Agent Orange May Boost Vietnam Vets' Hypertension Risk

Mar. 23 -- FRIDAY, July 27 (HealthDay News) -- Exposure to the defoliant herbicide Agent Orange during the Vietnam War may be raising blood pressure levels for the aging veterans of that conflict.

That's the biggest change in the latest of a series of reports from the U.S. Institute of Medicine on the long-term health effects of Agent Orange. The report was released Friday.

The IOM's Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides last issued its updated findings in 2005; this report is based on data collected up to 2006. The reports are compiled at the request of the U.S. Department of Veterans Affairs.

"In two new studies, Vietnam veterans with the highest exposure to herbicides exhibited distinct increases in the prevalence of hypertension; the prevalence of heart disease was also increased," the report found, although the IOM committee stopped short of suggesting that wartime exposure to Agent Orange is currently raising veterans' risk of ischemic heart disease.

The group said the latest data on hypertension risk is of a much higher quality than prior research looking at links between Agent Orange and heart disease or heart disease risk factors. However, the new findings are "consistent" with those gleaned from prior research.

There were other changes to the IOM's latest update of Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam, which is issued every two years (this is the seventh such report).

As new data have emerged, a few important cancer types -- malignancies of the brain, stomach, colon, rectum and pancreas -- were moved from a category labeled "limited or insufficient evidence of no association [with Agent Orange]" to a more neutral category --"inadequate or insufficient evidence to determine association."

The committee was deadlocked and indecisive on whether to move two more tumor types -- breast cancer and melanoma -- as well as ischemic heart disease, from the "inadequate or insufficient evidence to determine association" category up to a category that implies there might be a connection to Agent Orange exposure -- "limited or suggestive evidence of association."