Prevalence of self-reported diabetes and exposure to organochlorine pesticides among Mexican-Americans: Hispanic Health and Nutrition Examination Survey

Background The prevalence of diabetes is higher among Mexican-Americans when compared to non-Hispanic Whites. Higher serum levels of organochlorine pesticides in Mexican-Americans have been reported. Few studies have explored the association between pesticide exposure and prevalence of diabetes.

Methods This study was conducted among a sample of 1303 Mexican-Americans aged 20-74 years from the Hispanic Health and Nutrition Examination Survey. Serum concentrations were available for seven pesticides or pesticide metabolites at quantifiable levels in at least 1% of the study population: p, p'-DDT, p, p'-DDE, dieldrin, oxychlordane, beta-hexachlorocyclohexane (beta-BHC), hexachlorobenzene (HCB), and trans-nonachlor. Logistic regression was used to evaluate the association of self-reported diabetes with exposure to organochlorine pesticides. Data is presented with and without adjustment for total serum lipids. Mean values of non fasting serum glucose were compared by level of exposure.

Results Self-reported diabetes was significantly associated with exposure above the detectable limit for trans-nonachlor, oxychlordane, and beta-BHC and among those with the highest level of exposure to p, p'-DDT and p, p' –DDE. A dose response relationship was found for exposure to trans-nonachlor, oxychlordane, p, p'-DDT and p, p' –DDE. Upon adjustment for total serum lipids, only the association with p, p'-DDT remained significant. Serum glucose levels were elevated among those exposed to trans-nonachlor and beta-BHC.

Conclusions This study suggests that exposure to certain organochlorine pesticides may be associated with increased prevalence of diabetes. Causality and a mechanism of action are unclear; future studies may help answer questions related to organochlorine exposure and endocrine system related disorders.