This test allows for the routine detection of low concentrations of albumin in the urine. This test has become a standard for the screening, monitoring, and detection of deteriorating kidney function in diabetic patients. Studies have shown that diabetic patients who progress to kidney disease first excrete microscopic amounts of albumin and that, at this stage, intervening treatment can reverse the proteinuria and thus prevent progression to renal failure. This test is also used to monitor compliance with blood pressure control, glucose control, and protein restriction.

Microalbuminuria is an increase in urinary albumin that is below the detectable range of the standard protein dipstick test. It is not a different chemical form of albumin. Microalbuminuria occurs long before clinical proteinuria becomes evident.

<30 mg/24 hr (<30 mg/d) or <20 mg/L (timed collection)

30–300 mg/24 hr may indicate microalbuminuria

>300 mg/24 hr indicates advanced kidney disease

1. 24-hour: same as for total urine protein

2. Timed collection: first morning sample or specimen after four hours of not urinating

   1. Last voiding before sleep (10:00 p.m. or 2200)

   2. Collect all urine at first morning voiding (8:00 a.m. or 0800)

These results approximate 24-hour collection.

Microalbuminuria is associated with:

1. Diabetes with early diabetic nephropathy

2. Hypertension—heart disease

3. Generalized vascular disease

4. Preeclampsia

Pretest Patient Care

1. Explain purpose of test, procedure for 24-hour urine collection, and interfering factors.

2. See instructions for 24-hour urine collection (see Long-Term, Timed Urine Specimen [2-Hour, 24-Hour]).

3. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

1. Strenuous exercise

2. Hematuria

3. High-protein diet or high salt levels