Employees who spend more than 49 hours at work each week are more likely to develop high blood pressure, according to a study by the American Heart Association.
A silent disease, hypertension affects more than one in three people, half of whom are unaware of their condition and therefore do not take any treatment.
High blood pressure results in hardening of the arteries and their premature aging, which exposes them to an increased risk of cardiovascular accidents, in particular, myocardial infarction, stroke, and renal failure.
Although most people with high blood pressure are over 65, it can develop much earlier, especially in people who work long hours.
This is the discovery of a new study by researchers from the Department of Medicine at Laval University in Quebec, whose findings have just been published in the Hypertension Journal Report and the journal of the American Heart Association.
Risk of hypertension from 41 hours per week
To study the correlation between long working hours and hypertension, researchers used more than 3,500 employees from three Québec public institutions to undergo three waves of testing over five years. The researchers first provided the volunteers with a portable blood pressure monitor to check their blood pressure, which they had to use at rest three times in the morning and then during their working day. The data was then collected every 15 minutes. Mean resting readings were 140/90 mmHg or higher and mean working readings were 135/85 mmHg or higher, which is considered high.
The results showed that working 49 hours or more per week was associated with a 70% higher probability of having masked hypertension and a 66% higher probability of having sustained hypertension. Those working 41 to 48 hours a week were 54% more likely to have masked hypertension and 42% more likely to have sustained hypertension.
“Both masked and sustained hypertension is associated with an increased risk of cardiovascular disease,” says Xavier Trudel, assistant professor in the department of social and preventive medicine at Québec City’s Laval University and principal author of the study.
In total, almost 19% of employees followed for five years developed hypertension, including those who were already receiving treatment. Over 13% of the workers had masked hypertension and were not receiving treatment for hypertension. “The relationship between long working hours and hypertension in the study was more or less the same for men and women,” Trudel said.
Stress as an important factor
How can this relationship between hypertension and weekly working hours be explained? Researchers believe that while work stress is indeed a high-pressure factor, other “related stressors can have an impact”. “Future research may examine whether family responsibilities-such as the number of children a worker has, household chores and child-care roles-can interact with work circumstances to explain hypertension.
“People should be aware that long hours at work can have an effect on heart health and, if they work long hours, they should ask their doctor to check their blood pressure over time with a portable monitor,” recommends Xavier Trudel. “Masked hypertension can affect a person for a long period of time and is associated, in the long run, with an increased risk of developing cardiovascular disease. We have already shown that in five years, about one in five people with masked hypertension has never experienced hypertension in a clinical setting, which can delay diagnosis and treatment,” he recalls.