28th March 2012 -- Sleeping less than six hours a night may make you more likely to have a heart attack, stroke or heart failure.
A new study, based on more than 3,000 people older than 45, shows that those who slept less than six hours per night were about twice as likely to have a stroke or heart attack as people who got six to eight hours of sleep. They were also about 70% more likely to have congestive heart failure.
Maureen Talbot, Senior Cardiac Nurse at the British Heart Foundation said via e-mail: "This study confirms what we already know, which is that a good night’s sleep is important for both our heart and general health.
"Six to eight hours a night is just the ticket after a long and busy day."
The new study, presented at the American College of Cardiology's annual meeting, isn't the first to link sleep and heart health but it is one of the largest according to Dr Rohit Arora, chair of cardiology at Chicago Medical School in the US.
The study's findings suggest a lot of people in the UK could be at greater risk of heart trouble because of their sleep habits. According to The Sleep Council nearly half of us are getting just six hours sleep or less a night.
Exactly how sleep affects the heart is not clear. Dr Arora says he doubts not sleeping enough directly causes heart disease. However, there is evidence that not sleeping enough may ramp up the "fight or flight" response to stress, releasing hormones that speed up heart rate and raise blood pressure. It's also possible people could have other medical conditions, such as diabetes, that prevent them from sleeping through the night.
Sleep study details
In the study, people were asked how long they slept each night and if they had ever been told they had congestive heart failure, heart attack, coronary artery disease, angina, or stroke.
Among the findings:
Heart attack: More than 10% of people who slept less than six hours had had a heart attack vs. about 5% who slept six to eight hours.
Stroke: More than 9% of people who slept less than six hours had a stroke vs. nearly 5% who slept six to eight hours.
Heart failure: More than 7% of people who slept less than six hours had heart failure vs. 4.5% who slept more than eight hours.
Sleeping too much may also be an issue. The study's findings show that people who sleep more than eight hours a night may be more likely to have the chest pain of angina and coronary artery disease, a narrowing of the blood vessels that supply blood and oxygen to the heart.
The researchers considered other factors that affect heart health, including age, gender, cholesterol, and blood pressure but they didn't consider sleep quality.
In December last year, sleep expert and clinical psychologist Professor Colin Espie from the University of Glasgow who runs the Great British Sleep Survey told us the number of hours of sleep needed varies between individuals. "Some people only need five and a half, six. Other people need eight, eight and a half."
Maureen Talbot says if you are having trouble sleeping, you may want to speak to your doctor.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinise the data prior to publication in a medical journal.
American College of Cardiology’s 61st Annual Scientific Session, Chicago, March 24-27, 2012
Dr Rohit R. Arora, chairman of cardiology, Chicago Medical School, USA
The Sleep Council
British Heart Foundation
Professor Colin Espie, University of Glasgow
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