Recognizing and Treating Paediatric Sleep Disorders: A New Wake-Up Call
By: Rachel Dragas
Dr. Indra Narang, MD, FRCPCH
Director of Sleep Medicine and Staff Respirologist, Department of Respiratory Medicine, The Hospital for Sick Children
Associate Scientist, Department of Physiology and Experimental Medicine, The Hospital for Sick Children Research Institute
Associate Professor, Department of Paediatrics, University of Toronto
Associate Member, Institute of Medical Science
Dr. Indra Narang is a paediatric respirologist and the Director of Sleep Medicine at the Hospital for Sick Children. She is also an associate professor in the Department of Paediatrics and an associate graduate faculty member in the Institute of Medical Science at the University of Toronto. Dr. Narang’s research examines the cardiovascular, metabolic, and neurocognitive consequences of childhood sleep disorders like obstructive sleep apnea, and how they may be amplified by factors such as obesity. Aside from her work, she is also a tireless advocate for increasing awareness about paediatric sleep disorders and resource availability in Canada. I sat down with Dr. Narang to hear more about her successful career and the progress that’s been made in diagnosing and providing early treatment for children with sleep disorders, particularly obstructive sleep apnea.
Can you tell us a bit about your education, background, and training?
I’m originally from London, England where I completed medical school, my doctoral research degree, and postgraduate training in paediatrics and respirology. As part of this training, I completed a one year fellowship in paediatric respirology at the Hospital for Sick Children. This was my first real introduction to paediatric sleep medicine. I undertook further training in sleep medicine at the Children’s Hospital of Philadelphia. Following this, I was offered a position at the Hospital for Sick Children in 2007.
Can you give us some insight on sleep disorders in children and your research findings?
Our research is mainly focused on the diagnosis and optimal management, as well as the cardiovascular, metabolic, and neurocognitive consequences of sleep disorders in children. Sleep disorders encompass a variety of conditions, ranging from teenagers who have chronic sleep deprivation to very young children and teenagers who have obstructive sleep apnea. Sleep disorders, whether it be sleep deprivation or sleep apnea, can affect most of the physiological systems of the body, and treatment can have a significant positive impact not only on the child’s physical health, but mental health and wellbeing. Obstructive sleep apnea is a common childhood disorder that arises from narrowing of the upper airway. It is characterized by loud snoring and pauses in breathing, ultimately resulting in low blood oxygen levels and sleep fragmentation with impairment of daytime functioning. Historically, paediatric obstructive sleep apnea, which occurs in approximately 3% of all healthy children, was not recognized as a significant morbidity, and as such, many children were not diagnosed nor treated. We now recognize that sleep apnea can result in significant fatigue during the day and is an independent risk factor for cardiovascular disease, systemic hypertension, and insulin resistance. This disorder is further complicated by obesity. Up to 60% of obese children have sleep apnea, which may magnify the underlying cardiovascular and metabolic burdens associated with obesity.
What are the main impacts of your research?
We have developed a large clinical and research team, and together we have heightened awareness and highlighted the impact of sleep disorders on both health and disease. For example, our research has shown that children with sickle cell disease, Down syndrome, and metabolic disorders, have a very high rate of obstructive sleep apnea (> 30%) and treatment improves daytime functioning. Other research has shown that a significant number of teenagers are generally sleep deprived, resulting in an increase in both blood pressure and weight, both risk factors for health problems in adults. Moreover, as a result of our research, we now receive three times the number of referrals to our center compared to five years ago. This translates to more children getting the treatments they need in a timelier fashion. Furthermore, there has been an increasing interest, especially within the public, on the influence of sleep on health and disease.
Should every child with sleep apnea be treated? What is the best timing for intervention?
From a clinical perspective, if a child has a diagnosis of sleep apnea with daytime consequences (disruptive behavioural problems, hyperactivity, etc.), then the child should absolutely be treated. In children, the most common cause of obstructive sleep apnea is enlarged tonsils and adenoids in the upper airway, which block the nasal passages and make breathing through the nose difficult. The gold standard of care for a young, otherwise healthy child with obstructive sleep apnea, is an adeno-tonsillectomy. Timing of intervention is important because young children are often at a critical stage of brain development, and sleep apnea with related hypoxia can have detrimental effects on the developing brain. Timely intervention is crucial to prevent or limit any impact on learning, memory, and behaviour.
What are some of the challenges and controversies in this field?
Paediatric sleep medicine is a rapidly expanding field and it is hard to keep pace with all of the new and evolving research that ultimately determines our best models for clinical care. I think an enormous challenge for us right now is the obesity epidemic, as obese children and adolescents have a very high risk of developing obstructive sleep apnea. Conventional surgical treatments are not necessarily successful in these children and we are currently researching into the optimal treatment for these cases. However, the lack of resources in paediatric sleep medicine across Canada probably means a significant number of obese children will not be diagnosed or treated for obstructive sleep apnea. This is probably the greatest challenge for paediatric sleep specialists across Canada.
Was there a defining moment in your work as a scientist?
Recently, we have established a large sleep network across Canada. Paediatric and adult researchers have come together and established the Canadian Sleep and Circadian Network (CSCN), involving 17 universities in total. We all share the same core goal which is looking at sleep disorders across the life span, and this includes collecting DNA samples from patients with sleep disorders. Having the paediatric and adult team finally come together is a really big venture and was validated by a $4 million grant from CIHR and research institutes across Canada allowing us to do this work. Not only is there increasing awareness and work being done on paediatric sleep disorders, but we’ve also integrated paediatric sleep into a national sleep network.
What is the most rewarding part of your job?
The Hospital for Sick Children has the largest and most comprehensive sleep program in all of Canada. We have increasing academic output, most of which has been achieved within the last five years. To me, that’s immensely rewarding. Our sleep program provides state-of-the-art clinical care, conducts unique and innovative research, and is taking the lead in training excellent paediatric sleep physicians. It’s pretty incredible to look back and see how far we’ve come in such a short time.
What words of wisdom do you have for graduate students?
You have to be really passionate about wanting to do research. Research is incredibly hard work involving the most amazing ‘highs’ which are sadly balanced by ‘lows’ on the way. Being in the right institution with the right mentorship is vitally important for success as long as you are passionate about your work and motivated to succeed. Ultimately research can reap huge rewards!