Current Research

Facial photogrammetry to predict obstructive sleep apnea in a diverse paediatric population

Obstructive sleep apnea (OSA) is diagnosed based on an overnight sleep study, named polysomnography (PSG), which is the current study standard. Despite a universal healthcare system, access to PSG is extremely limited due to the lack of centers with PSG facilities and long wait times. Only 1 in 7 children with symptoms of OSA will have access to a PSG, with children from minority groups especially being affected. As such, many children with OSA symptoms will remain undiagnosed and left untreated. With this study, we will use facial photography as a tool to predict OSA in a diverse patient popûlation. We will enroll children with suspected OSA who are scheduled to have a PSG and take photographs of their faces using an iPhone. The photographs will be used to measure the shape of the face using a technique called 3-D facial photogrammetry, and a new computer-driven software created by our team will be applied to diagnose OSA. We will then test the accuracy of 3-D photogrammetry to diagnose OSA by comparing it to the PSG results. Conducting this study will help us determine if OSA can be diagnosed using a cheaper, faster tool than doing an overnight study, hopefully allowing us to improve the outcomes of children with OSA.

Recruitment for this study has not yet started. Please check back with updates.

Re-evaluating the definition of OSA severity in children

Obstructive sleep apnea (OSA) is diagnosed based on an overnight sleep study, named polysomnography (PSG), which is the current gold standard. The severity of OSA is quantified by the obstructive apnea hypopnea index (OAHI), which refers to the number of obstructive apneas and hypopneas per hour of sleep. It is widely accepted that children with an OAHI of 1 – <5 events/hour, 5 – <10 events/hour, and ≥10 events/hour are classified as having mild, moderate, and severe OSA, respectively. ­­However, the validity of this classification has been questioned as accumulating studies showed that it is poorly correlated with clinical outcomes. One possible explanation is that the index only reflects the number of respiratory events during sleep, but not the duration and severity of each event. Sleep apnea-specific hypoxic burden (SASHB) has been proposed to be a better alternative. It is derived from the pulse-oximetry tracing and is defined as the total area bounded by the baseline saturation level and the desaturation curve triggered by an obstructive or mixed apnoea or hypopnoea per hour of sleep, therefore reflecting both the duration and severity of each episode of airway obstruction. In adults, the sleep apnoea-specific hypoxic burden (SASHB) is a better predictor of cardiovascular diseases and all-cause mortality when compared to the apnoea hypopnoea index (AHI). There are currently no relevant paediatric data in the literature.

We are testing a few hypotheses about the use of the SASHB in children:

1. SASHB is better associated with nocturnal blood pressure in children with OSA when compared to OAHI
2. SASHB is better associated with daytime functioning and behavioural problems in children with OSA when compared to OAHI.

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(Jun Chun Ting Au)

Sleep Apnoea-Specific Pulse Rate Response (∆HR)

Pulse rate changes drastically when an apnea or hypopnea occurs during sleep. These changes are attributed to the activation of the autonomic nervous system triggered by intermittent hypoxia, arousals, and intrathoracic pressure swings that occur as a consequence of upper airway obstruction during sleep. The magnitude of the pulse rate change is associated with the severity of the apnea or hypopnea that induces the change, the presence and the intensity of arousal, and the responsiveness of the autonomic system. Therefore, the pulse rate response to respiratory event is a potential prognostic marker of future OSA-related cardiovascular risk.

We are testing the following hypothesis:

1. Adenotonsillectomy is effective in reducing ∆HR in children with OSA.
2. High flow nasal cannula (HFNC) is as effective as continuous positive airway pressure (CPAP) in reducing ∆HR in children with OSA.
3. ∆HR is associated with cardiovascular outcomes such as hypertension.

(Jun Chun Ting Au) 

The IPAD Cohort Study: Insomnia and Positive Airway Pressure Adherence in Children and Adolescents

This study addresses a critical knowledge gap regarding the impact of coexisting insomnia on positive airway pressure (PAP) therapy adherence amongst a diverse population of children with obstructive sleep apnea (OSA). OSA and insomnia are sleep disorders that are common in children and adolescents, and disproportionately affect individuals of self-reported racial and ethnic minority. The coexistence of these conditions, referred to as comorbid insomnia and sleep apnea (COMISA), is associated with greater morbidity than either condition alone. While PAP therapy is highly effective for the treatment of OSA, it is limited by adherence rates of less than 50% in children. Insomnia may be a modifiable risk factor for reduced PAP adherence. Building upon our previous work, we will complete a multicenter, prospective, longitudinal cohort study of children with OSA who are newly initiated on PAP therapy to assess the impact of baseline coexisting insomnia on PAP therapy adherence after 3 months of PAP use. The results of this study will inform the design of targeted treatment plans for COMISA in children, which will be the subject of future interventional studies. The identification of priority subgroups will ensure inclusive representation in the development and implementation phases of treatments.

(Dr. Lena Xiao)

Positional Sleep Therapy for the Management of Obstructive Sleep Apnea in Children- The POSAtive trial

Childhood obstructive sleep apnea (OSA) affects many key indicators of physical and mental health. The standard of care treatment for persistent OSA following adenotonsillectomy is continuous positive airway pressure (CPAP). Although highly efficacious, CPAP effectiveness is significantly limited by adherence rates of less than 50% in children. Consequently, there is a significant unmet need for novel, effective and easy to use interventions for the management of persistent OSA in children. There is increasing recognition regarding the prevalence of a distinct clinical phenotype in children with persistent OSA known as positional OSA (POSA). POSA occurs while sleeping in the supine position versus other sleeping positions. A potential effective therapy for POSA is a positional sleep belt, a belt worn around the chest, which prevents supine position. The overall aim of this study is to evaluate the effectiveness of a positional sleep belt for OSA management in children. Effectiveness will be measured by evaluating and comparing OSA severity using a sleep positional belt compared to a control during overnight sleep study tests.

(Dr. Lena Xiao)

Use of Heated Humidified High Flow Nasal Cannula Oxygen in Obstructive Sleep Apnea in Adolescents with Obesity and Complex Medical Conditions.

Obstructive sleep apnea (OSA) is a syndrome currently affecting one to four percent of children and up to 25% of obese youth. The long term effects of untreated OSA include an increase in cardiovascular and metabolic risk as well as neurocognitive dysfunction. The mainstay of treatment in obese teenagers and children with medical complexity (CMC) for OSA is continuous positive airway pressure (CPAP), however, adherence is challenging with adherence rates of approximately 40-50% despite the beneficial effects of therapy. More recently new developments have shown that the heated humidified high-flow air delivered by nasal cannula can provide positive distending pressure leading to upper airway distension and lung recruitment, similar to the effect seen in CPAP, but has the advantages of being more comfortable. However, limited information exists on its effect on children who have moderate to severe sleep apnea, those that are typically prescribed CPAP. Our aim is to investigate the effect of heated humidified high-flow air compared to CPAP in these patients to evaluate its efficacy compared to CPAP.

(Jun Chun Ting Au)

Dexamethasone as a Novel Treatment for Obstructive Sleep Apnea in Children

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder, occurring in 1-4% of otherwise healthy children, characterized by upper airway obstruction. The first-line treatment for OSA, adenotonsillectomy, is effective but often delayed due to long surgical wait times, leaving many children untreated and at increased risk of long-term health effects, such as cardiovascular and neurocognitive deficits. OSA is also a chronic inflammatory condition that often presents with upper airway inflammation. Despite this, oral anti-inflammatory treatments such as dexamethasone have not been fully explored. The purpose of this study is to evaluate the efficacy of a 3-day course of oral dexamethasone in reducing the severity of moderate to severe OSA in children. Efficacy will be assessed through changes in OSA severity using polysomnography to measure the obstructive apnea-hypopnea index (OAHI). The findings have the potential to establish dexamethasone as an accessible and effective non-surgical intervention for managing pediatric OSA.

(Mystica Terrance)

The Role of a Mindfulness Based Intervention to Improve CPAP adherence in Adolescents with OSA.

There is supporting evidence showing that mindfulness-based interventions can improve adherence to treatment by re-directing attention and avoiding negative thoughts and behaviours. We want to see whether mindfulness training can be beneficial with increasing CPAP adherence especially in adolescents who have severe OSA but rarely use CPAP.

In this randomized controlled study, we will assess the effectiveness of a mindfulness-based intervention in improving CPAP adherence when compared to regular peer support activities in adolescents with OSA. In this study, in addition to standard of care in-clinic CPAP support, adolescents will be randomized to either an online mindfulness-based intervention or a peer support group. There will be a total of 8 sessions and each session will last 60 minutes. We will measure adherence to CPAP therapy, daytime sleepiness, quality of life and psychosocial functioning before and after the interventions. 

(Jun Chun Ting Au/
Natalia Escobar)

The Canadian Sleep and Circadian Network (CSCN): A Longitudinal Study Identifying Children with Obesity Most at Risk for Obstructive Sleep Apnea and their Neurocognitive, Metabolic, and Cardiovascular Outcomes

In Canada, child and adolescent obesity represents one of the most common conditions affecting children. Obesity is not only complicated by cardiovascular and metabolic dysfunction, but it is also associated with obstructive sleep apnea OSA). OSA is characterized by snoring, recurrent partial (hypopneas) or complete obstruction (apneas) of the upper airway, frequently associated with intermittent oxyhemoglobin desaturations, sleep disruption and fragmentation. OSA is often associated with neurocognitive deficits and behavioral problems. Our aim is to identify children with obesity most at risk of OSA and to determine the independent effects of OSA on cardiovascular, metabolic, neurobehavioral and cognitive functions. 

(Jun Chun Ting Au/Zeina Beidas/
Giorge Voutsas)

Effect of Sleep Restriction on Cerebrovascular Health and Neurocognition in Adolescents

Adequate sleep is critical for optimal cognitive development during adolescence. Despite recommendations of 8 to 10 hours of sleep each night, 60% of adolescents report 7 hours or less of sleep each night. Sleep restriction impacts key indicators of physical and mental health, and has been declared an international public health concern by the American Academy of Pediatrics. Sleep restriction negatively impacts attention, executive function, memory and learning. It is associated with poor academic performance, greater risk-taking behaviours and increased accidental injuries in adolescents. However, there is a lack of literature to address the mechanisms behind these morbidities in sleep-deprived adolescents.

We want to understand how short sleep will impact neurocognition and cerebrovascular health in healthy adolescents. In this 2-week randomized crossover study, we will compare how a period of ideal sleep and sleep restriction affect cognitive, behavioural and cerebral vascular outcomes. We are recruiting 20 healthy adolescents between the ages of 15-18 years old without a history of neurological, psychiatric or sleep disorder. Sleep duration will be measured remotely using an accelerometer watch, and two study visits will be conducted at SickKids to assess cognitive ability and blood vessel function using MRI. Currently, this study is open and recruiting for participants.

(Jun Chun Ting Au / Amy Chan) 

Multiple Sleep Latency Tests Results in Pediatric Hypersomnolence: A Descriptive Study

We are working on reviewing the past 10 years of MSLTs performed in patients with hypersomnolence to describe the characteristics of those diagnosed with narcolepsy. Our focus is specifically on patients with clinically suggestive symptoms but negative MSLT results, aiming to better understand the diagnostic method and evaluate its diagnostic precision.

(Natalia Escobar)

Association and Impact of the Physical Environment on Sleep Duration, Physical Activity, and Sedentary Behaviours in an Asthmatic Paediatric Population

Asthma is a chronic disease affecting roughly 14.1 % of children worldwide, while 6.9 % of those with an asthma diagnosis suffer from severe asthma. Lifestyle factors, particularly increases in sedentary behaviour and decreased physical activity (PA) are thought to contribute to increased asthma severity and prevalence. However, the amount and intensity of PA in children with severe asthma have not been well described and further the factors contributing to decreased PA are not well understood. Of interest are validated geographic information system (GIS) methods to investigate the impact that neighbourhood factors have in promoting an environment conducive to PA. Other factors that may impact PA in children with severe asthma are nocturnal asthma symptoms, which result in increased awakenings with increased sleep disturbance resulting in consequential daytime fatigue for paediatric asthma populations. Thus the overall aim of this study is to evaluate the risk factors that may impact physical activity (PA) profiles in children with severe asthma and further assess the neighbourhood factors that can influence PA.

(Giorge Voutsas)