Having both a stressful job and difficulty sleeping may dramatically increase a person's risk of cardiovascular death.
The researchers found that in comparison with their peers who slept well and did not experience work-related stress, hypertensive employees with stress and insomnia were three times more likely to die from cardiovascular disease.
Researchers analyzed data from nearly 2,000 employees whose ages ranged from 25 to 65 years. These workers had high blood pressure, but, at the time of the study, they did not have cardiovascular disease or diabetes.
Although those with either job-related stress or insomnia did have an increased risk of cardiovascular death, the risk was higher when people had both of these factors present in their everyday lives.
The authors published their findings in the European Journal of Preventive Cardiology.
"These are insidious problems," notes Prof. Karl-Heinz Ladwig of the German Research Centre for Environmental Health and the Medical Faculty, Technical University of Munich.
"The risk is not having one tough day and no sleep. It is suffering from a stressful job and poor sleep over many years, which fade energy resources and may lead to an early grave."
Prof. Karl-Heinz Ladwig
Hypertension is a major risk factor for many
Researchers define hypertension as high blood pressure in the arteries.
According to the American Heart Association (AHA), normal blood pressure readings for adults sit below 120/80 millimeters of mercury (mm Hg), while people with hypertension have either a systolic pressure (upper number) of 130 mm Hg or higher or a diastolic pressure (lower number) of 80 mm Hg or above.
High blood pressure is a widespread problem in the United States, with the AHA estimating that close to 103 million adults have hypertension.
This number equates to almost half of all adults in the U.S., and experts note that the death rate stemming from hypertension is increasing. In fact, it rose by nearly 11% from 2005 to 2015.
However, other factors — such as smoking habits, high blood cholesterol, high blood pressure, physical inactivity, and being overweight — are modifiable.
High blood pressure is a significant risk factor for heart disease because when blood pressure becomes elevated, the heart has to work harder to pump blood around the body.
This extra work thickens the muscles of the heart, and it can also harden or damage artery walls. As a result, less oxygen makes its way to the body's organs, and the heart becomes damaged over time due to its increased workload.
How stress relates to sleep, heart health
Stress is another factor that can contribute to heart disease.
In the current study, the researchers defined a stressful job as one that places high demands on the employee without giving them much control over what they have to do and achieve each day.
They also noted that most of the people with sleep issues had problems staying asleep, while others had trouble falling asleep.
"Maintaining sleep is the most common problem in people with stressful jobs," says Prof. Ladwig. "They wake up at 4 o'clock in the morning to go to the toilet and come back to bed ruminating about how to deal with work issues."
Hypertension on its own is a major risk factor for heart disease, but pairing it with both insomnia and work-related stress compounds the potential problems.
Prof. Ladwig says that it would be a good idea for employers to offer stress management and sleep treatment in the workplace, while doctors should discuss sleep and job stress with people who have hypertension and may have a higher risk of issues with their cardiovascular health.