Kidney Function Tests
| Author: Judy Kohn, RN, BSN, CDE |
| Last Updated: Thursday, August 14, 2008 |
Q: "What lab tests can tell me if my kidneys are ok? I am worried about kidney damage."
A: That is a good question to ask, especially due to these facts:
- Diabetes and high blood pressure are the cause of approximately 70% of people in kidney failure.
- Usually, kidney damage (called Nephropathy) occurs very gradually over years. Early kidney disease has no signs or symptoms so you would not know it is occurring. In fact, it is often called a "silent" disease.
- If diabetes damages the blood vessels in the kidneys, the kidneys cannot adequately filter the blood. As more filters are damaged, the kidneys eventually are not able to keep your body healthy.
- If not treated, kidney disease can lead to kidney failure; if this happens, your only options are dialysis or a kidney transplant.
- On the other hand, there are tests to detect kidney disease in its early stages, and medications can help prevent or delay kidney failure. More importantly, keeping your diabetes and blood pressure well controlled may prevent kidney problems from ever occurring.
Risk factors for kidney disease:
- Diabetes—the leading cause of kidney disease
- High blood pressure—the second leading cause of kidney disease, because it makes your heart work harder, which can damage your kidneys over time
- Heart disease
- Having a mother, father, sister or brother with kidney disease
- Having protein in your urine--if protein leaks into the urine, it is a sign that the kidneys are not working well
Monitoring Kidney Function
-
Have a yearly blood and urine test to check your kidneys.
- GFR — A test that measures the level of creatinine in your blood. The GFR calculation uses your creatinine measurement along with weight, age, and values assigned for sex and race. This tells how much blood your kidneys filter each minute, which is known as your GFR (glomerular filtration rate), which indicates how well your kidneys are working. A GFR of 60 or higher is in the normal range. A GFR below 60 may mean you have kidney disease. You can't raise your GFR, but you can try to keep it from going lower.
- Urine Protein — A urine test checks for protein in your urine, which can be a sign of kidney disease. Protein can leak into the urine when the filters in the kidneys are damaged. This test has several different names, including a check for "proteinuria," "albuminuria," or "microalbuminuria." It can also be called a "urine albumin-to-creatinine ratio."
- Blood Pressure—Have your blood pressure checked at every office visit.
Prevention or Treatment
Kidney damage is progressive, meaning it will not get better and may get worse, and the damage is irreversible. But proper treatment can prevent or delay this progression. Here are some basic concepts:
- Keep your blood glucose in good control.
- Research has shown that tight blood sugar control reduces the risk of microalbuminuria (small amounts of protein in the urine) by one third. In people who already had microalbuminuria, the risk of progressing to macroalbuminuria (large amounts of protein in the urine) was cut in half. Other studies have suggested that tight control can reverse microalbuminuria in some instances.
- Eat healthy and be active; follow a personalized meal plan developed by a qualified dietitian and/or diabetes educator.
- Maintain your blood pressure below 130/80; this may require medications
such as a diuretic, or blood pressure medication. Two types of blood pressure
medications—ACE inhibitors and ARBs—have been shown to slow kidney disease and
delay kidney failure, even in people who do not have high blood pressure.
- While alcohol is often allowed if used in moderation, be sure to discuss your alcohol intake with your healthcare team since alcohol can also raise blood pressure.
- Avoid tobacco.
Conclusion
I know this can sound alarming, so the important message to remember is that most diabetes complications can be prevented or delayed. Talk to your diabetes team to be sure you are getting the proper tests. You can read more details in the related questions and links below.
Related Questions
Tests and visits:
Q:
"The Diabetes Standards of Care mention regular lab and blood pressure
checks, but what are the specific goals and frequency?"
Related Links
NDKEP (National Kidney Disease Education Program)
http://nkdep.nih.gov
NKUDIC (National Kidney and Urologic Disease Information
Clearinghouse)
http://kidney.niddk.nih.gov
NKDEP Quick Reference on GFR and UACR
http://nkdep.nih.gov
American Diabetes Association
http://www.diabetes.org
Important Notice: The responses provided by the team of Diabetes Educators are based on their personal experiences and expertise as practicing diabetes healthcare professionals, and are not to be considered diabetes management advice from Abbott Laboratories. Remember that information provided by the team of Diabetes Educators is for general background purposes and is not intended as a substitute for medical diagnosis or treatment by a trained professional. You should always consult your physician about any healthcare questions you may have, especially before trying a new medication, diet, fitness program, or approach to healthcare issues.
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