Mayo Clinic researchers develop way to measure growth factor linked to aging

Researchers at Mayo Clinic have found that GDF11 levels do not decline with chronological age, but they are associated with signs of advanced biological age, including chronic disease and frailty in older adults with cardiovascular disease, according to a recent study.

"Aging is the primary risk factor for the majority of chronic diseases, so it is critical to identify and understand the biomarkers, or indicators, in the body that are linked to this process," said Nathan LeBrasseur, Ph.D., director of the Mayo Clinic Robert and Arlene Kogod Center on Aging's Healthy and Independent Living Program and senior author of the study. "The role of GDF11 as a biomarker of aging and its association with age-related conditions has been largely contradictory, in part, because of how difficult it has been to measure. We have developed a new way to measure GDF11 that is accurate and effective."

The study found a new way of differentiating between the circulating levels of GDF11 and those of myostatin, a related protein, by developing a precise assay that can distinguish between unique amino acid sequence features of GDF11 and myostatin.

Using this analysis, researchers were able to compare age-associated changes in GDF11 and myostatin in healthy men and women between 20 and 94 years old. Results found that although myostatin is higher in younger men than younger women and declines in healthy men throughout aging, GDF11 levels do not differ between sexes and do not decline throughout aging. Older people with severe aortic stenosis had higher GDF11 levels and were more likely to be frail and have diabetes or prior cardiac conditions.

"As a methodological advancement, our assay will be useful for better understanding the basic biology of GDF11 and myostatin, and through its use, we've discovered that GDF11 may be an important biomarker of frailty and comorbidity. It's a great example of bench-to-bedside research with direct relevance to medical management decisions," said Marissa Schafer, PhD, a postdoctoral fellow and lead author of the study.