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.