but then, too many z’s can be just as problematic as too few. “in epidemiology studies, those who sleep nine or more hours per night tend to [also] be at increased risk of heart disease, obesity, depression or other psychiatric conditions,” says ayas, adding what they don’t know is whether it’s because of the increased sleep time, or if other issues, such as certain diseases disrupt your snooze time, making you sleep more to make up for it.
chronic insomnia is defined as sleeping for six hours or less a night, at least three times a week, for more than three consecutive months. getty
apnea and narcolepsy
those with sleep apnea, a potentially serious condition, are usually loud snorers who stop breathing periodically during the night and often gasp for air. as a result, they’re not only drowsy during the day, they’re also at increased risk for car accidents, occupational injuries, heart disease, stroke, diabetes, and alzheimer’s disease.
“we usually gauge the severity of sleep apnea by the number of times their airway narrows or closes per hour of sleep,” says ayas of the subjects in his lab. “everybody has a bit of instability of breathing at night so anything less than five times an hour we consider pretty normal; anything over 30 times an hour we consider severe.”
as for how common it is, he says that about 10 per cent of the population has sleep apnea, but about 50 per cent of the population snores — essentially, “the vast majority of people with sleep apnea will snore, but a lot of people who snore won’t necessarily have sleep apnea.”
dang-vu is also studying narcolepsy, a relatively rare genetic disease where people are overwhelmingly sleepy during the day and may fall asleep suddenly. he says he’s currently comparing research data from people with hypersomnia to those with narcolepsy to fully understand the specifics of their conditions.
sleep aids
as for tools to help us sleep, according to dang-vu, there have been many new discoveries about how and why we sleep (or don’t), but there is still a lot more to be learned.