Issue 92 Item 14 Do You Need - Kidney Tests?  Do You Know Your GFR? What are You

Many millions of people are at high risk for kidney disease and don't know it. If a patient has high blood pressure, diabetes or a family history of kidney disease or is just a senior citizen then they need to have a kidney test. 

The National Kidney Foundation recommends, if you have one of these risk factors, that the doctor should have you take three key tests -- your blood pressure, your blood creatinine level, and a check for protein in your urine. High blood pressure is a cause and a complication of kidney disease. The creatinine blood test measures a waste product filtered by the kidneys. And the urine protein is a marker of kidney damage.

NKF's guidelines are largely geared toward bringing kidney disease prevention into the popular mainstream, just as heart disease was in the 1980s. Millions of Americans now know their cholesterol levels and modify their diets or take medications to lower their chance of developing artery trouble or suffering a heart attack..

The panel is now recommending that high-risk individuals--including the elderly, those with diabetes, high blood pressure or a family history of kidney disease--get three key tests when visiting their doctor: a test to measure creatinine levels in the blood, a screen to check for protein in the urine, and a simple blood pressure measurement. Studies performed in recent years have linked elevated levels in each test to an increased risk of kidney disease and possible failure.

"The message is, 'know your numbers,'" said Dr. William F. Keane, the president of the American Kidney Foundation.

The new guidelines were published in the February issue of the American Journal of Kidney Diseases.

Levey advised Americans to know their glomerular filtration rate, or GFR (which is estimated from the creatinine test), a measure of the kidney's ability to filter blood.

"The same way people with high blood pressure know their blood pressure number and people with cholesterol know their cholesterol number, we think people should come to know their GFR," Levey said. "When you get to 60 or below, even if there's no evidence, that is chronic kidney disease, and more medical attention is required at that point."

The recommendations give doctors an 'action plan' designed to guide intervention depending on test results and the stage of kidney disease. The plan includes medication and lifestyle changes for up to 6 million Americans whose lab tests may reveal early but symptom-free kidney damage.

Approximately 300,000 Americans are currently on dialysis, a treatment that requires patients with kidney failure to hook into a blood-filtering machine several times a week to stay alive. More than 13,300 other patients underwent kidney transplants in 2000, and 51,000 more currently sit on transplant waiting lists, according to the United Network for Organ Sharing.

Kidney failure kills up to 60,000 Americans each year, and those that survive endure severe lifestyle restrictions with treatment that costs the health system some $15 billion per year, Keane said. Much of the cost is born directly by taxpayers, since the federal Medicare program finances all end-stage, or advanced, renal disease care in the US.

Obesity and smoking are both believed to be major causes of the diseases leading to kidney failure.

Still, experts acknowledged that many physicians might resist the guidelines since they call for increased testing in offices that are often pressed for time and sometimes squeezed for money. Doctors until now have been educated to view kidney disease mainly in the context of end-stage failure, not as a chronic, progressing ailment that can be slowed with treatment or lifestyle change, said Dr. Garabed Eknoyan, a professor at the Baylor College of Medicine, Houston, Texas, the co-chair of the NKF's quality outcomes initiative. 

"There will be resistance. That is the tradition with (new) guidelines," he said.