy and safety of EVT201 capsules compared to placebo in patients with insomnia disorders (http://www.chinadrugtrials.org), with the number of CTR20201068.
O002 High strain evening exercise disrupts sleep: Insights from a real-world examination of ~7-million nights
Authors: Leota J , Presby D , Czeisler M , Mascaro L , Capodilupo E , Drummond S , Rajaratnam S , Facer-Childs E
Published: October 2023

Introduction

Exercise is among the most effective daytime behaviors for promoting and maintaining sleep. However, late-night bouts of strenuous exercise that require high physiological demand (i.e., high strain) induce persistent increases in sympathetic arousal, which may disrupt sleep. We examined whether exercise strain moderates the relationship between evening exercise and objective sleep in free-living conditions.

Methods

A total of 19,977 individuals (26% female, M-age=37.9 years) wore a validated sleep and exercise biometric wearable device for 365 days between Sep 1, 2021 and Aug 31, 2022 (n=6,943,372 nights). Summated-heart-rate-zone-scores were used to categorize exercise strain into four groups: light, moderate, high, and all-out. Exercise timing was normalized to each individual’s habitual bedtime to account for individual differences in sleep/wake timing. Generalized additive mixed model analyses were used to model the non-linear relationship between exercise timing and sleep at different levels of exercise strain.

Results

Later exercise timing was associated with delayed sleep onset, reduced sleep quantity and quality, and increased sympathetic activity compared to no-exercise rest days (ps<.001). Importantly, a dose-response relationship was observed such that higher levels of exercise strain predicted worse sleep (ps<.001). Regardless of strain, exercise bouts ending at least 4 hours before habitual bedtime were not associated with changes in sleep.

Discussion

Evening exercise—particularly involving high exercise strain—can disrupt subsequent sleep (both duration and quality). It is recommended individuals stop exercising at least 4 hours before their habitual bedtime. However, when evening exercise is unavoidable, individuals could select lighter strain exercises to mitigate sleep disruption.
O007 Validation of an under-mattress sleep tracker to estimate sleep and wake during day and night sleep opportunities
Authors: Manners J , Kemps E , Lechat B , Stuart N , Guyett A , Proctor S , Eckert D , Catcheside P , Scott H
Published: October 2023

Introduction

Consumer sleep trackers are useful for tracking daily sleep, particularly in shift-workers, yet large, multi-night validations against direct sleep measures are lacking. Conducted as one of the largest sleep tracker validation studies to date, this study evaluated performance of an under-mattress sensor (Withings Sleep Analyzer [WSA]) to classify sleep and wake versus polysomnography (PSG) in a multi-night laboratory protocol with both day and night sleep opportunities.

Methods

27 healthy sleepers attended the laboratory twice, for 8 consecutive days (48% male, mean[SD] age=27[9]years). Participants underwent simultaneous PSG and WSA recordings for the initial night-time sleep (22:00-07:00) and 6 subsequent daytime sleeps (10:00-19:00) during simulated night-shift work. Epoch-by-epoch analysis of the 252 nights tested accuracy, sensitivity, and specificity for the first night-time sleep opportunity versus subsequent daytime sleeps. Sleep duration estimates were compared between WSA and PSG.

Results

Across all recordings, the WSA showed 83% sleep-wake classification accuracy, 87% sensitivity to sleep and 25% specificity to wake. The WSA significantly overestimated sleep duration versus PSG (25[65]minutes, p<0.05). Accuracy and specificity were higher for night versus day sleeps (88% and 38% versus 81% and 18% respectively, all p<0.05), while sensitivity (90% versus 88%) did not significantly differ.

Discussion

The WSA was moderately accurate compared to PSG, and comparable to other movement-based sleep trackers. The WSA was more accurate at classifying sleep and wake during night sleep opportunities compared to daytime sleeps. This differential performance is likely due to poorer sleep quality commonly observed during daytime sleep that is harder to accurately classify.
O008 Refining the Hypoxic Burden Algorithm by Investigating different Methods for Calculating the SpO2 Baseline
Authors: He S , Bin Y , Cistulli P , de Chazal P
Published: October 2023

Introduction

Intermittent hypoxia is a key mechanism linking Obstructive Sleep Apnoea (OSA) to cardiovascular disease (CVD). Oximetry analysis could enhance understanding of which OSA phenotypes are associated with CVD risk. The hypoxic burden (HB) is a measure calculated from the oximetry signal that shows promise for predicting CVD mortality, but its calculation is complex. With a view to simplifying its calculation, we investigated three different baseline calculation methods and its impact on predicting CVD mortality for the HB algorithm.

Methods

Data from Sleep Heart Health Study (SHHS) with CVD mortality outcome and complete covariate information was used. We implemented the HB method of Azarbarzin et al 2018 ERJ. The three baseline methods included an event-based baseline (same as Azarbarzin et al 2018 ERJ), a record-based baseline, and a fixed baseline. The performance of each parameter in predicting CVD mortality was assessed using an adjusted Cox proportional hazard ratio (HR) analysis.

Results

The best performing method was the record-based baseline method which returned a fully adjusted model hazard ratio of 1.83 (95% CI: 1.03-3.27, p<0.05). The results for the event-based and record-based baseline methods were 1.60 (95% CI: 0.86-3.00, p=0.14) and 1.73 (95% CI: 0.93-3.22, p=0.08) respectively.

Discussion

HB with the record-based baseline was easier to calculate than the original event-based baseline method by Azarbarzin at al. and resulted in improved CVD mortality prediction performance. We believe that this method provides a step towards providing a novel parameter with easy calculation providing early risk stratification in cardiovascular patients.
O011 Exploring Nocturnal Blood Pressure Surges Relationships with Brain Health and Cognitive Function.
Authors: Bull C , Zhang T , Burke P , Butlin M , Botansky C , Srirengan A , Cysique L , Lancaster K , Brown E , Bilston L , Jugé L
Published: October 2023

Introduction

Cerebral small vessel disease is a possible mechanism to explain the link between long-term incompletely treated obstructive sleep apnoea (OSA) and dementia. Recent evidence suggests nocturnal blood pressure (BP) surges triggered by OSA-related sympathetic hyperactivity could play a critical role. However, this remains to be determined as they often occur concurrently with desaturation events.

Methods

During an in-lab polysomnography study of 7 controls [AHI≤5] and 20 untreated OSA patients [AHI>5] aged 45-65 years the frequency of blood pressure surges (>10% systolic ↑BP) in the presence or not of desaturation events (↓SpO2>3%) were quantified with a SOMNOtouch™ NIBP device. Cerebral perfusion was assessed with pCASL MRI and brain lesions with anatomical MRI scans. The global deficit score was determined for cognitive function assessment. Inflammation was quantified with blood hs-CRP.

Results

After controlling for age, BMI, gender, blood glucose and cholesterol, higher AHI was associated with more frequent BP surges (r=0.52, P=0.03), BP surges occurring with desaturation events (r=0.87, P<0.001), but not with BP surges without oxygen desaturation (P = 0.11). Concurrent BP surges and oxygen desaturation was associated with increased hs-CRP (r=0.55, P=0.02). Frequency of BP surges was not related to cerebral perfusion, brain lesions or the global deficit score.

Conclusions

Recording nocturnal blood pressure surges during polysomnography may provide insight into the cardiovascular burden associated with OSA. Interestingly, an inflammatory response is associated with BP surges only during desaturations, i.e. during respiratory events. Further work is needed to assess the utility of BP surges in predicting longer-term cognitive deficits.
O015 Measuring Body Movements during Sleep. Sonomat Vs Video Polysomnography
Authors: Lu M , Fitzgerald D , Sullivan C , Waters K
Published: October 2023

Background

Restless sleep is common in children, and video polysomnography (vPSG) has been used to score body movements during sleep. The Sonomat provides a contactless, portable alternative for home sleep studies over several nights. This study aimed to compare body movements measured by the Sonomat with those scored using vPSG.

Methods

Twenty-nine children (13 females, 16 males) with a median age of 5.4 years underwent concurrent Sonomat and vPSG studies. Movement indices per hour of sleep period and movement duration (%) were blindly scored on separate days. Statistical analysis included the Wilcoxon rank test and Pearson's correlations.

Results

Movement indices were higher on the Sonomat than vPSG (median 38.6/hr vs. 22.7/hr, p < 0.001), but movement duration did not differ (median 10.8% vs. 10.5%, p = 0.092). Comparing movements above 5 seconds, the indices became more comparable (15.9/hr vs. 19.2/hr, p = 0.05). The correlation between devices was weak for movement indices (r = 0.37, p = 0.051) but strong for movement duration (r = 0.81, p < 0.001). The Sonomat identified 82.5% of movements seen on vPSG, while vPSG identified only 43.6% of those on the Sonomat.

Conclusion

The Sonomat offers a contactless and portable alternative to vPSG for assessing body movements during sleep in children. It exhibited higher sensitivity in detecting shorter movements and was comparable to vPSG in movement duration. These findings suggest that the Sonomat holds promise for evaluating restless sleep in children.
O016 Caregivers’ Perspectives on the Sonomat as a Polysomnography Alternative in Children with Down syndrome
Authors: Sclip K , Collaro A , Chawla J
Published: October 2023

Introduction

Children with Down syndrome (DS) frequently require repeated polysomnography (PSG) to diagnose and monitor sleep disordered breathing (SDB). PSG set-up can be distressing for this population, who may struggle with sensor and lead application. The Sonomat, a non-invasive mattress overlay, has now been shown to accurately detect and profile SDB in this population. The aim of this study was to evaluate caregiver experiences of undertaking home Sonomat monitoring in their child with DS, compared to conventional lab PSG.

Method

Children with DS aged 2-17yrs undergoing a diagnostic PSG at the Queensland Children’s Hospital completed a PSG questionnaire about their child’s experience of this test. Those that also undertook home Sonomat monitoring completed a questionnaire about their experience of using the Sonomat in the home.

Results

Caregivers of fifty-one children with DS (median age 7yrs, 52% male) completed the PSG questionnaire and twenty-five completed the Sonomat questionnaire. 45% (n=51) of caregivers reported that in-lab PSG was ‘hard’ or ‘very hard’ for their child. 100% (n=25) of the caregivers rated their experience of using the Sonomat at home as good, very good or excellent. 88% (n=25) of caregivers felt that the Sonomat was their preferred option for monitoring in children with DS, as opposed to a traditional in-lab PSG.

Conclusion

In this study, the Sonomat was viewed favourably by caregivers of children with DS, and in the majority of instances was preferred to in-hospital PSG.
O017 Real-World Utility of Overnight Oximetry for the Screening of Obstructive Sleep Apnoea in Children
Authors: Hartnett C , Wilson A , Kilner D , Davies K , Slee N , Chawla J , Iyer K , Kevat A
Published: October 2023

Obstructive sleep apnoea (OSA) is a common problem in children, and can result in developmental and cognitive complications if untreated. The gold-standard tool for diagnosis is polysomnography (PSG); however, it is an expensive and time-consuming test to undertake. Overnight oximetry has been suggested as a faster and cheaper alternative to PSG as it can be performed at home using limited, reusable equipment. This study aims to evaluate the effectiveness of a home oximetry service (implemented in response to extended waiting times for routine PSG) in reducing the time between patient referral and treatment. All patients who utilised the Queensland Children’s Hospital home oximetry service since its inception in 2021 (n=165) were compared to a historic group of patients who underwent PSG in 2018 (n=313). The time from request of the sleep-related study to definitive treatment (ENT surgery or continuous positive airway pressure trial) was significantly reduced (161 days for the HITH oximetry group vs 348 days for the comparable PSG group; p-value <0.02), and time from sleep study request to the report of results was significantly lower for patients in the oximetry group compared to those in the PSG group (12 days vs 86 days p-value <0.01). These results suggest that a home oximetry service can be effective in reducing the waiting time for patients diagnosed with OSA to receive treatment. Further research should examine larger sample sizes to confirm the study findings, investigate the health economic impacts of the service and explore patient/family perspectives.
O025 Sleep outcomes in paediatric patients pre- and post-pharyngoplasty
Authors: Jarvis S , Chatwal G , Jia M , Waters K
Published: October 2023

Background

Pharyngoplasty surgery is undertaken to correct velopharyngeal insufficiency (VPI). The resultant narrowing of the pharyngeal airway can cause obstructive sleep apnoea (OSA), but limited data is available regarding the incidence or severity of this problem. This study will evaluate the effect of pharyngoplasty on the development of OSA in children.

Methods

We are undertaking a retrospective audit of medical records for children who underwent both polysomnography (PSG) and pharyngoplasty at a tertiary paediatric centre between January 2013 and December 2022. Data from children who underwent PSG and pharyngoplasty will be evaluated and separated according to the timing pre- or post-pharyngoplasty. Analyses will determine the effect of pharyngoplasty on the development and or progression of sleep disordered breathing.

Results

176 paediatric patients underwent pharyngoplasty procedures from January 2013-December 2022, including 73 (41%) who also underwent PSG. Full PSG data are available for analysis including sleep staging, arousal, respiratory and gas exchange. Primary outcome will be the obstructive apnoea-hypopnoea index (OAHI), but additional impacts on total apnoea-hypopnea index (AHI), oxygen saturation, CO2, and arousals will also be evaluated. Not all children had studies before and after their surgery so statistical comparison will be made between parameters measured before and after pharyngoplasty, using both paired (where available) and unpaired (for the entire group) testing as appropriate.

Intended outcome/impact: This study will evaluate the impact of pharyngoplasty on children’s breathing during sleep. The results will assist in determining the indications for, and appropriate timing for PSG in children undergoing pharyngoplasty procedures for VPI.
O030 GABAA Receptor Expression in the Suprachiasmatic Nucleus under Different Light Conditions
Authors: Chong J , Cheeseman J , Pawley M , Kwakowsky A , Warman G
Published: October 2023

Our research group has made inroads investigating the phase shifting effects of general anaesthesia (GA) on the circadian clock. Most clinical anaesthetics function by potentiating the effect of GABA on the GABA type A receptor (GABAARs). While the precise role of GABA in the suprachiasmatic nucleus (SCN) is still not fully understood, it has been implicated in circadian functions including photic entrainment and clock coupling. However, we have discovered that the expression of GABAARs in the central circadian clock remains poorly understood. To address this gap in knowledge, we examined the expression of GABAAR subunits α1, α5, β3, and γ2 in male (n = 80) and female (n = 82) C57Bl/6 mice under light-dark (LD) and constant darkness (DD) conditions (male, n = 95). Analysis of GABAAR subunit expression in the SCN was quantified by immunohistochemical analysis. Additionally, we investigated the time-dependent effects of isoflurane GA and light on GABAAR subunit expression in the SCN (male, n = 60). Our findings revealed rhythmic expression of GABAAR subunits in the mouse SCN under LD conditions which differed by sex, suggesting environmental light conditions may regulate GABAAR expression in the circadian clock in a sex-specific manner. In the SCN, γ2 subunit expression was increased following light and GA treatment compared to light-alone, while α1 subunit expression was increased at times of large behavioural phase delays. We conclude that the expression of GABAAR’s in the SCN is phase-dependent and may contribute to the time-dependent relationship between light and GA on the clock.
O034 Insomnia Management in Australia: An Overview of Patient, Clinician and Health System Factors
Authors: Haycock J , Lack L , Hoon E , Sweetman A , Lovato N
Published: October 2023

Introduction

Insomnia is the most prevalent sleep disorder in Australia. The recommended treatment is Cognitive Behavioural Therapy for insomnia (CBTi), however most people with insomnia do not access this treatment. Understanding reasons for the discrepancy between clinical guidelines and clinical practice is essential to identify opportunities to increase access to CBTi. This research explores the perspectives of people with insomnia, clinicians, and the health system to provide a comprehensive picture of insomnia management in Australia.

Methods

A mixed-methods program was undertaken to comprehensively identify facilitators and barriers to CBTi access in Australia. This included two large quantitative surveys of the Australian community and people with insomnia, and semi-structured qualitative interviews with GPs and psychologists.

Results

Most people with chronic insomnia symptoms reported they did not receive a diagnosis of insomnia, only 37% had discussed sleep with their GP, 9% discussed sleep with a psychologist, and <1% received CBTi. Barriers to effective management of insomnia include low priority of sleep from all perspectives, impaired knowledge and awareness, and inadequate access to care. GPs are under substantial time pressure, other health conditions are often prioritised over insomnia, existing funding mechanisms are not clear, and few psychologists trained to deliver CBTi.

Discussion

To improve the management of insomnia in Australia efforts are needed to improve clinician and patient recognition of the importance of identifying and managing insomnia. More psychologists and primary care clinicians need to be trained in CBTi delivery, to increase awareness, understanding and access to CBTi in the community.
O035 Digital CBT-i versus digital sleep education control in an Australian community-based cohort: A randomised controlled trail.
Authors: Sweetman A , Reynolds C , Richardson C
Published: October 2023

Background

Insomnia is a prevalent and debilitating condition in Australia. Cognitive behavioural therapy for insomnia (CBT-i) is the recommended first-line treatment, but is accessed by very few people with insomnia. We aimed to develop and test an interactive self-guided digital CBT-i program in an Australian community-based sample.

Methods

A randomised controlled trial was used to investigate the effect of digital CBT-i, versus digital sleep education control, on changes in insomnia (ISI), depression (PHQ-9) and anxiety symptoms (GAD-7) by 8-week follow-up in people with insomnia symptoms (ISI≥15). Intention-to-treat linear mixed models and complete-case chi-square analyses were used.

Results

Participants included 62 adults with insomnia symptoms (82% female, Age M [sd] = 52.5 [16.3]). There were no between-group differences in baseline characteristics, or rates of missing data at 8-weeks. CBT-i was associated with significantly greater improvements in the ISI (M [95%CI] reduction = 9.7 [7.8-11.6], d = 3.5) and PHQ-9 (M reduction = 4.8 [3.1-6.6], d = 1.0), but not GAD-7, compared to control (M ISI reduction = 1.6 [-0.2-3.4]; M PHQ-9 reduction = 1.0 [-0.7-2.6]; both interaction p < 0.001). Compared to control, CBT-i resulted in greater rates of insomnia improvement (ISI reduction ≥6; 7%, vs 75%), insomnia remission (ISI<8; 0%, vs 42%), and lower rates of clinically significant insomnia by 8-weeks (ISI≥15; 61%, vs 12%, all p < 0.001).

Conclusion

This digital CBT-i program leads to large improvements in insomnia and depression symptoms adults with insomnia. Implementation programs are required to increase access to digital CBT-i in Australia.
O040 Assessment of Heart Rate Variability During Respiratory Events and Arousals Using Symbolic Dynamics
Authors: Behbahani S , Staykov E , Wilson D , Leppänen T , Mann D , Terrill P
Published: October 2023

Introduction

Beat-to-beat heart rate dynamics vary during obstructive respiratory events and in both respiratory and spontaneous arousals. However, conventional quantifications of heart rate variability (HRV) require segments of data substantially longer than the typical respiratory event or arousal. Subsequently, previous studies investigating dynamics in these significantly shorter segments have utilised simple quantifications such as peak heart rate. This study aimed to more-richly characterise HRV during obstructive respiratory events and arousals using symbolic dynamics.

Methods

One hundred individuals with suspected obstructive sleep apnoea (55 male, 57.1±12.9 years) were studied with diagnostic polysomnography, including electrocardiography. R-wave intervals were calculated and extracted during respiratory events terminating with/without arousals and during spontaneous and respiratory arousals. The symbolic dynamics tool “heart rate fragmentation” was applied to quantify HRV during the events, whereby the percentage of inflection points (PIP), defined as beat-to-beat transitions from heart-rate acceleration to heart-rate deceleration, were calculated. Statistical analysis was conducted with the Wilcoxon rank sum test.

Results

PIP was higher during respiratory events terminated with arousal compared with those without arousal (52.9±6.4% vs. 48.5±6.7%, P<0.05). PIP was also higher during spontaneous arousals than during respiratory arousals (51.3±6.1% vs. 45.8±6.7%, P<0.05).

Discussion

Previous mechanistic experiments have associated increased PIP with greater parasympathetic activity. Thus, our preliminary results suggest greater parasympathetic activity during respiratory events terminated by arousal than those without; and during spontaneous arousals compared with respiratory arousals. Further work is required to understand the pathophysiology underlying this and other similar metrics, potentially leading to novel obstructive sleep apnoea-related cardiorespiratory pathology biomarkers.
O043 Investigating Upper-Airway Mechanics with Computational Tongue Models
Authors: Lloyd R , Jugé L , Bilston L
Published: October 2023

With the use of computational models of the oral cavity, we aim to understand how changes in the morphology of the oral cavity and changes the stiffness of the tongue affect the movement of the posterior surface of the tongue.

Anatomical and diffusion weighted imaging from 20 healthy individuals (10M:10F, Age: 22-54years, BMI: 17-30kg/m²), were used to develop 3D models of the tongue including the fibre orientations of the tongue muscles. All models were aligned and scaled to match the volume of the average subject's mandible, so that only differences in shape were modelled. The muscles of the tongue were modelled as transversely isotropic, with a shear moduli of 2.9 and 1.0kPa, parallel and perpendicular to the muscle fibre direction, respectively. Each individual participant model was prescribed an active contraction producing 50kPa of stress in the horizontal component of the genioglossus. The influence of initial hyoid position on the average anterior displacement of the posterior surface of the tongue was assessed with linear regression.

On average the contraction moved the posterior tongue 4.0±0.7mm anteriorly. For every millimetre of hyoid elevation, anterior tongue displacement (i.e. airway dilation) decreased by 0.1mm. These initial models demonstrate that the automated modelling pipeline can identify how structural differences alter the efficacy of dilator muscles. Future implementations of these models will also incorporate experimentally measured pharyngeal pressures, and temporal and spatial patterns of muscle activations based on experimental data, to assess the how variation in the coordinated contractions contributes to airway collapse.
O046 Adherence to Dietary Guidelines Predicts Sleep outcomes in Older Australian Women: Findings from the Australian Longitudinal Study on Women’s Health
Authors: Gupta C , Khalesi S , Vandelanotte C , Irwin C , Vincent G , Mishra G
Published: October 2023

Introduction

Sleep quality and quantity is impacted by age, with women more susceptible to these age-related changes. Poor sleep in older adults is linked to adverse health outcomes and a greater risk of all-cause mortality. Given the ageing population in Australia, strategies to improve sleep in older adults is critical. Diet is a modifiable lifestyle factor that may improve sleep. This study investigated the relationship between adherence to dietary guidelines and sleep problems in older Australian women.

Method

Data from n=7956 Australian women from the 1946-1951 cohort of the Australian Longitudinal Study on Women’s Health were included (mean age±SD: 70.8±1.5 years). Participants completed a food frequency questionnaire, reported as a diet quality score (0-100, with 100 indicating best diet quality). Sleep problems were measured with five questions that asked about early waking, time taken to fall asleep, sleep quality, wake after sleep onset, and worry related awakenings at night.

Results

At least one sleep problem was reported by 70.2% of participants, and 20.5% reported between 3-5 sleep problems. Overall adherence to dietary guidelines was poor, with an average diet quality score of 56.9±10.7. Linear regression revealed that better adherence to dietary guidelines was associated with fewer sleep problems (β: –0·065, 95 % CI: –0·012, –0·005).

Discussion

While dietary adherence in older Australian women was poor, adherence to dietary guidelines was associated with fewer symptoms of sleep problems. To improve the sleep and overall health of older Australian women, strategies to improve dietary adherence should be prioritised.
O047 Representations of Sleep in Social Media: A Tik Tok Case Study
Authors: Voggenreiter A , Rossa K , Smith S , Maravilla J , Broccatelli C , Pfeffer J
Published: October 2023

Introduction

Social media platforms such as Tik Tok have broadened and potentially democratised access to health information. The narratives and quality of information about sleep on TikTok has not been studied. We sought to understand sentiment towards sleep, the types of sleep problems represented by users, and the nature and content of advice about sleep provided on TikTok.

Methods

All videos associated with the keyword “sleep” were collected twice daily using the keyword search function of the Ensemble data TikTok API between 4th-17th November 2022 for Great Britain, Australia, New Zealand and the USA. 7,373 unique videos were examined. After screening, videos were coded to a customised sleep narrative-specific code set. 1,913 discrete sleep-related videos were labelled according to 33 unique categories and underwent computational sentiment analysis.

Results

Overall, sleep was framed more positively than negatively, particularly for sleep advice. Videos about sleep problems were typically framed positively through humour. The main sleep narratives represented included (1) problems with sleep quality, initiation or maintenance due to factors such as children, worries or use of electronic media, and (2) advice for improving sleep quality through the use of sleep-promoting soundscapes, advice on improving children’s sleep, and implementation of routines/habits to support sleep.

Discussion

Platforms such as Tik Tok provide opportunities to disseminate timely, engaging, and evidence-based information about sleep health to a wide community. However, they equally carry risks of mass distribution of false information that warrants broader oversight and critical examination.
O048 Why don’t Australians with Private Health Insurance Prioritise their Sleep Health?
Authors: Sweet A , Smith M , Gibson L , Croci P , Maddison K , Beard D , Gradisar M , Walsh J
Published: October 2023

Introduction

This study sought to identify common routines and practices that may help or hinder sleep quality in a heterogenous population of Australians with private health insurance (PHI).

Methods

Members of a national not-for-profit health fund were invited to complete an online survey about the ‘pillars’ of sleep environment (place & practice), priority (value & knowledge), and impact (personal & community). Question responses were indexed on a scale of 1-100 and ratings were generated as a summation of each pillar (Low: 0-49; Neutral: 50-69; High: 70-100).

Results

Participants (n=1007) placed a high value on their individual sleep (73.9/100) and rated their place of sleep highly (74.5/100). However, sleep practice outcomes (56.5/100) and sleep impacts (personal: 50.4/100; community: 57.4/100) were considered neutral on average. Only 25% of participants were consistent in their sleep timing. 41% were distracted by other responsibilities (e.g., chores, children, and emails) and 30% indicated they prioritise yet cannot maintain consistency in their sleep routine. 75% of participants indicated they wanted more education on sleep and how to improve it.

Discussion

Australians with PHI are thought to be proactive in their health, with greater access to funded programs and claimable services to improve their health outcomes. However, the impact of poor sleep and severe lack of consistency was observed within this cohort, despite individuals placing high value on a healthy sleep routine.

Conclusion

With extensive benefits of good sleep, health funds should look to help improve their members’ sleep education for the 55% of Australians with PHI.
O049 A Quantitative EEG Analysis of Overnight Noise Exposure Effects on Sleep– A Laboratory Study
Authors: Dunbar C , Nguyen P , Vakulin A , Lechat B , Hansen K , Micic G , Zajamsek B , Liebich T , Scott H , Lack L , Decup F , Catcheside P
Published: October 2023

The impact of overnight wind farm noise exposure on sleep is unclear and traditional manual sleep scoring may not be sensitive enough to detect subtle changes in sleep. This study used quantitative EEG (qEEG) to assess subtle effects of noise on sleep under well-controlled laboratory conditions.

Sixty-eight individuals (Males: Females; 30:38) aged (Median [IQR]) 55.5yrs [31.3-66.3], from four groups (rural residents with and without WFN-related complaints, control rural residents, and urban traffic noise-exposed residents) underwent overnight polysomnography during six different noise exposure nights in random order. Noises included 20sec and 3min intermittent road traffic and wind farm noise exposures (full night averages 42dBA and 32dBA, respectively), continuous and intermittent wind farm noise at 25dBA, and a quiet control night (background noise,19dBA). Traditional polysomnography sleep metrics, qEEG power in delta (0.5-4Hz) to beta (32Hz) frequencies, and K-complex density (events/min) were compared between noise conditions, groups and sleep stages using likelihood ratio tests.

Wake after sleep onset, time spent in N1 sleep and relative beta activity were higher, whilst time spent in N3 was reduced on the 20 second noise exposure night compared to control (all p<0.05). Full night average qEEG outcomes were not different between nights. K-complex density was significantly increased during both 20sec and 3min intermittent noise exposure conditions compared to control (p<0.001).

Full night qEEG outcomes do not appear to be more sensitive to noise related sleep disturbance than traditional sleep scoring methods. However, K-complex density assessments may be particularly useful in future studies of noise effects on sleep.
O055 NIV titration: How to Match Ventilator Settings to the Patient?
Authors: Ridgers A , Ruehland W , Hannan L , Berlowitz D , Howard M
Published: October 2023

Introduction

Non-invasive ventilation (NIV) is a treatment that improves mortality and quality of life in chronic respiratory failure. The monitoring used to titrate NIV varies substantially; however, treatment is directed towards improving pulmonary gas exchange and sleep quality. The aim was to evaluate whether different montages of signals, influenced identification of respiratory and patient ventilator asynchrony (PVA) events and ventilation titration.

Method

50 laboratory NIV polysomnography (PSG) studies were reviewed under 3 different signal conditions: NIV PSG, ventilator derived signals (V) and polygraphy (PG): ventilator signals, respiratory bands, transcutaneous carbon dioxide and oximetry. Two respiratory and sleep physicians reviewed and scored respiratory and PVA events for each individual study with agreement quantified with Cohen’s kappa statistic. Physicians’ confidence and satisfaction of ventilator settings and titration recommendations were ranked on a 5-point Likert scale and compared with ordinal logistic regression.

Results

There were marked differences in the identification of respiratory events including upper airway obstruction with reduced respiratory drive; PSG vs V kappa 0.1 (CI -0.12, 0.32) and PSG vs V kappa 0.43(CI 0.2, 0.67). Ineffective effort, a measure of PVA, PSG vs V studies demonstrated kappa 0.02 (CI 0, 0.05) compared with PSG vs PG kappa 0.34 (CI 0.16, 0.53). Physician confidence for ventilation prescription was lower in PG and V studies at -1.3 and -3.5 points respectively when compared with PSG.

Conclusion

Ventilator only derived signals resulted in key differences in respiratory event, PVA identification and physician confidence. This may help inform future models of NIV care.
O068 Sleep Cyclists? Night-time Recovery of Competitors in the Tour de France and Tour de France Femmes
Authors: Sargent C , Capodilupo E , Powers J , Jasinski S , Miller D , Roach G
Published: October 2023

Introduction

The aim of this study was to examine the capacity of professional cyclists to recover between daily race stages while competing in the 2022 editions of the Tour de France and Tour de France Femmes.

Methods

The 17 participating cyclists were 8 males from a single team (aged 28.0yr) and 9 females from two separate teams (aged 26.7yr). Throughout the events, the cyclists wore a wrist-worn monitor (WHOOP 4.0) to capture recovery metrics related to sleep (quantity/quality) and autonomic activity (heart rate and heart rate variability). The primary analyses tested for a main effect of ‘day type’ – i.e., rest, flat, hilly, mountain or time trial for males; and flat, hilly or mountain for females – on the various recovery metrics.

Results

During their respective events, males obtained an average of 7.2(±0.1)h sleep each night, with sleep efficiency of 86.4(±1.2)%; and females obtained an average of 7.5(±0.3)h sleep each night, with sleep efficiency of 89.6(±1.2)%. For males, there was a main effect of ‘day type’ on recovery, such that heart rate variability during sleep was lowest after mountain stages. For females, there was a main effect of ‘day type’ on recovery, such that the percentage of light sleep in a sleep period (i.e., lower-quality sleep) was highest after mountain stages.

Discussion

Some aspects of recovery were compromised in cyclists after the most demanding days of racing, i.e., mountain stages. Overall however, the cyclists obtained a reasonable amount of good-quality sleep while competing in these highly demanding endurance events.
O069 Links between sleep outcomes and lifestyle factors in young adults who sustained traumatic brain injury in childhood
Authors: Botchway-Commey E , Godfrey C , Nicholas C , Anderson V , Catroppa C
Published: October 2023

Objective

We investigated the relationships between subjective and objective sleep and lifestyle factors (i.e., nap duration, screentime, chronotype, use of tobacco, alcohol, caffeine, and medications) in young adults who sustained traumatic brain injury (TBI) in childhood.

Methods

We report cross-sectional data collected at 20 years post-childhood TBI, as part of a prospective study. Participants included 54 young adults with TBI (Mean age, 27.7years) who were assessed at 20 years postinjury (mild (n = 14), moderate (n = 27), and severe (n = 13) TBI) and 13 healthy controls (Mean age, 26.0 years). The Pittsburgh Sleep Quality Index and actigraphy were used to assess sleep outcomes, and lifestyle factors were assessed with study-designed measures.

Results

Results showed that poor subjective sleep quality was significantly associated with evening chronotype (p < 0.001) and tobacco use (p < 0.001), while being a parent (p = 0.038) and alcohol use (p = 0.035) were significantly associated with poorer objective sleep efficiency in the TBI group.

Discussion

These preliminary findings highlight interesting associations between poor sleep quality and lifestyle factors in young adults who sustained TBI in childhood, and indicate the need to further explore these relationships in this TBI population to inform on potential avenues for sleep interventions.
O070 Prevalence of central sleep apnoea in people with tetraplegic spinal cord injury: a retrospective analysis of research and clinical data
Authors: Graco M , Ruehland W , Schembri R , Churchward T , Saravanan K , Sheers N , Berlowitz D
Published: October 2023

Study Objectives

Over 80% of people with tetraplegia have sleep disordered breathing, but whether this is predominantly obstructive or central is unclear. This study aimed to estimate the prevalence of central sleep apnoea (CSA) in tetraplegia and the contributions of central, obstructive and hypopnoea respiratory events to sleep disordered breathing summary indices in tetraplegia.

Methods

Research and clinical data from 606 individuals with tetraplegia and full overnight polysomnography were collated. The proportions of different respiratory event types were calculated; overall and for mild, moderate, and severe disease. The prevalence of Predominant CSA (central apnoea index 5 and more central than obstructive apnoeas) and Any CSA (central apnoea index  5) was estimated. Prevalence of sleep-related hypoventilation was estimated in a clinical sub-cohort.

Results

Respiratory events were primarily hypopnoeas (71%), followed by obstructive (23%), central (4%) and mixed apnoeas (2%). As severity increased, the relative contribution of hypopnoeas and central apnoeas decreased, while that of obstructive apnoeas increased. The prevalence of Predominant CSA and Any CSA were 4.3% (26/606) and 8.4% (51/606) respectively. Being male, on opiates and having a high tetraplegic spinal cord injury were associated with CSA. Sleep-related hypoventilation was identified in 26% (26/113) of the clinical sub-cohort.

Conclusions

This is the largest study to characterize sleep disordered breathing in tetraplegia. It provides strong evidence that obstructive sleep apnoea is the predominant sleep disordered breathing type; 9-18 times more prevalent than CSA. The prevalence of CSA was estimated to be 4-8%, significantly lower than previously reported.
O072 Simple Vestibular-Occular Motor Assessment as a Predictor of Alertness State and Driving Impairment during Extended Wakefulness
Authors: Nguyen P , Dunbar C , Guyett A , Nguyen K , Bickley K , Reynolds A , Hughes M , Scott H , Adams R , Lack L , Catcheside P , Cori J , Howard M , Anderson C , Lovato N , Vakulin A
Published: October 2023

Introduction

Driver fatigue contributes to 2-16% of road crashes, highlighting the need for improved detection of at-risk drivers. We used a novel and brief test of vestibular ocular motor system (VOMS) assessed via virtual reality goggles to predict alertness state and driving simulator performance during 29hr extended wakefulness.

Methods

49 individuals (Mean±SD Age, 32.6±12.9, 45% Males) undergone 9hr baseline sleep opportunity followed by ~29hrs extended wakefulness with five 60min driving assessments. Cluster analysis, combining steering deviation and number of crashes were used to split participants into groups of either poor vs good driving performance. VOMS assessment was conducted using virtual reality goggles approximately 10mins before and after each drive. Predictive importance of VOMs metrics were ranked using XGBoost machine learning model, which was then utilized to distinguish between poor vs good driving groups. Model performance was evaluated using a 5-fold cross-validation approach using ROC analysis.

Results

XGBoost machine learning ranked all 70 VOMS metrics on their importance in predicting driving performance group for each drive. Top 10 metrics from pre-drive VOMS test predicted both daytime driving (tests 1-3, AUC 0.8 [95%CI 0.64-0.93], p<0.001) and night-time driving (tests 4-5, AUC 0.78 [95%CI 0.6-0.95, p<0.001]). Post-driving VOMS assessments also predicted daytime (AUC 0.74 [95%CI 0.53-0.9, p<0.001] and night-time driving (AUC 0.76 [95%CI 0.52-0.94, p<0.001]).

Conclusion

VOMS assessment show promise as a short and effective assessment of sleepiness to predict driving failure. Future validation in independent samples, sleep disordered population and in-field on-road testing are needed to confirm these promising findings.
O077 The Impact of Breaking up sitting during Simulated Nightshifts on Driving Performance during the Commute Home
Authors: Gupta C , Cheriyapraniyeri R , Agostini A , Vincent G , Easton D , Vandelanotte C , Duncan M , Tucker P , Lastella M , Ferguson S
Published: October 2023

Introduction

The commute home from a nightshift is associated with increased accident risk. Driving performance strategies typically occur immediately before or during the commute, such as napping and caffeine. It is unknown whether strategies that target alertness throughout the nightshift could impact the commute home. Breaking up sitting with walking is an effective strategy to improve alertness during dayshifts. This study investigated the impact of breaking up sitting during the nightshift on driving performance post-shift.

Method

41 adults (age M±SD: 24.4±4.6 years; 21 females) participated in a 7-day laboratory study, with 5 nightshifts (2200-0630). Participants were randomly allocated to: Breaking up sitting (BUS; n=21) or Sedentary (SED; n=20). Every 30-min during the nightshift BUS participants completed 3-min bouts of light-intensity walking, while SED participants remained sitting. At 2130 (pre-shift) and 0700 (post-shift) participants completed a 20-min simulated drive and the Karolinska Sleepiness Scale.

Results

Linear mixed models revealed a significant interaction between time (pre- or post-shift) and nightshift on driving performance and sleepiness, such that there was increased lane variability (p=0.03), speed variability (p<0.05), and sleepiness (p<0.05) post-shift compared to pre-shift, with performance worse on the first nightshift. There were no significant 2-way or 3-way interactions between condition (BUS or SED), time, or nightshift.

Discussion

Breaking up sitting with light-intensity walking did not improve performance for the commute home. However, given that breaking up sitting did not increase risk on the commute home, and it has benefits for cardiovascular health, it is an important strategy to promote to nightshift workers.
O081 “My partner just wants to sleep”: A qualitative study of the experience of living with a partner with Narcolepsy or Idiopathic Hypersomnia.
Authors: Rodriguez C , Bullock B , Buzwell S
Published: October 2023

Introduction

Narcolepsy and Idiopathic Hypersomnia (IH) are chronic sleep disorders that negatively impact sufferers’ Health-Related Quality of Life (HRQoL) across physical, emotional, and social functioning. Narcolepsy and IH may also impact the HRQoL of those close to the patient (i.e., partners, parents). This project explored the experiences of partners of people with Narcolepsy or IH, including how living with someone with the diagnoses had impacted their own HRQoL.

Methods

In this qualitative study, a semi-structured interview was used to collect data from 8 partners of people with Narcolepsy T1, Narcolepsy T2 and IH. The data were analyzed using Reflexive Thematic Analysis to find common themes emerging from the participants’ narratives.

Results

Five themes (and 2 sub-themes) were identified: 1) changes in dyadic identity; 2) negative impact on intimacy; 3) loneliness; 4) sacrifices to maintain the relationship, and 5) dissatisfaction at the lack of knowledge and information among (a) the general public, and (b) health professionals.

Conclusions

This novel, exploratory study identified several themes of social and emotional functioning most impacted by a partner’s sleep disorder diagnosis; themes which correspond with the areas shown to be negatively affected in patients. Psychosocial interventions for Narcolepsy and IH should include patients’ partners to reduce the impact of the diagnoses on the family system, and improve overall HRQoL.