Experts Urge Widening Key Test for Diabetics

Screen could find heart, kidney problems in nondiabetics, too

FRIDAY, Nov. 12, 2004 (HealthDayNews) -- A test that signals heart and kidney trouble in diabetics should also be used on people without diabetes who might be at risk for kidney or cardiovascular disease, experts say.

For years, people with diabetes have undergone a routine screening to detect a protein called albumin in the urine. The test can diagnose a condition called microalbuminuria, which has long been associated with a higher risk of kidney and heart disease in diabetics.

More recently, a growing body of research suggests the test may also help predict heart disease risk in the general population, not just in those with diabetes. And some are suggesting use of the test should be expanded.

"Albumin tests have been recommended on a routine basis for diabetics for about a decade," said Dr. George Bakris, director of the Hypertension/Clinical Research Center at Rush University Medical Center in Chicago. Bakris was one of three guest editors of a Nov. 8 supplement to the journal Kidney International, summarizing findings earlier this year at the International Symposium on Albuminuria.

"The original discovery that small amounts of albumin were associated with higher kidney disease and cardiovascular risk was made in the 1970s," Bakris said. "At that time, a group in Denmark noticed that small amounts of albumin in people with type 1 diabetes were more likely to get end-stage kidney disease and to die of a heart attack."

Microalbuminuria is defined as excretion of greater than 30 milligrams a day of the protein.

"The presence of albumin in the urine is not an normal finding," said Dr. David Warnock, director of nephrology at the University of Alabama and president of the National Kidney Foundation.

"There are some benign explanations," he said. "It can be detected after heavy exercise and after a urinary tract infection. Otherwise, its presence could mean there is kidney disease, or it could be a sign of high blood pressure, or it could be an indicator of some sort of cardiovascular disease."

More recently, Bakris said, "microalbuminuria has been associated with a significant risk for cardiovascular events, and if you fail to control blood pressure and lipids and progress to proteinuria [an excessive amount of the protein], your risk for kidney disease is very high, whether you have diabetes or not."

In the past year, Bakris said, much data has found that albuminuria is associated with cardiovascular risk.

At the just-concluded American Heart Association scientific sessions in New Orleans, Dutch researchers suggested that albuminuria be added to the Framingham Risk Score (which includes factors such as blood pressure, cholesterol, age and presence of diabetes) when doctors are considering which drug choices are best in those with heart disease risk.

Who needs a test for the protein? "Healthy people don't," Warnock said.

"The current recommendation is, if you have documented kidney disease or have diabetes, you absolutely need the test," Bakris said. "If you do not have diabetes or kidney disease and, say, you have high blood pressure [which boosts the risk of kidney disease], the test is optional," said Bakris, who works as an unpaid consultant to a company that makes a test for the protein.

More information

To learn more about tests used to diagnose kidney disease, visit the National Kidney Foundation.

SOURCES: David Warnock, M.D., president, National Kidney Foundation, and director, nephrology, University of Alabama, Birmingham; George Bakris, M.D., professor, preventive and internal medicine, and director, Hypertension/Clinical Research Center, Rush University Medical Center, Chicago; November 2004 Kidney International
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