Women who get too little or too much sleep could be damaging their hearts, according to a study.

Study suggests that sleeping five hours a night or less is linked with a higher risk of coronary heart disease.

Astonishingly, spending more than the frequent eight hours in bed also seems to be bad for you.

In a study, women who slept for nine hours or more a night were also at advanced danger.

Sleep is the latest standard of living factor to be linked with coronary heart disease.

The situation is caused by the narrowing of the coronary arteries, a ordinary cause of heart attacks.

Lack of exercise, smoking and an unhealthy diet are all known to play a role.

Studies have shown that sleep deficiency increases blood pressure and affects hormone and blood sugar levels, which could have a crash on the heart.

The authors behind the data, drawn from a main study of the health of nearly 122,000 US nurses – say modern lifestyles are to blameworthiness.

Experts disagree on how much sleep you need to stay healthy. The suggestion that you can train yourself to sleep for just a few hours a night is a topic of debate.

According to Dr Adrian Williams of the sleep clinic at St Thomas’ Hospital in London, the national average is 8.1 hours.

The newest data, published in the Archives of Internal Medicine, is more evidence that sleep serves a very significant function.

Nonetheless, Professor Jim Horne, a sleep expert at Loughborough University, said there was no confirmation from animal studies that lack of sleep had a damaging consequence on the heart.

He said there could be other reasons for the link between coronary heart disease and sleep patterns.

Stress, for instance, is known to disturb sleep. People sleeping for very long periods could have other physical problems that influence them to heart disease.