Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alternative kidney test reveals hidden health risks

15.08.2006
Cystatin C test reveals risks for kidney disease, cardiovascular disease, and death that creatinine test misses

Elevated blood levels of the protein cystatin C accurately predict higher risk of chronic kidney disease, cardiovascular disease, and death among elderly people with no known kidney problems – risks that the standard kidney function test, which measures the protein creatinine, misses entirely, according to a study led by a researcher at the San Francisco VA Medical Center.

"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," says lead author Michael Shlipak, MD, chief of general internal medicine at SFVAMC and an associate professor of medicine, epidemiology, and biostatistics at the University of California, San Francisco. "It 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."

The study appears in the August 15, 2006 issue of Annals of Internal Medicine.

Shlipak and his colleagues tested blood samples from 4,663 elders living independently in the community who participated in the Cardiovascular Health Study, a national longitudinal study of people aged 65 and older sponsored by the National Institutes of Health.

The researchers measured each participant's creatinine – an end-product of muscle metabolism that is filtered through the kidneys and has been a standard marker of kidney health for "probably 100 years," according to Shlipak – and cystatin C, a blood protein that is also filtered through the kidneys. They then matched test results with health outcomes up to nine years later.

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.

"In contrast," the researchers report, "creatinine concentrations had associations with each outcome that were much weaker, and significant only for the outcome of cardiovascular death."

Shlipak says, "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."

Groups at risk for chronic kidney disease include people over 65, people with diabetes, hypertension, or cardiovascular disease, and African Americans, American Indians, and Hispanic Americans.

"This is also telling us that kidney function declines much more with age than we realized before," adds Shlipak. He terms this syndrome "pre-clinical kidney disease," or pre-CKD.

"We have the tools to slow kidney disease," he notes, including blood pressure control, sugar control for diabetes, and specific medications known as ACE inhibitors. "It's well-established that end-stage kidney disease is rising at a rate of 10 to 20 percent per year. With a heightened awareness of pre-CKD, we can be more aggressive in taking steps to prevent it."

Accurate knowledge of kidney function is also a matter of patient safety, according to Shlipak: "Surgery, some other medical procedures, and certain medications all can have an adverse impact on kidney health."

The cystatin test itself is relatively inexpensive and already widely available, he says. "As demand for it increases, it should become even more commonly available."

The next steps for researchers, says Shlipak, should include longitudinal studies that determine whether a screening test for cystatin C can improve clinical care and health outcomes for large patient populations. "We also want to map out the physiologic consequences of early mild kidney dysfunction, now that we can measure it."

Co-authors of the study are Ronit Katz, PhD, of the University of Washington; Mark J. Sarnak, MD, of Tufts-New England Medical Center; Linda F. Fried, MD, MPH, of the VA Pittsburgh Healthcare System; Anne B. Newman, MD, MPH, of University of Pittsburgh; Catherine Stehman-Breen, MD, MS, of Amgen, Inc.; Stephen L. Seliger, MD, Brian Kestenbaum, MD, and Bruce Psaty, MD, PhD, of the University of Washington; Russell P. Tracy, PhD, of the University of Vermont College of Medicine; and David S. Siscovick, MD, MPH, of the University of Washington.

Steve Tokar | EurekAlert!
Further information:
http://www.ncire.org
http://www.ucsf.edu

More articles from Health and Medicine:

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>