A stress-filled life really does seem to raise the odds of heart disease and stroke down the road, according to a large study from Sweden.

The researchers found that among more than 13,600 men and women followed since middle-age, those who reported chronic stress at the study’s outset faced a somewhat higher risk of fatal or non-fatal heart disease or stroke over the years.

The link was strong only among men, although a weak relationship between stress and cardiovascular ills was found in women, the study authors report in the European Heart Journal.

Researchers have long studied the possible role of chronic stress in heart problems and stroke, with many studies - though not all - supporting a relationship. It’s thought that constant stress may take a toll on the arteries in a number of direct or indirect ways, from causing chronically high levels of stress hormones to pushing people to maintain unhealthy habits like smoking.

The new study included middle-aged men and women who between 1974 and 1980 were questioned about their stress levels over the previous one to five years. They were then followed through 1999 to see who developed cardiovascular disease.

The researchers found that participants who reported chronic stress at the study’s start were 14 percent more likely to develop heart problems or suffer a stroke, regardless of other factors such as family history, body weight, smoking and high blood pressure.

But it was men’s risk of fatal stroke that showed the clearest relationship to stress; stressed-out men were twice as likely as their peers to die of a stroke.

The reason for this particularly strong link is unknown, the study’s lead author, Dr. Bertil Ohlin of University Hospital in Malmo, told Reuters Health.

He noted that other investigators have made similar findings, although he also said he knows of “no good biological hypothesis” to explain why stress might raise the risk of fatal stroke in particular.

It’s been suggested, Ohlin noted, that stress is related to lower income, which could mean that highly stressed people tend to seek hospital care later than others do. However, he and his colleagues factored in participants’ occupations, making lower income an unlikely explanation for the higher rate of fatal stroke.

As for the weaker findings among women, Ohlin said this is likely due to the fairly low number of heart disease and stroke cases among women, rather than a resistance to the health effects of chronic stress.

SOURCE: European Heart Journal, May 2004.