Longer workday increases risk for heart disease

June 1, 2011

Working 11 hours per day instead of 7 to 8 may make you wealthier, but it also may be deadly.

Working 11 hours per day instead of 7 to 8 may make you wealthier, but it also may be deadly. Researchers found that a longer work day increases the risk for developing coronary heart disease (CHD) by 67%.

They gathered data on more than 10,000 British civil servants since 1985; 7,095 had no symptoms of heart disease or angina and no medical histories of heart disease at the start of the study. All were full-time working men (n=4,986) and women (n=2,109).

The researchers then gathered data on heart disease risk factors such as cholesterol levels, blood pressure, age, smoking status, and diabetes. Participants reported their daily schedules, including the number of hours worked on an average weekday and time spent on work brought home. They followed the participants for 11 years, keeping track of the number of heart attacks that occurred; the development of other cardiovascular diseases; results of medical screenings, which occurred every 5 years; health records; and hospital data. During a median 12.3-year follow-up, 192 participants had incident CHD.

The authors of the study point out that the findings may not be generally applied to populations with a larger proportion of high-risk persons and were not validated in an independent cohort. However, they believe that because the increase in risk is so remarkable that including a measurement of workplace hours in a general practice interview should become standard practice.

Kivimäki M, Batty GD, Hamer M, et al. Using additional information on working hours to predict coronary heart disease: a cohort study. Ann Int Med. 2011;154(7):457-463.