According to a new study out of the United States, elevated levels of cystatin C (a type of protein) in the blood can accurately predict an elderly person’s increased risk for several conditions that include cardiovascular disease and chronic kidney disease, and even death. What’s the most interesting part of this study? These risks can be determined in people who have not exhibited kidney problems in the past.
The study, which was published in the journal Annals of Internal Medicine this month, looked at the risks that cystatin C can indicate in elderly individuals. This protein is found in the blood and is also filtered through the kidneys.
The risks mentioned above are not detected by the standard kidney function test that is regularly used today. This test measures for the presence of a protein called creatinine, which is produced by the metabolic function of your muscles and then filtered through the kidneys. This test has been around for a long time; it’s been used as a standard means of testing kidney health in patients for about a century now.
In the study, the researchers turned to cystatin C for answers, along with looking at creatinine as well. They looked at blood samples from 4,663 participants, who were 65 years old and up. Then they matched up the results from the samples with each individual’s health outcome nine years later down the road.
What the researchers found was that among the participants who were not diagnosed as having chronic kidney disease, those who did have high levels of cystatin C in their system also had a “significantly greater risk” of developing poor health than those participants who had normal levels of the protein in their bodies.
In fact, it turned out that participants in the study who had high cystatin C levels were 50% more likely to die, which stood at almost being twice as likely to succumb to death due to cardiovascular problems and 30% were more likely to die due to non-cardiovascular problems.
As if these findings were not startling enough, it was also discovered that participants with high cystatin C levels were also three times more prone to coming down with chromic kidney disease. It got worse: 40% were more likely to experience heart failure; 30% were more likely to have a heart attack; and 20% were more likely to have a stroke than those individuals with normal cystatin C levels.
According to the study’s authors, when it came to the concentration of creatinine in the participants’ system, the outcome was much less for each association with the risks, and was only significant when it came to cardiovascular concerns that resulted in death.
The study’s lead author, Dr. Micheal Shlipak, stated the following: “This tells us that the creatinine test, while broadly useful as a measure of kidney health, is insensitive. If a creatinine level is high, that’s probably an indication of kidney disease. But if it’s low, you don’t know. You would need to do a cystatin test if there’s any other indication of kidney disease or if the patient is in a group that’s at risk.”
“For the clinician who treats older people or others at risk for kidney disease, this is an important message. A normal creatinine level should not reassure you that your patient has normal kidney function. The study shows that cystatin is a very promising new tool that complements creatinine in the ongoing effort to detect early kidney disease and prevent its complications,” he added.