Tag: kidney function

Disagreement Between Two Kidney Function Tests Predicts Disease Risk

Photo by National Cancer Institute on Unsplash

A mismatch between two common tests for kidney function may indicate a higher risk for kidney failure, heart disease, and death, a new study shows.

Healthcare providers for decades have measured blood levels of creatinine to track the rate at which kidneys filter waste from muscle breakdown in the bloodstream. According to more recent guidelines, levels of cystatin C, a small protein made by all cells in the body, can also be used to measure kidney function. Since these two tests are influenced by different factors – including some related to disease or aging – using both markers together can provide a better measure of kidney function and risk of organ failure than either one alone.

Led by NYU Langone Health researchers, the new work reveals that many people, especially those who are sick, often have a large gap between the two readings, which may be a signal of future disease. Specifically, the global study shows that more than a third of hospitalised participants had a cystatin C-based readout of kidney function that was at least 30% lower than one based on their creatinine levels.

“Our findings highlight the importance of measuring both creatinine and cystatin C to gain a true understanding of how well the kidneys are working, particularly among older and sicker adults,” said study co-corresponding author Morgan Grams, MD, PhD. “Evaluating both biomarkers may identify far more people with poor kidney function, and earlier in the disease process, by covering the blind spots that go with either test.”

The study published online November 7 in the Journal of the American Medical Association and is simultaneously being presented at the American Society of Nephrology’s annual Kidney Week conference.

Beyond detecting signs of disease, assessing patients’ kidney function is important for calculating the appropriate dosage for cancer medicines, antibiotics, and many other drugs, says Dr Grams, Professor of Medicine at the NYU Grossman School of Medicine.

During another investigation, the results of which were published the same day, the same research team found that a record number of people worldwide have chronic kidney disease, which is now the ninth leading cause of death globally. Having new ways to spot the condition early can help ensure that patients receive swift treatment and avoid more-dramatic interventions such as dialysis and organ transplantation, says Dr Grams.

For the recent investigation, the research team analysed healthcare records, blood tests, and demographic data collected from 860, 66 men and women of a half-dozen nationalities. All participants had their creatinine and cystatin C levels measured on the same day and received follow-ups 11 years later, on average. The team considered factors unrelated to kidney function that influence the biomarkers’ readings, such as smoking, obesity, and history of cancer.

Performed as part of the international Chronic Kidney Disease Prognosis Consortium, the study is the largest to date to explore differences between the two tests and whether they may signal potential health problems, the authors say. Established to better understand and treat the condition, the consortium provides evidence for global definitions of chronic kidney disease and related health risks.

According to the new findings, those whose cystatin C-based measures of kidney filtration were at least 30% lower than their creatinine-based measures were at higher risk for death, heart disease, and heart failure than those who had a smaller difference between the two metrics. The former group was also more likely to be diagnosed with severe chronic kidney disease that required dialysis or an organ transplant. The same was found for 11% of outpatients and seemingly healthy volunteers.

Dr. Grams notes that while cystatin C testing was first recommended in 2012 by the international organization Kidney Disease—Improving Global Outcomes, a 2019 survey revealed that less than 10 percent of clinical laboratories in the United States performed it in-house. The two largest laboratories, Quest Diagnostics and Labcorp, now offer the test.

“These results underscore the need for physicians to take advantage of the fact that more hospitals and healthcare providers are starting to offer cystatin C testing,” said study co-corresponding author Josef Coresh, MD, PhD, director of NYU Langone’s Optimal Aging Institute. “Physicians might otherwise miss out on valuable information about their patients’ wellbeing and future medical concerns.”

Dr Coresh cautions that among the hospitalised Americans in the study, less than 1% were tested for cystatin C.

Source: NYU Langone Health

Could ‘Pausing’ Necrosis be the Final Frontier in Ageing and Medicine?

Necrosis, unprogrammed cell death, spews a host of toxic molecules into the cellular environment. Credit: University College London

In a new study, published in Oncogene, a world-leading international team of scientists and clinicians explore the potential of necrosis to reshape our understanding and treatment of age-related conditions and even protect astronauts on longer journeys into space.

Challenging prevailing views, the paper brings together evidence from cancer biology, regenerative medicine, kidney disease, and space health to argue that necrosis is not merely an endpoint, but a key driver of aging that presents an opportunity for intervention.

Dr Keith Siew, an author of the study from UCL Centre for Kidney & Bladder Health, said: “Nobody really likes talking about death, even cell death, which is perhaps why the physiology of death is so poorly understood. And in a way necrosis is death. If enough cells die, then tissues die, then we die. The question is what would happen if we could pause or stop necrosis.”

Dr Carina Kern, lead author of the study and CEO of LinkGevity, a biotech company based at Cambridge’s Babraham Research Campus and part of the NASA Space-Health program, said: “Necrosis remains one of the last frontiers in medicine – a common thread across aging, disease, space biology, and scientific progress itself.”

Cells are the fundamental building blocks of life and can die in various ways. ‘Programmed’ forms of cell death are beneficial, carefully orchestrated processes that allow our tissues to replenish themselves and function well throughout life.

But ‘unprogrammed’ cell death, or necrosis, is an uncontrolled and catastrophic process that leads to tissue degeneration and biological decline.

At the centre of the necrotic process is calcium, a vital resource that effectively controls the cell by determining which functions are switched on or off. Calcium ions are normally maintained at a level that is 10 000 to 100 000 times higher outside the cell than inside.

When this finely tuned balance fails, calcium floods the cell like an electrical short circuit, pushing the cell into chaos. Unlike programmed death, where cells dismantle in an orderly manner, necrosis causes cells to rupture, spilling toxic molecules into surrounding tissues.

This sparks a chain reaction that causes widespread inflammation and affects tissue repair, creating a snowball effect that ultimately leads to frailty and the onset of chronic age-related conditions such as kidney disease, heart disease and Alzheimer’s.

Dr Siew added: “When cells die, it’s not always a peaceful process for the neighbours.”

Dr Kern explains: “Necrosis has been hiding in plain sight. As a final stage of cell death, it’s been largely overlooked. But mounting evidence shows it’s far more than an endpoint. It’s a central mechanism through which systemic degeneration not only arises but also spreads. That makes it a critical point of convergence across many diseases. If we can target necrosis, we could unlock entirely new ways to treat conditions ranging from kidney failure to cardiac disease, neurodegeneration, and even aging itself.”

Notably, it is in the kidneys that necrosis may have its most devastating and underappreciated impact. Necrosis induces kidney disease, which can lead to kidney failure requiring a transplant or dialysis. By age 75 nearly half of all individuals develop some degree of kidney disease as part of the natural aging process.

Dr Siew added: “With kidney disease, there’s no one underlying reason that the kidneys fail. It could be a lack of oxygen, inflammation, oxidative stress, a build-up of toxins, and so on. All of these stressors eventually lead to necrosis, which initiates a positive feedback loop that spirals out of control, leading to kidney failure. We can’t stop all of these stressors, but if you could intervene at the point of necrosis, you’d effectively achieve the same result.”

Another area where interrupting necrosis could have a big impact is spaceflight, where astronauts often experience accelerated ageing and kidney-related decline due to the effects of low gravity and exposure to cosmic radiation. A 2024 study involving Dr Siew demonstrated that the human kidney may be the ultimate bottleneck for long-duration space missions.

The authors say finding solutions to this accelerated aging and kidney disease may be the final frontier for human deep space exploration.

Dr Kern said: “In many age-related diseases – affecting diverse organs such as the lungs, kidneys, liver, brain, and cardiovascular system – relentless cascades of necrosis fuel the progression of disease. This is often alongside impaired healing that leads to fibrosis, inflammation and damaged cells. Each cascade triggers and amplifies the next.

“If we could prevent necrosis, even temporarily, we would be shutting down these destructive cycles at their source, enabling normal physiological processes and cell division to resume – and potentially even allowing for regeneration.”

Source: University College London

Even Modest Drop in Kidney Function is Linked to Greater Health Risks

Photo by Robina Weermeijer on Unsplash

A Canadian study of more than 8 million adults suggests that even a modest loss of kidney function is associated with increased health risks. The study, published in The BMJ, could lead to better approaches to prevent chronic kidney disease and related conditions, particularly in younger adults.

“The dogma is that healthy, young adults don’t need to worry about kidney function unless it drops to around 50% of the normal level, but our research suggests that even a more modest 20–30% drop may have consequences and we may want to have earlier conversations about prevention and monitoring,” explained senior author Dr Manish Sood at the University of Ottawa.

The research team used health records from 2008 to 2021 for every Ontario, Canada adult aged 18–65 who had at least one blood test for kidney function, but no history of kidney disease. They found that 18% of those in the 18–39 age group had kidney function that was modestly below normal levels, but not low enough to be diagnosed with chronic kidney disease. Individuals in this ‘grey zone’ faced a modestly increased risk of kidney failure, death and cardiovascular events.

For example, in young adults (age 18–39), a 20–30% loss in kidney function was associated with a 1.4-fold increase in death, 1.3-fold increase in a cardiac event and a 6-fold increase in the risk of kidney failure. The absolute risk of any of these events was still low at less than 2 per 1000.

“Thankfully, the absolute risk for any one individual with kidney function in this grey zone is low, but when we look at the whole population, the impact could be quite significant,” said co-senior author Dr Greg Knoll, senior scientist, nephrologist and Head of the Department of Medicine at The Ottawa Hospital and the University of Ottawa. “We need further research to confirm these findings and then see if we can reduce the risk through lifestyle modification.”

While the blood creatine test for kidney function is relatively inexpensive and readily available, the researchers are not suggesting routine testing for all individuals at this time. However, if an individual has had a kidney test that shows a modest reduction in function, it could prompt consulting health care provider. All individuals can also reduce their risk of kidney disease by eating a healthy diet with lower salt, exercising regularly and limiting alcohol intake.

Dr. Sood and his colleagues previously developed the Project BigLife Chronic Kidney Disease calculator to help individuals calculate their kidney disease risk and see the impact of lifestyle changes. The calculator will continue to be refined as new research arises.  

Source: EurekAlert!