Combat service is a strong predictor of heart failure, according to a new US study which found that veterans with experience in the battlefield may be about five times more likely to develop heart failure than those who have not seen combat.
Researchers also found that veterans with posttraumatic stress disorder (PTSD) may have a nearly 50 per cent greater risk of developing heart failure.
The study of more than 8,000 veterans living in Hawaii and the Pacific Islands, adds to a growing body of evidence linking PTSD and heart disease, researchers said.
The research to date - including these latest findings - does not show a clear cause-and-effect relationship. But most experts believe PTSD, like other forms of chronic stress or anxiety, can damage the heart over time.
"There are many theories as to how exactly PTSD contributes to heart disease. Overall, the evidence to date seems to point in the direction of a causal relationship," said Dr Alyssa Mansfield, one of the study authors.
Mansfield was senior author on the study while with the Pacific Islands Division of the National Center for PTSD of the Department of Veterans Affairs (VA).
The study tracked 8,248 veterans who had been outpatients in the VA Pacific Islands system. The researchers followed them for an average of just over seven years.
Those with a PTSD diagnosis were 47 per cent more likely to develop heart failure during the follow-up period. The researchers controlled for differences between the groups in health and demographic factors.
Out of the total study group, about 21 per cent were diagnosed with PTSD. Of the total 371 cases of heart failure during the study, 287 occurred among those with PTSD, whereas only 84 cases occurred among the group without PTSD.
Combat service, whether or not it led to a full-blown PTSD diagnosis, was itself a strong predictor of heart failure.
Those veterans with combat experience were about five times more likely to develop heart failure during the study period, compared with those who had not seen combat.
The authors of the study said they didn't have access to a full range of data that would have provided further clues as to the PTSD-heart disease link.
For example, they were not able to distinguish in the data between those who had served in the Gulf during 1990 and 1991, and those who served more recently in Iraq or Afghanistan.
Nor were they able to analyse whether racial or ethnic identity plays a role one way or the other, as that information was not complete for most veterans in study.
The findings appear in the American Journal of Public Health.
