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Using multivariate statistical models, no significant relationship was found between the rate of 2,3,7,8-tetrachlorodibenzo-p-dioxin ( TCDD) elimination and the occurrence or time to onset of diabetes in 343 veterans of Operation Ranch Hand, the unit responsible for the aerial spraying of Agent Orange and other TCDD-contaminated herbicides during the Vietnam War. Without adjustment for age, body mass index, family history of diabetes, and smoking history, the time to onset of diabetes decreased and the risk of diabetes increased with a diminished elimination rate. However, after adjustment, diabetes time to onset and occurrence were not significantly associated with TCDD elimination. Analyses of covariance found no significant difference between the average elimination rates of diabetic and nondiabetic veterans, without or with adjustment for risk factors. To our knowledge, this is the only study to date to examine TCDD elimination and diabetes.

A combined analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) elimination in Seveso adults and Ranch Hand veterans found a period of fast elimination within the first 0.27 years after exposure in Seveso, followed by a period of slower elimination between 3 and 16.35 years from exposure. The mean TCDD elimination rate within the first 0.27 years after exposure among six adult males in the Seveso cohort was 2.0646 year(-1) (half-life=0.34 years). The mean rate from 3 to 16.35 years was 0.1011 year(-1) (half-life=6.9 years). The mean Ranch Hand elimination rate, 00924 year(-1) (half-life=6.9 years), measured between 9 and 33 years after exposure, was significantly less than the Seveso mean in the first 0.27 years after exposure, but not significantly different from the Seveso mean between 3 and 16.35 years after exposure. The fast elimination within the first 0.27 years followed by a slower rate after 3 years is consistent with the expected pattern in a two-compartment open model, with a distribution phase of rapid elimination followed by a slower elimination phase.