Web-based tool could aid in early detection and prevention of chronic kidney disease

Subtle abnormalities in kidney function – even within the range considered normal – may help identify people at risk of developing chronic kidney disease. This is shown in a new study from Karolinska Institutet, published in Kidney International. The researchers have therefore developed a web-based tool that could aid in early detection and thus primary prevention.

Chronic kidney disease is a growing global health concern afflicting 10−15 per cent of adults worldwide and is projected to become one of the top five leading causes of years of life lost by 2040. In the absence of effective screening programmes, patients are often diagnosed late, when more than half of their kidney function has already been lost.

To address this gap, researchers at Karolinska Institutet have constructed population-based distributions for estimated glomerular filtration rate (eGFR) - the most widely used measure of kidney function. The aim is to help doctors identify people at risk, thus enabling early preventive action.

We were inspired by the growth and weight charts used in paediatrics, which intuitively help clinicians identify children at risk of obesity or undergrowth."

Yuanhang Yang, first author of the study, postdoctoral researcher, Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet

Web-based calculator for healthcare professionals

The researchers have made their eGFR distribution charts openly available to healthcare professionals and developed a web-based calculator, developed by PhD student Antoine Creon, that can help assess how a patient's eGFR compares with population norms for their age.

The study included over 1.1 million adults in the region of Stockholm, Sweden, covering roughly 80 per cent of the population aged between 40 and 100 years. Nearly seven million eGFR tests collected between 2006 and 2021 were used to construct age- and sex-specific distributions.

The findings show that departures from the median eGFR for one's age and sex are associated with worse outcomes. Individuals with an eGFR below the 25th percentile had a markedly higher risk of developing kidney failure requiring dialysis or transplantation. Mortality also displayed a U-shaped relationship; both low and high percentile extremes were linked to increased risk of death.

Ability to act earlier

The study also illustrates this lack of awareness in healthcare, according to the researchers. Among those with a seemingly normal eGFR above 60 ml/min/1.73 m², but below the 25th percentile, only one fourth had received additional testing for urinary albumin, which is important for detecting early kidney damage.

"For example, consider a 55-year-old woman with an eGFR of 80. Most clinicians would not react to such a seemingly normal value. However, our charts show that this corresponds to the 10th percentile for women of that age, and that she has a three-fold higher risk of starting dialysis in the future. This signals an opportunity to act earlier," says Juan Jesús Carrero, professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

The study is part of the SCREAM project and has been funded by the Swedish Research Council, the Swedish Heart-Lung Foundation, Region Stockholm and the Swedish Kidney Foundation, among others. The researchers report no conflicts of interest related to the content of the study.