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Long work hours linked to higher risk of stroke

Occupational risk Need another reason to leave work on time?

Working 55 hours or more can significantly increase your risk of having a stroke, according to a new study.

The study, published in The Lancet , analysed data from 25 studies that tracked the health of over 600,000 men and women from Europe, the US and Australia for up to eight and a half years.

"Pooling of all available studies on this topic allowed us to investigate the association between working hours and cardiovascular disease risk with greater precision than has previously been possible," says the study's lead author Professor Mika Kivimäki of the Department of Epidemiology and Public Health, University College London.

The data showed that people working 55 hours a week had a 33 per cent greater risk of having a stroke than people who worked a standard 35 - 40 hour week.

And, the more hours people worked beyond standard hours, the higher their chance of having a stroke - even after accounting for other factors such as smoking, alcohol consumption, physical activity, blood pressure and cholesterol.

Working beyond 55 hours a week was also linked to a modest 13 per cent increased risk of developing coronary heart disease.

"Our findings suggest that more attention should be paid to the management of vascular risk factors in individuals who work long hours," say the researchers.

The researchers say a number of factors such as stress, physical inactivity, and high alcohol consumption may contribute to the higher risk of stroke seen in people who work longer hours.

Professor Dino Pisaniello of the University of Adelaide says physical inactivity for extended periods is an underlying risk factor for both stroke and coronary heart disease .

"Long working hours is a proxy for other risk factors, which may be more common in workers of low socio-economic status," says Pisanello.

"The [study] should provide a stimulus for workplaces and regulators to re-examine long working hours and in particular, long periods of physical inactivity for men in lower paid jobs."

Tony LaMontagne, a professor of work, health and wellbeing at Deakin University says the study reinforces a growing body of research that has linked long working hours to a variety of adverse health outcomes, as well as with work-family conflict.

Recent research by LaMontagne's group found that working over 49 hours was associated with lower mental health, especially for women working in jobs at higher occupational skill levels.

"[We] need to control working hours as a hazard to health just like we have controlled other workplace hazards in industrialised democracies, from traumatic fatalities on the job to asbestos-related cancers, says LaMontagne.

Related: Stressed at work? Look out for your heart