Newly found metabolites offer early indication of kidney disease

Newly discovered metabolites could be used as serum markers to improve and hasten diagnoses of kidney disease, according to a study published online October 8, 2015 in Journal of the American Society of Nephrology.

More than 10% of adult Americans have chronic kidney disease (CKD), which contributes to kidney failure, heart disease, and premature death.

Researchers in Germany sought to identify metabolic markers that might improve on the current measurement of kidney function—glomerular filtration rate (GFR), which is based on the clearance of the metabolite creatinine.

While the current GFR is the best test available, serum creatinine has some limitations. Concentrations of creatinine can remain in the normal range even if 50% of the kidneys’ function has already been lost. In addition, creatinine concentrations are influenced by other factors such as muscle mass.

In this investigation, the researchers measured concentrations of almost 500 metabolites in the blood of several thousand individuals.

After analysis, 6 of the metabolites showed particularly strong correlations with kidney function. Of these, 2 of the metabolites—pseudouridine and C-mannosyltryptophan—were equally as good as creatinine for measuring kidney function and disease progression in patients with CKD. In contrast with serum creatinine, C-mannosyltryptophan and pseudouridine concentrations showed little dependence on sex.

“These markers therefore represent promising candidates to further improve the estimation of kidney function by combining them with information on creatinine concentrations. This will facilitate an improved diagnosis of CKD, enabling treatment and prevention of complications,” said investigator Anna Köttgen, MD, MPH, of the Division of Nephrology at the Medical Center of the University of Freiburg, in Freiburg, Germany.