Work stress, poor sleep, high blood pressure a deadly trio
In a study of nearly workers with high blood pressure who were followed for almost 18 years, those who reported having both a stressful job and poor sleep were three times more likely to die from heart disease than those who slept well and didn't have a trying job, the investigators found.
"As many as 50% of adults have high blood pressure," said Dr Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles.
It's a major risk factor for heart attack, stroke, heart failure, kidney disease and premature cardiovascular death, said Fonarow, who had no role in the new study.
"A number of studies have found associations between greater work stress and subsequent risk of cardiovascular events. Impairment in sleep has also been associated with increased risk," he said. However, these associations did not prove a cause-and-effect relationship.
Good sleep habits
In the new study, the researchers reported that among people with high blood pressure ("hypertension"), those who had work stress alone had a twofold higher risk of dying from cardiovascular disease, as did those who reported having poor sleep alone.
According to lead researcher Dr Karl-Heinz Ladwig, "Sleep should be a time for recreation, unwinding and restoring energy levels. If you have stress at work, sleep helps you recover." Ladwig is a professor at the German Research Centre for Environmental Health and also with the Technical University of Munich.
"Unfortunately, poor sleep and job stress often go hand in hand, and when combined with hypertension, the effect is even more toxic," he added in a statement.
According to the study authors, a stressful job is one where employees have many demands but little control over their work. For example, an employer demands results but denies authority to make decisions.
"If you have high demands but also high control, in other words you can make decisions, this may even be positive for health," Ladwig said. "But being entrapped in a pressured situation that you have no power to change is harmful."
Poor sleep was defined as having difficulty falling asleep and staying asleep. "Maintaining sleep is the most common problem in people with stressful jobs," Ladwig said.
These problems combine over time to sap your energy and "may lead to an early grave," he added.
Ladwig suggested that to lower the risk of an early death, people have to keep their blood pressure low, develop good sleep habits and find ways to cope with stress.
Mika Kivimaki, a professor of social epidemiology at University College London, thinks this study provides a unique look at workplace risk.
Most previous research on work stress has targeted the general working population, he said.
"The effects on health have been relatively modest. However, recent findings suggest stress might be a much bigger problem for those with pre-existing disease. This new study supports this notion," said Kivimaki, who had no part in the study.
Focusing on people with high blood pressure was a good choice, he noted.
"In this group, atherosclerosis [hardening of the arteries] is common," Kivimaki said. And for these patients, "stress response could increase cardiac electrical instability, plaque disruption and thrombus [clot] formation," which can contribute to an irregular heartbeat (arrhythmia), heart attack or stroke.
The researchers think that employers can help by implementing programs that teach employees how to relax.
Employers should provide stress management and sleep treatment in the workplace, Ladwig added, especially for staff with chronic conditions like high blood pressure. Such programs should also include helping employees to quit smoking.
It is well known that people with high blood pressure can substantially lower their risk of heart attack and stroke by achieving and maintaining healthy blood pressure levels, Fonarow said. Whether or not workplace programs designed to reduce stress and improve sleep will pay off remains to be seen, he said.
The report was published April 28 in the European Journal of Preventive Cardiology.
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