Melinda Sothern, PhD, CEP, Professor and Director of the Behavioral and Community Health Sciences Program at LSU Health Sciences Center New Orleans School of Public Health, has been awarded $675,000 in grant funding to advance her research on the role of social, genetic, environmental and behavioral determinants of future obesity. Five years later, Dr. Sothern is bringing back the same group of healthy children, now adolescents, in which she previously discovered early predictors of metabolic syndrome when they were 7-9 years old. The funding, from the National Institute on Minority Health and Health Disparities, is a sub-project in collaboration with the University of Alabama Birmingham.
"With soaring obesity rates and the earlier emergence of related conditions like type 2 diabetes, this type of research is critical," notes Dr. Melinda Sothern, principal investigator, one of the few scientists conducting cross-sectional studies of obesity in children and adolescents. "The identification of biomarkers at an early age may offer targets for diagnosis, treatment, and prevention."
Dr. Sothern previously documented evidence that supports relationships seen in adolescents between insulin sensitivity and fatty liver, belly fat, and total body fat and identified additional potential early markers of insulin resistance and metabolic syndrome in healthy 7-9 year-old children, including fat in muscle cells, blood pressure, physical activity, and birth weight. The study found that fat in the liver, abdominal fat, and fat oxidation predicted insulin resistance and appear to be early markers for the metabolic syndrome via a mechanism of impaired lipid metabolism and fat oxidation. Impaired metabolic function may be due, in part, to pre-and post natal factors that are modified by current physical activity. Therefore, race, low or high pregnancy weight and/or birth weight, and low physical activity collectively create a phenotype for poor metabolic function leading to increased risk for insulin resistance in young children.
"In order to fully capitalize on the wealth of data that we have successfully gathered and analyzed thus far, we feel it is essential that we establish a longitudinal group," says Dr. Sothern. "This will enable us to examine prospectively the development of obesity and metabolic dysfunction and its relationship to inflammation from puberty to adolescence in healthy, non-obese and obese children."
In the current research project, Dr. Sothern will be re-measuring BMI and also analyzing blood tests for metabolic and genetic parameters in 100 healthy obese and non-obese adolescents. Because obesity and the metabolic syndrome are associated with inflammation, Dr. Sothern's group will examine the role of genetically determined pro and anti-inflammatory compounds and the change in obesity and biomarkers from pre-adolescence to adolescence. Over the same period of time, they will also examine the contribution of social determinants such as stress, economic disadvantage, neighborhood deterioration, violence, diet, and physical activity environment that can modify these compounds. The researchers will factor in maternal pregnancy weight and whether or not participants were breast-fed and for how long, as well.
To date no studies have documented the progression of obesity, insulin resistance and inflammation through the pubertal period of development using objective measures in relation to molecular, social and behavioral determinants of health in multi-ethnic children and adolescents.
Correlating the molecular basis of the metabolic syndrome in developing children with the social determinants of health such as maternal stress, neighborhood deterioration, food and physical activity environment and behavioral factors, diet and exercise, is an innovative approach to preventing and managing obesity.
"Determining the precise role of inflammatory compounds in the development of future obesity-related metabolic diseases will allow us to define a genetic profile in children at risk, which could be used to tailor interventions for cardio-metabolic disease," concludes Dr. Sothern. "In addition, potential protective environmental and behavioral factors, such as increased access to fruits and vegetables after considering the confounding effects of maternal pregnancy weight, nutrition and physical activity could be targets for early intervention."
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