Simple blood test identifies persons at highest risk for kidney disease complications

Dec 16, 2010

An infrequently used blood test can effectively identify individuals at increased risk of developing complications associated with chronic kidney disease (CKD), according to a study appearing in an upcoming issue of the Journal of the American Society Nephrology (JASN). Use of this simple test might help physicians identify persons with CKD who are at high risk for complications, and identify persons with impaired kidney function at earlier stages of disease.

To assess kidney function, doctors most often measure an individual's level of creatinine in the blood. Creatinine is produced by muscles and filtered by the kidneys. Unfortunately, creatinine tests are inaccurate at detecting mild kidney impairment, and creatinine levels can vary with muscle mass and protein intake. Recently, cystatin C blood measurements have emerged as an alternative test of kidney function. Because the protein is removed from the bloodstream by filtration in the kidneys, cystatin C levels rise in the blood when kidney function declines.

Carmen A. Peralta, MD, MAS, Michael G. Shlipak, MD, MPH (San Francisco Veteran's Affairs Medical Center and University of California, San Francisco) and their colleagues studied the ability of cystatin C levels to identify impaired kidney function. Their study included 11,909 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS), two studies designed to investigate various aspects of cardiovascular disease. The investigators defined CKD using both creatinine and cystatin C and compared their links to higher risks for , cardiovascular events, heart failure, and kidney failure—all of which are known complications of CKD.

In MESA, 9% of individuals had CKD by a creatinine-based equation only, 2% had CKD by a cystatin C-based equation only, and 4% had CKD by both equations. In CHS, these percentages were 12%, 4%, and 13%, respectively. Compared with those without CKD, individuals in MESA with CKD based on creatinine only had similar risk of premature death, while individuals with CKD based on cystatin C only had more than a 3-fold increased risk, and those with CKD based on both had nearly a 2-fold increased risk. In CHS, individuals with CKD based on creatinine only also had a similar risk of premature death compared with those without CKD, while individuals with CKD based on cystatin C only had a 1.78-fold increased risk, and those with CKD based on both had a 1.74-fold increased risk. The pattern was similar for cardiovascular disease, , and .

The authors concluded that among adults diagnosed with CKD using the creatinine-based equation, poor prognosis is limited to patients who also have CKD according to the cystatin C-based equation. Therefore, cystatin C may have an important role in distinguishing the persons suspected of having CKD, based on the current creatinine definition, who have the highest risk for CKD complications. In addition, cystatin C may identify persons with high risk for CKD complications who are currently missed by creatinine.

"Our findings suggest that the creatinine-based CKD definition captures a large number of adults who are actually at low risk for important complications of CKD. Based on our findings, we believe that cystatin C should be a confirmatory test among persons identified as having impaired based on creatinine levels," said Dr. Peralta. She noted that in doing so, individuals at highest risk may benefit the most from aggressive treatment and specialty referral. In addition, many other persons whose CKD is not confirmed by cystatin C may be reassured that they have low risk for CKD complications. Future research should investigate the cost-effectiveness of using multiple markers to identify and risk-stratify CKD.

Explore further: Recorded Ebola deaths top 7,000

More information: The article, entitled "Cystatin C Identifies Chronic Kidney Disease Patients at Higher Risk for Complications" will appear online on December 16, 2010, doi:10.1681/ASN.2010050483

add to favorites email to friend print save as pdf

Related Stories

Simple blood test helps predict chronic kidney disease

Oct 21, 2010

Measuring three biomarkers in a single blood sample may improve physicians' ability to identify patients at high risk of developing chronic kidney disease (CKD), according to a study appearing in an upcoming issue of the ...

Low thyroid function common in chronic kidney disease

Jun 11, 2008

Many patients with chronic kidney disease (CKD) have mild reductions in thyroid function, or subclinical hypothyroidism—a condition that becomes more common as kidney function declines, according to a study in the September ...

Recommended for you

Recorded Ebola deaths top 7,000

22 hours ago

The worst Ebola outbreak on record has now killed more than 7,000 people, with many of the latest deaths reported in Sierra Leone, the World Health Organization said as United Nations Secretary-General Ban ...

Liberia holds Senate vote amid Ebola fears (Update)

Dec 20, 2014

Health workers manned polling stations across Liberia on Saturday as voters cast their ballots in a twice-delayed Senate election that has been criticized for its potential to spread the deadly Ebola disease.

Evidence-based recs issued for systemic care in psoriasis

Dec 19, 2014

(HealthDay)—For appropriately selected patients with psoriasis, combining biologics with other systemic treatments, including phototherapy, oral medications, or other biologic, may result in greater efficacy ...

Bacteria in caramel apples kills at least four in US

Dec 19, 2014

A listeria outbreak believed to originate from commercially packaged caramel apples has killed at least four people in the United States and sickened 28 people since November, officials said Friday.

Steroid-based treatment may answer needs of pediatric EoE patients

Dec 19, 2014

A new formulation of oral budesonide suspension, a steroid-based treatment, is safe and effective in treating pediatric patients with eosinophilic esophagitis (EoE), according to a new study in Clinical Gastroenterology and Hepatology, the official clinical practice journal ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.