Salman M. Tajuddin, M.D., Ph.D., M.P.H.

Image of Salman Tajuddin

Postdoctoral Visiting Fellow
National Institute on Aging

Project Title: “The Impact of Plasma Metabolites on Genome-Wide DNA Methylation and Accelerated Aging in African Americans”

Evidence shows that African Africans have a higher risk of death from common age-related chronic diseases and have shorter life expectancy at birth than Whites. African Americans also develop aging-related diseases earlier in life, suggesting that they are predisposed to accelerated biological aging. Health disparities have several causes, but their molecular basis is poorly understood.

Altered levels of DNA methylation, a mechanism that influences gene expression, are a hallmark of aging associated with various age-related diseases. Development of the “epigenetic clock,” a reliable indicator of biological age acceleration, based on genome-wide DNA methylation levels provides an opportunity to unravel the molecular drivers of accelerated aging disparities. According to previous research, DNA methylation is influenced by metabolites, byproducts of metabolism. Understanding metabolites’ role in genome-wide DNA methylation and accelerated epigenetic age may provide important insights into the biological bases of age-related health disparities. However, a lack of blood plasma metabolite studies in African Americans and other U.S. minority populations hampers further study of metabolites’ effect on DNA methylation and the rate of biological aging.

The researchers will investigate how plasma metabolites influence the epigenetic clock and changes in genome-wide DNA methylation levels over time in groups of African American and White participants who live above and below poverty. The researchers will measure 180 metabolites in fasting plasma samples from participants from the Healthy Aging in Neighborhoods of Diversity across the Life Span study. Analysis of measurement data will identify metabolites and metabolic signatures that drive both longitudinal DNA methylation changes and epigenetic age acceleration. The results from this study could advance understanding of the biological bases of health disparities in age-related diseases and lead to biomarkers that identify at-risk individuals for targeted public health interventions.