Testing for Albuminuria
Jane Botcha has had diabetes for over six years. When she was tested in 1996, her microalbuminuria was 2.4. In 1997 it rose to 7.4, and this year it was 17.1.
"I'm really concerned about kidney damage," writes Botcha. "My doctor, however, won't give me all the answers."
Better Odds for Patients with Diabetes
Dr. Michael Maurer, a nephrologist and professor of pediatrics at the University of Minnesota, says Botcha's albumin excretion level falls within the normal range. For patients like her, their chances of developing kidney disease are much slimmer nowadays.
Thanks to improved treatment and early detection, the chances of getting kidney disease has dropped significantly.
How Often Should You Test?
Annual screening for microalbuminuria helps identify patients with kidney disease at a very early point in its course. Urine tests for kidney disease usually involve collecting all urine within a 24-hour period. It is then tested for albumin, or protein. A physician can also measure a ratio of the albumin to the creatinine, which is another substance that predicts kidney disease when elevated. A person without diabetes normally excretes less than 25 Âµg/mg of albumin in their urine each day.
Many physicians prescribe ACE inhibitors to people with diabetes when they are in the low to high microalbuminuria range. When a person reaches the proteinuria stage, immediate treatment, such as kidney dialysis, is needed.
Measuring the Total Kidney Function
Richard K. Bernstein, MD, FACE, FACE, CWS, of the Diabetes Center in Mamaroneck, New York, routinely uses the 24-hour urine test to check for microalbuminuria, as well as creatinine clearance (CR CL), which measures the glomerular filtration rate or total kidney function.
"To measure creatinine clearance, a lab requires not just a 24-hour urine sample, but also a few ccs of blood since the serum creatinine must also be measured," says Bernstein. Multiple tests over a period of time will allow a physician to track the creatinine clearance rate and catch any early signs of kidney disease. Bernstein adds that diabetic kidney disease is also associated with an elevated serum fibrinogen* level. Therefore, he routinely tracks serum fibrinogen at least annually, even in people who have not yet had abnormal tests of their 24-hour urine.
"We find that when [diabetic kidney disease] or elevated serum fibrinogen is caught early, we can reverse the condition with normalization of blood sugar."
Repeated Tests are Needed for a Diagnosis of Kidney Disease
Richard Solomon, MD, Associate Professor of Medicine at Harvard Medical School and Clinical Director for the Division of Nephrology at the Joslin Diabetes Center, writes that if the albumin level is normal on an initial screening, a yearly screening thereafter is enough.
Don't Panic if Your Initial Reading is a Little High
Albumin levels fluctuate, and if you have been exercising vigorously or had an infection at the time of your 24-hour urine test, these may give a misleadingly high reading. In these case, the elevated levels may be temporary and at least two additional tests should be performed over the next six months. If the results from two or three consecutive tests remain higher than 18 Âµg/mg for men and 26 for women, the patient will be defined as having microalbuminuria.Click Here To View Or Post Comments