TheDigger Intelligence Unit
A routine kidney test may appear normal, yet mask early signs of future disease, warn researchers at Sweden’s Karolinska Institutet. They say subtle changes in kidney function can predict chronic illness years before symptoms appear—often overlooked by doctors.
The study analysed nearly 7 million test results from over 1 million adults in Stockholm, challenging traditional views of how kidney health is assessed.
The Silent Threat
Chronic kidney disease is already a global crisis, affecting up to 15 per cent of adults. By 2040, it is expected to rank among the top five causes of years of life lost worldwide. The tragedy is that many patients only learn of their condition after losing more than half of their kidney function, when treatment options are limited, and the damage is irreversible.
Rethinking the Numbers
The Karolinska team focused on the estimated glomerular filtration rate (eGFR), the standard measure of kidney function. Traditionally, doctors use a single cutoff value to decide whether results are “normal.”
But the researchers argue this approach misses the nuances. Instead, they built reference charts showing how a person’s kidney function compares with peers of the same age and sex. “We were inspired by the growth and weight charts used in paediatrics,” explained Yuanhang Yang, a postdoctoral researcher. “They help clinicians spot risks early. We wanted to do the same for kidney health.”
A Tool for Everyday Care
To make the findings practical, the team created a free web‑based calculator. Doctors can enter a patient’s eGFR and instantly see where it falls on the age‑based chart.
Developed by PhD student Antoine Creon, the tool is meant to guide everyday decisions in clinics.
The results are striking. People whose kidney function fell below the 25th percentile for their age faced a much higher risk of progressing to kidney failure.
The study also revealed a U-shaped curve for mortality: both unusually low and unusually high values were linked to a greater risk of death.
Missed Chances
The research shows early warning signs are often overlooked. For example, among patients with eGFR above 60 but below the 25th percentile for their age, only 1 in 4 received further testing for urinary albumin, an early marker of kidney damage.
Professor Juan Jesús Carrero offered a vivid example: “Take a 55-year-old woman with an eGFR of 80. Most clinicians would not react to such a value.
But our charts show it corresponds to the 10th percentile for women her age. She has a threefold higher risk of starting dialysis in the future. That’s an opportunity to act earlier.”
Looking Ahead
The study is part of the SCREAM project and was funded by the Swedish Research Council, the Swedish Heart‑Lung Foundation, Region Stockholm, and the Swedish Kidney Foundation. The researchers report no conflicts of interest.
By reframing how kidney function is evaluated, the team hopes to give doctors sharper tools to detect risk before it becomes irreversible disease. For patients, the message is sobering but hopeful: what looks “normal” today may not be normal at all — and spotting the difference early could save lives.