Fulltimegipsy/shutterstockWorking long hours may seem like a smart investment in your future, but it’s just not that simple. For starters, people who work long hours tend to pull back from the rest of their lives, which hurts their quality of life and actually their work by extension. In Sweden, companies have begun scaling back to a six-hour workday because it seems to result in happier, healthier employees, which translates into better work product. Now it turns out that people who work long hours have a significantly higher risk of developing an irregular heart rhythm, according to a study published in the European Heart Journal. And an irregular heart rhythm is known to increase your risk of stroke and heart failure.
The research team, led by Mika Kivimaki, professor of epidemiology at University College London, analyzed data from 85,494 men and women from the four European countries (the United Kingdom, Denmark, Sweden, and Finland) who took part in one of eight long-term studies. The data included how many hours each person worked per week and each person’s existing cardiovascular health. None had atrial fibrillation, or AFib (the most common form of arrhythmia, which is an irregularity in the rate or rhythm of the heart beat) at the start of the studies, but 1,061 developed it over the next 10 years.
Crunching the data, Kivimaki’s team found that those who worked 55 hours or more were about 40 percent more likely than their counterparts who worked fewer hours to be in the group that developed the condition. Even adjusting for factors that could affect heart risk—age, sex, socioeconomic status, obesity, leisure time physical activity, smoking, and risky alcohol use, those who worked the long hours had nearly one and a half times the risk of developing arrhythmia. That means those who worked long hours had a 1.4 times higher risk of developing AFib.
Here is how it all fits together: AFib is known to increase the risk of stroke (as well as heart failure). Working long hours also specifically increases the risk of having a stroke, according prior research conducted by Professor Kivimaki. Accordingly, this new study may have shown that AFib is one of the mechanisms behind that increased risk of stroke for those toiling away at work for long hours.
As to why long hours increase the risk of AFib, Professor Kivimaki told Reader’s Digest: “Studies show that stress often precedes arrhythmia episodes.” He explained that stress creates certain responses in the autonomic nervous system (such as the release of adrenaline), and the autonomic nervous system, in turn, regulates the heart rate. Professor Kivimaki also hypothesizes that deterioration of healthy habits during stress periods may further increase atrial fibrillation risk.