In a community of 1,506 people aged 65 and older, followed from 2009 onward, researchers at Ulm University traced how the kidneys fade with the years and found that the rhythm of a day may leave a mark on that fading. Kidney filtration, the quiet work that cleans the blood, tends to weaken as life lengthens, and for some it slides toward disease, frailty and an earlier death. Those who moved more, and sat less, were less likely to follow the steeper path, suggesting that the ordinary choice to walk or to rest may bear on a body's slow passage through age. The finding does not yet prove that mo
Older Adults Who Move More Show Lower Odds of Steep Kidney Function Decline, Study Finds
Individuals in the faster kidney-decline trajectory had higher mortality than those in the other trajectory.
Each extra 1,000 steps carried lower odds of the faster kidney decline
In a community of 1,506 people aged 65 and older, followed from 2009 onward, researchers at Ulm University traced how the kidneys fade with the years and found that the rhythm of a day may leave a mark on that fading. Kidney filtration, the quiet work that cleans the blood, tends to weaken as life lengthens, and for some it slides toward disease, frailty and an earlier death. Those who moved more, and sat less, were less likely to follow the steeper path, suggesting that the ordinary choice to walk or to rest may bear on a body's slow passage through age. The finding does not yet prove that movement can rescue a failing kidney, but it opens a question that the next generation of studies must answer.
In 2009, 1,506 adults aged 65 and older, all living in the community rather than in care, joined a study at Ulm University in Germany. Each wore an accelerometer at the start, and over the following years they returned for up to three more rounds of measurement. The researchers wanted to understand something that has long troubled those who study aging: as people grow older, their kidneys tend to lose strength, and for many this slide leads to chronic kidney disease, disability and early death. Yet the routes that decline takes, and what might guard against it, remained poorly mapped among the very old.
To follow those routes, the team tracked estimated glomerular filtration rate, a standard measure of how well the kidneys clean the blood, across 2,812 observations. Using a method that grouped people by the shape of their decline while linking each group to mortality, they found two distinct paths. One group began with lower filtration and fell more steeply, and this group also died at higher rates during follow-up. The other started higher and declined more gently.
The next question was whether daily habits at the start of the study could tell which path a person would follow. Here the signals pointed in opposite directions. More physical activity was associated with lower odds of the worse trajectory, and step counts told a similar story. Sedentary time moved the other way, with each additional 100 minutes of sitting linked to much higher odds of the faster decline.
The authors suggest that programs encouraging older adults to move more could become a viable way to slow age-related kidney decline. They are careful, however, to note that this study shows association rather than cause. Their next step is to test whether deliberately increasing activity truly changes the course of kidney outcomes.
A group of 1,506 adults aged 65 and older, all living in the community rather than in care, were enrolled in a study in 2009. Each wore an accelerometer at the start, and researchers then followed them for up to three further rounds of measurement. The question was about the kidneys: how does their function change as people age, and does the way older adults move through a day have anything to do with it?
The researchers, working at Ulm University in Germany, framed the problem plainly. Kidney function tends to deteriorate with age, and in many people that leads to chronic kidney disease, significant disability and early death. But the paths that decline takes, and the factors that might protect against it, are still poorly understood, particularly among older people.
To trace those paths, the team used estimated glomerular filtration rate, or eGFR, a standard measure of how well the kidneys filter blood. Across the follow-up they collected 2,812 eGFR observations. They analyzed them with joint latent class models, a method that groups people by the shape of their decline over time while also linking each group to mortality.
Two trajectories emerged. One group began with a lower average eGFR and declined more steeply as time passed. That same group also had higher mortality. The other group started higher and fell more gently. The finding puts a number of lives on one side of a line: those on the faster-declining path were more likely to die during follow-up than those on the slower one.
The researchers then asked whether baseline activity predicted which group a person fell into. They compared accelerometer data with trajectory membership using logistic regression, adjusting for other factors. The results pointed in opposite directions for movement and for sitting.
More physical activity went with lower odds of belonging to the worse trajectory. The odds ratio was 0.72 for every additional 10 minutes of activity (95% confidence interval 0.60 to 0.87). Step counts told a similar story: 0.73 for every additional 1,000 steps (0.62 to 0.86). Sedentary time moved the other way. Each additional 100 minutes of sedentary behavior was linked to an odds ratio of 2.51 (1.65 to 3.81) for being in the faster-declining group.
The authors say this may indicate that programs to raise activity levels could be a viable way to prevent impaired kidney function and slow age-related functional decline. They are careful about the limits of that claim, calling for future studies to investigate it. The design shows associations between activity measured at baseline and later trajectory, not proof that adding movement changes the course of the kidneys.
The work was funded by the Ministry of Science, Research and Arts of Baden-Wuerttemberg as part of Ulm University's Geriatric Competence Center, and by the German Research Foundation's SFB 1506 Aging at Interfaces program. One author, identified as DD, was supported by Ulm's Hertha Nathorff program for women physicians in research. The funders had no role in the study's design, analysis or decision to publish. The next step is testing whether deliberately increasing activity in older adults alters kidney outcomes.
Citações Notáveis
Interventions for increasing physical activity may potentially be viable strategies to slow age-related functional decline, and should be investigated in future studies.— Study authors, Ulm University
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