WHAT IS URINALYSIS (FRACTIONAL) TEST?
Fractional urine involves testing as many as four timed urine collections within a 24-hour period for the presence of sugars, acetone, or albumin, all of which are abnormal. Glucose results reflect serum glucose levels because levels above the renal threshold for glomerular glucose reabsorption into the bloodstream are excreted in the urine. Acetone levels are an indication of the state of fatty acid metabolism in diabetic clients. The detection of microalbuminuria in an aliquot of a fractional specimen can be predictive of diabetic nephropathy at an early and potentially reversible stage. This test used to be performed more frequently for diabetic clients. However, as studies demonstrated that renal thresholds for glucose reabsorption vary from client to client, this test is no longer considered the most accurate reflection of insulin needs. Routine daily blood glucose monitoring has replaced fractional urine analysis for ongoing diabetes monitoring. Fractional urine testing is more often used to measure the excretion rate of albumin.