Lung health research
The cost we pay when you don`t sleep
An interview with Dr. Najib Ayas by Larry Pelizzarri
Why is sleep so important?
Probably the most important function of sleep is that it provides rest for your brain and body. After 24 hours of continuous wakefulness, cognitive performance is similar to that of someone who’s legally intoxicated. That gives you a sense of the degree of impairment that you can suffer from sleepiness. From a safety standpoint, especially for driving, sleepiness is a huge issue. It is probably as important as alcohol and speeding in terms of risks of motor vehicle crashes.
Data has been accumulating that sleep deprivation may lead to adverse health consequences as well. If you take healthy individuals and deprive them of sleep, such as having them sleep only four hours per night for a week, their physiology becomes abnormal. They’ll become glucose intolerant, a pre-diabetic state. Their blood pressure, stress hormones, and inflammatory markers will rise. A lot of these changes are risk factors for heart disease.
Can you talk about your current research?
My major research focus is looking at the public health, safety and economic consequences of sleep apnea. This includes trying to understand whether (and by how much) patients with sleep apnea are at increased risk of heart disease, motor vehicle crashes, occupational injuries, and also the types of accidents they have. We also want to assess whether sleep apnea therapy improves risks of injuries and increases work productivity, and to develop cost-effective strategies to diagnose and treat sleep apnea.
How “at risk” for motor vehicle accidents are sleep apnea sufferers?
Studies have shown a three to seven time increased risk in patients with sleep apnea. We’ve also found that patients with sleep apnea tend to have much more severe accidents. You can imagine that if someone falls asleep at the wheel, those are the kinds of accidents where they cross the centre line and drive into oncoming traffic, resulting in catastrophic accidents.
This is very important because sleep apnea is very common and under diagnosed. We’re talking five to ten percent of the population over the age of 40 that have this.
Does sleep apnea have any physical outcomes for sufferers?
There’s a clear link between sleep apnea and cardiac disease. Patients with sleep apnea have a three to five time higher risk of cardiovascular events such as strokes, heart attacks, and sudden death. We don’t yet know how effective treatment is on reducing these risks, which is one of our current research interests. Furthermore, the mechanisms whereby sleep apnea predisposes you to these adverse outcomes is unclear and is an intense area of investigation.
Then what is considered a healthy night’s sleep?
We published a paper a couple years ago where we took a large group of nurses and followed them for 10 years. We found that the individuals who reported sleeping six or less hours per night had a significantly greater risk of heart disease. The least risk was in those people who slept seven to eight hours per night.
What sparked your interest in this field?
Sleep is a very young field with many unanswered questions. Sleep apnea per se was only described in the 1970s and CPAP has only been around since the 80s. Also, treating patients with sleep apnea is very rewarding. Patients with severe sleep apnea are basically disabled by their disease, but proper treatment can provide a new lease on life for them. Sometimes I feel badly for some of these people, as some of them have been symptomatic for many years and should have been treated a lot earlier. Another great thing about sleep apnea is that you treat these patients and they become more productive and satisfied workers. That’s why the economic and productivity aspects also became interesting for me.
Dr. Najib Ayas is an assistant professor of medicine in the respiratory division at Vancouver General Hospital. He graduated with distinction from the University of Alberta in 1992, completed a residency at the Mayo Clinic in 1996, and post-graduate training in at Brigham and Women's Hospital/Harvard Medical School in 2000. He joined the Sleep Disorders Program at the University of British Columbia in September 2002. In studies partly funded by the British Columbia Lung Association, he is looking at the public health, safety and economic consequences of sleep apnea.