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 New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

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: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>