Reuters Health News | June 28, 2018

Men with heart disease, diabetes, or a history of stroke are more likely to die prematurely when they have a stressful job even when they’re relatively healthy, a large European study suggests.

Doctors have long advised patients with heart disease and diabetes to try to reduce major sources of stress in their lives as one way to help minimize their risk of heart attacks and strokes. But studies to date haven’t offered decisive proof that this approach helps people live longer, researchers note in the Lancet Diabetes & Endocrinology.

For the current study, they examined data on 102,633 men and women living in Finland, France, Sweden, and the UK who participated in one of seven studies examining the relationship between work stress and mortality.

“We found that work stress is particularly harmful for those with problems in the cardiovascular and metabolic systems, such as those with diabetes, heart disease, or a history of stroke,” said lead study author Mika Kivimaki, a researcher at the University College London and the University of Helsinki.

“We found that this excess risk remained even if the person was free of conventional risk factors, such as smoking, high blood pressure, or high cholesterol concentration,” Kivimaki said by email.

Researchers examined two aspects of work stress: having high demands or responsibility but little control or authority, and having a large difference between effort and reward.

At the start of the study, 3,441 participants had health problems such as heart disease, diabetes, or a history of stroke. After an average follow-up period of almost 14 years, 3,481 people had died.

Men with health problems like heart disease and diabetes were 68% more likely to die when they had work stress than when they did not, the study found.

Even when men diagnosed with these health problems followed a healthy lifestyle, they were twice as likely to die if they had stressful jobs. For those who had achieved normal blood pressure and cholesterol levels, work stress was nonetheless associated with more than a six-fold increase in their risk of a premature death.

None of the women in the study appeared to have an increased risk of premature death when they suffered from work stress. For men without heart disease but with an “effort-reward imbalance” at work, the mortality risk was increased by 22%.

The mortality rate for men with work stress and heart disease, diabetes, or a history of stroke was about 150 fatalities for every 10,000 people per year; absent a stressful job, the annual rate was 98 fatalities for every 10,000 people.

Stress was associated with almost as much increased death risk as current or former smoking, with 78 fatalities a year out of every 10,000 people.

Work stress was also linked to a bigger increase in death rates than high blood pressure, high cholesterol, obesity, physical inactivity, and heavy drinking.

However, people with chronic health problems like heart disease and diabetes tend to experience more depression and other psychological problems than individuals without these health issues, and this might at least partially explain the study results, Yulong Lian of Nantong University in Jiangsu, China, writes in an accompanying editorial. Lian didn’t respond to requests for comment.

Past research has found that chronic work-related stress corrodes health in two major ways: directly, by affecting the nervous and hormonal systems that control heart rhythms, blood vessels, blood clotting, inflammation, and other factors; and indirectly, by fostering unhealthy coping mechanisms like smoking, unhealthy eating, alcohol abuse, and lack of exercise.

The current study wasn’t a controlled experiment designed to prove whether or how work stress might hasten death. Another limitation is that researchers lacked data on the duration and severity of work stressors or chronic health problems like heart disease and diabetes.

Still, it would be a mistake for women or for men without heart problems to think a stressful job can’t take a toll on their health, said Dr. Pouran Faghri, director of the Center for Environmental Health and Health Promotion at the University of Connecticut in Storrs.

“The consequence of chronic stress on the body is the same for both men and women,” Faghri, who wasn’t involved in the study, said by email.

“Unfortunately, many people in low socioeconomic status are working in these types of jobs,” Faghri added. “They have no control in changing their work situation.”

—Lisa Rapaport