Drs. Stella Aslibekyan, Bertha Hidalgo and Marguerite Ryan Irvin from the department of epidemiology and Dr. Hemant Tiwari from the department of biostatistics at the University of Alabama at Birmingham School of Public Health worked with a team of researchers looking at metabolic syndrome in African-American adults.
The high prevalence of obesity among U.S. adults has resulted in significant increases in associated metabolic disorders such as diabetes, dyslipidemia, and high blood pressure. Together, these disorders constitute metabolic syndrome, a clinically defined condition highly prevalent among African-Americans.
Data on metabolic syndrome and DNA methylation was assessed on 614 African-Americans from the Hypertension Genetic Epidemiology Network (HyperGEN) study. Metabolic syndrome was defined using the joint harmonized criteria, and DNA methylation was assessed using the Illumina HumanMethylation450K Bead Chip assay on DNA extracted from buffy coat. Linear mixed effects regression models were used to examine the association between CpG methylation at > 450,000 CpG sites and metabolic syndrome adjusted for study covariates. Replication using DNA from a separate sample of 69 African-Americans, as well as meta-analysis combining both cohorts, was conducted.
In conclusion, MetS in African-American adults was associated with increased methylation at the cg06500161 locus in the ABCG1 gene, located in a highly conserved regulatory region of the genome. ABCG1, involved in cholesterol and phospholipid transport, has been associated with MetS and component traits in other studies. The high prevalence of MetS among African-Americans and the consistent associations between MetS and many chronic diseases such as cancer highlight the need for future prospective confirmatory studies that may inform clinical strategies and interventions.