A new study from the University of Minnesota School of Public Health is the first genome-wide epigenetic exploration of obesity in African Americans.

[Photo: Dr. Ellen Demerath]

Lead author, Dr. Ellen Demerath, associate professor at the School of Public Health, conducted the study in collaboration with University of Minnesota colleagues and researchers at three other U.S. institutions. All are working on the large on-going Atherosclerosis Risk in Communities (ARIC) Study, a 30-year prospective study of coronary heart disease risks in both White and African American adults ages 45-55 when the study began in 1985.

“Study participants are tracked annually and also brought in for blood draws and detailed examinations,” said Dr. Demerath. “This includes the measurement of body mass index (BMI) and waist circumference, typical markers of obesity.”

When comparing their results for over 2,000 African American individuals with 3,000 White individuals in other studies, researchers were interested to learn signatures of obesity were largely similar across race/ethnic groups.

“This has not been shown before,” said Dr. Demerath. “It supports the idea that many of the same molecular pathways disrupted in obesity are probably operating in both African Americans and Whites.

The study appeared in Human Molecular Genetics.

The researchers found that the level of DNA methylation (addition or subtraction of a methyl group on the DNA molecule) in blood was related to levels of  the body mass index (BMI) and waist circumference. Adiposity traits are associated with DNA methylation at numerous sites across the genome  and these successfully replicate across studies despite variation in tissue type, ethnicity, and analytic approaches, the study reads.