Epigenetic age estimated by changes in DNA methylation predicts mortality
A person’s life expectancy is known to vary with chronological age, risk factors such as smoking, and health conditions such as heart disease. Add to that list a person’s “epigenetic age”—an estimate of biological age based on changes in DNA methylation at particular locations along the genome—according to a study that analyzed data from more than 13,000 individuals. The results of the study, supported and conducted in part by the National Institute on Aging (NIA), appeared in the Sept. 28 issue of Aging.
Led by Steve Horvath, Ph.D., Sc.D., of the University of California, Los Angeles, a team of researchers from the United States, Europe, and Australia analyzed data from 13 population-based studies, including NIH’s Women’s Health Initiative, the National Heart, Lung, and Blood Institute’s Framingham Heart Study, and NIA’s Baltimore Longitudinal Study of Aging. They found that the difference between a person’s epigenetic age and chronological age predicted his or her risk of mortality, independent of known mortality risk factors. About 5 percent of adults aged substantially faster than others (i.e., epigenetic age was more than 10 years older than chronological age), leading to a nearly 50 percent increased risk of death.
The results were adjusted for mortality-related risk factors, including smoking, obesity, and health conditions such as cancer, high blood pressure, and diabetes. The associations also held across sex and racial groups, as the analysis encompassed data from 13,089 non-Hispanic whites, Hispanics, and blacks.
The study adds to the growing body of research looking to identify biomarkers that help describe different aspects of biological age. More research is needed to better understand the process of epigenetic aging and how it affects the contributors to mortality.
Reference: Chen B.H., et al. DNA methylation-based measures of biological age: meta-analysis predicting time to death. Aging. 2016;8(9):1844-1865.