bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract

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&lt;0.05). PIP was also higher during spontaneous arousals than during respiratory arousals (51.3±6.1% vs. 45.8±6.7%, P&lt;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

Abstract
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

Abstract

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

Abstract

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

Abstract

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

Abstract
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&lt;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&lt;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

Abstract

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

Abstract

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

Abstract

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 &lt; 0.001) and tobacco use (p &lt; 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

Abstract

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

Abstract

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&lt;0.001) and night-time driving (tests 4-5, AUC 0.78 [95%CI 0.6-0.95, p&lt;0.001]). Post-driving VOMS assessments also predicted daytime (AUC 0.74 [95%CI 0.53-0.9, p&lt;0.001] and night-time driving (AUC 0.76 [95%CI 0.52-0.94, p&lt;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

Abstract

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&lt;0.05), and sleepiness (p&lt;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.