Occupation can alter heart attack risk
Having an unexciting occupation may increase your risk of a heart attack, believe researchers.
Dull, steady work is associated with a faster and less variable heart rate, which, in turn, is linked to heart disease, say UK scientists.
The team from University College London studied more than 2,000 male civil servants.
The British Heart Foundation said the Circulation study findings could be linked to underlying depression.
It is already known that people in low-paying jobs and with lower educational achievements have a higher risk of heart disease. Depression has also been linked with heart disease.
Many of the men with low-grade jobs that Dr Harry Hemingway and colleagues studied also reported being depressed.
Heart rate variability
Heart rate variability (HRV) is a measure of the heart's ability to adapt to current circumstances. For instance, during exercise the heart needs to beat faster to pump more oxygen to the muscles, while during sleep a fast heart rate is unnecessary.
A decreased HRV therefore means that the heart is less able to adapt. It also increase the risk of developing an irregular heart beat - known as an arrhythmia - which in extreme circumstances can trigger sudden death.
The heart beat is controlled by the autonomic nervous system, which is responsible for regulating basic body functions that are not under our conscious control.
Therefore, a decreased HRV is a sign that the autonomic nervous system is not regulating heart beat in the way that it should.
Dr Hemingway's team found that men with lower-grade jobs - meaning they had little control over their daily tasks - and those in low social positions had unchanging heart rhythms compared to the other men.
The effect was apparent even when the researchers considered other factors that can change heart risk, such as smoking and lack of exercise.
Dr Hemingway said: "We hope this information provides insight into the mechanisms at work so that there is a possibility for interventions that will change this outcome."
He said it might be possible to help prevent heart disease by changing workplace conditions.
Alison Shaw, medical spokesperson for the British Heart Foundation, said: "Over recent years researchers have suggested that psychological factors, such as depression, are linked with reduced heart rate variability, which in turn has been linked to coronary heart disease (CHD).
"This study helps to increase our understanding of the mechanisms that link depression with CHD and the way it may affect people working in jobs in which they have little control.
"It is important that we learn more about the influence of depression on heart rate variability and its effect on cardiac disease.
"It must be remembered that heart rate variability is also dependent on age and inactivity.
"Although depression and isolation are clear factors that need to be addressed, it is also vital to consider lifestyle issues such as levels of physical activity, diet and smoking to reduce the risk of coronary heart disease."