An Environmental Perspective of the American Diabetes Association’s 75th Scientific Sessions

written by Sarah Howard
Coordinator of the Diabetes-Obesity Spectrum Working Group

Over 18,000 people from around the globe gathered in Boston June 5-9, 2015, for the American Diabetes Association’s premier annual scientific conference. Thanks to CHE, I was able to attend, and here summarize information I found on the development of diabetes—including environmental factors (especially chemicals), developmental origins, and the natural history of the disease.

Environmental chemicals

While there were not any sessions on environmental chemicals per se, I did find ten posters on this topic (see below for links to abstracts and online e-posters). The one that struck me most was by Su Hyun Park, who found an association between levels of persistent organic pollutants (POPs) and beta cell dysfunction in 7-9 year old Korean children. Exposure to POPs, as well as to other chemicals, have been associated with beta cell dysfunction in other studies before, but there are few studies in humans, even fewer in children, and few at exposure levels found in the general population. (I told her I thought that hers was the most important poster of all 2373 of them and she laughed, but I stand by my opinion).

Review of the Evidence on Developmental Exposure to Certain Endocrine Disrupting Chemicals and Obesity

written by Sarah Howard
CHE Diabetes-Obesity Spectrum Working Group Coordinator

A review article on prenatal exposure to endocrine disrupters and obesity was just published. Overall, it found that, “For certain EDCs, early life exposure may be associated with weight homeostasis later in life, however not necessarily in an obesogenic direction.” The review includes both human and laboratory evidence (19 studies) published since 1995. (The review did not include studies on BPA.) Here are their findings for the chemical classes included:

Organotins

Organotins are well-documented obesogens in laboratory studies. Human studies, however, are not available. Prenatal exposure to tributyltin causes adioposity in exposed mice, and these effects may be transmitted to future generations as well.

Top 10: 1st Quarter 2014

CHE offers this selection of research, news and announcements that were of special significance during the first quarter of 2014. Items include research that made a noteworthy contribution to the field, news and announcements that took a conversation to a new level and/or new audience and some welcome action. As before, we offer both the scientific report and media reporting on it, when available, to meet the needs of our various audiences.

1. Tobacco use
   Three items relating to tobacco use are of particular note this quarter:
   1. Historic smoking report marks 50th anniversary
      Those of us old enough to remember the Virginia Slims commercials from the 1970s will appreciate the irony of employing their slogan regarding changing the culture of smoking: “You’ve come a long way.” As described in this news article, “fifty years ago, ashtrays seemed to be on every table and desk. Athletes and even Fred Flintstone endorsed cigarettes in TV commercials. Smoke hung in the air in restaurants, offices and airplane cabins. More than 42 percent of US adults smoked, and there was a good chance your doctor was among them. The change of culture around smoking in public is one of the biggest public health success stories, done largely without heavy regulation.” This sea change in tobacco’s acceptance provides both hope and lessons for current campaigns. See a related article: Eight million lives saved since US alarm on smoking 50 years ago, the JAMA themed issue: 50 Years of Tobacco Control, and The Health Consequences of Smoking — 50 Years of Progress: A Report of the Surgeon General, 2014.
   2. Health effects of “thirdhand smoke”
      A growing body of research on harmful effects of smoke and ash residue shows that this is a health concern: Cigarette smoke toxins deposited on surfaces: implications for human health, Thirdhand smoke causes DNA damage in human cells, plus older but relevant Third-hand smoke exposure and health hazards in children and The impact of second-hand tobacco smoke exposure on pregnancy outcomes, infant health, and the threat of third-hand smoke exposure to our environment and to our children.
   3. Policy shifts in smoking
      CVS drugstores to stop selling cigarettes over health issues: “Drugstore chain CVS will stop selling cigarettes this year after corporate leaders decided that offering tobacco products is antithetical to the company’s goal of improving customer health. This decision came with an expected economic loss to the company.” A large review bolsters the case for such policy shifts: Effect of smoke-free legislation on perinatal and child health: a systematic review and meta-analysis.
2. Chlorinated persistent organic pollutants, obesity, and type 2 diabetes
   Not only does this article review the extensive evidence linking these conditions, it also explains puzzling findings in the field related to high vs low dose exposures and nonmonotonic dose-response curves, found in not only laboratory but also in epidemiological studies. It addresses the perplexing role of POPs in adipose tissue– perhaps a safer place to store them than in organs– but also causing harmful inflammatory effects in fatty tissue. It reviews the role of POPs as potential obesogens, as well as their potential interaction with gut microbiota, mitochondrial dysfunction, and other mechanisms. It outlines how future research may address some of the remaining questions in the field.
3. Research and controversy around BPA
   1. Bisphenol A (BPA) pharmacokinetics with daily oral bolus or continuous exposure via silastic capsules in pregnant rhesus monkeys: relevance for human exposures: This research addresses the ongoing controversy in BPA research about using silastic capsules versus oral bolus. This study suggests that oral bolus exposure is not an appropriate human exposure model. Differences in pharmacokinetics of dBPA were evident between pre-pregnancy, early and late pregnancy, likely reflecting changes in maternal, fetal and placental physiology.
   2. FDA finding on BPA: The FDA’s publication, Toxicity evaluation of bisphenol A administered by gavage to Sprague-Dawley rats from gestation day 6 through postnatal day 90 generated a great deal of comment. See opposing views of the review: BPA is A-OK, says FDA and Scientists condemn new FDA study saying BPA is safe: “it borders on scientific misconduct.” Also compare FDA’s finding to news from France: RAC proposes to strengthen the classification of bisphenol A.
4. The Elk River chemical spill in West Virginia
   This event and its repercussions kept water quality, chemical contamination, testing and regulation in Americans’ minds for weeks. Most notably it highlighted the failures of the Toxic Substances Control Act (TSCA) and need for chemical policy reform. Though there were dozens of news articles and analyses, one example of the reach and possible impact of this story is Data deficit on Elk River chemicals shows need for TSCA reform, legislators say. “Members of a House subcommittee pointed to the lack of toxicity and other data on chemicals that recently contaminated drinking water for hundreds of thousands of West Virginia residents as illustrating a key reason the Toxic Substances Control Act needs to be revised.”
5. Inheriting fear
   New research demonstrates that fear can be passed on from one generation of laboratory animals to the next. Epigenetic changes are most likely responsible, and this provocative study is bringing new challenges to how scientists think about behavior and evolutionary change.
   1. See the study: Parental olfactory experience influences behavior and neural structure in subsequent generations.
   2. See also similar research regarding “inherited” stress: Is stress contagious? Study shows babies can catch it from their mothers and the study: Stress contagion: physiological covariation between mothers and infants.
6. Fracking and health
   As more research and news regarding fracking emerges, the concerns and controversies about fracking’s potential impact on human health continue to deepen. In this last quarter, a few important new studies and reports were published:
   1. 4 states confirm water pollution from drilling: “In at least four states that have nurtured the nation’s energy boom, hundreds of complaints have been made about well-water contamination from oil or gas drilling, and pollution was confirmed in a number of them, according to a review that casts doubt on industry suggestions that such problems rarely happen.”
   2. Study shows fracking is bad for babies: researchers found that proximity to fracking increased the likelihood of low birth weight by more than half, from about 5.6 percent to more than 9 percent. The chances of a low Apgar score, a summary measure of the health of newborn children, roughly doubled, to more than 5 percent. See the study: Birth outcomes and maternal residential proximity to natural gas development in rural Colorado but also State questions study linking fracking to birth defects.
   3. Ohio earthquakes linked to fracking: “Ohio authorities shut down a hydraulic fracturing natural gas operation in Mahoning County on Monday after two earthquakes were felt in the area.”
   4. Report: Big Oil, Bad Air: Fracking the Eagle Ford Shale of South Texas: “an eight-month investigation found Texas regulators are largely ignoring air pollution problems caused by fracking the Eagle Ford Shale.” See also Planning for fracking on the Barnett shale: urban air pollution, improving health based regulation, and the role of local governments: “Using the community experience on the Barnett Shale as a case study, this article focuses on the legal and regulatory framework governing air emissions and proposes changes to the current regulatory structure.”
7. The Textbook of Children’s Environmental Health
   This textbook edited by Philip Landrigan, MD, MSc, and Ruth Etzel, MD, PhD, provides one of the most comprehensive overviews of the research and clinical applications to date and the scientific basis in clear and accessible language for why promoting children’s environmental health now is essential for a healthy, thriving society in the future. As the first course textbook of its kind, it could be used as the basis for the possible inclusion of questions on environmental health as part of the medical board certification process.
8. In many neighborhoods, the main obstacle to good health is poverty
   For decades, activists and scholars around the country have emphasized that focusing solely on changing individual behaviors is not enough to change the broader patterns of inequities in health. Researchers who study disparities have found that social and economic factors, such as employment, education, and social networks, also strongly influence whether people have the resources to protect their health. In racially segregated neighborhoods such as the one discussed in this article, with its crumbling infrastructure and history of institutional neglect, the main obstacle to good health is poverty. Though this is not news, we chose to include this piece because it highlights not just the problem, but shifts the conversation toward a more ecological model of health and includes possible solutions and some emerging evidence to bolster them as well.
9. Study questions fat and heart disease link
   “A large and exhaustive new analysis by a team of international scientists found no evidence that eating saturated fat increased heart attacks and other cardiac events.” This negates several decades of nutritional guidance and reopens a crucial conversation about what are the fundamentals of a healthy diet. See the study: Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis.
10. Climate risks as conclusive as smoking and lung cancer link – scientists
    In an unusual policy intervention, one of the world’s largest scientific bodies said evidence that the world is warming is as conclusive as the link between smoking and lung cancer. There has been much hyping from climate deniers of the uncertainty around climate science and predictions. This statement provides context for non-scientists. See the statement: What We Know and also the newest report from the Intergovernmental Panel on Climate Change: Climate Change 2014: Impacts, Adaptation, and Vulnerability.

New report: “Review of the Science Linking Chemical Exposures to the Human Risk of Obesity and Diabetes”

Sarah Howard
Coordinator of the CHE Diabetes and Obesity Spectrum Working Group

The UK nonprofit organization CHEM Trust (Chemicals, Health and Environment Monitoring Trust) just released a report on the links between chemicals and diabetes/obesity. Studies published in recent years provide compelling evidence that human chemical contamination can play a part in both conditions. The report concludes that the chemicals that we accumulate throughout life, via our everyday lifestyles, is likely to contribute to these modern epidemics. This is the same conclusion reached by the National Toxicology Program’s review of the scientific evidence on chemicals and diabetes/obesity, published last month.  

The CHEM Trust report, entitled Review of the Science Linking Chemical Exposures to the Human Risk of Obesity and Diabetes, is written by two of the world’s leading experts: Professor Miquel Porta, MD, MPH, PhD, of Spain and Professor Duk-Hee Lee, MD, PhD, of South Korea.