Why your heart needs at least 6 hours of sleep each night

Study examines how not enough sleep, poor quality of sleep can increase odds of a heart attack or stroke

Your room's temperature, caffeine and more can affect your sleep.

Your heart needs at least six hours of sound sleep each night to stay healthy, a new study says.

People who don’t get enough sleep increase their risk for cardiovascular disease and coronary heart disease — regardless of age, weight, smoking and exercise habits — the National Sleep Foundation says.

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The new study, by National Center for Cardiovascular Research in Madrid, seems to confirm that assertion.

"But this study emphasizes we have to include sleep as one of the weapons we use to fight heart disease — a factor we are compromising every day," lead researcher Jose Ordovas said.

Not enough sleep can cause atherosclerosis — the hardening and narrowing of arteries — which is the usual cause of heart attacks and strokes.

Ordovas and the other researchers tracked nearly 4,000 Spanish adults whose average age was 46 and had no heart disease when the study began.

People who slept fewer than six hours a night were 27 percent more likely to have bodywide atherosclerosis than those who slept seven to eight hours, Ordovas and his team reported.

But too much sleep was shown to be problematic as well. Women in the study who slept more than eight hours a night also had an increased risk of atherosclerosis.

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The study also found that participants with "poor-quality" sleep, meaning they awoke often during the night or had trouble falling asleep, were 34 percent more likely to have atherosclerosis.

"This is the first study to show that objectively measured sleep is independently associated with atherosclerosis throughout the body, not just in the heart," Ordovas said in a news release.


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