A better understanding about the mechanisms of action and dose-response patterns of EDCs has indicated that EDCs can act at low doses, and in many cases a nonmonotonic dose-response association has been demonstrated. This is a paradigm shift for traditional toxicology in which it is “the dose that makes the poison,” and some toxicologists have been critical of the claims of low-dose potency for EDCs.
A team of epidemiologists, toxicologists, and other scientists, including myself, critically analyzed in vitro, animal, and epidemiologic studies as part of a National Institute of Environmental Health Sciences working group on BPA to determine the strength of the evidence for low-dose effects (doses lower than those tested in traditional toxicology assessments) of BPA. We found that consistent, reproducible, and often adverse low-dose effects have been demonstrated for BPA in cell lines, primary cells and tissues, laboratory animals, and human populations. We also concluded that EDCs can pose the greatest threats when exposure occurs during early development, organogenesis, and during critical postnatal periods when tissues are differentiating (Endocr Disruptors [Austin, Tex.]. 2013 Sep;1:e25078-1-13).
A potential risk factor for GDM
Quite a lot of research has been done on EDCs and the risk of type 2 diabetes. A recent meta-analysis that included 41 cross-sectional and 8 prospective studies found that serum concentrations of dioxins, polychlorinated biphenyls, and chlorinated pesticides – and urine concentrations of BPA and phthalates – were significantly associated with type 2 diabetes risk. Comparing the highest and lowest concentration categories, the pooled relative risk was 1.45 for BPA and phthalates. EDC concentrations also were associated with indicators of impaired fasting glucose and insulin resistance (J Diabetes. 2016 Jul;8[4]:516-32).