Researchers at the University of Pittsburgh have discovered markers in the blood that indicate biological age, developing an index that accurately differentiates between healthy and rapid aging. This could lead to early lifestyle interventions to improve long-term health.
Researchers at the University of Pittsburgh have identified blood markers associated with healthy, accelerated aging. These markers can help predict a person’s biological age, which reflects the rate of aging of their cells and organs, independent of their chronological age.
The new research, published in Aging cellhighlights pathways and compounds that may drive biological age, shedding light on why people age differently and suggesting new targets for interventions that may slow aging and promote lifespan , the length of time a person is in good health.
“Age is more than just a number,” said lead author Aditi Gurkar, Ph.D., assistant professor of geriatric medicine at Pitt School of Medicine and member of the Aging Institute, a joint venture of Pitt and UPMC. “Imagine two 65-year-olds: one bikes to work and goes skiing on weekends, and the other can’t climb stairs. They have the same chronological age, but very different biological ages. Why do these two people age differently? This question guides my research.
Methodology and results of the study
To answer this question, Gurkar and his team compared 196 older adults whom they classified as healthy or rapidly aging based on how easily they completed simple walking challenges. Because walking ability is an overall measure of cardiovascular fitness, physical strength, and neurological health, other studies have shown it to be the best predictor of hospitalization, disability, functional decline, and death. in the elderly.
Aditi Gurkar, Ph.D., assistant professor of geriatric medicine at Pitt’s School of Medicine and member of the Aging Institute, a joint venture of the University of Pittsburgh and UPMC. Credit: Aimee Obidzinski, University of Pittsburgh
Healthy people were 75 years or older and could climb a flight of stairs or walk for 15 minutes without resting, and rapidly aging people, ages 65 to 75, were required to rest during these challenges.
According to Gurkar, this study is unique because rapidly aging people were chronologically younger than healthy older people, which allowed researchers to focus on markers of biological – not chronological – aging, unlike others. studies comparing young adults to older people.
To define a molecular fingerprint of biological aging in the participants’ blood samples, they performed metabolomics – an analysis of metabolites, molecules produced by chemical pathways in the body – with blood samples from both groups.
“Other studies have looked at genetics to measure biological aging, but genes are very static: the genes you are born with are the genes you die with,” Gurkar said. “We chose to look at metabolites because they are dynamic: they change in real time to reflect our current health and how we feel, and we have the power to influence them through our lifestyle, our diet and our environment. »
Rapidly aging and healthy people had clear differences in their metabolomes, indicating that metabolites in the blood may reflect biological age.
Development of the HAM index
Gurkar and his team then identified 25 metabolites that they called the Healthy Aging Metabolic Index (HAM). They found that the HAM index was better than other commonly used measures of aging—including the frailty index, walking speed, and the Montreal Cognitive Assessment Test—at distinguishing between healthy and aging people. those who age quickly.
To validate their new index, the researchers analyzed a separate cohort of older adults from a Wisconsin-based study. The HAM index correctly predicted whether individuals could walk outside for 10 minutes without stopping with a precision about 68%.
“We took a very different cohort of people from a different geographic region and found that the same metabolites were associated with biological aging,” Gurkar said. “This gives us confidence that the HAM index can truly predict who is aging healthily versus rapidly aging.” »
Using an artificial intelligence model capable of predicting potential drivers of biological traits, the team identified three main metabolites most likely to promote healthy aging or promote rapid aging. In future research, they plan to examine how these metabolites and the molecular pathways that produce them contribute to biological aging and explore interventions that could slow this process.
Gurkar also plans more research to assess how youth’s metabolome changes over time. Ultimately, she hopes to develop a blood test that could estimate the biological age of young adults or predict those who might develop age-related diseases.
“While it is great to be able to predict biological aging in older people, what would be even more exciting would be a blood test that, for example, could tell a 35-year-old that they are close to biological age. that of a 45 year old person. » said Gurkar. “This person might then think about changing some aspect of their lifestyle early on – whether it’s improving their sleep, diet or exercise regime – to hope to reverse their biological age. »
“Today, in medicine, we tend to wait until a problem arises before treating it,” she adds. “But aging doesn’t work that way: it’s about prevention. I think the future of medicine will be about knowing early on how a person ages and developing personalized interventions to delay disease and extend life expectancy.
Other authors of the study were Shruthi Hamsanathan, Ph.D., Tamil Anthonymuthu, Ph.D., Denise Prosser, Anna Lokshin, Ph.D., Susan L. Greenspan, MD, Neil M. Resnick, MD, Subashan Perera, Ph.D. and Satoshi Okawa, Ph.D., all of Pitt or UPMC; and Giri Narasimhan, Ph.D., of Florida International University.
This research was supported in part by the Pittsburgh Claude D. Pepper Older Americans Independence Center (P30 AG024827). The Gurkar Lab is supported by the National Institutes of Health (R00 AG049126, R01HL161106, U54AG075931, P30CA047904, R01AG054047 and RF1AG054047), National Academy of Medicine Catalyst grant, AFAR/Hevolution and RK Mellon Foundation.
