bluuebunny/crossref_metadata_2025_split huggingface dataset:
O070 Objective impact of daylight-savings time shifts on sleep: a global-scale study
Authors: Pinilla L , Nguyen P , Lechat B , Scott H , Manners J , Sansom K , Dunbar C , Fitton J , Vakulin A , Catcheside P , Eckert D 
Published: December 2024

Abstract

Introduction
The twice-yearly transitions between standard time and daylight-savings time (DST) introduce mild circadian misalignments, which are associated with disrupted sleep, and increased risks for adverse public health and safety consequences. Previous evidence is based on self-reported data, limited geographical locations, and relatively small sample sizes. Here, we quantify the acute impact of seasonal clock time changes on objective measures of sleep in a large global sample.

Methods
Data were collected from users of a validated under-the-mattress sleep sensor between March 2018 and September 2023, located across 27 countries covering 36 different clock-timed regions (&gt;500 users/region) where DST changes occur. Total sleep time and sleep offset timing on the dates of clock adjustment were compared to the Sunday immediately preceding each time shift, using linear mixed models with a random intercept for time zone.

Results
Data from &gt;60,000 individuals were analysed (82% males, age 49±13 years). Setting the clock forward was associated with a reduction in sleep duration of 13.7 minutes (95%CI 9.1 to 16.1), and a sleep offset timing delay of 33.1 minutes (28.9 to 37.4). The end of DST (clock backwards) was related to longer sleep durations, increasing by 9.84 minutes (6.9 to 12.78), and earlier sleep offset times by 33.6 minutes (29.1 to 38.1).

Conclusions
This large-scale global study shows that clock time adjustments derived from daylight saving regulations have immediate repercussions on objective sleep duration and timing. These findings may help inform the ongoing policy debate of the impact of DST on sleep and associated consequences.
O071 Chronic non-cancer pain in patients attending a diagnostic sleep study
Authors: Jarvie L , O’Driscoll D , Young A , Obadara O , Ogeil R 
Published: December 2024

Abstract

Introduction
Chronic non-cancer pain (CNCP) is the leading cause of disability globally affecting 20% of adults in Australia. It is associated with poor sleep and increased substance use including prescription medications. This study aimed to determine its prevalence in patients attending a tertiary referral sleep laboratory and assess impact on sleep and the nature of substance use.

Methods
Participants (n=245, 112 females, 50.0 ± 15.3 years) completed in-lab overnight diagnostic polysomnography and validated pain and sleep questionnaires (including Brief Pain Inventory [BPI]). Pain questionnaires (BPI [Yes/No] and Pain Sleep Questionnaire [75+]) were used to indicate probable CNCP. Fifteen participants with CNCP completed an interview exploring pain and sleep.

Results
59.6% indicated CNCP. Those with CNCP were more likely to be older (CNCP 51.6, Controls 47.6, p&lt;0.05), female (p&lt;0.001), had higher BMI (p=0.008) and to rate sleep as fairly or very bad (p&lt;0.05).
Participants with BPI interference 5+ (clinically significant) had a higher AHI (p=.028), increased REM latency (p&lt;0.001) and %REM sleep (p&lt;.001).
Interviewees indicated poor sleep to be a consequence of pain. Nine described misusing medication including taking more than prescribed (2), medication prescribed to someone else (5), pain medication for sleep (3), and six misusing alcohol (6).

Discussion
CNCP prevalence in patients attending for a diagnostic sleep study is triple that of the general population.
There is concern regarding misuse of prescription medication and alcohol in people with sleep disturbance and CNCP. Consideration should be given to an interdisciplinary approach to pain and sleep management.
O072 Sex-based differences in pain perception with short sleep: an experimental study in healthy individuals
Authors: Rouhi S , Brumley N , Jordan A 
Published: December 2024

Abstract

Introduction
Experimental sleep deprivation has been shown to induce pain hypersensitivity, with more pronounced impacts on females than males. However, whether the effect of chronic short sleep on pain perception differs between sexes is unclear. This study investigated the effects of chronic self-reported short sleep (&lt;6 hrs) on pain perception in males and females.

Methods
Objective sleep data were collected using a Somfit device. Quantitative sensory testing, including heat, cold, and pressure pain thresholds, temporal summation and conditioned pain modulation of pain, was conducted in the morning following sleep monitoring to measure pain perception.

Results
The study included 25 healthy participants (15 females) with an average age of 23.16±4.8. Both sexes exhibited similar (short) total sleep times (TST: Males: 232.4 ± 14.9 minutes vs. Females: 244.7 ± 11.7 minutes; p = 0.52). However, females experienced significantly longer REM latency, as compared to males (Males: 62.5 ± 14 minutes vs. Females: 101.1 ± 11.5 minutes; p=.04). All other sleep stages were comparable between sexes (p &gt; 0.05). A General Linear Model revealed significant sex-based differences in pain perception between males and females (F = 5.1; B = 0.66; power = 0.97; p = 0.002), primarily driven by conditioned pain modulation (mean difference = 98.77 ± 33.9; 95% CI: 28.6 to 168.89; p = 0.008).

Discussion
These preliminary results suggest that short sleeping females have a dysfunctional pain suppressive response, while sleep-deprived males exhibited stronger pain inhibitory response, despite similar (low) sleep amounts.
O073 The effect of blue-enriched light in older adults with sleep disturbance on sleep and daytime performance: A randomised, placebo-controlled crossover trial
Authors: Pun T , Phillips C , Marshall N , Rahimi M , Wassing R , Comas M , D’Rozario A , Hoyos C , Bartlett D , Hu W , Naismith S , Cain S , Postnova S , Grunstein R , Gordon C 
Published: December 2024

Abstract

Introduction
Light therapy is a non-pharmacological intervention for circadian and sleep disorders. However, there is limited evidence about the effect on electroencephalographic (EEG) sleep in older individuals with sleep disturbance.

Methods
Twelve participants (8 female; mean ± SD age, 65.6 ± 8.7 years) with self-reported poor sleep completed two randomly allocated 72-hour in-laboratory visits separated by 2 weeks. The intervention light condition consisted of blue-enriched light (melanopic EDI=843.6 lux) during the day and blue-depleted light (melanopic EDI=49.5 lux) 3-hours before lights out. The control light condition consisted of polychromatic light (melanopic EDI=215.8 lux) during the day and reduced light (melanopic EDI=60.8 lux) 3-hours before lights out. The primary outcome was wake after sleep onset (WASO), with secondary outcomes of sleep micro-architecture parameters (256-channel high-density EEG) and neurobehavioural performance.

Results
The intervention light did not improve WASO compared to the control (p=0.338) but there was a significant increase in N1 sleep (p=0.046). The only neurobehavioural difference was in Stroop text accuracy (2.2%, p=0.028). High-density EEG analysis showed the intervention light significantly increased sigma activity (12–16 Hz) in the frontal and parietal cortex during N2 sleep relative to control light (p=0.017).

Conclusions
Overall, blue-enriched light over three days did not improve EEG sleep (WASO) or neurobehavioural performances except for accuracy (Stroop) in older adults with sleep disturbance. Further research is required to determine the ideal intensity, spectral composition, duration and timing of blue-enriched lighting on objective sleep outcomes in individuals with poor sleep quality.
O074 “We just have to be there; we just have to listen”: Experiences of staff supporting older adults with sleep disturbances in aged residential care
Authors: Gibson R , Dustin J , Koreshi S , Webster L 
Published: December 2024

Abstract

Introduction
Deterioration of sleep is acknowledged as a key factor associated with older adults, particularly those with dementia, (transitioning into formal care. However, further research is required concerning sleep status within such facilities.

Methods
Semi-structured interviews were conducted with 11 Care Partners from two New Zealand care homes. Interviews covered types of sleep disturbances encountered; the impact of sleep disturbances for residents, co-residents, staff and wider networks; and strategies for supporting sleep. Recordings were transcribed, coded, and analysed thematically.

Results
Many sleep ‘disturbances’ were not considered abnormal in the context of aged care. These included confusion between night and day, fatigue associated with illness, continence needs, and/or confusions or hallucinations at night. Sleeplessness was largely discussed in relation to residents feeling lonely, confused, or depressed as well as fears around falling asleep. The challenge of moving into a new living and sleeping environment was also raised as key, along with the ‘domino affect’ that sleep disturbances can have for other residents. Strategies to support sleep (and wakefulness) were presented in relation to key frameworks around person-centred care. This included acknowledging residents’ sleep and routine preferences whilst balancing opportunities for social connection, maintaining regular fluid and nutritional needs, and reducing the risk of falls. Overarching was the sense of being patient and present for the residents ‘around the clock’.

Discussion
Findings provide psychosocial insights into the nature of sleep in the context of aged care. Highlighting staff’s beliefs and attitudes around problematic sleep, current strategies, and future needs.
O076 The use of home humidified high-flow nasal cannula therapy for children with sleep-disordered breathing
Authors: Krishnananthan T , Saddi V , Teng A 
Published: December 2024

Abstract

Background
Humidified High-flow nasal cannula (HHFNC) therapy is a method of respiratory support that facilitates delivery of humidified heated air or oxygen at a high flow rate. The physiological benefits of HHFNC include generation of a low level of positive airway pressure leading to alveolar recruitment and an increase in functional residual capacity; improvement in oxygenation, decrease in nasal resistance and washout of nasopharyngeal dead space. Whilst HHFNC is now used widely for children hospitalised with acute indications including bronchiolitis, there is a paucity of data on HHFNC in the home setting.

Methods
Single centre retrospective study of children treated with home HHFNC. Data include demographic parameters, clinical indication, previous CPAP/BPAP use, age at initiation and flow rate, polysomnography results and adverse events.

Progress
A literature review about the use of HHFNC in the home setting has been undertaken. Median (Interquartile range [IQR]) age of initiating home HFNC in 11 children was 60 (12.5, 138) months. Indications were obstructive sleep apnoea (3; 27%), neuromuscular disease (4; 36%), hypoventilation (2; 18%), chronic lung disease (1; 9%) and central sleep apnoea (1; 9%). HHFNC was instituted as palliative management for five patients. Ten (91%) patients failed CPAP/BPAP. No serious adverse effects were observed. Issues with HHFNC included increased secretions (1, 9%), increased moisture (1, 9%) and higher flow rate (2; 18%).

Intended outcome and impact
The study aims to describe the safety and tolerability of HHFNC in the home setting and add to the literature on its use across different clinical settings.
O077 Nocturia as a Marker for Cardiovascular Risk in Obstructive Sleep Apnoea
Authors: Graffen S , Bin Y , Kairaitis K , Wheatley J , Yee B , Piper A , Cistulli P 
Published: December 2024

Abstract

Background
Obstructive Sleep Apnoea (OSA) is highly prevalent and is associated with cardiovascular (CV) risk. Factors beyond AHI alone appear to influence this risk. Clinical biomarkers of cardiovascular risk in OSA are needed to assist clinicians in making treatment decisions. Nocturia is a commonly reported symptom in OSA. This study aims to assess the association between nocturia and cardiovascular risk.

Methods
Patients with OSA (AHI&gt;5/h) were selected from the Sydney Sleep Biobank. Patients aged 30-74yrs who had adequate data to calculate an office-based Framingham Risk Score (FRS) and who had answered the relevant question relating to nocturia in Pittsburgh Sleep Quality Index. The sample was divided into groups based on FRS or pre-existing cardiovascular disease. We then compared the frequency of significant nocturia, defined as ≥3 times per week disrupting sleep.

Progress to Date
605 patients (69% male, mean [±sd] age 52.9 ± 13.6 years, body mass index (32.8 ± 8.6) were included. 55% reported significant nocturia. FRS was low in 16.9%, moderate in 36.4% and high in 35.0% and pre-existing cardiovascular disease was reported in 11.7% and nocturia was reported by 56%, 71%, 81%, and 83% of those groups respectively. Nocturia was associated with increased cardiovascular risk (χ² = 21.1, df 2 with p&lt;0.001).

Intended Outcome and Impact
Patient reported nocturia was associated with increased CVD risk. This exploratory study is limited by a lack of detailed reporting on nocturia, but suggests clinical utility of nocturia for assessment of CVD risk. Further analysis is planned regarding confounding factors.
O081 Neural aperiodic activity as a novel objective measure of wakefulness in patients undergoing a maintenance of wakefulness test
Authors: Seow K , Chatburn A , Bay M , Kang T , Johnston S , Yeo A , Lushington K 
Published: December 2024

Abstract

Background
The maintenance of wakefulness test (MWT) measures the ability of an individual to stay awake and is used to assess treatment response for conditions of hypersomnolence. The MWT is a laborious test with a strict and standardised protocol. The interpretation of a MWT and what is deemed ‘normal’ is also fraught with debate.
Wake and sleep states are characterised by oscillatory activity on EEG namely delta, theta, alpha, beta and gamma. There is also a less utilised non-oscillatory component of background neural activity (aperiodic activity) which can be calculated from the EEG. There is emerging evidence that shows clinical associations of aperiodic activity with cognition, visuomotor learning, schizophrenia and anaesthesia.
We aim to determine if there is a relationship between EEG aperiodic activity and the ability of an individual to maintain wakefulness.

Methods
All patients who underwent a MWT from 2010 to 2023 will be included. Clinical data including demographics, comorbidities and mean sleep latency will be extracted from the sleep study database of the Royal Adelaide Hospital. Raw EEG data will be obtained from the ProFusion Study Manager software. Statistical analysis (linear mixed models) will be performed to determine if there is a correlation between the aperiodic exponent and the mean sleep latency.

Progress
Awaiting ethics committee approval

Intended outcome
To demonstrate that a longer mean sleep latency in the MWT will be associated with a higher aperiodic exponent which could lead to further research into the utility of aperiodic activity as a novel measure of wakefulness.
P001 Sleep disturbance in patients with long-term neurological sequelae of COVID-19
Authors: Lung K , Brown E , Bilston L , Juge L , Cysique L 
Published: December 2024

Abstract

Introduction
Post COVID-19 neurological sequelae (popularly termed “Long COVID”), which include chronic sleep disruption and “brain fog” are widespread; however, studies have not yet comprehensively evaluated the concurrent effects of these disruptions of neurocognitive function and their relationship to sleep disturbance.

Methods
Participants aged between 40-65, with no more than 2 cardiovascular risk factors were stratified into three groups of ten: Group 1 (pre-pandemic datasets), Group 2 (individuals recovered from COVID-19), and Group 3 (individuals diagnosed with Long COVID under the WHO criteria). Polysomnography (PSG), Multiple Sleep Latency Test (MSLT), participant surveys and neurocognitive testing, among other data, were collected.

Results
Control group 1 included more participants (70%) with obstructive sleep apnoea (OSA) compared to the Long COVID group, resulting in a markedly greater arousal index (ANOVA p=0.03), but no significant differences in percentage of Slow Wave Sleep (SWS) and Rapid Eye Movement (REM) sleep were observed between all three groups (ANOVA p=0.29). The Long COVID group displayed heightened daytime sleepiness, based on MSLT, Epworth Sleepiness Scores, and fatigue severity scores (Group 2: 28±10 vs Group 3:44±11, unpaired t-test p=0.01).

Discussion
Initial observations suggest sleep architecture (proportion of SWS and REM sleep) in Long COVID does not differ from controls, however the reduced sleep latency and elevated subjective fatigue suggest dysfunction of sleep in Long COVID which needs to be further explored.
P003 Effect of ethnicity on positive airway pressure acceptance for obstructive sleep apnoea
Authors: Cheng T , Young A , Tolson J , O’Driscoll D 
Published: December 2024

Abstract

Introduction
Despite having a similar prevalence, OSA in patients of Chinese descent is driven more by anatomical factors compared to Caucasians. However, there is a dearth of evidence investigating the effect of ethnicity on acceptance and usage of positive airway pressure (PAP). This study investigated the PAP acceptance rate and predictors in an ethnically diverse population referred for PAP acclimatisation in a tertiary referral hospital.

Methods
A retrospective analysis of consecutive PAP acclimatisation trials between 2014-2020 was performed. Patient demographics, polysomnographic variables, and PAP trial variables were compared between groups. Multivariate stepwise logistic regression analyses were performed to identify predictors of PAP acceptance in each group.

Results
543 PAP acclimatisation trials were included (10.7% Chinese patients). There were no differences in age, gender or AHI between groups, however the Chinese group had a lower BMI (p&lt;0.001), and higher ESS (p&lt;0.05). There was no difference between groups for average PAP use, residual AHI or PAP acceptance rate (86% vs 92%). Logistic regression analysis revealed that PSG AHI, residual AHI and average PAP usage were predictors of PAP acceptance in Caucasians (adjusted ORs 1.03, 0.90 and 1.01 respectively), but only residual AHI and PAP usage were predictors in Chinese patients (adjusted ORs 0.86, 1.01).

Conclusion
PAP acceptance was similar in Chinese and Caucasian patients, however severity of disease did not predict acceptance in Chinese patients. Future research should focus on determining if Chinese versus Caucasian ethnicity is an important contributing factor to clinical outcomes and therapeutic responses in OSA.
P005 Sex differences in the association between sleep and depressive symptoms in an outpatient sleep disorders clinic
Authors: Zhong Y , Saunders W , Yap R , Ng Y , Lu S , Cahill F , Oh S , Chen A , Thornton T , Stout J , Rajaratnam S , Hamilton G , Mansfield D , Bei B 
Published: December 2024

Abstract

Introduction
Inadequate sleep duration and quality increases the risk and severity of depressive symptoms. Sex differences may influence these associations, but research findings are inconsistent and largely based on healthy populations. This study examined sex differences in the association between sleep and depressive symptoms in people seeking treatment primarily for sleep disorders at an outpatient clinic.

Methods
1806 participants were recruited from an outpatient multidisciplinary sleep clinic (48% female; Mean-age = 43.93±16.00 years). Participants self-reported sleep duration, sleep quality (rated 1-4, higher scores represent better sleep quality), and depressive symptoms (PROMIS Short Form v1.0 - Depression 8a) prior to receiving treatment.

Results
Participants self-reported sleeping 6.49±1.73 hours and depressive symptoms were above population mean (55.95±10.09). Males reported more depressive symptoms than females (p &lt;.001), however there were no significant sex differences in the association between sleep variables and depressive symptoms. Overall, lower sleep quality was associated with greater depressive symptoms (p &lt;.001); and there was a U-shape relationship between sleep duration and depressive symptoms (p =.003), in which both shorter and longer sleep are associated with greater depressive symptoms.

Conclusion
This study revealed that depressive symptoms were elevated in an outpatient sleep clinic sample compared to population norm, underscoring the importance of recognising and addressing mental health symptoms that coexist with sleep problems. Associations between sleep and depressive symptoms were similar between males and females, but males reported significantly higher depressive symptoms than females. Future studies should explore biopsychosocial factors that may contribute to sex differences in depressive symptoms.
P006 Effect of CPAP on Heart Rate and Heart Rate Variability in Patients with Obstructive Sleep Apnoea
Authors: Suryo A , McDermott E , Cuesta R , Spiteri M , Nguy R , Davies S , Kaur-Bains S , Slater B , VanBraak E , Beranek R , Roebuck T , Naughton M , Dal Corso S 
Published: December 2024

Abstract

Introduction
Heart Rate (HR) and Heart Rate Variability (HRV) are both indicators of the autonomic nervous system. Both low HR and high HRV indicate greater vagal/sympathetic ratio consistent with better sleep quality. However, high HRV may also reflect untreated OSA due to the large negative intra-thoracic pressure swings. Thus, effects of CPAP treatment of OSA on HR and HRV are poorly described.

Aim
To assess HRV and HR in patients with OSA before and after CPAP controlled for sleep stage (SS) and body position.

Methods
15 Patients (age 33-75, (8M/7F), average BMI 33.7kg/m2) with a confirmed diagnosis of sleep-disordered breathing, mean AHI of 42.9 (range: 23.8-118.0), underwent a diagnostic and CPAP in-laboratory polysomnography. HR and HRV were measured using 5-10min blocks in each SS (wake, N2, N3, REM) in lateral, prone and supine positions using ProfusionTM PSG4 (Compumedics, Abbotsford). LabChart® (ADInstruments, Dunedin) was used for HRV analysis. HRV was measured using the non-linear metrics of SD1 and SD2, derived from Poincaré plots. HRV and HR were then compared off and on CPAP.

Results
Preliminary results in 5 patients (age 33-72, 4M/1F, average BMI 30.5kg/m2) show HR decreased 9.6±2.4% and R-R interval increased 12.2±2.3% with CPAP. Preliminary analysis does not show that HRV decreased with CPAP (Diagnostic vs CPAP, SD1: 33.3 + 10.5ms vs 34.5 + 12.9ms and SD2: 76.3 + 18.6ms vs 73.6 + 22.1ms, respectively).

Conclusion
CPAP treatment of OSA is associated with a fall in HR representing a rise in vagal/sympathetic ratio. Further analysis may be needed to determine whether there is a rise in HRV.