bluuebunny/crossref_metadata_2025_split huggingface dataset:
O050 Regional electromyographic activity in genioglossus during quiet breathing in supine, awake individuals with and without sleep apnoea
Authors: Yeung J , Brown E , Burke P , Jugé L , Knapman F , Chiang A , Eckert D , Butler J , Bilston L 
Published: December 2024

Abstract

Introduction
Inspiratory-related genioglossus electromyography (EMG) activity is crucial to maintain upper airway patency during inspiration. Recent findings suggest variations in anterior/posterior genioglossus multiunit EMG activation during awake supine quiet breathing in healthy adults. However, whether such differences extend to EMG across oblique (middle) and horizontal (base) genioglossus compartments, and whether activation differ in obstructive sleep apnoea (OSA) is unclear.

Methods
Prior to in-lab polysomnography, intramuscular electrodes were placed into the horizontal and oblique compartments of the genioglossus in 9 controls (AHI≤5 events/hr) and 45 age- and BMI- matched OSA patients (AHI range 5-94.3 events/hr). Multiunit EMG patterns were classified as phasic or tonic during awake supine quiet nasal breathing. Phasic pattern recordings were quantitatively analysed (% maximum of swallowing or tongue protrusion). The effects of OSA status and genioglossus compartments were assessed through mixed linear analysis, controlling for nadir Pepi and repeated measures in participants.

Results
More than half (57.6%, n=106/184) of the recording sites had a phasic pattern. A more negative nadir Pepi correlated with reduced likelihood of tonic activity (OR: 0.819, P=0.042). Within phasic patterns, a more negative nadir Pepi correlated with increased peak EMG (beta=-0.847, P=0.011), phasic EMG (beta=-0.654, P=0.005), and tonic EMG (beta=-0.253, P=0.048). No significant effects of OSA status or genioglossus compartment on activity patterns or EMG measurements were observed.

Conclusions
No compartmental disparity in EMG or differences between OSA and non-OSA individuals were found. Understanding mechanisms driving efficient dilatory activity of the genioglossus compartments is pivotal to develop OSA treatments targeting pharyngeal muscle activity.
O051 Understanding the uptake of non-invasive ventilation in motor neurone disease: results of a national survey
Authors: Graco M , Carey K , Russo K , Sheers N , Berlowitz D 
Published: December 2024

Abstract

Introduction
Non-invasive ventilation (NIV) is an effective therapy for extending survival and enhancing quality of life in people with motor neurone disease (pwMND). According to Australian registry data from 2005-2015, just 19% of pwMND ever commenced NIV. This study aimed to estimate the current rates of NIV uptake among pwMND and identify demographic factors associated with its uptake.

Methods
National cross-sectional survey. PwMND (or their carers) were invited to complete an online survey about their NIV use and health care experiences. Multivariate logistic regression modelling investigated associations between various demographic factors and NIV uptake.

Results
224 responses were received. Mean(SD) age was 64(11) years, 62% were male, median(IQR) time since diagnosis was 2(1-5) years. 46%(n=104) were using NIV; 6%(n=14) had started NIV and stopped; 4%(n=9) were referred and waiting to start; 3%(n=7) had declined NIV; 14%(n=32) had discussed NIV with a health care professional (HCP) but not been referred; and 26%(n=58) had never discussed NIV with a HCP. NIV uptake was significantly (p&lt;0.05) associated with being male, residing in Victoria, residing in a metropolitan area, and longer time since diagnosis.

Conclusion
This study suggests that the uptake of NIV by pwMND in Australia is higher than previously reported, though registry-based cohort studies are needed to confirm this. Access to this highly effective therapy appears to be related to the person’s gender and where they live. A deeper understanding of the determinants and barriers to NIV uptake will enable targeted strategies that reduce health care inequity and improve outcomes for pwMND.
O052 Hypoxemia and arousals modulate nocturnal respiratory event-related cardiac function variations in obstructive sleep apnea patients
Authors: Ebrahimian S , Sillanmäki S , Rissanen M , Staykov E , Grote L , Bonsignore M , Baumert M , Leppanen T , Kainulainen S 
Published: December 2024

Abstract

Introduction
Obstructive sleep apnea (OSA) and its related consequences (i.e. desaturations or arousals) are known to immediately impact cardiac function. However, the dynamics of variations in heart function due to individual obstructive events and their consequences are not fully explored. We hypothesized that the respiratory events without immediate physiological consequences cause no post-event variations in cardiac function.

Methods
Variations in RR and rate-corrected QT (QTc) intervals were studied separately before, during, and after 4310 respiratory events from 134 OSA patients with no comorbidities (except diagnosed hypertension) or medications affecting heart function. Mixed-effect models were used to assess the impact of desaturation and arousal on cardiac function variations, independent of age, body mass index, sex, and diagnosed hypertension.

Results
In general, mean QTc intervals significantly (p&lt;0.05) decreased during and increased after respiratory events compared to before events. Detailed analysis revealed that arousal (RR estimate= -23.6 millisecond, p&lt;0.05; QTc estimate= 5.7 millisecond, p&lt;0.05) or both desaturation and arousal (RR estimate= -33.0, p&lt;0.05; QTc estimate= 8.4, p&lt;0.05) modulated mean post-events RR and QTc intervals independently of confounding factors and between-subject variations, while desaturation alone affected only the RR interval (estimate= -9.4, p&lt;0.05). In respiratory events without desaturation and arousal, mean post-event RR and QTc intervals showed no significant variation compared to before events.

Discussion
Respiratory events cause distinct cardiac responses if severe enough to cause desaturations and arousal. This indicates that the impact of respiratory events on cardiac function varies based on their immediate physiological consequences; without them, post-event cardiac variations are non-significant.
O054 Targeted ansa cervicalis nerve stimulation restores airflow to airway narrowing in obstructive sleep apnoea during propofol anaesthesia
Authors: Osman A , Carney A , Ooi E , Joshi H , Tran C , Hudson A , Catcheside P , Nguyen P , O’Reilly C , Gelekis N , Gibson D , Walsh J , Maddison K , Mackay S , Lewis R , Eckert D 
Published: December 2024

Abstract

Introduction
The pathophysiology of upper airway collapse in obstructive sleep apnoea (OSA) is multifactorial. Earlier animal and recent human data indicate that ansa cervicalis nerve stimulation may improve pharyngeal airflow via increased airway traction. We investigated a novel, targeted, neurostimulation approach of ansa cervicalis to improve upper airway function in people with OSA.

Methods
Participants with OSA (AHI&gt;15 events/h) were administered drug-induced sleep endoscopy with propofol and equipped with a nasal mask connected to a pneumotachograph to measure airflow and a modified continuous positive airway pressure (CPAP) device. Ultrasound was used to identify and guide percutaneous insertion of a temporary multi-electrode array to target the ansa cervicalis nerve. Therapeutic CPAP was reduced to induce transient airflow limitation. Ansa cervicalis stimulation was applied at varying stimulus amplitudes and electrode configurations until optimised. Changes in peak inspiratory airflow (PIF) from therapeutic CPAP levels to transient CPAP reductions were compared without and with optimal ansa cervicalis stimulation.

Results
13 (3 female) predominantly non-obese (BMI=28±4Kg/m²) participants with OSA (AHI=38±16 events/h) aged 51±14 years (mean±SD) were studied. Preliminary findings in 10 participants show that 9/10 had increased PIF with 3.2±1.2mA stimulation. PIF at therapeutic CPAP was 0.37±0.13L/s. During CPAP reductions, PIF decreased to 0.18±0.13L/s (p&lt;0.05) but returned to therapeutic CPAP levels (0.39±0.19L/s) during ansa cervicalis stimulation.

Conclusion
A novel, minimally-invasive, percutaneous stimulation approach to target the ansa cervicalis can markedly improve upper airway function during transient airway narrowing/closure in people with OSA during drug-induced sleep endoscopy.
O055 Fatigue risk in Search and Rescue operations: The challenge of sleep inertia and on-call work
Authors: Signal T , van den Berg M , Ladyman C 
Published: December 2024

Abstract

Introduction
Offshore Oil and Gas operations are normally supported by 24/7 Search and Rescue (SAR) services, which often involve fly-in-fly-out (FIFO) rosters. The current study followed SAR crew during two 21-day FIFO rosters to identify operational features that may increase fatigue risk.

Methods
Actigraphy was used to measure periods of sleep. At the start and end of each shift crew completed a 3-minute Psychomotor Vigilance Task and recorded ratings of fatigue and sleepiness. At the end of shifts workload ratings were made. Mixed model ANCOVAs were used to identify workplace factors associated with changes in fatigue, sleepiness and performance.

Results
Eighteen crew participated across 546 shifts. At the start of a shift, less prior sleep (p&lt;.01) and less time awake (p&lt;.001) were associated with greater fatigue and sleepiness. Fatigue and sleepiness were higher for shifts starting after 1500 (p&lt;.01), whereas reaction time performance was slower for shifts starting before 0800 (p&lt;.05). At the end of a shift, fatigue and sleepiness ratings were higher for longer shifts (p&lt;.001), shifts with higher workload (p&lt;.05), when crew had been awake longer (p&lt;.05), or had been on-call the night prior (p&lt;.05).

Discussion
A range of possible fatigue risks were identified. These included sleep inertia at the start of shifts, indicated by greater fatigue when time between waking and starting work was short. Being on call the night prior increased fatigue risk at the end of the next day’s shift. Through understanding where the fatigue risks are, an organization can ensure mitigations are appropriate.
O057 Sleep patterns and their associations with mental health and financial well-being in ride-hail drivers
Authors: Jaydarifard S , Smith S , Mann D , Rossa K , Shekari Soleimanloo S 
Published: December 2024

Abstract

Introduction
Driving is an activity where the need for sleep and work schedules can clash, with potentially severe consequences. Ride-hail drivers may be at particular risk, as characteristics of this form of precarious employment impact both sleep opportunity and the overall well-being of drivers. This study aimed to explore characteristic profiles of sleep in ride-hail drivers, and evaluated the relationships between these profiles and both mental health and financial well-being.

Methods
One hundred ride-hail drivers (12% female) completed an online survey assessing their perspectives on their working conditions, financial well-being (assessed by the 5-item financial well-being scale), and various aspects of their health, including sleep duration, sleep quality (assessed by the PROMIS sleep disturbance scale (SF-4a)), and mental health (two-item PROMIS Global Mental Health). Latent Profile Analyses, utilizing both sleep duration and quality, were used to categorise participants into two distinct sleep profiles, poor sleepers (36%) and good sleepers (64%). A binary logistic regression model was then employed to investigate the predictors of these sleep profiles.

Results
Poor mental health was associated with an odds ratio of 0.34 (95% CI: 0.17, 0.65) for the poor sleep profile. Lower financial well-being was associated with an odds ratio of 0.51 (95% CI: 0.27, 0.95) for the poor sleep profile.

Discussion
These results support a relationship between mental health, financial well-being, and poor sleep among ride-hail drivers. These findings may contribute to more effective policies that address both the unfavourable working conditions and sleep quality of ride-hail drivers.
O058 Sleep estimates from an under-mattress sensor can predict vigilance, working memory, and mental arithmetic performance
Authors: Manners J , Scott H , Guyett A , Stuart N , Catcheside P , Kemps E 
Published: December 2024

Abstract

Introduction
Sleep is vitally important to maintain cognitive function. Sleep trackers can reliably estimate several sleep metrics to help predict cognitive performance, but associations between sleep-tracker estimated sleep and cognitive domains are unclear. This study examined associations between sleep tracker-estimated sleep and next-day cognitive performance across several domains, including vigilant attention, working memory, and risky decision-making.

Methods
Twenty four participants (mean[SD] age=28[9] years, 12/12 male/female) attended the sleep laboratory twice for 8-day simulated shift-work experimental protocols under two lighting conditions (dim, blue-depleted vs. blue-enriched circadian-informed lighting). Following a baseline sleep, participants remained awake for 27h and transitioned to sleeping between 10:00-19:00 and undertaking cognitive tasks from 00:00-08:00 for four days. Cognitive tasks included the Digit-Symbol Substitution task (DSST), Continuous Performance task, Iowa Gambling task, Operation Span task, Psychomotor Vigilance test (PVT), and Stroop task. Sleep was assessed using an under-mattress sensor (Withings Sleep Analyzer). Mixed effects and random forest models tested associations between estimated sleep and cognitive performance.

Results
Significant associations were found between sleep metrics and PVT reaction time (R²=.13, p=.008), Operation Span arithmetic errors (R²=.15, p=.023), proportion correct on DSST and Stroop tasks, (R²=.06, p=.045; R²=.09, p=.003), and Stroop reaction time (R²=.19, p=.004). Random forest models demonstrated strong associations between cognitive performance and estimates of sleep architecture, snoring, and cardiovascular estimates.

Conclusion
Sleep trackers can help predict next-day cognitive performance, particularly in vigilance, working memory, and mental arithmetic. This may be a practical strategy to help manage sleep-related cognitive impairments and enhance worker safety in shift work conditions.
O061 Living with narcolepsy and driving in Australia: Exploring lived experience and clinician perspectives
Authors: Schokman A , Cheung J , Milton A , Naehrig D , Thornton N , Bin Y , Kairaitis K , Glozier N 
Published: December 2024

Abstract

Introduction
Narcolepsy is a rare neurological sleep disorder. International data suggests a large proportion of persons with narcolepsy experience symptoms that impact their driving (e.g. EDS, cataplexy, microsleeps, fatigue). Driving and narcolepsy has not been explored within the context of the Australian regulatory system.

Methods
24 adult persons with narcolepsy (PwN) and 12 clinicians participated in semi-structured interviews exploring the lived experience of narcolepsy in Australia. A sub-study explored responses around driving ability, regulation, and therapeutic relationship; analysed thematically by a multidisciplinary team.

Results
Preliminary results suggest PwN acknowledge the impact symptoms have on driving, including how feeling tired/fatigued led to increased risky behaviour (e.g. speeding to get home faster and avoid falling asleep at the wheel). Yet most believed narcolepsy did not affect their ability to drive or hold an unrestricted license. This dissonance appears driven by fear of loss of license, associated personal/economic hardship and fear of being vulnerable when asleep on public transport. Most PwNs were unaware of state-based regulatory requirements around diagnosis disclosure and reported their clinicians had not raised this issue. Conversely, not all clinicians appeared aware of regulations and spoke of difficulties broaching the topic, its impact on the patient-physician relationship, and limited resourcing to organise objective measures of driving ability.

Discussion
Our results suggest increased awareness for all parties is needed around the risks/implications of driving with narcolepsy and regulatory disclosure. Better-quality information, support, and regulatory guidance around fitness to drive would likely help PwN and clinicians navigate this space.
O063 Cognitive behavioural therapy for insomnia improves obstructive sleep apnoea severity, but not any of the endotype traits in those with comorbid insomnia and sleep apnoea (COMISA)
Authors: Brooker E , Landry S , Edwards B , Drummond S 
Published: December 2024

Abstract

Background
Evidence suggests cognitive behavioural therapy for insomnia (CBT-I) improves obstructive sleep apnoea (OSA) severity in those with comorbid insomnia and sleep apnoea (COMISA), though the mechanisms behind this change are unstudied. CBT-I, which promotes sleep continuity and reduces hyperarousal, may improve OSA by raising the respiratory arousal threshold, a key OSA endotype trait. We aimed to replicate prior findings on CBT-I improving OSA severity and investigate its impact on the arousal threshold.

Methods
In a single-arm trial, we recruited 20 patients (11M:9F; Mage = 53.48, SDage = 9.42 years) with comorbid insomnia and OSA defined by an apnoea hypopnea index (AHI) ≥ 10 events per hour. Overnight sleep studies were conducted before and after seven weekly sessions of CBT-I over telehealth with a psychologist to measure OSA severity and sleep architecture. The arousal threshold and other endotype traits were assessed via the ventilation flow signal from polysomnography.

Results
There was a significant 8.9 event/h reduction in the AHI following CBT-I 95%CI[3.48, 14.49], p =.003, to a moderate effect (d = 0.52). There was no change in the arousal threshold, the other endotype traits, nor was the change in arousal threshold associated with the change in the AHI (p &gt;.05).

Conclusions
In these preliminary findings, we provide further support CBT-I improves OSA severity. Despite the reduction in the AHI, there was no change in the arousal threshold. These results underscore the importance of managing insomnia in COMISA, with further research needed to elucidate why CBT-I improves OSA severity.
O064 Tirzepatide reduced sleep apnea severity in adults with obstructive sleep apnea and obesity: results from the SURMOUNT-OSA trial
Authors: Grunstein R , Malhotra A , Fietze I , Wever T , Dunn J , Chakladar S , Bunck M , Bednarik J 
Published: December 2024

Abstract

Introduction
We aimed to investigate the efficacy and safety of tirzepatide in treating moderate-to-severe obstructive sleep apnea (OSA) in adults with obesity.

Methods
SURMOUNT-OSA (NCT05412004) was a randomized, 52-week phase 3 trial comparing the efficacy and safety of tirzepatide to placebo in adults living with moderate-to-severe OSA and obesity. Under a master protocol, the trial involved Study 1, (participants who were unable or unwilling to use positive airway pressure (PAP), and Study 2, (participants who were and planned to stay on PAP therapy during the trial). 469 participants were randomised in a 1:1 ratio to receive tirzepatide maximum tolerated dose (MTD) 10 or 15 mg once weekly, or placebo.

Results
Baseline AHI (apnea-hypopnea index) and BMI were 50.1 events/h and 38.8 kg/m2. At 52 weeks, tirzepatide led to a mean AHI reduction from baseline of 27.4 (55.0%) and 30.4 (62.8%) events per hour compared to 4.8 (5.0%) and 6.0 (6.4%) events per hour for placebo in Study 1 and Study 2, respectively. Tirzepatide led to a mean weight reduction from baseline of 18.1% and 20.1%, compared to 1.3% and 2.3% for placebo, in Study 1 and Study 2, respectively. The most commonly reported adverse events in SURMOUNT-OSA studies were gastrointestinal-related and generally mild to moderate in severity in keeping with previous studies.

Discussion
Tirzepatide significantly reduced the AHI compared to placebo in adults with moderate-to-severe OSA and obesity, with and without PAP therapy, and therefore may represent a therapeutic option for this patient group.
O067 Personalisation of comfort settings on CPAP devices using machine learning
Authors: Wimms A , Emami H , Liu N , Sadr N , Pongrass S , Gupta C , McGann S , Tan Y , Sopha T , Yan Y , Nguyen C 
Published: December 2024

Abstract

Introduction
Machine learning (ML) technology provides a novel mechanism to identify patterns in large data sets, draw inferences and develop algorithms to simplify complex problems. Sleep apnea is a uniquely positioned health condition in the ML space due to the large amounts of data collected by diagnostic and CPAP devices.
We developed, validated, and tested a ML model which recommends personalised combinations of CPAP comfort settings for new users.

Methods
Data sets from 718,421 anonymous OSA patients were used to develop the ML models. Our ML method adopted the Doubly-Robust Learner to estimate the effect of comfort settings combinations on CPAP compliance. A multilayer perceptron model has been developed at each stage of the DR-learner method to provide the propensity model and the outcome models.
A clinical trial was then conducted to measure the impact of the model on patient outcomes.

Results
Development and validation of the ML models, utilising observational data, demonstrated a promising capability to enhance CPAP compliance through suggesting personalised comfort settings.
A double-blinded, RCT was conducted on 58 patients with newly diagnosed OSA. 30 days after setup, more patients in the ML model group were still using CPAP compared with the control group (96% vs 80%, p=ns).

Discussion
We developed and validated a unique machine learning algorithm aimed at providing personalised comfort CPAP settings in an area where limited guidance currently exists. This pilot study has shown that the ML model may provide benefit to new CPAP patients.
O068 Vascular and Autonomic Function in Comorbid Insomnia and Sleep Apnoea
Authors: Tong B , Stewart G , Flood J , de Chazal P , Cistulli P 
Published: December 2024

Abstract
Comorbid insomnia and sleep apnoea (COMISA) is a common sleep disorder and may be associated with increased cardiovascular risk. This study aimed to compare polysomnography-derived biomarkers of cardiovascular risk in patients with COMISA, obstructive sleep apnoea (OSA) only, insomnia only, and without OSA or insomnia.
Patients were identified from the Sydney Sleep Biobank database. Insomnia was defined as a positive test on the Insomnia Symptom Questionnaire (self-report of poor sleep and daytime impairment at least three times per week for four weeks). COMISA was defined as having insomnia and an apnoea-hypopnoea index &gt;5 events/h. Heart rate variability (HRV) during stage N2 sleep and pulse wave amplitude drop (PWAD) parameters were derived from the electrocardiograms and plethysmography signals of polysomnograms, and compared between groups.
To date 471 patients (median[IQR] age: 50[37, 62] years; 62% males) have been analysed. Forty-two percent of patients had OSA only, 22% had insomnia only, 23% percent had COMISA and 14% did not have OSA or insomnia. Patients with COMISA had lower HRV measures (SDNN, P=0.0218; Total Power, P=0.046; pNN50%, P=0.044; absolute low frequency power, LF, P=0.0034). After adjusting for age, sex and BMI, these metrics were not significant (P &gt;0.05). PWAD frequency and duration were similar between groups (P &gt;0.05).
These preliminary data indicate patients with COMISA have altered cardiovascular autonomic function specifically reduced parasympathetic modulation indicated by lower pNN50%, Total Power and LF. This finding supports previous work demonstrating elevated cardiovascular risk in patients with COMISA, although age, sex, and BMI may be potential mediators.