A study on childhood obesity highlights significant epigenetic differences between European American and African American children, shedding light on the diverse gene regulation associated with obesity.
Childhood obesity is a significant problem globally. Epidemiological data from 2016 suggest that there are 340 million obese children and adolescents. Though childhood obesity appears to have peaked, its rates are significantly higher than in the 1980s for certain subgroups. Childhood obesity is not just due to high calorie intake. Genetic and environmental interactions play a vital role.
Additionally, childhood obesity disproportionately affects children of different racial backgrounds. Data from 2017 to 2020 showed that 24.8% of Black children were obese, whereas just 16.6% of White children were obese. To understand these disparities, it is vital to explore heritable causes that are not explained by modifications in DNA.
Epigenetics is a science that explores these heritable changes in gene expression activity. Epigenetics plays a vital role in the development of metabolic disorders. Thus, this study, published in the journal Genes, explored the role of epigenetics in childhood obesity in different racial groups.
Study Data Confirm Significant Epigenetic Differences Between Children of Different Racial Backgrounds
This clinical investigation enrolled 31 participants aged between 6 and 10 years from Lee County and Macon County in Alabama. Of them, 11 were normal weight (NW), and 20 were overweight or obese (OW/OB). Sixteen of the children were European American (EA), and 15 were African American (AA). The study used the Illumina Human MethylationEPIC BeadChip microarray to identify differently methylated DNA regions.
In the study, researchers targeted 3133 gene locations associated with 2313 genes. Out of them, 792 were hypermethylated, and 1239 targets were hypomethylated. They found a significant epigenetic difference between the racial groups. Of the targeted genes, 739 genes corresponding to 1239 target IDs were significantly differentially methylated. Of these, 643 were hypermethylated and 596 were hypomethylated in AS compared to EA participants, respectively. The study also identified some novel genes associated with the epigenetic regulation of childhood obesity.
The Bottom Line
The study found that there were significant differences in the epigenetic causes of obesity among various racial groups. This is evident from the fact that most genes were differentially methylated between EA and AA obese children. This shows that countering obesity in different racial groups would require different interventions. Further studies are required to understand the clinical relevance of these differences. Further studies are also needed in pregnant women to identify these epigenetic differences. Finally, much more research is needed to understand how to modify these epigenetic changes that increase the risk of obesity. It is known that certain interventions, like breastfeeding infants and supplementation with docosahexaenoic acid during pregnancy, help. One significant limitation of the study has been the small sample size. Nonetheless, it opens a window for further exploring the topic, and it could confirm that genes are differentially methylated between EA and AA ethnicitities and between NW and OW/OB individuals.
Source:
Patel, P., Selvaraju, V., Babu, J. R., Wang, X., & Geetha, T. (2023). Novel differentially methylated regions identified by Genome-Wide DNA methylation analyses contribute to racial disparities in childhood obesity. Genes, 14(5), 1098. https://doi.org/10.3390/genes14051098
