As pediatric clinicians continue to see growing numbers of obese patients, Vanderbilt University Medical Center’s chief of pediatrics, Shari L. Barkin, M.D., is conducting deep-dive research into the interaction of multiple factors that affect children’s health and health disparities, including genetics, parent and child behaviors and the built and social environment.
Barkin, the William K. Warren Foundation Chair of Pediatrics at Vanderbilt, has spent her career examining how sometimes subtle influences can impact obesity, overall health and health disparities. The National Academy of Medicine elected Barkin as a member in October 2021 in recognition of her work.
Conducting research in settings from rural Appalachia to urban Los Angeles, Barkin has become internationally known for addressing big public health problems, such as youth violence and childhood obesity, and for applying a pragmatic approach by partnering with community organizations to ask and answer important questions.
While conducting research at Wake Forest University in North Carolina in the late 1990s, Barkin said she came face to face with the reality of obesity in rural communities.
“Many common chronic diseases in our society don’t happen one at a time or all at once, they happen together over time.”
“I could see that it was not something simple and not something that affected everybody equally,” she said. “At a macro level, it was impacting the Latino and African American populations most and seemed to suddenly tip. This was not sudden changes in nutrition or physical activity.”
Uncovering Health Disparities
Barkin’s focus on the interaction of genetics, behavior and environment is helping paint a picture of how metabolic changes occur over time.
“In science, we tend to look for cause and effect with a linear relationship; however, chronic diseases like obesity often have many interacting parts over time requiring consideration of delayed effects and non-linear relationships,” she said. “As an integrated scholar, I recognize that many common chronic diseases in our society don’t happen one at a time or all at once, they happen together over time.”
In a 2020 study, Barkin and colleagues found that DNA methylation patterns in the saliva of Hispanic children can be associated with obesity later in life.
“It is clear that susceptibility to obesity within an ‘obesogenic’ environment varies among individuals, it is not clear why,” the authors wrote. “This line of epigenetic inquiry using saliva as an accessible tissue for pediatric study holds promise for guiding further exploration in both understanding and intervening before the emergence of childhood obesity.”
Innovative Intervention Components
Another hallmark of Barkin’s work is the ability to translate research findings in ways that address health challenges in the real world.
In a July 2021 article, for example, Barkin and her co-authors examined the use of social networking by parents as part of an intervention effort for children at risk of obesity. Those parents who were in a network with another member of the intervention team spent 77 fewer minutes engaging in sedentary behavior per week during the study period, thus changing the pattern of behavior being modeled at home. The results show the “potential importance of promoting new social networks in community-based health promotion interventions to elicit and support behavior change,” the authors wrote. This guides the way forward in developing behavioral interventions that use the power of social networks.
Barkin also conducted the longest and largest randomized controlled trial in preschool-age children from underserved populations to examine obesity prevention. Published in the Journal of the American Medical Association in 2018, this study demonstrated changes in nutrition and physical activity consistent with recommended guidelines were not sufficient to slow the development of emerging early childhood obesity in underserved populations.
Lessons from Malnutrition
Barkin posits that examining social determinants in addition to behavior and epigenetics is critical to understanding context, something that individual behavior alone cannot overcome.
While obesity has emerged as a major health problem for the U.S. and many developed countries, its spread follows the same pattern as the malnutrition that spread across America in the previous century, Barkin said.
“It’s the same map where obesity is most prevalent now,” Barkin said. “Obesity is one of the most common forms of malnutrition. Such people often have sufficient calories but are lacking in sufficient nutrition.”
