Extended analyses of the association between serum concentrations of persistent organic pollutants and diabetes.

W e recently reported on serum concentrations of six persistent organic pollutants (POPs) and prevalence of diabetes in a random U.S. sample (1). Most previous epidemiological studies were restricted from studying several POPs given cost and serum amounts needed. Focus on selected POPs may be appropriate in occupational or accidental high exposure, but, in the general population with only background POP exposure, there is a need to study the concentrations of many interrelated POPs. Our initial approach to risk characterization was to calculate a summary to accumulate risk of exposure across six POPs (1). Even though the summary of six POPs was strongly associated with diabetes, individual POPs had substantial differences in strength of association (1). Thus, it is also of interest to estimate risk within subclasses of POPs that have similar physical and chemical properties. All POPs measured in the National Health and Nutrition Examination Survey (NHANES) can be div i d e d i n t o fi v e s u b c l a s s e s : polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), nondioxin-like PCBs, and organochlorine (OC) pesticides. Such specificity about diabetogenicity of POP subclasses would be especially important from the viewpoints of both toxicology and regulation. Therefore, in this article we report on the diabetes associations of 19 POPs within five POP subclasses, each detected among at least 60% of study subjects, i.e., in a manner identical to our most recent analysis of POPs and insulin resistance in the NHANES dataset (2).