The interrelationships between sleep regularity, obstructive sleep apnea, and hypertension in a middle-aged community population

STUDY OBJECTIVES

Little is known about the interrelationships between sleep regularity, obstructive sleep apnea (OSA) and important health markers. This study examined whether irregular sleep is associated with OSA and hypertension, and if this modifies the known association between OSA and hypertension.

METHODS

Six hundred and two adults (age mean(SD) = 56.96(5.51) years, female = 60%) from the Raine Study who were not evening or night shift workers were assessed for OSA (in-laboratory polysomnography; apnea-hypopnea index ≥ 15 events/hour), hypertension (doctor diagnosed, or systolic blood pressure ≥140 mmHg and/or diastolic ≥90 mmHg) and sleep (wrist actigraphy for ≥5 days). A sleep regularity index (SRI) was determined from actigraphy. Participants were categorized by tertiles as severely irregular, mildly irregular, or regular sleepers. Logistic regression models examined the interrelationships between SRI, OSA and hypertension. Covariates included age, sex, body mass index, actigraphy sleep duration, insomnia, depression, activity, alcohol, smoking, and antihypertensive medication.

RESULTS

Compared to regular sleepers, participants with mildly irregular (OR 1.97, 95% confidence intervals [CI] 1.20 to 3.27) and severely irregular (OR 2.06, 95% CI: 1.25 to 3.42) sleep had greater odds of OSA. Compared to those with no OSA and regular sleep, OSA and severely irregular sleep combined had the highest odds of hypertension (OR 2.34 95% CI: 1.07 to 5.12; p for interaction = 0.02) while those with OSA and regular/mildly irregular sleep were not at increased risk (p for interaction = 0.20).

CONCLUSIONS

Sleep irregularity may be an important modifiable target for hypertension among those with OSA.

Prevalence of excessive daytime sleepiness and its association with daily life factors in Japanese first-year university students

As lifestyles have shifted to favor nighttime activities, daytime sleepiness and sleep-related problems have become increasingly common in Japan. Excessive daytime sleepiness (EDS) is an adverse consequence of sleep loss and an important public health concern. EDS may cause academic difficulties, behavioral abnormalities, and psychological dysfunction; therefore, it is a particularly important issue among university students. We conducted a cross-sectional study to investigate the prevalence of EDS and its associated lifestyle factors among Japanese university students. A questionnaire was completed by 1470 first-year university students, aged 19.0 (± 1.0) years. Using the questionnaire, we collected information on (1) demographic variables, (2) lifestyle variables, and (3) sleep habits and daytime sleepiness. Daytime sleepiness was measured using the Japanese version of the Epworth Sleepiness Scale, a frequently used subjective scale for assessing sleepiness. The overall prevalence of EDS was 57% (53% in men and 61% in women). Multivariate logistic regression analysis revealed that the following factors were associated with EDS: female sex, exercise habits, long commuting times, later wake-up times, and shorter sleep duration. Given that more than 50% of first-year university students reported having EDS, interventions should be considered to decrease its risk, including educational programs that provide strategies to extend sleep duration and delay wake-up time. Such strategies may also be valuable for students with other potential risk factors, such as exercise habits or long commute times, that are associated with EDS.

Insomnia and workplace productivity loss among young working adults: a prospective observational study of clinical sleep disorders in a community cohort

OBJECTIVE

To examine associations between three clinically significant sleep disorders (chronic insomnia, obstructive sleep apnoea, restless legs syndrome) and workplace productivity losses among young Australian adults.

DESIGN, SETTING

Prospective, observational study; 22-year follow-up of participants in the longitudinal birth cohort Raine Study (Perth, Western Australia).

PARTICIPANTS

Currently employed 22-year-old Raine Study participants who underwent in-laboratory sleep disorder screening for moderate to severe obstructive sleep apnoea (apnoea-hypopnea index of more than fifteen events/hour or obstructive sleep apnoea syndrome) and were assessed for insomnia and restless legs syndrome using validated measures.

MAIN OUTCOME MEASURES

Total workplace productivity loss over twelve months, assessed with the World Health Organization Health and Work Performance Questionnaire.

RESULTS

Of 1235 contactable 22-year-old Raine Study cohort members, 554 people (44.9%; 294 women [53%]) underwent overnight polysomnography, completed the baseline sleep questionnaire, and completed at least three quarterly workplace productivity assessments. One or more clinically significant sleep disorders were identified in 120 participants (21.7%); 90 participants had insomnia (17%), thirty clinically significant obstructive sleep apnoea (5.4%), and two restless legs syndrome (0.4%). Seventeen people (14% of those with sleep disorders) had previously been diagnosed with a sleep disturbance by a health professional, including fourteen with insomnia. Median total workplace productivity loss was greater for participants with sleep disorders (164 hours/year; interquartile range [IQR], 0-411 hours/year) than for those without sleep disorders (30 hours/year; IQR, 0-202 hours/year); total workplace productivity loss was 40% greater for participants with sleep disorders (adjusted incidence rate ratio, 1.40; bias-corrected and accelerated 95% confidence interval, 1.10-1.76). The estimated population total productivity loss (weighted for disorder prevalence) was 28 644 hours per 1000 young workers per year, primarily attributable to insomnia (28 730 hours/1000 workers/year).

CONCLUSION

Insomnia is a risk factor for workplace productivity loss in young workers. Tailored interventions are needed to identify and manage sleep disorders, particularly as most of the sleep disorders detected in the Raine Study had not previously been diagnosed.

Sleep health of young adults in Western Australia and associations with physical and mental health: A population-level cross-sectional study

OBJECTIVES

This article aims to report on the sleep health characteristics of a population-level sample of young Australian adults and examine associations with measures of physical and mental health.

METHODS

A cross-sectional study using data from the Raine Study. Data from participants (n = 1234) born into the study (Generation 2) at the 22-year follow-up were used, including data from a self-report questionnaire and polysomnography.

RESULTS

The highest prevalence of suboptimal sleep health was seen on measures of sleep duration (30%), onset latency (18%), satisfaction (25%) and regularity (60%). Dissatisfaction with sleep (physical health: β =0.08; mental health: β =0.34) and impaired daytime alertness (physical health: β =0.09; mental health: β =0.08) were significantly associated with poorer physical and mental health and inadequate polysomnography-measured sleep duration was associated poorer mental health (β =0.07) (all ps<0.05).

CONCLUSIONS

Satisfaction with sleep and daytime alertness, both of which are assessed via self-report, are essential aspects of sleep health for young adults.

IMPLICATIONS FOR PUBLIC HEALTH

Findings could inform public health interventions, including screening guidelines, to improve the sleep health and, in turn, the physical and mental health of young adults in Australia.

Estimating sleep duration: performance of open-source processing of actigraphy compared to in-laboratory polysomnography in the community

Comparisons of actigraphy findings between studies are challenging given differences between brand-specific algorithms. This issue may be minimized by using open-source algorithms. However, the accuracy of actigraphy-derived sleep parameters processed in open-source software needs to be assessed against polysomnography (PSG). Middle-aged adults from the Raine Study (n = 835; F 58%; Age 56.7 ± 5.6 years) completed one night of in-laboratory PSG and concurrent actigraphy (GT3X+ ActiGraph). Actigraphic measures of total sleep time (TST) were analyzed and processed using the open-source R-package GENEActiv and GENEA data in R (GGIR) with and without a sleep diary and additionally processed using proprietary software, ActiLife, for comparison. Bias and agreement (intraclass correlation coefficient) between actigraphy and PSG were examined. Common PSG and sleep health variables associated with the discrepancy between actigraphy, and PSG TST were examined using linear regression. Actigraphy, assessed in GGIR, with and without a sleep diary overestimated PSG TST by (mean ± SD) 31.0 ± 50.0 and 26.4 ± 69.0 minutes, respectively. This overestimation was greater (46.8 ± 50.4 minutes) when actigraphy was analyzed in ActiLife. Agreement between actigraphy and PSG TST was poor (ICC = 0.27-0.44) across all three methods of actigraphy analysis. Longer sleep onset latency and longer wakefulness after sleep onset were associated with overestimation of PSG TST. Open-source processing of actigraphy in a middle-aged community population, agreed poorly with PSG and, on average, overestimated TST. TST overestimation increased with increasing wakefulness overnight. Processing of actigraphy without a diary in GGIR was comparable to when a sleep diary was used and comparable to actigraphy processed with proprietary algorithms in ActiLife.

Self-supervised learning of accelerometer data provides new insights for sleep and its association with mortality

Background

Sleep is essential to life. Accurate measurement and classification of sleep/wake and sleep stages is important in clinical studies for sleep disorder diagnoses and in the interpretation of data from consumer devices for monitoring physical and mental well-being. Existing non-polysomnography sleep classification techniques mainly rely on heuristic methods developed in relatively small cohorts. Thus, we aimed to establish the accuracy of wrist-worn accelerometers for sleep stage classification and subsequently describe the association between sleep duration and efficiency (proportion of total time asleep when in bed) with mortality outcomes.

Methods

We developed and validated a self-supervised deep neural network for sleep stage classification using concurrent laboratory-based polysomnography and accelerometry data from three countries (Australia, the UK, and the USA). The model was validated within-cohort using subject-wise five-fold cross-validation for sleep-wake classification and in a three-class setting for sleep stage classification wake, rapid-eye-movement sleep (REM), non-rapid-eye-movement sleep (NREM) and by external validation. We assessed the face validity of our model for population inference by applying the model to the UK Biobank with 100,000 participants, each of whom wore a wristband for up to seven days. The derived sleep parameters were used in a Cox regression model to study the association of sleep duration and sleep efficiency with all-cause mortality.

Findings

After exclusion, 1,448 participant nights of data were used to train the sleep classifier. The difference between polysomnography and the model classifications on the external validation was 34.7 minutes (95% limits of agreement (LoA): -37.8 to 107.2 minutes) for total sleep duration, 2.6 minutes for REM duration (95% LoA: -68.4 to 73.4 minutes) and 32.1 minutes (95% LoA: -54.4 to 118.5 minutes) for NREM duration. The derived sleep architecture estimate in the UK Biobank sample showed good face validity. Among 66,214 UK Biobank participants, 1,642 mortality events were observed. Short sleepers (<6 hours) had a higher risk of mortality compared to participants with normal sleep duration (6 to 7.9 hours), regardless of whether they had low sleep efficiency (Hazard ratios (HRs): 1.69; 95% confidence intervals (CIs): 1.28 to 2.24 ) or high sleep efficiency (HRs: 1.42; 95% CIs: 1.14 to 1.77).

Interpretation

Deep-learning-based sleep classification using accelerometers has a fair to moderate agreement with polysomnography. Our findings suggest that having short overnight sleep confers mortality risk irrespective of sleep continuity.

Cross-sectional interrelationships between chronotype, obstructive sleep apnea and blood pressure in a middle-aged community cohort

Chronotype is linked to adverse health measures and may have important associations with obstructive sleep apnea and blood pressure, but data are limited. This study aimed to determine the separate and combined associations of chronotype with obstructive sleep apnea and blood pressure in a middle-aged community population. Adults (n = 811) from the Raine Study (female = 59.2%; age mean [range] = 56.6 [42.1-76.6] years) were assessed for chronotype (Morningness-Eveningness Questionnaire), blood pressure and hypertension (doctor diagnosed or systolic blood pressure ≥ 140 mmHg and/or diastolic ≥ 90 mmHg), and obstructive sleep apnea at different in-laboratory apnea-hypopnea index thresholds (5, 10, 15 events per hr). Linear and logistic regression models examined relationships between chronotype and the presence and severity of obstructive sleep apnea, blood pressure, hypertension, and blood pressure stratified by obstructive sleep apnea severity at above-mentioned apnea-hypopnea index thresholds. Covariates included age, sex, body mass index, alcohol consumption, smoking, physical activity, sleep duration, anti-hypertensive medication, insomnia, and depressive symptoms. Most participants were categorised as morning (40%) or intermediate (43%), with 17% meeting criteria for evening chronotypes. Participants with apnea-hypopnea index ≥ 15 events per hr and morning chronotype had higher systolic (9.9 mmHg, p < 0.001) and a trend for higher diastolic blood pressure (3.4 mmHg, p = 0.07) compared with those with an evening chronotype, and higher systolic blood pressure compared with those with an intermediate chronotype (4.8 mmHg, p = 0.03). Across chronotype categories, no differences in systolic or diastolic blood pressure or odds of hypertension were found at apnea-hypopnea index thresholds of ≥ 5 or ≥ 10 events per hr. Among participants with apnea-hypopnea index ≥ 15 events per hr, systolic blood pressure is higher in those with a morning chronotype than evening and intermediate chronotypes. Assessment for morning chronotype may improve risk stratification for hypertension in patients with obstructive sleep apnea.

Telemedicine compared to standard face-to-face care for CPAP treatment: real-world Australian experience

STUDY OBJECTIVES

We tested a telemedicine model of care to initiate continuous positive airway pressure (CPAP) for patients with obstructive sleep apnea (OSA) living in remote Western Australia.

METHODS

A prospective study comparing telemedicine for CPAP initiation in a remote population versus standard face-to-face CPAP initiation in a metropolitan population. The primary outcome was average nightly CPAP use in the final week of a CPAP trial.

RESULTS

A total of 186 participants were allocated to either telemedicine (n=56) or standard care (n=130). The average distance from the study centre for the telemedicine group was 979 km (±792km) compared to 19km (±14km) for the standard care group. The CPAP trial duration in the standard care group was less than the telemedicine group (37.6 vs 69.9 days, p<0.001). CPAP adherence in the telemedicine group was not inferior to standard care (Standard 4.7±0.2 hours, Telemedicine 4.7±0.3 hours, p=0.86). No differences were found between groups in residual apnea-hypopnea index, symptom response, sleep specific quality of life at the end of the trial and continued CPAP use (3 to 6 months). Participant satisfaction was high in both groups. Total health care costs of the telemedicine model were less than the standard model of care. An estimated A$4,538 per participant in travel costs was saved within the telemedicine group by reducing the need to travel to the sleep center for in-person management.

CONCLUSIONS

In remote dwelling adults starting CPAP for the treatment of OSA, outcomes using telemedicine were comparable to in-person management in a metropolitan setting.

Novel avenues to approach non-CPAP therapy and implement comprehensive OSA care

Recent advances in obstructive sleep apnoea (OSA) pathophysiology and translational research have opened new lines of investigation for OSA treatment and management. Key goals of such investigations are to provide efficacious, alternative treatment and management pathways that are better tailored to individual risk profiles to move beyond the traditional, continuous positive airway pressure (CPAP)-focused, "one size fits all", trial and error approach which is too frequently inadequate for many patients. Identification of different clinical manifestations of OSA (clinical phenotypes) and underlying pathophysiological phenotypes (endotypes), that contribute to OSA have provided novel insights into underlying mechanisms and have underpinned these efforts. Indeed, this new knowledge has provided the framework for precision medicine for OSA to improve treatment success rates with existing non-CPAP therapies such as mandibular advancement devices and upper airway surgery, and newly developed therapies such as hypoglossal nerve stimulation and emerging therapies such as pharmacotherapies and combination therapy. These concepts have also provided insight into potential physiological barriers to CPAP adherence for certain patients. This review summarises the recent advances in OSA pathogenesis, non-CPAP treatment, clinical management approaches and highlights knowledge gaps for future research. OSA endotyping and clinical phenotyping, risk stratification and personalised treatment allocation approaches are rapidly evolving and will further benefit from the support of recent advances in e-health and artificial intelligence.

Developmental trajectories of sleep during childhood and adolescence are related to health in young adulthood

AIM

Sleep behaviour is correlated and causally related to physical and mental health. Limited longitudinal data exist on the associations of poor sleep behaviour in childhood and adolescence with adult health. Parent-reported sleep behaviours from 1993 participants of the Raine Study (at ages 5, 8, 10, 14, 17) were used to determine sleep trajectories (using latent class growth analysis).

METHODS

Measures of physical and mental health were compared between sleep trajectories using generalised linear models (at age 20).

RESULTS

Three sleep trajectories were identified as follows: 43% of participants belonged to a trajectory with 'consistently minimal' sleep problems, 49% showed some 'declining' in reporting of sleep problems incidence and 8% had 'persistent' sleep problems. Participants in the 'consistently minimal' trajectory had better physical and mental health outcomes at age 20 compared to those in the 'declining' and 'persistent' trajectories. For example, 'consistently minimal' participants had significantly lower body fat percentage (mean difference: -3.89% (95% CI: -7.41 to -0.38)) and a higher (better) SF-12 mental component score (mean difference: 4.78 (95% CI: 2.35-7.21)) compared to participants in the 'persistent' trajectory.

CONCLUSION

Poor sleep behaviour across childhood and adolescent years is related to poorer physical and mental health in young adulthood.

Predicting sleep apnea from three-dimensional face photography

STUDY OBJECTIVES

Craniofacial anatomy is recognized as an important predisposing factor in the pathogenesis of obstructive sleep apnea (OSA). This study used three-dimensional (3D) facial surface analysis of linear and geodesic (shortest line between points over a curved surface) distances to determine the combination of measurements that best predicts presence and severity of OSA.

METHODS

3D face photographs were obtained in 100 adults without OSA (apnea-hypopnea index [AHI] < 5 events/h), 100 with mild OSA (AHI 5 to < 15 events/h), 100 with moderate OSA (AHI 15 to < 30 events/h), and 100 with severe OSA (AHI ≥ 30 events/h). Measurements of linear distances and angles, and geodesic distances were obtained between 24 anatomical landmarks from the 3D photographs. The accuracy with which different combinations of measurements could classify an individual as having OSA or not was assessed using linear discriminant analyses and receiver operating characteristic analyses. These analyses were repeated using different AHI thresholds to define presence of OSA.

RESULTS

Relative to linear measurements, geodesic measurements of craniofacial anatomy improved the ability to identify individuals with and without OSA (classification accuracy 86% and 89% respectively, P < .01). A maximum classification accuracy of 91% was achieved when linear and geodesic measurements were combined into a single predictive algorithm. Accuracy decreased when using AHI thresholds ≥ 10 events/h and ≥ 15 events/h to define OSA although greatest accuracy was always achieved using a combination of linear and geodesic distances.

CONCLUSIONS

This study suggests that 3D photographs of the face have predictive value for OSA and that geodesic measurements enhance this capacity.

Determinants of sleep problems in children with intellectual disability

Children with intellectual disabilities are more likely to experience sleep disorders of insomnia, excessive daytime sleepiness and sleep breathing disorders than typically developing children. The present study examined risk factors for these sleep disorders in 447 children (aged 5-18 years), diagnosed with an intellectual disability and comorbid autism spectrum disorder, cerebral palsy, Down syndrome or Rett syndrome. Primary caregivers reported on their child's sleep using the Sleep Disturbance Scale for Children (SDSC), as well as medical comorbidities and functional abilities. Multivariate linear and logistic regressions were used to examine the effects of these factors on SDSC t scores and a binary indicator, respectively for the relevant subscales. Receiving operating characteristic curves were generated for each logistic regression model to determine their ability to discriminate between poor and good sleep. Comorbidities rather than functional abilities were associated with poorer sleep. In particular, recurrent pain, frequent seizures, frequent coughing, constipation and prescription of sleep medications were associated with abnormal sleep across the entire sample, but predictors differed between diagnostic groups. The present study suggests that comorbidities are more strongly associated with quality of sleep than functional impairments. The present study provides new information on potential associations between frequent coughing, prescription sleep medications and sleep quality that should be further investigated.

Obstructive sleep apnea is associated with depressive symptoms in pregnancy

STUDY OBJECTIVES

In pregnancy, the prevalence of both obstructive sleep apnea (OSA) and depression increases. Research reveals an association in the general population with up to 45% of patients diagnosed with OSA having depressive symptoms. Therefore, this study aimed to investigate the relationship between OSA and depression in pregnant women.

METHODS

One hundred and eighty-nine women ≥26 weeks pregnant were recruited from a tertiary perinatal hospital. This cross-sectional study measured OSA (Apnea Hypopnea Index, AHI, using an ApneaLink device) and symptoms of depression (Edinburgh Postnatal Depression Scale, EPDS). Data were collected from medical records including participant age, ethnicity, parity, BMI, smoking status, history of depression, and use of antidepressants.

RESULTS

Of the consenting women, data from 124 were suitable for analysis. Twenty women (16.1%) had OSA (AHI ≥ 5 events/h) and 11 (8.8%) had depressive symptoms (EPDS > 12). Women with OSA were more likely to have depressive symptoms after adjusting for covariates, odds ratio = 8.36, 95% CI [1.57, 44.46]. OSA was also related to higher EPDS scores and these were greater in women with a history of depression.

CONCLUSIONS

During late pregnancy women with OSA had eight times the odds of having depressive symptoms. Furthermore, an interaction was found between OSA and history of depression. Specifically, in women with no history of depression, OSA increases depressive symptoms. In women with a history of depression, OSA has an even stronger effect on depressive symptomology. This suggests screening for OSA in pregnancy may identify women prone to future depressive episodes and allow for targeted interventions.

Modeling the upper airway: A precursor to personalized surgical interventions for the treatment of sleep apnea

An accurate benchtop model was developed to mimic the different forms of human upper airway collapse in adult sleep apnea patients. This was done via modeling the airway through digital imaging. Airway representative models were then produced in two steps via a customized pneumatic extrusion 3D printing system. This allowed the pressure of collapse and planes of collapse to be manipulated to accurately represent those seen in sleep apnea patients. The pressure flow relationships of the collapsible airways were then studied by inserting the collapsible airways into a module that allowed the chamber pressure (P_c ) around the airways to be increased in order to cause collapse. Airways collapsed at physiologically relevant pressures (5.32-9.58 cmH₂ O). Nickel and iron magnetic polymers were then printed into the airway in order to investigate the altering of the airway collapse. The introduction of the nickel and iron magnetic polymers increased the pressure of collapse substantially (7.38-17.51 cmH₂ O). Finally, the force produced by the interaction of the magnetic polymer and the magnetic module was studied by measuring a sample of the magnetic airways. The peak force in (48.59-163.34 cN) and the distance over which the forces initially registered (6.8-9.7 mm) were measured using a force transducer. This data set may be used to inform future treatment of sleep apnea, specifically the production of an implantable polymer for surgical intervention.

Preoperative identification of children at high risk of obstructive sleep apnea

Obstructive sleep apnea is a common childhood disorder which can lead to serious health problems if left untreated. Enlarged adenoid and tonsils are the commonest causes, and adenotonsillectomy is the recommended first line of treatment. Obstructive sleep apnea poses as an anesthetic challenge, and it is a well-known risk factor for perioperative adverse events. The presence and severity of an obstructive sleep apnea diagnosis will influence anesthesia, pain management, and level of monitoring in recovery period. Preoperative obstructive sleep apnea assessment is necessary, and anesthetists are ideally placed to do so. Currently, there is no standardized approach to the best method of preoperative screening for obstructive sleep apnea. Focused history, clinical assessments, and knowledge regarding the strengths and limitations of available obstructive sleep apnea assessment tools will help recognize a child with obstructive sleep apnea in the preoperative setting.

An emerging technology for the identification and characterization of postural-dependent obstructive sleep apnea

STUDY OBJECTIVES

Body posture has a significant impact on the presence and severity of obstructive sleep apnea (OSA). The majority of polysomnography (PSG) systems have the capacity to categorize body (torso) posture as supine, left-lateral, right-lateral or prone, each within a 90-degree range. However, such broad categorization may limit the identification of subtle relationships between posture and OSA severity. The aim of this study was to quantify sleeping posture as a continuous variable; and to develop an intuitive tool for visualizing the relationship between body posture and OSA severity.

METHODS

A customized triaxial accelerometer-based posture sensor which quantifies torso posture as a continuous variable was developed. 38 participants attending the sleep laboratory for suspected OSA were recruited. Each participant underwent a diagnostic PSG with an additional customized posture sensor securely attached to the sternum. Individual data were presented using a novel circular histogram-based visualization which displays sleeping position and position-specific OSA severity.

RESULTS

Acceptable measurements were obtained in 21 participants. The mean ± standard deviation percentage of total sleep time spent within ± 15 degrees of the center of supine, left-lateral, right-lateral and prone was 59.7 ± 26.0%. A further 40.3 ± 26.0% of sleep time was spent in intermediate positions outside these traditional categorizations. The novel visualization revealed a wide variety of positional OSA phenotypes.

CONCLUSIONS

Quantification of torso posture as a continuous variable and analysis of these data using a novel visualization enables the identification of subtle relationships between body posture and OSA severity that are not apparent using standard clinical sensors and summary statistics.

Western Australian pregnancy cohort (Raine) Study: Generation 1

PURPOSE

The purpose of the Raine Study is to improve human health and well-being by studying the life-course of a cohort of Western Australians, based on a life-course conceptual framework that considers interactions between genetics, phenotypes, behaviours, the environment and developmental and social outcomes.

PARTICIPANTS

Between May 1989 and November 1991, 2900 pregnant women were enrolled in the Raine Study in Perth, Western Australia. In total, 2730 women gave birth to 2868 children (Generation 2) between August 1989 and April 1992. The mothers and fathers of Generation 2 are referred to as Generation 1 of the Raine Study. In the most recent Generation 1 follow-up, 636 mothers and 462 fathers participated.

FINDINGS TO DATE

Until the 26-year follow-up of Generation 1 the focus of research within the Raine Study was on outcomes in Generation 2, with information on the parents mainly being used to examine its influence on their children's outcomes. For example, recent findings showed that several characteristics of mothers, such as obesity, early mid-gestational weight gain and socioeconomic status were associated with non-alcoholic fatty liver disease, adiposity and cardiometabolic characteristics in offspring. Other findings showed that parents with back pain were more likely to have offspring who experienced back pain. Also, non-linear and dynamic relationships were found between maternal working hours and offspring overweight or obesity.

FUTURE PLANS

The Raine Study will continue to provide access to its dense longitudinal genetic, phenotypic, behavioural, environmental, developmental and social data to undertake studies with the ultimate goal of improving human health and well-being. Analyses of data from the recent Generation 1 year 26 follow-up are underway.

TRIAL REGISTRATION NUMBER

ACTRN12617001599369.

Treating Chronic Hypoventilation With Automatic Adjustable Versus Fixed EPAP Intelligent Volume-Assured Positive Airway Pressure Support (iVAPS): A Randomized Controlled Trial

Objectives

New noninvasive ventilation (NIV) modes can automatically adjust pressure support settings to deliver effective ventilation in response to varying ventilation demands. It is recommended that fixed expiratory positive airway pressure (FixedEPAP) is determined by attended laboratory polysomnographic (PSG) titration. This study investigated whether automatically determined EPAP (AutoEPAP) was noninferior to FixedEPAP for the control of obstructive sleep apnea (OSA) during intelligent volume-assured pressure support (iVAPS) treatment of chronic hypoventilation.

Methods

In this randomized, double-blind, crossover study, patients with chronic hypoventilation and OSA used iVAPS with AutoEPAP or FixedEPAP over two separate nights of attended PSG. PSG recordings were scored by an independent scorer using American Academy of Sleep Medicine 2012 criteria.

Results

Twenty-five adults (14 male) with chronic hypoventilation secondary to obesity hypoventilation syndrome (n = 11), chronic obstructive pulmonary disease (n = 9), or neuromuscular disease (n = 5), all of whom were on established home NIV therapy, were included (age 57 ± 7 years, NIV for ≥3 months, apnea-hypopnea index [AHI] >5/hour). AutoEPAP was noninferior to FixedEPAP for the primary outcome measure (median [interquartile range] AHI 2.70 [1.70-6.05]/hour vs. 2.40 [0.25-5.95]/hour; p = .86). There were no significant between-mode differences in PSG sleep breathing and sleep quality, or self-reported sleep quality, device comfort, and patient preference. Mean EPAP with the Auto and Fixed modes was 10.8 ± 2.0 and 11.8 ± 3.9 cmH2O, respectively (p = .15).

Conclusions

In patients with chronic hypoventilation using iVAPS, the AutoEPAP algorithm was noninferior to FixedEPAP over a single night's therapy.

Protocol of the PLeural Effusion And Symptom Evaluation (PLEASE) study on the pathophysiology of breathlessness in patients with symptomatic pleural effusions

INTRODUCTION

Pleural effusion is a common clinical problem that can complicate many medical conditions. Breathlessness is the most common symptom of pleural effusion of any cause and the most common reason for pleural drainage. However, improvement in breathlessness following drainage of an effusion is variable; some patients experience either no benefit or a worsening of their breathlessness. The physiological mechanisms underlying breathlessness in patients with a pleural effusion are unclear and likely to be multifactorial with patient-related and effusion-related factors contributing. A comprehensive study of the physiological and symptom responses to drainage of pleural effusions may provide a clearer understanding of these mechanisms, and may identify predictors of benefit from drainage. The ability to identify those patients whose breathlessness will (or will not) improve after pleural fluid drainage can help avoid unnecessary pleural drainage procedures, their associated morbidities and costs. The PLeural Effusion And Symptom Evaluation (PLEASE) study is a prospective study to comprehensively evaluate factors contributing to pleural effusion-related breathlessness.

METHODS AND ANALYSIS

The PLEASE study is a single-centre prospective study of 150 patients with symptomatic pleural effusions that require therapeutic drainage. The study aims to identify key factors that underlie breathlessness in patients with pleural effusions and develop predictors of improvement in breathlessness following effusion drainage. Participants will undergo evaluation pre-effusion and post-effusion drainage to assess their level of breathlessness at rest and during exercise, respiratory and other physiological responses as well as respiratory muscle mechanics. Pre-drainage and post-drainage parameters will be collected and compared to identify the key factors and mechanisms that correlate with improvement in breathlessness.

ETHICS AND DISSEMINATION

Approved by the Sir Charles Gairdner Group Human Research Ethics Committee (HREC number 2014-079). Registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616000820404). Results will be published in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

ACTRN12616000820404; Pre-results.

Prenatal testosterone exposure is related to sexually dimorphic facial morphology in adulthood

Prenatal testosterone may have a powerful masculinizing effect on postnatal physical characteristics. However, no study has directly tested this hypothesis. Here, we report a 20-year follow-up study that measured testosterone concentrations from the umbilical cord blood of 97 male and 86 female newborns, and procured three-dimensional facial images on these participants in adulthood (range: 21-24 years). Twenty-three Euclidean and geodesic distances were measured from the facial images and an algorithm identified a set of six distances that most effectively distinguished adult males from females. From these distances, a 'gender score' was calculated for each face, indicating the degree of masculinity or femininity. Higher cord testosterone levels were associated with masculinized facial features when males and females were analysed together (n = 183; r = -0.59), as well as when males (n = 86; r = -0.55) and females (n = 97; r = -0.48) were examined separately (p-values < 0.001). The relationships remained significant and substantial after adjusting for potentially confounding variables. Adult circulating testosterone concentrations were available for males but showed no statistically significant relationship with gendered facial morphology (n = 85, r = 0.01, p = 0.93). This study provides the first direct evidence of a link between prenatal testosterone exposure and human facial structure.

Study of a Novel APAP Algorithm for the Treatment of Obstructive Sleep Apnea in Women

STUDY OBJECTIVES

To assess the efficacy of a novel female-specific autotitrating continuous positive airway pressure (CPAP) algorithm (AutoSet for her, AfH) in premenopausal women relative to a standard autotitrating algorithm (AutoSet, S9) (ResMed Ltd., Bella Vista, New South Wales, Australia).

DESIGN

Prospective randomised crossover noninferiority trial.

SETTING

Tertiary hospital sleep clinic and university research sleep laboratory.

PARTICIPANTS

20 female patients with obstructive sleep apnea (OSA) established on long-term CPAP treatment.

INTERVENTIONS

Treatment with 1 night each of AfH and AutoSet while monitored with overnight laboratory-based polysomnography (PSG); order randomly allocated.

MEASUREMENTS AND RESULTS

The primary outcome variables were the apnea-hypopnea index (AHI) and 3% oxygen desaturation index (ODI 3%) determined from PSG. Treatment efficacy on the AfH night was noninferior to the AutoSet night as assessed by median (IQR) AHI (1.2 [0.60-1.85]/h versus 1.15 [0.40-2.85]/h, respectively, P = 0.51) and 3% ODI (0.85 [0.25-1.5]/h versus 0.5 [0.25-2.55]/h, respectively, P = 0.83). Other PSG measures were similar, except for the percentage of the night spent in flow limitation, which was lower on the AfH (0.14%) than the AutoSet night (0.19%, P = 0.007). The device-downloaded 95th centile pressure on the AfH night was also lower than on the AutoSet night (10.6 ± 1.7 versus 11.6 ± 2.6 cmH2O, respectively; mean difference [95% confidence interval]: -1.1 [-2.13 to -0.01] cm H2O).

CONCLUSION

Among premenopausal women a novel female-specific autotitrating algorithm (AfH) is as effective as the standard AutoSet algorithm in controlling obstructive sleep apnea (OSA). The new algorithm may reduce flow limitation more than the standard algorithm and achieve control of OSA at a lower (95th centile) pressure.

Prenatal testosterone exposure is related to sexually dimorphic facial morphology in adulthood

Prenatal testosterone may have a powerful masculinizing effect on postnatal physical characteristics. However, no study has directly tested this hypothesis. Here, we report a 20-year follow-up study that measured testosterone concentrations from the umbilical cord blood of 97 male and 86 female newborns, and procured three-dimensional facial images on these participants in adulthood (range: 21-24 years). Twenty-three Euclidean and geodesic distances were measured from the facial images and an algorithm identified a set of six distances that most effectively distinguished adult males from females. From these distances, a 'gender score' was calculated for each face, indicating the degree of masculinity or femininity. Higher cord testosterone levels were associated with masculinized facial features when males and females were analysed together (n = 183; r = -0.59), as well as when males (n = 86; r = -0.55) and females (n = 97; r = -0.48) were examined separately (p-values < 0.001). The relationships remained significant and substantial after adjusting for potentially confounding variables. Adult circulating testosterone concentrations were available for males but showed no statistically significant relationship with gendered facial morphology (n = 85, r = 0.01, p = 0.93). This study provides the first direct evidence of a link between prenatal testosterone exposure and human facial structure.

Effect of evening postexercise cold water immersion on subsequent sleep

PURPOSE

This study investigated the effect of cold water immersion after evening exercise on subsequent sleep quality and quantity in trained cyclists.

METHODS

In the evenings (~1900 h) on three separate occasions, male cyclists (n = 11) underwent either no exercise (control, CON), exercise only (EX), or exercise followed by cold water immersion (CWI). EX comprised cycling for 15 min at 75% peak power, then a 15-min maximal time trial. After each condition, a full laboratory-based sleep study (polysomnography) was performed. Core and skin temperature, heart rate, salivary melatonin, ratings of perceived fatigue, and recovery were measured in each trial.

RESULTS

No differences were observed between conditions for any whole night sleep measures, including total sleep time, sleep efficiency, sleep onset latency, rapid eye movement onset latency, wake after sleep onset, or proportion of the night spent in different sleep stages. Core temperature in EX and CWI trials was higher than CON, until it decreased below that of EX and CON until bedtime in CWI. After bedtime, core temperature was similar for all conditions throughout the night, except for a 90-min period where it was lower for CWI than EX and CON (3.5-4.5 h postexercise). Heart rates for EX and CWI were both significantly higher than CON postexercise until bedtime, whereas skin temperature after CWI was significantly lower than EX and CON, remaining lower than EX until 3 h postexercise. Melatonin levels and recovery ratings were similar between conditions. Fatigue ratings were significantly elevated after exercise in both CWI and EX conditions, with EX still being elevated compared with CON at bedtime.

CONCLUSION

Whole night sleep architecture is not affected by evening exercise alone or when followed by CWI.

Predicting uptake of continuous positive airway pressure (CPAP) therapy in obstructive sleep apnoea (OSA): a belief-based theoretical approach

PURPOSE

Obstructive sleep apnoea (OSA) is a common disorder, for which continuous positive airway pressure (CPAP) therapy is a standard treatment. Despite its well-established efficacy, many patients choose not to initiate CPAP treatment. The present study investigated the degree to which biological measures (e.g. Apnoea-Hypopnoea Index [AHI]), symptom experiences (e.g. fatigue) and illness representations (e.g. perceived consequences) predict the decision of individuals newly diagnosed with OSA to undergo a trial of CPAP therapy.

METHODS

Four hundred forty-nine individuals (316 males) newly diagnosed with OSA. Epworth sleepiness scale (ESS), Fatigue Severity Scale, Depression Anxiety Stress Scale and Illness Perception Questionnaire-Revised (IPQ-R) were administered at time of sleep study. These, patient demographics and sleep study variables were used to determine factors predicting patient decision to proceed with a trial of CPAP.

RESULTS

The participants were most likely to attribute their OSA to unchangeable and psychological factors. For those with moderate OSA (AHI, 15 to 30) IPQ-R illness consequence was predictive of decision to initiate CPAP (p = 0.002). For severe OSA (AHI >30) age, ESS and IPQ illness causal beliefs were predictive of decision to initiate CPAP (p < 0.001).

CONCLUSIONS

Illness beliefs are important determinants of the choice of recently diagnosed OSA patients whether or not to undertake a trial of CPAP therapy. Concerns about illness consequences were important in those with moderate OSA. In severe OSA, sleepiness symptoms are more prominent and a more significant determinant of CPAP uptake along with age and causal beliefs.

Symptoms of aerophagia are common in patients on continuous positive airway pressure therapy and are related to the presence of nighttime gastroesophageal reflux

STUDY OBJECTIVES

Continuous positive airway pressure (CPAP), the mainstay treatment for obstructive sleep apnea (OSA), involves administration of air under pressure to the upper airway. A well-known but poorly understood side effect of positive airway pressure therapies is aerophagia, air entering the esophagus and stomach rather than the lungs. Gastric distension, a consequence of aerophagia, can increase gastroesophageal reflux (GER) by increasing transient lower esophageal sphincter relaxations, the most common cause of reflux. This study aimed to determine: (i) the prevalence of aerophagia symptoms in a group of OSA patients on CPAP therapy, and (ii) whether aerophagia symptoms are related to an increase in prevalence of GER symptoms.

METHODS

Consecutive OSA patients undergoing polysomnography for the purpose of optimizing their CPAP therapy completed a validated questionnaire regarding GER symptoms and aerophagia symptoms. Complete datasets were collected for 259 individuals (203 males).

RESULTS

The group with aerophagia symptoms (n = 130) had a greater prevalence of frequent (≥ once a week) GER symptoms (29% vs. 10%, p < 0.05) and nighttime GER symptoms (9 vs. 2%, p < 0.05) than those without aerophagia (n = 129). The group with nighttime GER symptoms (n = 27) had a greater prevalence of aerophagia symptoms (63% vs. 23%, p < 0.05) than those without nighttime GER symptoms (n = 232).

CONCLUSIONS

In patients with OSA being treated with CPAP, the prevalence of GER and nighttime GER symptoms is greater in those with symptoms of aerophagia than those without. CPAP-induced aerophagia might precipitate GER, particularly nighttime GER, by exacerbating transient lower esophageal relaxations through gastric distension.