Shift work link to 'increased risk of heart problems'

An analysis of studies involving more than 2m workers in the British Medical Journal said shift work can disrupt the body clock and have an adverse effect on lifestyle.

It has previously been linked to an increased risk of high blood pressure and diabetes.

Limiting night shifts would help workers cope, experts said.

The team of researchers from Canada and Norway analysed 34 studies.

In total, there were 17,359 coronary events of some kind, including cardiac arrests, 6,598 heart attacks and 1,854 strokes caused by lack of blood to the brain.

These events were more common in shift workers than in other people.

The BMJ study  calculated that shift work was linked to a 23% increased risk of heart attack, 24% increased risk of coronary event and 5% increased risk of stroke.

But they also said shift work was not linked to increased mortality rates from heart problems and that the relative risks associated with heart problems were "modest".

The researchers took the socioeconomics status of the workers, their diet and general health into account in their findings.

No rest

Dan Hackam, associate professor at Western University, London, Ontario in Canada, said shift workers were more prone to sleeping and eating badly.

"Night shift workers are up all the time and they don't have a defined rest period. They are in a state of perpetual nervous system activation which is bad for things like obesity and cholesterol," he said.

The authors say that screening programmes could help identify and treat risk factors for shift workers, such as high blood pressure and cholesterol levels.

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