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 Journal of the American Society of Nephrology.
"Our results identify biomarkers that can improve CKD risk prediction," comments Caroline S. Fox, MD, MPH of the National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Mass.
The study included more than 2,300 participants in the Framingham Offspring Study, a long-term follow-up study of heart disease risk factors and outcomes. All participants had normal kidney function when they provided blood samples in 1995-98. An average of 9.5 years later, nine percent of patients had developed CKD. Another eight percent had high levels of protein in the urine (macroalbuminuria) at follow-up--a key sign of deteriorating kidney function
Stored blood samples from 1995-98 were tested to see if any of six different biomarkers could predict which patients were most likely to develop CKD. A combination of three biomarkers significantly improved the ability to identify patients at high risk of CKD, including homocysteine, a marker of atherosclerosis risk, and aldosterone, a hormone that affects salt handling by the kidneys. The same two biomarkers also predicted the risk of macroalbuminuria, as did B-type natriuretic peptide (BNP)--an indicator of heart damage in patients with heart failure.
Adding the biomarker results to standard risk factors like high blood pressure and diabetes would lead to an additional seven percent of patients being classified at high risk of CKD.
"Chronic kidney disease affects 13 percent of the adult population in the United States and is an important risk factor for cardiovascular disease," Fox explains. "It is difficult to identify early abnormalities using serum creatinine, the most commonly used measure to assess kidney function."
With further testing, these biomarkers identified could improve estimates of CKD risk. In addition, the nature of the three biomarkers may provide important clues into how CKD develops. Further studies are needed to see if treatments that reduce homocysteine levels or target the processes involving aldosterone and BNP can reduce the long-term risk of CKD.
The study was limited to participants of European ancestry; more research is needed to see if the results are generalizable to multiethnic populations.
Disclosures: This study was supported by the National Heart, Lung, and Blood Institute's Framingham Heart Study (N01-HC-25195), 2-K24-HL04334, R01-HL-077477, R01-DK-080739, 1R01 AG028321. Study coauthors included Vasan Ramachandran, MD (also of the Framingham Study).
The article, "A Multi-Marker Approach to Predict Incident CKD and Microalbuminuria," will appear online at http://jasn.
The American Society of Nephrology (ASN) does not offer medical advice. All content in ASN publications is for informational purposes only, and is not intended to cover all possible uses, directions, precautions, drug interactions, or adverse effects. This content should not be used during a medical emergency or for the diagnosis or treatment of any medical condition. Please consult your doctor or other qualified health care provider if you have any questions about a medical condition, or before taking any drug, changing your diet or commencing or discontinuing any course of treatment. Do not ignore or delay obtaining professional medical advice because of information accessed through ASN. Call 911 or your doctor for all medical emergencies.
Founded in 1966, ASN is the world's largest professional society devoted to the study of kidney disease. Comprised of 11,000 physicians and scientists, ASN continues to promote expert patient care, to advance medical research, and to educate the renal community. ASN also informs policymakers about issues of importance to kidney doctors and their patients. ASN funds research, and through its world-renowned meetings and first-class publications, disseminates information and educational tools that empower physicians.