Working more than 55 hours a week increases risk for an abnormal heart rhythm called atrial fibrillation, based on a recent study published in the European Heart Journal.
Known as the IPD-Work Consortium (Individual-Participant-Data Meta-analysis in Working Populations), this study tracked the health of nearly 85,500 adults in the UK and Scandinavia from 1991 through 2014. Its aim was to explore the impact of work-related stress on risk for chronic diseases, disability and mortality, as job strain has been linked to poorer health outcomes.
In the recent analysis, researchers explored the association between working hours and risk for atrial fibrillation. Atrial fibrillation, often referred to as AFib, is the most common type of abnormal heart rhythm, which affects anywhere from 2.7–6.1 million Americans. AFib increases a person’s risk for stroke by up to five times and contributes to an estimated 130,000 deaths each year.
A total of 85,494 men and women participated in the study, all of which completed questionnaires about their health and work hours upon enrollment. Work hours were categorized as fewer than 35 hours a week, 35–40 hours, 41–28 hours, 49–54 hours and 55 or more hours a week. No participants had atrial fibrillation at the start of the study.
After following participants for ten years, researchers found that adults who worked 55 hours or more a week were 40% more likely to develop AFib than those who worked 35–40 hours a week. This association existed even after taking into account factors that could affect risk for AFib, such as age, sex, obesity and physical activity.
“These findings show that long working hours are associated with an increased risk of atrial fibrillation, the most common cardiac arrhythmia,” explains lead author, Professor Mika Kivimaki from the Department of Epidemiology at University College London. “This could be one of the mechanisms that explain the previously observed increased risk of stroke among those working long hours. Atrial fibrillation is known to contribute to the development of stroke, but also other adverse health outcomes, such as heart failure and stroke-related dementia.”
However, authors note that findings should not cause alarm in healthy patients. Professor Kivimaki explains that for a young, healthy person with few cardiovascular risk factors, their risk for AFib is still very small, even if they do work long hours. On the other hand, the increased risk is concerning for adults already at high risk for heart problems, such as adults with high blood pressure, high cholesterol or diabetes.