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News from the National Academies
Date: Oct. 11, 2000
Contacts: Vanee Vines, Media Relations Associate
Mark Chesnek, Media Relations Assistant
(202) 334-2138; e-mail <news@nas.edu>

FOR IMMEDIATE RELEASE:

NEW REVIEW SUGGESTS POSSIBLE ASSOCIATION BETWEEN AGENT ORANGE AND ADULT-ONSET DIABETES

WASHINGTON -- New evidence supports the possibility of an association between chemicals used in herbicides during the Vietnam War and adult-onset (Type 2) diabetes, but it stops short of making a clear link, says a new report from the Institute of Medicine (IOM) of the National Academies. The report is the latest in a series examining the impact of Agent Orange on veterans' health.

Using the latest scientific studies, the committee that wrote the report re-evaluated whether exposure to the chemical defoliant Agent Orange and other herbicides used in Vietnam, some of which contained dioxin, was linked in any way with the development of adult-onset diabetes. The re-evaluation found new "limited or suggestive" evidence of an association, but the finding is not conclusive. Previous IOM reports had said that there was "inadequate or insufficient" evidence to determine whether a link existed.

Type 2 diabetes occurs when something goes wrong with the way that insulin is produced or used in the body. Increased sugar levels in the blood and urine, excessive thirst, and frequent urination characterize the disease. Over time, high sugar levels may cause damage to the eyes, kidneys, nervous system, or heart.

"Research findings that have now accumulated over a long period of time seem to support the possibility of a link between Agent Orange exposure and Type 2 diabetes," said committee chair David Tollerud, professor of public health and director, Center for Environmental and Occupational Health, MCP Hahnemann University School of Public Health, Philadelphia. "It must be emphasized, however, that any increased danger from herbicide or dioxin exposure appears to be small. The known predictors of diabetes risk - family history, physical inactivity, and obesity - continue to greatly outweigh any suggested increased risk from wartime exposure to herbicides."

A classification of "limited or suggestive" means that while there is evidence suggestive of an association between exposure and disease, the evidence is not conclusive enough to say definitively that chance or other factors did not influence the results of the studies that were evaluated, or that the studies have isolated all of the variables that could have affected the outcome. Although there is a plausible link between dioxin exposure and biologic changes associated with diabetes, the committee did not find that dioxin exposure leads to diabetes.

The ability of researchers to pinpoint the health risks faced by veterans is hampered by inadequate information about exposure levels of troops in Vietnam. Some of the evidence reviewed by the committee comes from evaluations of Air Force and Army troops who worked with herbicides. Most information, however, is from studies of people who were exposed to herbicides on the job or in industrial accidents. Although most veterans probably experienced lower levels of exposure than those who worked with the chemicals over long periods in occupational or agricultural settings, it is difficult to say precisely which troops may have encountered higher levels.

U.S. forces sprayed Agent Orange and other defoliants over parts of south Vietnam beginning in 1962. Most large-scale sprayings were conducted using airplanes and helicopters, but considerable quantities of herbicides were dispersed from boats and ground vehicles or by soldiers wearing back-mounted equipment. A 1969 scientific report concluded that one of the primary chemicals used in Agent Orange could cause birth defects in laboratory animals. The U.S. military therefore suspended the use of Agent Orange in 1970 and halted all herbicide spraying in Vietnam the following year.

The committee's work was sponsored by the U.S. Department of Veterans Affairs. The Institute of Medicine is a private, nonprofit institution that provides health policy advice under a congressional charter granted to the National Academy of Sciences. A committee roster follows.

Read the full text of VETERANS AND AGENT ORANGE: HERBICIDE/DIOXIN EXPOSURE AND DIABETES for free on the Web, as well as more than 1,800 other publications from the National Academies. Printed copies are available for purchase from the National Academy Press Web site or at the mailing address in the letterhead; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain a pre-publication copy from the Office of News and Public Information at the letterhead address (contacts listed above).

INSTITUTE OF MEDICINE
Division of Health Promotion and Disease Prevention

COMMITTEE TO REVIEW THE EVIDENCE REGARDING THE LINK BETWEEN EXPOSURE TO AGENT ORANGE AND DIABETES

DAVID J. TOLLERUD, M.D., M.P.H (CHAIR)
Professor of Public Health and Director
Center for Environmental and Occupational Health
MCP Hahnemann University School of Public Health
Philadelphia

MICHAEL J. AMINOFF, M.D.
Professor of Neurology
School of Medicine, and
Director of the Clinical Neurophysiology Laboratories,
and of the Movement Disorders Clinic and the Epilepsy Program
Medical Center
University of California
San Francisco

STEVEN N. GOODMAN, M.D., M.H.S., PH.D.
Associate Professor of Oncology, Pediatrics, Epidemiology,
and Biostatistics
Department of Oncology
Division of Biostatistics
School of Medicine
Johns Hopkins University
Baltimore

ROBERT F. HERRICK, PH.D., C.I.H., SC.D.
Lecturer on Industrial Hygiene
Department of Environmental Health
School of Public Health
Harvard University
Boston

IRVA HERTZ-PICCIOTTO, PH.D.
Associate Professor
Department of Epidemiology
School of Public Health
University of North Carolina
Chapel Hill

DAVID G. HOEL, PH.D.*
Distinguished University Professor
Department of Biometry and Epidemiology, and
Associate Director
Hollings Oncology Center
Medical University of South Carolina
Charleston

ANDREW F. OLSHAN, PH.D.
Associate Professor
Department of Epidemiology
School of Public Health
University of North Carolina
Chapel Hill

HOWARD OZER, M.D., PH.D.
Eason Chair and Chief of the Hematology/Oncology
Section, and
Director, Cancer Center
University of Oklahoma
Oklahoma City

KENNETH S. RAMOS, PH.D.
Professor
Department of Physiology and Pharmacology
College of Veterinary Medicine, and
Vice Chairman, Faculty of Toxicology
Texas A&M University
College Station

NOEL R. ROSE, M.D., PH.D.
Professor of Pathology and of Molecular Microbiology
and Immunology
Department of Molecular Microbiology and Immunology
School of Hygiene and Public Health
Johns Hopkins University
Baltimore

ARTHUR H. RUBENSTEIN, M.B.B.CH.*
Dean
Mount Sinai School of Medicine, and
Executive Vice President
Mount Sinai Center
New York City

MICHAEL P. STERN, M.D.
Professor of Medicine
Department of Medicine, and
Chief
Division of Clinical Epidemiology
Health Science Center
University of Texas
San Antonio

SUSAN WOSKIE, PH.D., C.I.H.
Associate Professor
Department of Work Environment
University of Massachusetts
Lowell

INSTITUTE STAFF

DAVID A. BUTLER, PH.D.
Study Director


*Member, Institute of Medicine