(RxWiki News) If you're feeling sleepy or irritable during the day, you may not be getting enough sleep. And not enough sleep could mean you're at higher risk for a range of heart problems.
A recent study reveals that people who get less than six hours of sleep or more than eight hours of sleep are more likely to experience a variety of cardiovascular events, including heart attack, stroke, heart failure and coronary artery disease.
"Get 6-8 hours of sleep each night."
Rohit Arora, M.D., chairman of cardiology at the Chicago Medical School, and colleagues examined the records of 3,019 patients over age 45 who were part of the National Health and Nutrition Examination Survey.
Their sample was therefore nationally representative and among the largest to look at links between sleeping time and a person's likelihood of experiencing heart problems.
Participants were asked about their sleeping habits and divided into three groups: getting fewer than six hours of sleep each night, getting six to eight hours nightly, or getting more than eight hours nightly.
The researchers looked for five different cardiac conditions that may be related to the time a person spends sleeping each night: stroke, heart attack, congestive heart failure, coronary artery disease and chest pain (angina).
Coronary artery disease occurs when blood vessels that deliver oxygenated blood to the heart become narrower.
Results were adjusted to account for patients' age, gender, cholesterol levels, lipoprotein levels, blood pressure, smoking status and weight. They were also adjusted if a patient had diabetes, sleep apnea or another diagnosed sleep problem known to be associated with heart conditions.
The researchers found that patients getting fewer than six hours of sleep were twice as likely to have a heart attack or stroke and 60 percent more likely to have congestive heart failure.
Those getting potentially too much sleep were also at risk for cardiac health concerns. Patients sleeping more than eight hours nightly had double the risk of having chest pain and 10 percent more likely to have coronary artery disease.
“Based on these findings, it seems getting six to eight hours of sleep everyday probably confers the least risk for cardiovascular disease over the long term,” Dr. Arora said.
Past research have already shown repeatedly that lack of sufficient sleep is associated with a higher risk of diabetes, higher stress levels, higher blood pressure and a higher resting heart rate, all of which also can be risk factors for a cardiovascular condition.
Researchers are unsure why a longer period of sleeping might relate to heart problems. They called for more studies into this issue and into whether conditions such as diabetes, obesity or high blood pressure may also influence the link between cardiac events and sleep duration.
“Clinicians need to start asking patients about sleep, especially with those who are already at greater risk for heart disease,” Dr. Arora said. “It’s a really simple thing to assess as part of a physical exam, it doesn’t cost anything and it may help encourage patients to adopt better sleep habits.”
Dr. William Kohler, M.D. director of the Florida Sleep Institute in Spring Hill, echoed this recommendation.
"People with cardiovascular disease should be questioned about sleep problems - not only sleep apnea, but the length of their sleep and sleep habits," Dr. Kohler said. " And, people with sleep problems should bring that up with their doctor."
He pointed out that sleep recommendations encourage people to get six to nine hours of sleep each night but that people must determine what number is right for them within that range.
"Each individual has his own sleep needs. Some people need nine hours or need eight and a half hours," Dr. Kohler said. "If the person is getting an adequate amount of sleep, their emotional function and cognitive function should be maximal for them."
Dr. Kohler said feeling tired and/or irritable during the day is an indication that a person may not be getting enough sleep, even if they are getting at least six hours. They should then increase the amount of sleep they get by a half hour to see if that improves their daytime sleepiness and irritability - and then continue to adjust as necessary until they establish the appropriate amount of sleep for them.
The research was presented March 25 at the American College of Cardiology's 61st Annual Scientific Session. Information regarding funding and financial disclosures was unavailable.