Working long hours 'raises heart attack risk'

5 April 2011

Engraving of the heart

Working more than 11 hours a day increases your risk of heart disease by 67 per cent, compared with those working a standard 7-8 hours a day, according to a new UCL study.

The authors suggest that information on working hours could be useful to GPs when calculating a patient’s risk of heart disease, alongside other health measures such as blood pressure, diabetes and smoking habits.

The research, led by Professor Mika Kivimäki (UCL Epidemiology & Public Health) and funded by the Medical Research Council, used data from the Whitehall II study which has followed the health and wellbeing of over 10,000 civil service workers since 1985. For this study, men and women who worked full time and were free of heart disease or angina at the start of the study were selected, a total of 7095 study participants.

The researchers collected information on heart risk factors, such as age, blood pressure, cholesterol levels, smoking habits, and diabetes. They also asked participants how many hours they worked (daytime and work brought home) on an average weekday. During the 11-year follow-up, the researchers collected information about heart health, including those who had suffered from heart attacks, from medical screenings every 5 years, hospital data, and health records. They found that adding working hours to the normal assessment measures of risk of heart disease improved the ability of doctors to predict the risk of heart disease by five percent.

Professor Kivimäki said: "We have shown that working long days is associated with a remarkable increase in risk of heart disease. Considering that including a measurement of working hours in a GP interview is so simple and useful, our research presents a strong case that it should become standard practice. This new information should help improve decisions regarding medication for heart disease. It could also be a wake-up call for people who overwork themselves, especially if they already have other risk factors."

The study was also funded by the BUPA Foundation, the British Heart Foundation, National Institutes of Health and the National Heart, Lung and Blood Institute. The research is published today in the journal Annals of Internal Medicine.


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UCL study: Overtime ‘bad for your heart’