Urine tests for protein levels

Protein normally is not found in urine. When the kidneys are damaged by diabetes, small amounts of protein begin to leak into the urine. If blood sugar levels stay high and early kidney damage is left untreated, larger amounts of protein may be lost, possibly leading to kidney failure.

Urine tests for protein levels in people with diabetes check for amounts of albumin (protein). A urine test for protein can be done on a sample of urine collected randomly (usually the first time you urinate in the morning), a sample collected over 24 hours, or a sample collected over a specific period, such as 4 hours or overnight.

No preparation is needed for this test, but results can be affected by factors such as high blood sugar levels, recent exercise, urinary tract infections, high blood pressure, heart failure, or a high fever during an infection.

Abnormal results differ slightly among the three different types of urine samples.¹

Abnormal urine test results

Results	24-hour urine sample	Timed urine sample	Random urine sample
	Milligrams of protein per 24 hours	Micrograms of protein per minute	Micrograms of protein per milligram of creatinine
Normal	Less than 30	Less than 20	Less than 30
Tiny amounts of protein (microalbuminuria)	30–299	20–199	30–299
High protein (macroalbuminuria)	300 or more	200 or more	300 or more

Because the amount of protein lost through urine varies, 2 of 3 urine samples within a 3- to 6-month period need to show abnormal results for a diagnosis of diabetic kidney disease (nephropathy).

Citations

1. American Diabetes Association (2004). Nephropathy in diabetes. Clinical Practice Recommendations 2004. Diabetes Care, 27(Suppl 1): S79–S83.