Diabetic nephropathy is diagnosed using tests that check for a protein (albumin) in the urine, which points to kidney damage. Your urine will be checked for protein (urinalysis) when you are diagnosed with diabetes.
An albumin urine test can detect very small amounts of protein in the urine that cannot be detected by a routine urine test, allowing early detection of nephropathy. Early detection is important, to prevent further damage to the kidneys. The results of two tests, done within a 3- to 6-month period, are needed to diagnose nephropathy.
When to begin checking for protein in the urine depends on the type of diabetes you have. After testing begins, it should be done every year.1
| Type of diabetes|| When to begin yearly testing|
Type 1 diabetes
After you have had diabetes for 5 years
Type 2 diabetes
When you are diagnosed with diabetes
Diabetes present during childhood
After age 10 and after the child has had diabetes for 5 years
An albuminuria dipstick test is a simple test that can detect small amounts of protein in the urine. The strip changes color if protein is present, providing an estimate of the amount of protein. A spot urine test for albuminuria is a more precise lab test that can measure the exact amount of protein in a urine sample. Either of these tests may be used to test your urine for protein.
You will also have a creatinine test done every year. The creatinine test is a blood test that shows how well your kidneys are working.
If your doctor suspects that the protein in your urine may be caused by a disease other than diabetes, other blood and urine tests may be done. You may have a small sample of kidney tissue removed and examined (kidney biopsy).
It is important to check your blood pressure regularly, both at home and in your doctor's office, because blood pressure rises as kidney damage progresses. For most people who have diabetes, the ideal blood pressure is below 120/80. High blood pressure is 140/80 or higher when you have diabetes. In between these two levels is called prehypertension. Keeping your blood pressure at or below your target can prevent or slow kidney damage.
Blood levels of cholesterol and triglycerides also should be checked regularly to see whether diabetes, nephrotic syndrome, or other factors are raising your blood cholesterol level. High cholesterol can increase the risk of hardening of the arteries (atherosclerosis), possibly leading to heart disease, peripheral arterial disease, and stroke.