Author Interviews, Duke, Endocrinology, Environmental Risks, Thyroid Disease, Weight Research / 27.03.2019
Chemicals in Household Dust May Promote Fat-Cell Development
MedicalResearch.com Interview with:
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Dr. Kassotis[/caption]
Christopher D. Kassotis, Ph.D.
NRSA Postdoctoral Research Scholar
Stapleton Lab
Duke University
Nicholas School of the Environment
Durham, NC 27708
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Kassotis[/caption]
Christopher D. Kassotis, Ph.D.
NRSA Postdoctoral Research Scholar
Stapleton Lab
Duke University
Nicholas School of the Environment
Durham, NC 27708
MedicalResearch.com: What is the background for this study? What are the main findings?
- So this was something that Heather Stapleton had been curious about for years, as she's been one of several researchers characterizing the hundreds of chemicals that have been measured in indoor house dust. Before I came to Duke, one of her PhD students had measured the ability of many common indoor contaminants to activate the peroxisome proliferator activated receptor gamma (PPARg). The majority of these chemicals did, often quite well, which led to them testing indoor house dust extracts, also finding that the majority of dust extracts were also able to do so at very low levels. As PPARg is often considered the master regulator of fat cell development, the next obvious question was whether these common contaminants (and house dust) could promote fat cell development in cell models. My first work at Duke evaluated a suite of common indoor contaminants, finding that many of these chemicals could promote fat cell development, and that low levels of house dust extracts did as well.
- We next explored this more systematically in a group of adults involved in a thyroid cancer cohort (this was just recently published in Science of the Total Environment: https://www.sciencedirect.com/science/article/pii/S0048969719307715?dgcid=author
- In this study we evaluated the extent to which house dust extracts could promote fat cell development in a common cell model, and associated this with the metabolic health of adults living in these homes. We found that the greater extent of fat cell development was associated with significantly greater thyroid stimulating hormone concentrations (control residents only, with no evidence of thyroid dysfunction) and lower free triiodothyronine (T3) and thyroxine (T4). We further found a significant and positive association between extent of fat cell development and the body mass index (BMI) of all adults in the study. So this suggested that the indoor environment might play a role in the BMI and metabolic health of residents, and we next wondered if this would be more pronounced in children, who may be exposed to these contaminants during a critical window of development.
- The next step, for our current work, was to substantiate these effects in a larger group of households, each with children.
- Our major conclusions thus far have been that ~80% of house dust extracts promote significant fat cell development in a cell model - either via development from precursor cells into mature fat cells, measured via accumulation of lipids into the cells, or via the proliferation of those precursor fat cells. We also reported positive correlations of fat cell development with the concentrations of 70 different contaminants in the dust from these homes, suggesting that mixtures of contaminants are likely all acting weakly to produce these effects in combination. We’ve also begun to assess the other chemicals present in dust - chemistry can be either targeted (measuring concentrations of specific known chemicals in a sample), or non-targeted, where you try and determine the identity of the other chemicals in a sample. This has greater utility for identifying many more chemicals, though you will often not get chemical concentrations from this, nor absolute confirmed identification - just varying degrees of certainty based on evidence. Thus far we report approximately 35,000 chemicals in house dust samples across this study, and differential analyses have begun to pick out the few (less than 10 in each case) chemicals most differentially expressed between samples that exhibit high degrees of fat cell development in the lab vs inactive samples, for example, or which are differentially present in the homes of children categorized as obese or overweight. We are now working to confirm identity of these select contaminants that are more likely to be causative factors in the results we have observed.
Dr. McCrory[/caption]
Megan A McCrory, PhD, FTOS
Research Associate Professor
Dept of Health Sciences
Sargent College of Health and Rehabilitation Sciences
Boston University 02215
MedicalResearch.com: What is the background for this study?
Response: The prevalence of overweight and obesity has increased in the US, along with documented increases in portion size in the food supply. Fast food is popular, making up about 11% of adult daily calorie intake in the US, and over 1/3 of U.S. adults eat at fast food establishments on any given day. We therefore sought to examine changes in portion size, calories, and selected nutrients in fast-food entree, side, and dessert menu items across the years 1986, 1991, and 2016.
Dr. Ard[/caption]
Dr. Jamy Ard MD
Professor of Epidemiology and Prevention
Co-director,the Wake Forest Baptist Health Weight Management Center
Wake Forest School of Medicine
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Obesity continues to be a growing health challenge, and doctors need as many resources as possible to help their patients achieve success. The OPTIWIN trial shows that a total meal replacement program like OPTIFAST can help with significant and sustained weight loss.
The OPTIFAST Program is a medically monitored weight loss program that combines meal replacement with behavioral counseling and personalized support. In the OPTIWIN study, participants were randomized to either the OPTIFAST Program (OP) or a behavioral intervention using a food-based diet (FB).
At both 26 and 52 weeks, the OP group lost, on average, twice as much of their initial body weight as the FB group:
Jennifer Woo Baidal, MD, MPH
Assistant Professor of Pediatrics
Director of Pediatric Weight Management,
Division of Pediatric Gastroenterology, Hepatology, and Nutrition,
Columbia University Medical Center &
New York-Presbyterian Morgan Stanley Children’s Hospital
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Childhood obesity prevalence is historically high, with most incident obesity among children occurring before age 5 years. Racial/ethnic and socioeconomic disparities in childhood obesity are already apparent by the first years of life. Latino/Hispanic children in low-income families are at-risk for obesity. Thus, understanding potentially effective ways to prevent childhood obesity, particularly in vulnerable populations, should focus on early life.
Sugar-sweetened beverage (SSB) consumption is a modifiable risk factor for obesity and is linked to other adverse health outcomes. Maternal SSB consumption in pregnancy and infant sugar-sweetened beverage consumption in the first year of life are linked to later childhood obesity.
We sought to describe beverage consumption in a modern cross-sectional cohort of 394 low-income, Latino families, and to examine the relationship of parental attitudes toward sugar-sweetened beverages with parental and infant SSB consumption.
Dr. Janey Pratt, MD
Clinical Associate Professor, Surgery
Stanford University
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In 2013 obesity became recognized as a disease. The rate of pediatric obesity continues to rise. Severe pediatric obesity is rising at a even faster rate than obesity in pediatrics. Despite this Metabolic and Bariatric Surgery (MBS) remains underutilized in the treatment of severe pediatric obesity. There is a significant amount of adult data and now pediatric data about effective treatments for severe obesity. These support the use of MBS as a primary treatment for severe obesity in children. (BMI > 120% of 95th percentile with a comorbidity or BMI > 140% of 95th percentile).