My son just had a test for microalbuminuria and was told that he was borderline for protein in his urine. His other tests were normal, and his hemoglobin A1c has been in the 6 and 7% range. Can you tell me more about the possibility of protein in the urine? What can be done about it?

Very, very small amounts of albumin in the urine is called microalbuminuria. Albumin is the main type of protein in blood (like in egg whites) and is actually a fairly big molecule. So, the presence of even small amounts of albumin in urine can suggest “leaky” blood vessels in the kidneys and therefore can be used as a screen for diabetes-related kidney disease.

Indeed, short of kidney biopsy, it seems to be the most sensitive screen for the presence of diabetes-related kidney disease (nephropathy), but it is not specific for nephropathy because other things unrelated to nephropathy can cause this. Common examples include other kidney problems, but also non-worrisome conditions: illnesses with fever, exercise, etc., can be associated with periodic micro amounts of protein in the urine.

Many diabetes centers will screen for microalbumin with a random urine test. If there is microalbuminuria, this then often leads to a more quantifiable test which can include a carefully timed overnight or 24 hour urine collection to measure the degree of microalbumin lost in the urine over the course of time (and usually expressed as how much microalbumin per minute). If the test is negative in these collections, especially in someone with apparent good control, no further evaluation is done. If there is a worrisome amount of microalbumin (more than 20 micrograms per minute), treatment then usually involves a medication to alter blood pressure flow to the kidneys, plus attention to even better glycemic control. Such medications are usually in a class called ACE inhibitors. Often, your diabetes team would prescribe those medications and a referral to a kidney specialist is sometimes requested, especially if there are other confounding issues that might require a kidney biopsy to help clarify.

DS