SERUM DIOXIN AND DIABETES-MELLITUS IN VETERANS OF OPERATION RANCH HAND

We studied diabetes mellitus and glucose and insulin levels in Air For ce veterans exposed to Agent Orange and its contaminant, 2,3,7,8-tetra chlorodibenzo-p-dioxin (dioxin), during the Vietnam War. The index sub jects of the Air Force's ongoing 20-year prospective epidemiologic stu dy are veterans of Operation Ranch Hand (N = 989), the unit responsibl e for aerial herbicide spraying in Vietnam from 1962 to 1971. Other Ai r Force veterans who served in Southeast Asia during the same period b ut were not involved with spraying herbicides serve as Comparisons (N = 1,276). The median serum dioxin level in the Ranch Hand group was 12 .2 parts per trillion (ppt) (range = 0-617.8 ppt), and the median diox in level in the Comparison group was 4.0 ppt (range = 0-10 ppt). We fo und that glucose abnormalities [relative risk = 1.4; 95% confidence li mits (CL) = 1.1, 1.8], diabetes prevalence (relative risk 1.5; 95% CL = 1.2, 2.0), and the use of oral medications to control diabetes (rela tive risk = 2.3; 95% CL = 1.3, 3.9) increased, whereas time to diabete s-onset decreased with dioxin exposure. Serum insulin abnormalities (r elative risk = 3.4; 95% CL = 1.9, 6.1) increased with dioxin exposure in nondiabetics. These results indicate an adverse relation between di oxin exposure and diabetes mellitus, glucose metabolism, and insulin p roduction.