bluuebunny/crossref_metadata_2025 huggingface dataset:
O019 Sleep spindles are reduced in children with Down syndrome and sleep disordered breathing
Authors: Shetty M , Tan B , Davey M , Nixon G , Walter L , Horne R
Published: October 2023

Background

Children with Down syndrome (DS) are at increased risk of sleep disordered breathing (SDB), which is associated with sleep disruption affecting daytime functioning. There is growing evidence that sleep spindles may serve as a sensitive marker of sleep quality. We investigated sleep spindle activity and its relationship with daytime functioning in children with DS compared to typically developing (TD) children matched for SDB severity.

Methods

Children with DS and SDB (n=44) and TD children matched for age, sex and SDB severity underwent overnight polysomnography. Fast or Slow sleep spindles were identified manually during N2 and N3 sleep. Spindle activity was characterised as spindle number, density (number of spindles/h) and intensity (density x average duration) on central (C) and frontal (F) electrodes. Parents completed the Child Behavior Checklist (CBCL) and OSA-18 questionnaires.

Results

Spindle number, density, and intensity were lower in the children with DS compared to TD children for F Slow and F Slow&Fast spindles combined (p<0.001 for all). In children with DS, there were no correlations between the density of any spindle type and subscales of the CBCL, however, spindle number, density and intensity for C Fast and C Slow&Fast were negatively correlated with OSA-18 emotional symptoms and caregiver concerns and C Fast number, density and intensity were also negatively correlated with daytime function and total problems.

Conclusions

The reduced spindle activity in the children with DS, indicates sleep micro-architecture is disrupted and this disruption may underpin the negative effects of SDB on quality of life and behaviour.
O021 Indigenous Sleep Health Survey
Authors: Yeo S , Toson B , Jamieson L , Hedges J , Ju X , Adams R , Appleton S , Lovato N , Whetham H , Micic G , Reynolds A , Chai-Coetzer C
Published: October 2023

Background

There is increasing evidence of ongoing inequity in the provision of sleep healthcare for Indigenous Australians. This cross-sectional review aims to capture the prevalence self-reported symptoms of poor sleep and correlating factors influencing this from an Indigenous perspective.

Methods

This survey data was collected as part of the Indigenous Human Papilloma and Oropharyngeal Squamous Cell Carcinoma study with demographic data and sleep indices collected at the 24 month follow up time point. Participants were >18 years of age, identified as Aboriginal and/or Torres Strait Islanders, and were recruited from Aboriginal Community Controlled Health Organisations in South Australia from February 2018 to January 2019.

Progress to date

729 responses were collected from participants aged 18 to 79, with 227 (31.1%) males and 502 (68.9%) females . Most participants lived in rural locations (62.9% [457/727]). 21.9% (75/343) participants reported witnessed loud snoring three or more times/week, with 16.1% (55/342) reporting witnessed apnoea once or more per week. Top End Sleepiness Score of ≥8 which has been associated with moderate to severe obstructive sleep apnoea was reported in 6.6% (48) of participants. Further data analysis is underway.

Intended outcome and impact

This survey of Indigenous Australians included demographic details, OSA-50 scores, TESS scores, subjective assessment of factors determining sleep quality, as well as social determinants of sleep health. Correlating this data will provide a fuller understanding of the current self-perception of sleep and factors affecting it in this population.
O023 Quality of Life in Central Disorders of Hypersomnolence
Authors: Kinder S , Winter S , Duce B , Ellender C
Published: October 2023

Background

Whilst sleep disorders are common, with up to 5.8% of Australian adults experiencing excessive daytime somnolence due to a sleep disorder, there is a relative paucity of quality-of-life data in those with central disorders of hypersomnolence. The available evidence suggests a significant impact attributable to these disorders, though it is also noted that much of this data was obtained through patient associations as opposed to sleep medicine clinics with potentially more security of diagnosis.

Methods

A retrospective, single-centre review will be undertaken of patients seen as new cases in the sleep clinic between January 2013 and December 2022 with a diagnosis of a central disorder of hypersomnolence. Quality of life at baseline will be assessed using metrics collected as standard-of-care, including the Epworth Sleepiness Scale, Short-Form 36, FOSQ, and PSQI. Demographics, comorbidity, baseline pharmacotherapy will also be analysed.

Progress to date

Planning in conjunction with co-investigators and key stakeholders has been undertaken, and a complete protocol has been drafted and submitted for ethics committee approval. Data collection is anticipated to commence and be complete by end of July 2023.

Intended outcome and impact

It is hypothesised that baseline quality of life in these patients will be poorer than in the general population. This study will improve upon the volume and quality of existing data, and serve to assist in planning for a potential subsequent investigation into the impact of cognitive behavioural therapy for hypersomnia.
O027 Patterns of nocturnal swallow frequency and related tachycardia with sleep stages and obstructive sleep apnoea severity
Authors: Lin A , Bull C , Burke P , Lewis C , Bilston L
Published: October 2023

Background

Swallowing is a complex activity associated with cortical arousal and tachycardia in sleep(1). Obstructive sleep apnoea (OSA) has been associated with dysfunction and altered biomechanics of swallow (2-3). This study seeks to investigate patterns of swallow frequency and associated tachycardia in relation to OSA severity.

Methods

Anthropometric and polysomnographic data for 70 subjects were analysed. Swallow index (SI; swallows per hour) and average heart rate changes from 30 seconds pre- to 10 seconds post-swallow were derived from epiglottic pressure and electrocardiogram signals respectively. This study had approval from the local district ethics committee.

Progress to date

Analysis has been completed for 34 subjects (median age 47.5, range 24-64; 24 males), most with at least moderate OSA (n=20/26). Mean SI was 3.2 in subjects without OSA (n=2), 8 in mild OSA (n=4), 5.8 in moderate OSA (n=10) and 9 in severe OSA (n=10). Mean swallow-related tachycardia was 24.3bpm in subjects without OSA, compared to 14.0bpm in those with severe OSA. Mean swallow-related tachycardia increased with progressive sleep stages (14.8bpm in wakefulness; 16.8bpm Stage 1; 16.8bpm Stage 2; 19.0bpm Stage 3; 19.4bpm in REM). A negative correlation was observed between sleep SI and magnitude of associated tachycardia (Pearson correlation r=-0.387, p=0.026).

Intended outcome and impact

Our results support existing observations that swallow-associated tachycardia is reliably conserved in sleep, and suggest possible new relationships between swallow frequency and associated tachycardia with OSA severity and sleep stage. We intend with further dataset analyses to explore relationships between sleep swallow physiology and OSA pathophysiology.
O029 Clinical features and outcomes of patients referred to a Respiratory Failure service
Authors: Moore E , Howard L , Wheatley J , Falland K , Chien J , Wu P , Kairaitis K
Published: October 2023

Non-invasive ventilation (NIV) improves quality of life and mortality in patients with hypercapnic respiratory failure. We reviewed the last decade of long-term home NIV provision in a single centre via an observational retrospective study.

Data were prospectively collected in a database. Anthropometric and demographic data were expressed as mean±SD. Indications for chronic home NIV were categorised into: neuromuscular diseases (NMD) [including motor neuron disease (MND)]; obstructive sleep apnoea/obesity hypoventilation (OSA/OHS); pulmonary disease; and others. Linear regression analysis was performed for the annual incidence by indication, and multivariate Cox regression performed compares MND mortality with other causes.

541 new patients (Age 60.8 ±17.1 years; 273 Female; BMI 33.4±13.9 kg/m2 (n=380)) were commenced on NIV between 2012-2022. Patient numbers increased by 2.3 (0.4-4.1) per year (slope, (95% confidence intervals); p<0.02). Indications for treatment included: 52% NMD (29% MND); 19% OSA/OHS; 19% pulmonary disease; and 10 % other causes. Average referral age, BMI and gender composition were stable over the time period. There was an increase in patients with pulmonary disease commenced on NIV of 0.6 (0.7-3.5)% per year (p<0.008), other indications for treatment were unchanged. 31.4% patients died (16.8% MND). Multivariate Cox regression analysis showed that a diagnosis of MND was associated with an increased likelihood of death (HR 11.42, p<0.0001).

In the last decade, there’s been a gradual increase in patient numbers treated with chronic home NIV, with an increasing percentage of patients with pulmonary disease commenced on treatment. Mortality in MND patients on NIV is higher compared with other indications.
O032 It's OK to Lose your Head!
Authors: Omond S
Published: October 2023

Introduction

Sleep is something that we all do, regardless of how much or how little. But why we sleep, and how sleep evolved is still something of a mystery. This research looks at a novel attribute of flatworms – the ability to regenerate whole body structure, and how neural regeneration may impact sleep.

Methods

Using behavioural methods, I observed the behaviour of flatworms under a 12:12 LD lighting condition. Once the baseline was established, I used a small razor to cut the head off each individual. Recordings took place every two weeks, for baseline, post-decapitation, and then at full regeneration.

Results

Animals that were re-growing their brains moved a lot less than their original intact data showed, a small circadian rhythm was still present. Once the animal had regained its eyespots, and thus regenerated, this rhythm was more prominent and on its way to returning to intact levels. Animals that were re-growing their bodies also showed a persistent circadian rhythm in their activity throughout the regeneration process.

Discussion

This research is very exciting for several reasons. It shows that flatworms themselves rely on more than just their brain and eyespots to sense the light and environment around them. It also suggests that circadian rhythms are deeply engrained and that behaviours that arise from this, such as locomotion can still be influenced even without the presence of a brain – the neurons in the ventral nerve cords, and other body systems may be equally as important.
O037 Diagnostic Accuracy of OSA Screening Tools for Acute Coronary Syndrome
Authors: Tong B , Dissanayake H , Patel S , Skilton M , McClintock S , Sutherland K , Ucak S , Yee B , Sarkissian N , Cistulli P
Published: October 2023

Obstructive sleep apnoea(OSA) is associated with cardiovascular diseases including acute coronary syndrome(ACS). Current estimates suggest some 70% of patients with ACS have OSA. OSA in this population remains under-recognised. This high prevalence calls for effective OSA screening tools for this high-risk population. We aimed to assess the diagnostic accuracy of the Epworth Sleepiness Scale (ESS), Berlin and STOP-BANG questionnaire in screening for OSA in patients with ACS.

70 patients with ACS (age IQR: 58[52,63] years, BMI: 27[24,30]kg/m2) were recruited from the cardiology department following an admission for ACS. Patients were administered with the ESS, Berlin and STOP-BANG questionnaires within 6 months of ACS admission. A level 2 polysomnogram was conducted to confirm the presence and severity of OSA (AHI≥5). The diagnostic accuracy of ESS>10, Berlin questionnaire (high-risk category), STOP-BANG score ≥3 (intermediate-high risk) and STOP-BANG score ≥5 (high-risk) was compared to a level 2 polysomnogram for different OSA severity.

OSA (AHI≥5 events/h) was diagnosed in 94% of patients with ACS. 67% of patients had moderate-severe OSA (AHI≥15 events/h). ESS, Berlin and STOP-BANG questionnaires have poor diagnostic accuracy across all severity of OSA (ESS>10, AUC:0.60 (95%CI: 0.42-0.79); Berlin, high risk, AUC:0.54 (95%CI: 0.39-0.68); STOP-BANG ≥3, AUC:0.69 (95%CI: 0.56-0.82); STOP-BANG ≥5, AUC: 0.66 (95%CI: 0.53-0.79)).

This study confirms a very high prevalence of OSA in patients with ACS. The Berlin and STOP-BANG questionnaires alone are inadequate to identify OSA in this high-risk cohort. Simplified objective measures to screen for OSA may be better suited for this patient population.
O042 Healthy lifestyle is Associated with Reduced Cardiovascular Disease, Depression and Mortality in People at Elevated risk of Sleep Apnea
Authors: Melaku Y , Appleton S , Reynolds A , Milne R , Lynch B , Eckert D , Adams R
Published: October 2023

Background

We evaluated 1) the independent and combined influence of obstructive sleep apnea (OSA) risk and a healthy lifestyle on typical OSA outcomes [excessive daytime sleepiness (EDS), depression, cardiovascular disease (CVD), and stroke]; and 2) the impact of a healthy lifestyle on survival in individuals presenting a heightened risk of OSA.

Method

We utilized data from 13,694 adults (median age 46 years; 50% men) for both cross-sectional and longitudinal analyses (15 years). A healthy lifestyle score ranging from 0 (most unhealthy) to 5 (most healthy) was computed based on diet, alcohol consumption, physical activity levels, smoking habits, and body mass index.

Results

A dose-response relationship was found between OSA risk and all examined chronic conditions and EDS (p for trend < 0.001). A healthy lifestyle was found to be inversely related to all chronic conditions (p for trend < 0.001), except EDS (p for trend = 0.379). A higher healthy lifestyle score correlated with lower odds of depression and CVD. An inverse relationship was found between healthy lifestyle score and depression (P for trend < 0.001), CVD (P for trend = 0.003), and stroke (P for trend = 0.025) in those with high OSA risk. An inverse relationship was observed between a healthy lifestyle and all-cause mortality in general, and in the moderate/high and high OSA risk groups (p for trend < 0.001).

Discussion

This study highlights the role of a healthy lifestyle in reducing chronic conditions and in enhancing survival rates in individuals with a heightened risk of OSA.
O057 The Impact of Surgical Weight Loss on the Physiological Endotypes causing Obstructive Sleep Apnea
Authors: Beatty C , Wong A , Landry S , Thomson L , Collet J , Joosten S , Playfair J , Brown W , Kee K , Naughton M , Sutherland K , Cistulli P , Patel S , Hamilton G , Edwards B
Published: October 2023

Background

Weight loss improves upper airway collapsibility in people with obstructive sleep apnoea (OSA). However, it’s unclear how weight loss affects the other endotypes responsible for OSA (loop gain, arousal threshold and muscle compensation). We investigated the effect surgical weight loss has on the OSA endotypes and whether the baseline endotypes predict response to surgery.

Methods

Endotypes were measured using non-invasive methods in 43 OSA patients who had a clinical polysomnogram before and after (~6-18 months) receiving weight loss surgery. Linear regression was used to assess whether the baseline endotypes predicted improvement in OSA severity defined by the apnoea-hypopnoea index (AHI).

Results

Weight loss surgery was associated with significant improvements in AHI (43.4[28.6-64.8]events/hr vs. 16.9[11.6-33.3]events/hr, p<0.001), body mass index (42.1 ±5.5kg/m2 vs. 32.8 ±4.5kg/m2, p<0.001), upper airway collapsibility (73.8[65.2-78.5]%eupnea vs. 77.1[71.7-81.3]%eupnea, p=0.034) and loop gain (0.62[0.53-0.71] vs. 0.54[0.44-0.72], p=0.012). Weight loss surgery was also associated with a reduced arousal threshold (144.5[130.1-160.5] vs.136.9[121.9-156.4], p=0.007). A greater reduction in OSA severity was associated with greater improvements in upper airway collapsibility (p=0.001, r2 =0.23) and reductions in the arousal threshold (p<0.001, r2=0.27). Poor upper airway collapsibility at baseline was weakly predictive of a greater improvement in OSA severity (p=0.018, r2 =0.13). No other endotype was predictive of OSA improvement.

Discussion

Weight loss surgery is associated with improvements in weight, OSA severity, upper airway collapsibility and loop gain. There was a paradoxical worsening of arousal threshold. Furthermore, weight loss surgery may be particularly effective in improving OSA in those with poor upper airway collapsibility.
O065 Autonomic Dysregulation During Sleep in Parkinsonian Spectrum Disorders
Authors: Levendowski D , Cho Y , Walsh C , Tsuang D , Lee-Iannotti J , Berka C , Mazieka G , Boeve B , Neylan T , St. Louis E
Published: October 2023

Introduction

Symptoms associated with autonomic nervous system dysfunction are common to patients with neurodegenerative disorders (NDD) resulting from the accumulation of α-synuclein in the neurons and glial cells. In this study we investigate whether a novel biomarker, the autonomic activation index, can discriminate these potentially affected NDD groups.

Methods

After ethics review and with informed consent, patients with Lewy body disease (DLB/PDD: n=20%), Alzheimer’s disease dementia (AD: n=27), Parkinson disease (PD: n=14), mild cognitive impairment (MCI: n=37), isolated REM sleep behavior disorder (iRBD: n=15) and a control group (CG: n=58) were studied with the Sleep Profiler. AAI was based on a 6 BPM increase in pulse rate compared to the previous/subsequent 10th second. Between-group comparisons were assessed with Mann-Whitney U and Chi-square tests.

Results

The AAI values for the DLB/PDD patients were decreased compared to the AD, MCI (both p<0.03), and CG (p<0.0005), while the PD was less than AD and MCI (both < 0.05) and CG (p<0.002). The proportions of cases with abnormal AAI values (<10 events/h) was greatest in DLB/PDD patients, and greater than in ADem (p<0.02), MCI (p<0.02) and CG (p<0.0001), while AAI in PD and iRBD was greater than in CG (p<0.007 and 0.05 respectively).

Conclusions

These findings suggest that the AAI can be used to objectively confirm subjective complaints of autonomic dysfunction symptoms in patients with synucleinopathies. Longitudinal studies are needed determine factors that influence changes in the AAI.
O075 Improving Sleep Health in Paramedics through an App-based Intervention: A Randomised Waitlist Control Trial
Authors: Shriane A , Vincent G , Ferguson S , Rebar A , Kolbe-Alexander T , Rigney G
Published: October 2023

Introduction

Paramedics engaging in shiftwork arrangements face unique challenges that impact their sleep health, potentially compromising performance and wellbeing. This study investigated whether tailored sleep health advice delivered through the Sleepfit mobile application improved sleep health in paramedics.

Methods

We conducted a two-group randomised waitlist-controlled trial. Fifty-eight paramedics were randomised to the intervention group (n = 29) or the waitlist group (n = 29). Intervention group participants trialled Sleepfit for 14 days, during which waitlist control participants continued as usual, before being provided with Sleepfit for 14 days. During the 14-day intervention period, Sleepfit provided tailored sleep health education for shift workers, relaxation exercises, and a sleep diary to track sleep quantity and quality. Measures of sleep health (e.g., ISI, FSS, ESS, SHI) were completed at baseline, 14 days following, and 3-month follow-up. Multiple linear regression models were conducted to test the impact of the intervention on sleep health outcomes.

Results

Participants reported an average two-point reduction in both ISI (p = 0.01) and SHI (p = 0.01) scores, as well as a significant improvement in sleep satisfaction (p = 0.01) at post-intervention measurement. All other measures remained unchanged. This may be due to limited intervention impact, insufficient participant numbers, a short intervention period, or a ceiling effect.

Conclusion

This study provides preliminary evidence supporting the use of Sleepfit as an intervention in improving measures of sleep health in some shiftworkers. Further investigations, including objective assessments of sleep, are needed to validate these self-report measures in larger cohorts of shiftworkers.
O079 Investigating Hypersomnolence Disorders in South Australia: A Retrospective Audit of Multiple Sleep Latency tests
Authors: O'Reilly M , Mukherjee S , Chai Coetzer C , Mercer J , Ullah S , Naik G , Catcheside P , Walker A
Published: October 2023

Introduction

This study aims to evaluate the characteristics of patients with Narcolepsy Type 1 (NT1), Narcolepsy Type 2 (NT2), and Idiopathic Hypersomnolence (IH) along with diagnostic outcomes in patients referred for a multiple sleep latency test (MSLT) at an Australian hospital.

Methods

A retrospective audit was performed of all patients who completed an MSLT between January 2018 to January 2023.

Results

431 participants (62.4% female; mean±SD age 40.2±16.4 years; BMI 28.6±7.4 kg/m²) who completed MSLTs were included. 95 participants (22%) had a positive MSLT of ≤ 8 minutes, of which 87% (n=83) had a prior night total sleep time on polysomnography of > 6 hours. Gender, age, and BMI did not vary significantly between participants with a mean sleep latency (MSL) ≤ 8 versus >8 minutes (p=0.9, p>0.9, p=0.1 0, respectively). Participants with an MSL ≤ 8 minutes had higher Epworth Sleepiness Scale scores 14.6 ± 5.1 vs 12.5 ± 5.0 (p < 0.001), with more sleep onset REM periods (SOMREPs) 0.82 ± 1.35 vs 0.14 ± 0.49 compared to those with MSL >8 minutes. Further data collection is in progress, but to date, diagnoses were available for 34 participants with MSL ≤ 8 minutes (6 NT1, 8 NT2, 8 IH, 12 Other [i.e., shiftwork disorder, sleep restriction, medication-induced]).

Discussion

This study seeks to estimate diagnostic frequency and characteristics of patients presenting for evaluation of hypersomnolence. The prevalence of MSL < 8 minutes (22.0%) is consistent with prior studies1,2. Analysis of diagnostic outcomes is pending further data collection in progress.
O080 The Associations Between Sleep Environment Factors and Sleep Health in Individuals Living with Neurological Conditions
Authors: Cruickshank T , Turner M , Laws M , Beranek P , Griffiths M
Published: October 2023

Introduction

Accumulating evidence indicates that sleep health is worse in individuals living with a neurological condition and may hasten neurodegeneration. The extent to which the sleeping environment, particularly air temperature and light, influence sleep health has not been investigated in individuals living with a neurological condition. This research aimed to explore, for the first time, associations between air temperature and light in the sleeping environment and sleep health in individuals living with a neurological condition.

Methods

The sleep health, including the domains of sleep quality, duration, and disorders, of 46 individuals with a neurological condition was measured using the Sleep Health Index. Air temperature and light data were captured across seven days using a light/temperature data logger positioned next to the participant's bed. Data recorded during the participants' sleeping periods (determined using a sleep diary) were analysed. Linear regression models were used to assess the associations between air temperature and light and sleep health (including domains).

Results

This study showed that for every additional minute of low (10 to 50 lux) light exposure during sleep periods, sleep quality decreased by 9%.

Discussion

Our findings suggest that low light exposure during sleep periods may be detrimental to the sleep quality of individuals with neurological conditions.
O001 Remote Monitoring Paediatric Non-invasive Ventilation Adherence: Utilising Airview to Support Paediatric Patients and Clinicians
Authors: Angliss M , Leclerc M , Hartnett C
Published: October 2023

Aim

To determine if starting a remote non-invasive ventilation service improves adherence and process efficiency.

Method

Three time points were considered for comparison of the service for patients on NIV initiation:- pre-covid-19 (N-9,2019), during covid-19 (N=9,2021) and post-Airview implementation (N=7,2023). A comparison of the time from NIV initiation to first download, download adherence, percentage of patients from rural/remote areas, number and type of download. Anova test was used for statistical significance.

Results

Pre and post covid had longer time to download with mean 53 (std 49) and 63 days (std 51), respectively, compared to Airview downloads 21.5 days (std 8), though not significant. 44% of the pre-covid group had mean adherence >= 6hours by first download, 12.5% in covid group and 50% in Airview group. The percentage of the group in rural/remote were 40% (pre-covid), 55.5% (covid) and 50% (Airview). None of the pre-covid or Airview group sent data by post, only 55% of the covid group. For non-adherent patients within the first three months of use, the Airview group had median 2.5 downloads post first download, with the other groups only achieving median of one.

Discussion

The covid group of patients had the lowest adherence, possibly due to telehealth and lack of download data as the mean time to download was the longest. Implementing a remote NIV download service with Airview showed significant improvements in availability of adherence data earlier and identify patients with low adherence. Supporting patients with low adherence remains a priority for patients and clinicians.
P008 Pilot and Feasibility of Bright Light Therapy in Improving Sleep and Quality of Life in Children with Acute Lymphoblastic Leukaemia
Authors: Wijayaratne P , Williams K , Walter L , Horne R , Nixon G
Published: October 2023

Introduction

Bright light therapy (BLT) improves sleep and quality of life (QOL) in adults with cancer and adolescents with mood disorders. Children with acute lymphoblastic leukaemia (ALL) are vulnerable to poor sleep, related to their new cancer diagnosis and impaired sleep-wake cycles from dexamethasone treatment. To date no studies have investigated the feasibility and utility of BLT to improve sleep, daytime functioning and QOL in this population.

Methods

The intervention group (N=7) underwent BLT for 30 minutes each morning during dexamethasone treatment. Actigraphy and psychometric questionnaires measured at baseline, at the end of dexamethasone treatment and at six months post treatment, in addition to actigraphy following three dexamethasone treatments, were compared between the intervention and non-intervention groups (N=5). Feasibility measures included study acceptance, retention and limited efficacy testing.

Results

The Moods and Feelings questionnaire and both the child and parent reported PedsQL Multidimensional Fatigue Scale had the lowest completion rates both at the end of treatment or at follow up for BLT (57-67%) and in the non-intervention group (50-60%). Negligible differences were observed in sleep outcomes during dexamethasone treatment between the two groups. The largest effect sizes of BLT were seen for total sleep time, sleep efficiency and wake after sleep onset at the end of dexamethasone treatment and at follow up.

Discussion

This study demonstrates limited preliminary feasibility of BLT in children with ALL during dexamethasone treatment. A successful future trial should consider modifications to the data collection periods and the type of questionnaires.
P011 How Sex and Age moderate the effect of Sleep Loss on Pain Perception: A Systematic Review and Meta-analysis
Authors: Rouhi S , Topcu J , Egorova-Brumley N , Jordan A
Published: October 2023

Females tend to exhibit increased sensitivity to pain and are more susceptible to developing chronic pain conditions. Sleep disturbances are comorbid with chronic pain and exacerbate pain symptoms. Sleep disturbances have been found to affect pain perception distinctly, but whether these effects are consistent in men and women is unclear. This systematic review investigated how sex and age moderate the sleep-pain interaction under various forms of sleep disturbances. We searched EBSCO, MEDLINE, Psych INFO, Science Direct, and Web of Science from January 2001 to November 2022. A total of 38 studies with 978 participants were included in the review. The meta-regression was conducted based on the predicted value of effect size and its estimated standard error at a significance level of 0.05. The results showed that sex moderated the effect of sleep disturbance on pain facilitation (SMD=.13; 95%CI:.004 to .022; p=.009) and pain inhibition (SMD=.033; 95%CI:.011 to .054; p=.005). Females exhibited increased pain facilitation and decreased pain inhibition, whereas males showed the opposite direction of effect. Further, age moderated the effects of total sleep deprivation (SMD=-.194; 95%CI -.328 to -.060; p=.008) on pain sensitivity and fragmented sleep (SMD=-.110; 95%CI: -.148 to -.072; p<.001) on pain threshold. Although the moderating effects of sex and age on the sleep-pain interaction were relatively small, these findings highlight the importance of considering these factors in future sleep-pain studies.
P012 Head Position During Sleep: Potential Implications for Patients with Neurodegenerative Disorders
Authors: Levendowski D , Walsh C , Neylan T , Lee-Iannotti J , Tsuang D , Berka C , Mazeika G , Boeve B , St. Louis E
Published: October 2023

Introduction

In 2015, Lee et al. observed sleeping position influenced the efficiency of glymphatic clearance in rats. In 2018, Levendowski et al. reported supine sleep was independently associated with neurodegenerative disorders (NDD)(odds ratio=3.7). This update further evaluates the comparative frequency of the supine sleep position across a spectrum of cognitive impairment, including patients diagnosed with a Parkinsonian spectrum disorder (PSD), Alzheimer’s disease dementia (AD) and mild cognitive impairment (MCI), compared with a control group (CG) of patients without a known cognitive disorder.

Methods

After ethics review and with informed consent, a control group (CG: n=170), PSD (n=36), AD (n=29) and MCI group (n=41) were studied in-home with the Sleep Profiler; 89% across two-nights. Between-group comparisons were assessed with Mann-Whitney U and Chi-square tests.

Results

The hours of supine sleep were greater in PSD=3.0 + 1.9, AD=3.2 + 2.0 and MCI=3.0 + 2.0 vs. CG=1.9 + 1.8 (all p<0.002). The proportion of patients with >2 hours of supine sleep were PSD=69%, AD=69% and MCI=59% vs. CG=39%, with odds ratios of PSD=3.6, AD=3.5 and MCI=2.2 (all p<0.001).

Conclusions

Here we provide further evidence for a relatively strong association between supine sleep and neurodegenerative disease including PSD, AD and MCI cohorts. The nature of this association remains unclear from cross sectional study designs. Future prospective studies should test if there is a causal link between supine sleep and subsequent development of neurodegeneration.
P013 The Effect of Noise Exposure during Sleep on the Cortisol Awakening Response
Authors: Nagarajan P , Nguyen D , Dunbar C , Lechat B , Liebich T , Zajamsek B , Hansen K , Vakulin A , Lack L , Lovato N , Scott H , Decup F , Catcheside P , Micic G
Published: October 2023

Introduction

Environmental noise could negatively impact the sleep and well-being of nearby residents. This study tested for overnight noise exposure effects on the cortisol awakening response (CAR), a potential marker of noise-related stress responses, and for differences in CAR and hair cortisol between different prior noise exposure groups.

Methods

A randomised controlled laboratory trial was conducted in 68 individuals from four groups; including WFN-exposed residents n=14 with and n=18 without WFN-related complaints, n=18 quiet rural control and n=18 urban traffic-noise exposed residents. Across six nights, after an initial adaptation night, participants were exposed in random order to different noise conditions, which included intermittent WFN and road traffic noise (RTN), WFN at average exposure levels throughout wake, sleep or both and a quiet control night. Salivary CAR responses were evaluated from 5 serial saliva samples collected following awakening. Hair cortisol levels were also collected. Mixed effects models were used to examine group and night effects on CAR and group effects on hair cortisol.

Results

There was a significant main effect of condition on CAR (p=0.038), but no significant pairwise differences between the control night and noise exposure nights, and no further differences between nights or groups on CAR or hair cortisol concentrations.

Conclusions

Acute in-laboratory noise-related sleep disturbance at the levels used in this study do not appear to alter acute cortisol awakening responses. A better understanding of chronic noise exposure effects and stress responses is important to help clarify and mitigate potential environmental noise exposure effects on nearby residents.
P018 The Relationships Between Multidimensional Sleep Health and Work Productivity in Individuals with Neurological Conditions
Authors: Turner M , Laws M , Griffiths M , Turner K , Dempsey L , Laws S , Cruickshank T
Published: October 2023

Numerous studies have reported the negative impacts of poor sleep on work productivity in the general population. However, despite the known sleep issues individuals living with neurological conditions experience, no study has explored its impact on their work productivity. Sleep health is a concept that includes multiple domains of sleep, measured with a combination of objective and subjective measures. Therefore, this study aimed to ascertain the associations between sleep health and its domains and work productivity in individuals with neurological conditions. Sleep health domains were determined through actigraphy data collected over one week and sleep questionnaires. Work productivity was assessed via the Work Productivity and Activity Impairment Questionnaire. A comparison of sleep health scores between demographic variables was performed using Mann-Whitney U and Kruskal Wallis Tests. Associations between the sleep health domains and work productivity were performed using linear regression models. There were no significant differences in sleep health scores between sex, smoking status, education level, employment status or any work productivity domain. Individuals with extreme sleep timing had greater absenteeism (22.99%) than the non-extreme group. Individuals with extreme sleep quality had an increase in presenteeism (30.85%), work productivity loss (26.44%) and activity impairment (25.81%) compared to those in the non-extreme group. The findings from this study highlight that self-reported sleep quality has the largest impact on work productivity. Improving individuals' sleep quality through triage for potential sleep disorders or improving their sleep hygiene (sleep behaviour and environment) may positively impact work productivity.
P019 Sleep and Circadian Interventions for Mental Health and Mood in Athletes
Authors: Walsh E , Facer-Childs E , Drummond S , Liddle S
Published: October 2023

Introduction

There are only a small number of evidence-based interventions that address sleep and circadian rhythms in athletes despite it being well-recognized that sleep has a bidirectional relationship with mental health conditions, wellbeing, mood disorders and may be protective against concussions and injury risk. Athletes, both during and after their career, face unique stressors that, if not well managed and mitigated, could become a source of mental health issues. The aim of this review was to discuss the current evidence on sleep and circadian interventions to improve mental health and mood in athletes.

Methods

The following databases—PubMed, Scopus, EMBASE, SPORTDiscus, and Google Scholar—were searched for initial studies of interest from inception to July 2023.

Results

Very few sleep and circadian strategies have been implemented in sporting environments to improve the mental health and mood of athletes. The interventions that have been investigated are constrained by limited sample sizes, lack of female representation, low quality study design and inconsistent measurement of mental health and mood, making it difficult to draw definitive conclusions of the efficacy of these strategies. Overall, the evidence base for the effectiveness of the interventions was limited.

Discussion

There remains a need for larger, adequately powered interventions that are individually tailored, with considerations for the specific challenges of athletes at different levels of professionalism, season time and in particular sporting contexts.
P024 The Obstructive Sleep Apnoea Endotypes are Similar in Elderly Veterans with and without PTSD.
Authors: Brooker E , Landry S , Prguda E , McLeay S , Drummond S , Edwards B
Published: October 2023

Background

Approximately 60% of veterans living with post-traumatic stress disorder (PTSD) experience obstructive sleep apnoea (OSA). Why OSA is so prevalent in individuals with PTSD remains unknown, though the presence of PTSD may influence the underlying endotypes known to cause OSA. We examined whether upper airway collapsibility, muscle compensation, loop gain, and the arousal threshold differ in trauma exposed elderly male veterans with OSA with and without comorbid PTSD.

Methods

Using the ventilatory flow pattern from diagnostic polysomnography, the four OSA endotypes were measured in a retrospective cohort of 21 OSA patients with PTSD and 27 OSA-only patients. All participants are male Vietnam War veterans with mild-to-severe OSA (AHI M=26.8, SD=18.6; range: 6.0-105.9 events/h). Age (M=71.3, SD=3.5) and BMI (M=27.4, SD=3.4 kg/m²) were similar between groups.

Results

There were no statistically significant differences (p-values>0.3) in the OSA endotype traits between OSA-only and OSA+PTSD patients for upper airway collapsibility (78.35 [72.81-83.82] vs. 76.68 [71.53-83.56]%eupnea), muscle compensation (5.41 [1.83-7.21] vs. 4.27 [0.34-9.18]%eupnea), arousal threshold (146.95 [128.64-151.28] vs. 135.76 [126.59-147.54]%eupnea), and loop gain (M=0.60, SD=0.14 vs. M=0.56, SD=0.17).

Conclusion

The endotypes underlying OSA in elderly male veterans with PTSD were similar to their trauma exposed OSA-only counterparts. PTSD may exert little influence on the OSA endotypes in elderly samples beyond the effect that age and trauma exposure may have in OSA patients. What underlies the increased prevalence of OSA in PTSD remains unclear and further work examining these endotypes using larger and more diverse samples is needed before robust conclusions can be made.
P039 Genioglossus motor control during mandibular advancement.
Authors: Dawson A , Avraam J , Thornton T , Nicholas C , Jordan A
Published: October 2023

Introduction

High genioglossus muscle activity is thought to prevent/resolve upper airway collapse. Overall genioglossal activity results from the simultaneous firing of many motor units (MUs) which typically have one of 5 firing patterns: active only (IP) or at higher frequency (IT) during inspiration; active only (EP) or at higher frequency during expiration (ET); and constantly active without respiratory modulation (TT). To date, most experimental manipulations tested (e.g. hypoxia, hypercapnia, resistive loading) have influenced IP and IT MUs, with minimal changes in ET, EP and TT MUs. We hypothesized that IT/IP MUs respond to respiratory drive, whereas TT/EP/ET MUs will change in response to airway anatomical manipulations.

Methods

The number and firing frequencies of genioglossal MUs were assessed with intramuscular electrodes in healthy individuals during wakefulness, before and during mandibular advancement (MAD) to 80% of maximum with an myTAP device, to change airway anatomy but minimally alter respiratory drive.

Results

201 MUs were identified from 55 trials in 14 participants. Ventilation did not differ between baseline and MAD. At baseline, 175 MUs were active: EP=0.6%, ET=12.6%, IP=14.9%, IT=48%, TT=24%. During MAD, 35 MUs ceased firing, but an additional 26 MUs began firing, with the resulting MUs proportions not differing from baseline: EP=0%, ET=10.2%, IP=21.1%, IT=36.7%, TT=31.9%, χ2(9)=12.0, p=.213. The mean firing frequency of MUs did not change during MAD (baseline=20.9±4.7Hz, MAD=21.9±5.4Hz).

Discussion

Contrary to the hypothesis, the firing patterns of genioglossal MUs did not differ from baseline during mandibular advancement. What controls the non-respiratory/expiratory MUs of the genioglossus remains unclear.
P045 Noxturnal cRIP: A Comparative Analysis of Sensors for the Identification of Respiratory Events in Polysomnography
Authors: Eriksson N , Carballo A , Roberts C
Published: October 2023

Introduction

AASM recommends the use of nasal pressure (NP), oronasal thermal flow (TF), and respiratory inductance plethysmography (RIP) for detecting and characterising respiratory events in polysomnography. The use of both NP and TF sensors is reported to be more accurate in respiratory event identification than either alone. However, these sensors can be unreliable if dislodged and cause discomfort. Noxturnal calibrated RIP flow (cRIPflow), derived from RIP, may provide a non-invasive alternative method for flow measurement in identification of respiratory events.

Method

Respiratory scoring was performed manually by a single experienced scorer on 10 diagnostic sleep studies under AASM standards. Scoring was repeated using three different measurements for each study: cRIPflow only, Thermistor (Th) only and both Th+NP (AASM recommendation). Apnoea hypopnoea index (AHI), central apnoea index (CAI), obstructive apnoea index (OAI), mixed apnoea index (MAI) and hypopnoea index (HI) were calculated and paired t-test analysis utilised for comparison between measurements.

Results

No statistical differences were identified in comparison of cRIPflow with Th or Th+NP in respiratory event identification: CAI (cRIPflow 3.2/hr±7.1, Th 3.9/hr±8.9, Th+NP 3.1/hr±7.5), OAI (cRIPflow 6.1/hr±6.8, Th 5.3/hr±8.2, Th+NP 6.7/hr±8.9), MAI (cRIPflow 5.2/hr±9.7, Th 4.3/hr±8.7, Th+NP 4.7/hr±9.2), or HI (cRIPflow 12.5/hr±13.9, Th 11.1/hr±10.5, Th+NP 10.4/hr±10.7). There was a statistical difference for AHI (cRIPflow 26.9/hr±26.6, Th 24.5/hr±26.4, Th+NP 25.0/hr±26.5).

Discussion

This study suggests cRIPflow may provide an alternative measurement in the detection and characterisation of respiratory events, however further analysis with larger sample size would provide more insight into sensitivity and specificity of this method.
P049 Actigraphic rest-activity rhythms in older adults ‘at risk’ for dementia: associations with reduced cortical thickness in frontal, temporal and occipital cortices
Authors: Mckinnon A , Espinosa N , Palmer J , Hoyos C , Hickie I , Pye J , Duffy S , Grunstein R , Naismith S
Published: October 2023

Background

Rest-activity rhythm disturbance is common in older adults ‘at risk’ for dementia. This may be an early marker of underlying disease pathology and risk of future decline. However, our understanding of how rest-activity rhythm relates to brain integrity remains unclear.

Methods

This study used vertex-wise analyses to examine the association between nonparametric actigraphy measures and cortical thickness in older adults ‘at risk’ for dementia. Primary measures of interest were intra-daily variability (IV), relative amplitude (RA), inter-daily stability (IS), and average activity during the least active 5-hour period (L5).

Results

143 older adults ‘at risk’ for cognitive decline were included (mean age=67.41, SD=7.96). Higher IV was associated with lower cortical thickness in the right cuneus (CWP< 0.001), left middle frontal gyrus (CWP< 0.001) and lateral orbital frontal cortex (CWP=0.004). Higher L5 was linked with cortical thinning in the left superior temporal sulcus (CWP=0.004), superior middle temporal cortex (CWP=0.010) and middle temporal gyrus (CWP=0.013), as well as right inferior parietal lobe (CWP< 0.001). Lower IS was associated with cortical thinning in the left (CWP=0.002) and right (CWP< 0.001) superior frontal gyri, left superior temporal gyrus (CWP=0.043) and left post-central gyrus (CWP=0.033).

Conclusions

Markers of circadian rhythmicity are associated with reduced cortical thickness in frontal, temporal and occipital cortices in older adults ‘at risk’ for dementia. Future work is still required to delineate whether brain degeneration leads to altered daily rhythms and/or if circadian misalignment contributes to cognitive decline longitudinally.
P051 Associations between Chronotype and Symptoms of Depression in Patients attending an Outpatient Sleep Clinic
Authors: Mendes J , Ng Y , Lu S , Saunders W , Cahill F , Oh S , Wasgewatta S , Rajaratnam S , Hamilton G , Mansfield D , Bei B
Published: October 2023

Introduction

Chronotype (or morningness-eveningness), individuals’ time-of-the-day preference for activity, has been associated with depressive symptoms. This cross-sectional study examined the association between chronotype and symptoms of depression in outpatients attending a sleep disorders clinic.

Method

The sample included individuals attending an outpatient sleep disorders clinic and provided opt-out consent for their data to be used for research purposes. Individuals included in the analyses provided demographic data, their typical weekly total sleep time (TST), and complete responses prior to treatment on the reduced Morningness-Eveningness Questionnaire (rMEQ; for chronotype), and the PROMIS depression scale.

Results

A total of 1641 (44.5% female, Mage = 45.20 years, SDage = 16.06 years) participants were included. On average, the sample scored intermediate chronotype (M = 14.73, SD = 4.35) and higher depressive symptom scores that were half a standard deviation higher compared to community norms (M = 55.80, SD = 10.01). Multiple linear regression controlling for age, sex, and TST showed that greater eveningness preferences predicted higher symptoms of depression, p<0.01, explaining 2.76% additional variance in depression scores above that of the covariates.

Discussion

Overall, sleep clinic outpatients had an intermediate chronotype and above average depressive symptoms. The findings are consistent with existing literature in other populations indicating that eveningness may be a risk factor for greater symptoms of depression. Future studies need to explore whether interventions to alter chronotype may benefit symptoms of depression in individuals with sleep complaints.