- A new study of people with chronic kidney disease indicates there is accelerated biological aging from the disease.
- The researchers reported that the accelerated aging was slowed by kidney transplantation but not dialysis.
- Through this study, researchers say they were able to develop a more accurate “epigenetic clock” to help determine biological age in people with as well as without kidney disease.
In the study of aging, there are generally two categories: The age you have by the calendar and the age you are biologically.
The former is straightforward. Understanding the latter is very much an emerging science.
Key to this new science of aging is the concept of the “epigenetic clock,” which involves examining DNA for signs of aging and comparing that to a person’s chronological age.
Now, a research team from the Karolinska Institutet in Sweden and the University of Glasgow in Scotland believe they’ve developed a fitter, more accurate epigenetic clock from a study of people with chronic kidney disease.
Looking at a cohort of 400 people with chronic kidney disease and 100 “control” participants, the research team used existing measures of biological age to compare the effects of dialysis treatment and kidney transplantation on patients’ epigenetic clocks compared to healthy tissue.
People with chronic kidney disease were chosen partly because the condition is known to produce hallmarks of accelerated aging, making it a good target for this sort of study
Their researchers’ findings were published in the Journal of Internal Medicine.
“Biological age provides a more comprehensive understanding of a person’s aging process and reflects how well their body is functioning compared to what is expected at their chronological age,” said Gil Blander, PhD, the founder and chief scientific officer at biomedical company InsideTracker who was not involved in the study.
The researchers looked at a group of 47 people after they began kidney dialysis or one year after kidney transplantation. They then compared that to the healthy tissue of 48 similarly chronologically aged people.
The scientist reported that biological clocks kept ticking faster among people on dialysis compared to a person who received a kidney transplantation or people without kidney disease.
“These results are not surprising since dialysis only provides a temporary solution to the disease outcome, whereas successful transplantation is a real reversal of the disease,” Blander told Medical News Today.
However, Dr. Nathan Goodyear, an integrative medicine practitioner and the medical director of Brio-Medical, disagreed.
“The surgical-associated stress, immune dysfunction associated with surgery, and the chronic immune suppression from the chronic immunosuppression required post transplantation would likely accelerate epigenetic modification, aging, and its associated biological aging,” Goodyear told Medical News Today. “Yet, the restoration of the ability of the body to restore optimal detoxification oxidant/antioxidant balance [via a new kidney] to maintain optimal mitochondrial energy production slowed epigenetic modification and slow epigenetic aging — and biological aging as a result.”
The researchers reported that initial epigenetic clocks all showed that chronic kidney disease accelerated biological aging, but the clocks didn’t necessarily sync with each other.
In addition, none of the clocks were completely accurate compared to actual clinical results and were all inaccurate when tested against healthy tissue.
That led the team to develop a new epigenetic clock based on these results using “methylation tagging” that worked in both diseased and healthy tissue.
This is a refinement of existing techniques, as methylation is a natural byproduct of the aging process where methyl groups accrue in DNA, reducing gene transcription and altering a person’s phenotype — that is, their observable characteristics.
“This is the first clinical test of epigenetic clocks, and the discovery that most are inaccurate when compared with medical evidence has led us to develop a new, more accurate test we have proven is accurate to the high standards of a clinical setting,” said Helen Erlandsson, PhD,, a study lead author from the Karolinska Institutet, in a press release. “Methylation tagging of DNA is impacted by what we eat and also our gut microbiome. As a result, this new clock has real potential to be able to evaluate lifestyle interventions, including diet, that could benefit the public and help to address issues such as health inequalities.”
However, not everyone agrees on the science of the usefulness of epigenetic clocks as a tool.
“Epigenetic clocks are a fad right now,” said Charles Brenner, PhD, the chair of Diabetes and Cancer Metabolism at City of Hope and the chief scientific officer at aging science research company ChromaDex who was not involved in the study.
“They are an attempt to quantify biological aging using biomarkers that can be measured in blood,” he told Medical News Today. “There is no consumer use case for epigenetic clocks. If people want to know their biological age, they can compare their fitness to other people their age. It’s function that matters.”
To that end, epigenetics isn’t the be-all and end-all of a person’s biological age.
“It’s important to know that our lifestyle plays a major role in the aging process, accounting for up to 93 percent [of aging],” Blander said. “Factors such as environment, diet, physical activity, and sleep are just a few examples.”
Brenner agreed.
“Eating right, staying physically and mentally active, socially engaged, prioritizing sleep, and avoiding drugs and alcohol are the most important steps,” he explained. “We think there is also a use case for nicotinamide riboside in preserving youthful resiliency. This is a form of vitamin B3 that is undergoing extensive clinical testing for diseases and conditions of metabolic stress and aging.”
