MONDAY, Sept. 14, 2009 (HealthDay News) -- U.S. troops in Iraq and Afghanistan who go into combat are more likely to develop high blood pressure over the long term than those who serve in supporting roles, a new military study finds.
"Deployment with multiple combat exposures appeared to be a unique risk factor for newly reported hypertension," Nisara S. Granado, an epidemiologist at the Naval Health Research Center in San Diego and lead author of a report in the Sept. 14 online issue of Hypertension, said in a statement.
Hypertension, or high blood pressure, thus joins the list of problems resulting from constant exposure to the life-threatening experience of combat. They include post-traumatic stress disorder, depression, substance abuse and attention deficits.
Nisara and her colleagues drew on the records of 36,061 service members, including 8,829 deployed to Iraq and Afghanistan between 2001 and 2003. After a three-year follow-up, the researchers found that those who reported multiple combat exposures were 33 percent more likely to report they had high blood pressure than those spared combat.
Troops sent to combat areas but not exposed to combat were 23 percent less likely to report high blood pressure than those who saw action, the researchers said.
The finding comes as no surprise, said Dr. Kirk Garratt, director of interventional cardiovascular research at Lenox Hill Hospital in New York City.
"We know that the shock response to combat involves the release of catecholamines," Garratt said. Catecholamines are the "fight-or-flight" hormones, such as adrenaline.
"People in combat have stress syndromes afterward, and those stress syndromes involve high releases of adrenaline," Garratt said. "There are changes in the vascular tree that affect blood pressure. This finding makes perfect sense."
One very significant finding was that "for the deployers reporting combat exposure, only a certain type of combat exposure -- personally witnessing or being exposed to a person's death because of war or disaster -- was statistically significantly associated with newly reported hypertension," said Simon A. Rego, an assistant professor of psychiatry and behavioral sciences at Albert Einstein College of Medicine in New York City.
"Thus, it appears that deployment and even combat exposure in general do not increase the risk of hypertension," said Rego, who is also associate director of psychology training at Montefiore Medical Center. "Rather, it is being deployed and then experiencing or witnessing multiple stressful combat exposures involving a person's death."
Among the factors associated with high blood pressure were obesity, which tripled the risk; ethnicity, with blacks 84 percent more likely to report high blood pressure than whites, and general health. Those reporting poorer general health were 68 percent more likely to say they had high blood pressure.
"The finding will likely increase in significance in terms of the potential health consequences related to the operations in Iraq and Afghanistan, in particular as the wars continue on and soldiers face multiple deployments and an increased risk of stressful combat exposures," Rego said.
Common risk factors for high blood pressure are listed by the U.S. National Heart, Lung, and Blood Institute.