Key Points:
- Based on blood plasma protein markers of aging, researchers found associations between accelerated aging of single organs and age-related diseases affecting multiple organs.
- Accelerated aging in the lungs, kidney, heart, arteries, liver, pancreas, and immune system but not the brain or intestines was associated with an increased risk for death.
Not only can people age faster than their peers of the same age, but individual organs within each person can age faster than others. These observations come from studies measuring biological age—an age measurement reflecting how much physiological damage has accumulated—on the whole body and specific organs.
Biological age differs from chronological age—how many years have passed since birth—which people typically use to describe how old they are. In that sense, an individual or an organ with a biological age more than their age in years is predicted to age faster than average.
As far as organ aging goes, a previous Nature study found an association between faster aging of particular organs and age-related diseases affecting those specific organs. For example, individuals with accelerated heart aging had about a 250% increased risk of heart failure. Thus, previous research has suggested that accelerated aging in certain organs is tied to age-related conditions in those particular organs. However, no studies had unraveled whether accelerated aging in certain organs contributes to age-related diseases across other organs.
Now, as published in The Lancet Digital Health, Partridge and colleagues from University College London in the UK unveil an association between faster aging of nine organs and physiological systems and age-related diseases affecting multiple organs and systems. For example, immune system aging was associated with lung, kidney, and cardiovascular diseases. Furthermore, the nine organs and systems assessed were the lungs, kidneys, heart, arteries, immune system, liver, pancreas, intestines, and brain. The study’s data also suggested that accelerated aging in all of these organs and systems except for the brain or intestines was associated with an increased risk for death. These findings highlight that age-related dysfunction in one organ adversely affects other organs, increasing the likelihood of multi-organ diseases, and pinpointing fast-aging organs and treating them may delay age-related conditions.
Most Age-Related Diseases Assessed Were Associated with Faster Aging Organs In Locations Other than the Disease-Affected Organ
The study included 6,235 middle-aged government employees of the UK who had their blood drawn for an initial assessment of protein markers of organ aging between 1997 and 1999. Utilizing the blood plasma protein profiles of the participants, the researchers used statistical analyses to identify fast-aging organs. Following this assessment, the research team followed the participants for 20 years, monitoring health outcomes related to 45 age-related diseases.
In their assessment to find which of the 45 age-related diseases examined are associated with accelerated organ aging, Partridge and colleagues found individuals with fast-aging organs had an increased risk for 30 age-related diseases. Of these 30 age-related diseases, only six were exclusively associated with accelerated aging in their respective organ or physiological systems. For example, liver failure was associated with accelerated liver aging, and chronic heart failure was associated with accelerated heart aging. Other organs and systems for which faster aging was associated with age-related conditions specifically affecting the same organ or system included the lungs and immune system. These findings suggest that accelerated aging in the heart, liver, lungs, and immune system increases the risk of age-related conditions in their respective organ or physiological systems.
All the same, Partridge and colleagues found that 24 of the 30 diseases associated with fast-aging organs were associated with more than one organ aging faster. The fast-aging organs associated with these 24 age-related diseases were not directly related to the location of the age-related disease within the body. This data suggests that faster aging of a certain organ increases the susceptibility to age-related diseases affecting multiple organs.
To then unravel whether accelerated aging in each organ and physiological system increases the risk of death, Partridge and colleagues assessed the risk of mortality. The researchers found that accelerated aging in the lungs, kidneys, heart, arteries, immune system, liver, and pancreas was associated with a significantly increased risk of death. However, faster brain or intestinal aging was not associated with an increased risk of death. These results suggest that faster aging in some organs more than others increases the risk of death.
Utilizing Blood-Based Protein Signatures to Identify Fast-Aging Organs
The study highlights the interconnectedness of organs and physiological systems and how the functional deterioration of one can adversely affect others. In that sense, identifying organs or systems aging at a faster pace than others and intervening with medical treatments to potentially slow their aging may also work to preserve the function of other organs.
Since the study used a method not typically used in clinics to identify fast-aging organs— blood-based protein signatures of organ aging—the findings shine a light on the potential of this new means to assess organ aging. The researchers say in their publication that more work is needed before healthcare providers can use this technique in a clinical setting. However, drawing blood samples to analyze protein markers associated with fast-aging organs and physiological systems could serve as a quick and non-invasive way to monitor which organs or systems may be undergoing age-related deterioration the fastest. Currently, clinicians typically use expensive and invasive methods like tissue biopsies and imaging techniques to identify which organs and/or physiological systems are deteriorating.
Using blood proteins to monitor organ function can improve the diagnosis of problems with organs to intervene against their decline and delay age-related diseases. This is important because many patients cannot afford to undergo tissue biopsies and imaging regularly. With more cost-effective blood protein marker monitoring in the future, clinicians may treat organ and physiological system functional decline earlier, which may prevent age-related diseases that affect multiple organs. In turn, blood protein monitoring may serve as a new way to extend life without debilitating diseases—a concept known as healthspan—and possibly lifespan.
It appears that monitoring blood protein markers for organ aging is developing at a relatively fast pace. Although Partridge and colleagues did not give a prediction of how long it might take for clinicians to start using this technique to monitor organ aging, it may very well become more widely available in the next decade or so. For people interested in finding whether they can somehow receive a blood protein assessment of organ aging, asking a physician if he or she can administer such a test may work.
Following an online search of the current cost of having a blood protein analysis done, it appears that such a procedure would cost thousands of dollars for complex analysis and data interpretation. Moreover, it is very unlikely that insurance would cover a blood protein analysis to detect fast-aging organs. Therefore, these tests may only be available to people who are relatively wealthy, unless these tests become common in future clinical settings.
Along those lines, identifying organ deterioration early with blood protein signature analysis may help slow age-related diseases and prevent disabilities, which could help the national economy. As such, it may be worthwhile to instill blood protein analyses into standard medical care to identify fast-aging organs once researchers refine this technique.
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