Working long hours linked to stroke and heart disease

20 August 2015        

A woman working alone in a room

A new study, part-funded by us, has found that working long hours is linked to an increased risk of stroke and coronary heart disease. 

Researchers, led from University College London, have examined data from hundreds of thousands of people and found that there was a greater risk of stroke and coronary heart disease for people who work 55 hours or more per week, compared with working a standard 35 to 40 hour week. 

The research team, including BHF Professor Andrew Steptoe, used systematic reviews and meta-analyses of published and unpublished data to study the effects of long working hours on a large number of people up to August 2014.

What did they find out?

Comparing 25 studies, involving over 600,000 men and women from around the world for an average eight and a half years, the team found a 13% increased risk of coronary heart disease in people working 55 hours or more per week compared with the normal 35 to 40 hour week, even after accounting for other factors like gender, age and socioeconomic status. 

The team also collated information from 17 world-wide studies involving nearly 550,000 men and women for an average of just over seven years, and found a 33% higher risk of stroke in those working 55 hours or more a week compared with those working standard hours. This increased risk remained even after taking into account health behaviours such as smoking, alcohol consumption, and physical activity, and risk factors like high blood pressure and high cholesterol.

The researchers found that as people worked longer, their risk of stroke consistently rose. For example, compared with people who worked standard hours, those working between 41 and 48 hours had a 10% higher risk of stroke, and those working 49 to 54 hours had a 27% increased risk of stroke.

What does this mean?

Our Associate Medical Director, Dr Mike Knapton, said:

This research shows an association between long working hours and an increased risk of having a stroke and heart disease. It is plausible that there could be a causal relationship behind the link as sudden death following long working hours is often caused by stroke, due to long and repeated periods of stress, although that was not demonstrated in this study. 

"More research is needed if we are to understand and treat the biological processes that can lead to increased risk of stroke and heart disease for people who work long hours.

"This study highlights to doctors that they need to pay particular attention to cardiovascular risk factors when they advise people who work long hours."

Health at Work is our programme to inspire and support health and wellbeing in the workplace, and thousands of employers have already signed up. Join our fight and help keep the nation’s hearts working.