Image caption Work-related stress may have a role in heart disease

Being unemployed in your 50s and early 60s may raise heart-attack risk by a similar magnitude as smoking, findings suggest.

The study of more than 13,000 people in the US indicated heart-attack risk went up by a quarter in the first year after job loss and increased incrementally with further sackings or redundancies.

The same was not seen in people who gave up work voluntarily, Archives of Internal Medicine reports.

Experts suspect stress may be to blame.

They say more research is needed to explore this.

This confirms other work that shows life stressors can increase your risk of a heart attack Dr Donna Arnett of the American Heart Association

Past work has suggested that doing a stressful job may similarly increase your risk of having a heart attack.

The British Heart Foundation advises that stress in itself is not a direct cause of heart disease, although it may contribute to your risk level.

Stress link

In the latest study, which spanned nearly 20 years, there were more than 1,000 heart attacks among the 13,451 participants.

When the researchers looked specifically at to whom these events had happened, they found a number of trends.

Men and women in the study who smoked, were overweight and did little or no exercise were more likely to have a heart attack.

So too were those who were older and those who had high blood pressure or diabetes.

After accounting for these more well-established heart-risk factors, the researchers found job loss was also independently linked with heart attack risk.

Heart attacks were significantly (27%) more common among people who were recently unemployed, regardless of occupation type.

And the effect was cumulative - the chances of having a heart attack went up by two-thirds (63%) for people who had lost four or more jobs.

What is a heart attack? The heart beats around 70 times a minute to push blood around the body

Like any busy muscle, the heart tissues need a good supply of blood from their blood vessels

When this process is interrupted or doesn't work properly, serious illness and even death can result

A heart attack occurs when blood flow to part of the heart is blocked, often by a blood clot, causing damage to the affected muscle

The clot, often caused by rupturing or tearing of plaque in an artery, is sometimes called a coronary thrombosis or a coronary occlusion

If blood supply is cut off for a long time, the muscle cells are irreversibly damaged and die, leading to disability or death depending on the extent of the damage Source: BBC Health Heart attack symptoms What is heart disease?

For smoking, the likelihood of a heart attack went up by nearly half (44%).

Researcher Dr Linda George, from Duke University in North Carolina, said: "This is a sizeable effect and of a similar size to other well-known, established risk factors for heart attack including smoking and obesity.

"We think it is the stress of dealing with unemployment that may explain this.

"And, probably, job loss has a stronger effect than a stressful job."

Dr Donna Arnett, of the American Heart Association, said: "This confirms other work that shows life stressors can increase your risk of a heart attack.

"Being out of work can be very stressful.

"But we still don't know how stress effects cardiovascular risk. It's an area that needs more research."

She said there were ways to handle stress to minimise its effects.

"Doing some exercise is a great way to reduce stress levels," Dr Arnett said.

Ann McCracken of the International Stress Management Association said: "You may not be able to change the fact you are unemployed but you can change how you think about it and that will affect your health outcomes both short and long term.

"When unemployment occurs consider what you can do to keep yourself physically active and mentally engaged as that is a key element to maintaining your wellbeing.

"Home study, re-training, part-time charity work or volunteering, helping a neighbour, undertaking the DIY jobs you've been meaning to do for ages, or maybe even some gardening. Become pro-actively resourceful..."