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Hints of altered microRNA expression in women exposed to EDCs


 

Endocrine-disrupting chemicals (EDCs) are structurally similar to endogenous hormones and are therefore capable of mimicking these natural hormones, interfering with their biosynthesis, transport, binding action, and/or elimination. In animal studies and human clinical observational and epidemiologic studies of various EDCs, these chemicals have consistently been associated with diabetes mellitus, obesity, hormone-sensitive cancers, neurodevelopmental disorders in children exposed prenatally, and reproductive health.

In 2009, the Endocrine Society published a scientific statement in which it called EDCs a significant concern to human health (Endocr Rev. 2009;30[4]:293-342). Several years later, the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine issued a Committee Opinion on Exposure to Toxic Environmental Agents, warning that patient exposure to EDCs and other toxic environmental agents can have a “profound and lasting effect” on reproductive health outcomes across the life course and calling the reduction of exposure a “critical area of intervention” for ob.gyns. and other reproductive health care professionals (Obstet Gynecol. 2013;122[4]:931-5).

Shelves of polycarbonate plastic bottles University of Cincinnati
More recently, the International Federation of Gynecology and Obstetrics similarly called for action to both prioritize research on women’s health and toxic reproductive agents and to address the consequences of exposure (Int J Gynaecol Obstet. 2015 Oct 1;131[3]:219-25).

Despite strong calls by each of these organizations to not overlook EDCs in the clinical arena, as well as emerging evidence that EDCs may be a risk factor for gestational diabetes (GDM), EDC exposure may not be on the practicing ob.gyn.’s radar. Clinicians should know what these chemicals are and how to talk about them in preconception and prenatal visits. We should carefully consider their known – and potential – risks, and encourage our patients to identify and reduce exposure without being alarmist.

Low-dose effects

EDCs are used in the manufacture of pesticides, industrial chemicals, plastics and plasticizers, hand sanitizers, medical equipment, dental sealants, a variety of personal care products, cosmetics, and other common consumer and household products. They’re found, for example, in sunscreens, canned foods and beverages, food-packaging materials, baby bottles, flame-retardant furniture, stain-resistant carpet, and shoes. We are all ingesting and breathing them in to some degree.

Bisphenol A (BPA), one of the most extensively studied EDCs, is found in the thermal receipt paper routinely used by gas stations, supermarkets, and other stores. In a small study we conducted at Harvard, we found that urinary BPA concentrations increased after continual handling of receipts for 2 hours without gloves but did not increase significantly when gloves were used (JAMA. 2014 Feb 26;311[8]:859-60).

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