Elevated hormone FGF23 could indicate kidney failure imminent

Researchers have found a hormone that, if elevated, could catch kidney failure before it happens. But, first, a little background on phosphorus. Just enough phosphorus in our bodies is a good thing. We need it for things like building and repairing bones and to help cells function and maintain DNA. Too much phosphorus, however, is a bad thing. One of the many services our kidneys perform for us is it controls the amount of phosphate in the blood by eliminating the excess. And helping to fine-tune and regulate our phosphate levels, and our kidneys, are hormones like fibroblast growth factor 23 (FGF23).

When everything is working properly, there's a synchronous dance going on between FGF23, phosphate and our kidneys. But when something goes wrong in the kidneys, everything gets tripped up. Phosphate levels go up, the kidneys can't handle it and, as a result, the kidney disease gets even worse. But the first indication that something is going wrong with this synchronous dance is elevated levels of FGF23. And that is why researchers, writing in the Journal of the American Medical Association, believe that FGF23 is a possible biomarker to predict progressive kidney failure.

"Since FGF23 rises before phosphate in people with early or intermediate-stage chronic kidney disease, this hormone could be an early marker--like a road sign--pointing to patients who may benefit from early management of phosphate levels, which may help preserve kidney function and reduce deaths," said University of Miami researcher Myles Wolf in a news release.

Wolf and colleagues report that patients with earlier stage kidney disease and high FGF23 are at nearly two times higher risk of kidney failure if their baseline estimated agglomerate filtration rate (egret) is 45 milliliters or higher, while all chronic kidney disease patients are at three times higher risk of death compared to patients with lower levels of the hormone. The egret is a measure of kidney function.

"FGF23 could be the critically important puzzle piece that separates those who might have stable kidney function from those who have progressively worsening kidney disease and heart disease that requires more intensive therapy," Robert A. Star of the National Institute of Diabetes and Digestive Diseases and Kidney Diseases, which sponsored the study, said in a release. "FGF23 might work better than more traditional measures, such as protein in the urine, in certain settings."

- take a look at the release
- and the abstract in JAMA