WE ALL KNOW WHAT ALBUMIN IS

Evaluating microalbuminuria

We all know what albumin is – That gooey stuff in an egg that turns into egg whites. It is delicious with pepper. But albumin is not only found in chicken eggs; we make it in our livers and use it to bolster our blood pressure or to ferry other products around in the blood. It is an index of good health, for when we become sick, our livers must help provide the resources we need to fight the inflammation or infection, and cannot also make the albumin that we need.

The kidneys have specialized cells to hold back the albumin so that it does not leak into the urine. They are very complex and influenced by many factors that affect our general health and the health of our kidneys. Therefore, it is no surprise that there are many causes for an elevated urine albumin.

It is not normal to have albumin in one’s urine. A crude test for albumin is the simple urine dipstick. More accurately one can quantify the urine albumin by either measuring a 24-hour sample or more simply measuring the ratio of urine albumin to urine creatinine. Since creatinine is an index of kidney function, it is a fairly reliable marker to measure albumin against. 

We like to think of urine albumin abnormalities as either overt or covert. Microalbuminuria refers to the small amount of albumin that can indicate either early kidney disease or systemic disorders. When the kidney filters are badly damaged the urine albumin levels rise.

Microalbuminuria is defined as a urine excretion of 30-300 mg/day. For instance, a urine albumin of 3 mg/dL would be either 30 mg if one put out 1 liter of urine in a 24 hour period or 60 mg if one put out 2 liters and is probably not normal. (A dL or decaliter is 100 cc; a liter is 1000 cc).

The presence of microalbuminuria is an important finding. It may be an early warning sign.

1.     It can be a sign of early kidney disease.

2.     It may be associated with hypertension or metabolic syndrome.

3.     It is an early warning sign of heart disease and stroke.

4.     It is a marker in diabetic nephropathy.

Recommendations for lowering the urine albumin are to be made in concert with advice from your doctor. Doctors who are treating you regularly know your condition and can be a big help.

1.     Treat the underlying disease.

2.     Consider blood pressure treatment with an angiotensin-converting enzyme inhibitor (ACE inhibitor) or angiotensin receptor blocker (ARB).

3.     Lower your salt intake to World Health Organization expectations of < 2 grams sodium per day (http://who.int).

4.     Consider eating more plant-based foods.

5.     Keep your body mass index less than 25 kg/m2.

PHOTO BY STEPHEN FADEM