My 12 year old daughter, diagnosed with diabetes three years ago, had a 24-hour urine protein of 20 which the doctor said was within normal range but higher than she felt it should be. She said she will repeat the test in about three months, and we would go from there. What, if anything, should we be concerned about? If the test is within normal range, doesn’t it mean that there are no kidney problems?

I don’t think that you need to be too concerned about the result of this test. Rather, you should be reassured that the endocrinologist is taking very good care of your daughter. I take it that the actual figure refers to micrograms of urinary albumin/minute in the 24 hour specimen. This is a little high for a twelve year old girl who has only had clinical diabetes for three years and who, because she is on a insulin pump, is probably in very good control.

In our clinic up to 7.6 ug/min. is considered unequivocally normal, and greater than 20 ug/min abnormal. Values between 7.6 and 20 are regarded as borderline and an indication to repeat the test. For one thing, and this is especially true for girls, there can be other reasons for minute traces of microalbumin in the urine besides a complication of the diabetes. A transient and clinically undetected post streptococcal glomerulonephritis might be one and a previous asymptomatic urinary tract infection another.

There is now good evidence that a group of drugs called ACE inhibitors can reverse early diabetic changes in the kidney which is another reason why the doctor is likely to repeat this test occasionally in future years.

My own feeling is that the upcoming test will show either a diminution of the microalbumin or no change.

DOB

[Editor’s comment: If perhaps your daughter’s microalbumin level was determined by a single random sample (not a 24 hour timed or overnight specimen), I would suggest asking your daughter’s diabetologist to have your daughter’s collect a timed specimen. If your daughter has done one of these, I would suggest that he do a repeat the collection on a day when she has not exercised for a minimum of 48 hours. Short-term hyperglycemia, exercise, urinary tract infections, marked hypertension, heart failure, puberty, and acute febrile illness can cause transient elevations in urinary albumin excretion which are often considered physiologic.

The American Diabetes Association’s Position Statement on Diabetic Nephropathy states that if a test for microalbumin is positive, efforts should made to look for any condition that would invalidate the results. Then, if present, that condition should be treated and resolved first of all. Once this done, or if no condition is found, the microalbuminuria screen (timed collected as noted) should be repeated twice within a three to six month period. If two of those three tests are positive, treatment with ACE inhibitors should be initiated.

I suggest sharing these guidelines with your daughter’s diabetologist and perhaps asking for a referral to a nephrologist if this protocol has not been followed.

SS]