The standard test for kidney function is the creatinine test. It may be ordered particularly when kidney dysfunction si suspected, or at regular intervals to monitor patients with kidney disorders or with diseases that may affect kidney function (e.g. diabetes) or be exacerbated by dysfunction. Its sensitivity is low, however, and therefore its usefulness as a diagnostic tool is limited.
Researchers have discovered that measuring levels of a protein in the blood called cystatin C may be a promising complementary diagnostic tool to the creatinine test to detect early kidney disease, particularly in the elderly, and therefore prevent other complications such as cardiovascular disease.
Among participants with no diagnosed chronic kidney disease, those with high levels of cystatin C had significantly greater risk for poor health than those with normal cystatin C levels. Individuals in the high cystatin group were 50 percent more likely to die overall, nearly twice as likely to die of cardiovascular problems, and 30 percent more likely to die of non-cardiovascular problems. They had increased risks of 40 percent for heart failure, 30 percent for heart attack, and 20 percent for stroke. Finally, they were more than three times more likely to develop chronic kidney disease.