Hard Physical Labor May Boost Heart Disease Risk
Researcher says higher mental stress, lower income could be factors
"This delicate interaction between work and leisure-time activity warrants further research in order to appropriately guide public health," she said.
The study was presented at a meeting of the European Society of Cardiology, taking place this week in Rome.
In a second study presented at the same meeting, researchers looked at more than 14,000 middle-aged men who did not have heart disease and were followed for about three years on average. The investigators found that physically demanding work was a risk factor for developing coronary heart disease.
They also found that men with physically demanding jobs who also did moderate to high levels of exercise during their leisure time had an even greater risk (more than four-fold higher) of developing coronary heart disease.
Phillips, who also is an assistant professor in the department of medicine at NYU Langone, said the finding was a bit surprising. "This is a new finding that was not previously seen," he said. "Further studies to support this finding will be needed. As with many areas of medicine, a one-size-fits-all approach to leisure exercise might not work."
Study author Dr. Els Clays, of the department of public health at the University of Ghent, in Belgium, weighed in on the study in a society news release.
"From a public health perspective, it is very important to know whether people with physically demanding jobs should be advised to engage in leisure-time activity," Clays said.
"The results of this study suggest that additional physical activity during leisure time in those who are already physically exhausted from their daily occupation does not induce a 'training' effect but rather an overloading effect on the cardiovascular system," Clays said.
On the other hand, the study did find that men with less physically demanding jobs were 60 percent less likely to develop heart disease if they exercised during their leisure time.
"Further studies will be needed to find out the cause of increased heart disease in those people who have high physical job demands," Phillips said.
Both studies could point only to an association between hard physical labor and increased heart risk, not a cause-and-effect. Studies presented at a medical meetings typically are viewed as preliminary until published in a peer-reviewed journal.