Physicians agree getting enough sleep is just as important as diet and exercise for good health. A new study shows the amount of shut-eye you get on a nightly basis can cause serious consequences.
The study found that people who sleep more than eight or less than six hours a night may be at increased risk for stroke. The National Sleep Foundation guidelines recommend between seven and eight hours of sleep for older adults.
Researchers at The University of Cambridge analyzed 9.5 years of data for nearly 10,000 stroke-free participants ages 42 to 81. Nearly 1,000 of the study’s participants slept more than eight hours a night. The people who slept longer were 46 percent more likely to have a stroke than people who slept between six and eight hours a night.
“In fact, the risk of stroke was highest for people who slept longer,” says Irene Katzan, MD, MS, a stroke specialist at Cleveland Clinic.
Sleeping too little already has been linked to obesity, diabetes, and high blood pressure – all stroke-related risk factors – but the association between people who sleep a long time and stroke is less known.
“It’s difficult to understand how sleep directly impacts health,” Dr. Katzan says. “There often are multiple factors at play.”
Dr. Katzan also says the association between longer sleep duration and stroke risk could be a marker rather than a risk itself.
“For instance, it’s possible the study participants who slept longer may have obstructive sleep apnea, adding to the stroke risk.”
People who slept less than six hours per night had an 18 percent increased risk for stroke. This was less surprising, Dr. Katzan says.
“There has been a lot of research on people who sleep too few hours,” Dr. Katzan says.
People who don’t get at least six hours of sleep per night suffer from an inability to concentrate during the day, in addition to stroke and other cardiovascular events.
“It’s easier to hypothesize why short sleep duration is associated with increased risk of stroke,” Dr. Katzan says.
A 2012 study found that 30 percent of working adults of normal weight who routinely slept less than six hours a night were four times more likely to suffer stroke. A 2008 study found that short sleep duration increased coronary calcium deposits, a good predictor of heart disease.
Over the years, scientists have concluded that good, quality sleep is a good predictor of cardiovascular events, and recently, stroke has become of particular interest.