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Eliminating extraneous confounding factors in a study of Vietnam vets with PTSD reveals their risk of heart disease long after that war ended.

PTSD was linked to an increased risk of dying relatively young of heart disease among U.S. Army Vietnam War-era veterans—especially among those stationed in Vietnam, according to a 15-year prospective study.

The study was based on data collected in 1985 and 1986 from a sample of 4,328 men who served in the U.S. Army from 1965 to 1971. Included in the sample were 2,409 individuals who were sent to Vietnam. All study participants completed a telephone questionnaire, and a random subsample was given extensive physical examinations at baseline.

To ensure the study’s validity, the researchers sought to eliminate extraneous, confounding factors by excluding from analysis those veterans who had heart disease at the study’s start, reported Joseph Boscarino, Ph.D., M.P.H., senior investigator at the Henry Hood Center for Health Research at the Geisinger Clinic in Danville, Pa.

Veterans in the subsample were given electrocardiograms, Boscarino explained in an interview. Blood-pressure readings and cardiovascular-medication use were used to screen out borderline heart disease cases. The researchers also controlled for family history of heart disease, smoking, obesity, and diabetes.

About 10 percent of veterans who served in Vietnam (regardless of their nominal combat status) and 3 percent of those who were in the Army but served elsewhere were diagnosed with posttraumatic stress disorder (PTSD) in 1985. All veterans were assessed for PTSD diagnostic and symptom status by two scales, one based on DSM-III criteria (D-PTSD) and another developed by Terence Keane, Ph.D., and based on the Minnesota Multiphasic Personality Inventory (K-PTSD).

By the completion of follow-up in 2000, 52 of the veterans in the total sample had died of a heart attack, chronic ischemic heart disease, atherosclerotic disease, hypertensive heart disease, or heart failure.

“[H]aving a diagnosis of PTSD at baseline, such as having a positive D-PTSD case definition, doubled the risk of death from early onset heart disease at follow-up,” wrote Boscarino in an article in the July Psychosomatic Medicine. “[I]n addition to the short-term psychological consequences previously reported among returning war-fighters, for some we can expect longer-term stress injuries to manifest as clinical disease decades after exposure.”

He also analyzed outcomes by symptom levels as well as by diagnostic case definition, then adjusted results for duty location, age, smoking, depression, and other factors.

Among all veterans, the association between PTSD and heart disease mortality was no longer statistically significant for those who met the case definition, but remained so for those with PTSD symptoms. However, among veterans who served in Vietnam, the statistically significant link between death from heart disease and PTSD remained even after adjustment for lifetime depression, diabetes, and combat exposure.

The study showed a dose-response pattern, as well. “[A] 5-point increase on either the D-PTSD or the K-PTSD scale … resulted in a 20 percent increase in future heart disease mortality,” wrote Boscarino.

There are biologically plausible mechanisms to connect PTSD to heart disease, ranging from the hypothalamic-pituitary-adrenal or sympathetic-adrenal-medullary axes to health behaviors such as overeating or drinking alcohol, said Boscarino. Alternatively, some common genetic pathway might underlie a predisposition to both PTSD and heart disease.

The study points to the long-term outcomes of PTSD but began at least a decade after American troops returned from Vietnam, said Boscarino. Current investigations of PTSD and its effects resulting from the wars in Iraq and Afghanistan should benefit from better design and from being able to look at soldiers before, during, and after their exposure to combat.

“The current scale of research, screening, and treatment seems impressive to me,” he told Psychiatric News. “There is better coordination between the Department of Defense and the VA now, and they are putting a lot of funding into basic science, clinical studies, and epidemiology.”

An unrelated study, based on the 2001 National Survey of Veterans and published in the September Military Medicine, found that veterans under age 60 who served in Vietnam had worse self-reported health and higher rates of stroke than those who served elsewhere during that time. Vietnam veterans older than 60 had poor self-rated health and a higher risk for cancer than their peers.

Authors of both reports suggested that studies like these can be used to encourage treatment among the newest veterans and to plan for treatment services as they age.

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