A Matched Analysis of Diabetes Mellitus and Herbicide Exposure in Veterans of Operation Ranch Hand
Abstract
We studied diabetes in Air Force veterans exposed to Agent Orange and its contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (dioxin) during the Vietnam War. The index subjects of the Air Force's ongoing 20-year prospective epidemiological study were veterans of Operation Ranch Hand, the unit responsible for aerial herbicide spraying in Vietnam from 1962 to 1971. Other Air Force veterans who served in Southeast Asia during the same period but were not involved with spraying herbicides serve as Comparisons. The median dioxin level in the Ranch Hand group was 12.2 parts per trillion (ppt) [range: 0.6 to 617.8 ppt] and the median dioxin level in the Comparison group was 4.0 ppt (range: 0.4 to 54.8 ppt). We estimated relative risk in matched pairs, overall, and by dioxin exposure category, matched on year of birth, family history of diabetes, race, military occupation, and percent body fat while in Vietnam (to within 1%). We found the risk of diabetes significantly increased among Ranch Hands (relative risk=1.4, 95% CI 1.0 to 1.8, p=0.02) and a borderline significantly increased risk in the High exposure category (relative risk=1.6, 95% CI 1.0 to 2.5, p=0.06). These data also suggest that a previously observed "check mark" pattern of decreased risk at low dioxin levels and an increased risk at high levels may have been artifactual.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2006
- Accession Number
- ADA450788
Entities
People
- Joel E. Michalek
- Norma S. Ketchum
Organizations
- Air Force Research Laboratory