Quantitation of microalbuminuria using random urine samples.
Microalbuminuria is a harbinger of progressive renal disease and cardiovascular complications in patients with diabetes mellitus. The method most commonly used to measure microalbuminuria relies on a timed urine collection, either a 24-h or overnight specimen, which is time-consuming, cumbersome, and often inaccurate. We compared microalbumin-creatinine ratio (U(MA)/U(Cr)) in a random urine sample obtained after the first voided morning specimen with the quantity of microalbumin in a 24-h collection to determine whether the U(MA)/U(Cr) correlates with the microalbumin content of 24-h urine collection. In a study of 124 urine samples from 97 pediatric patients with type I diabetes, daily microalbumin excretion varied from 7 to 108 mg/24-h with a mean of 55.7 +/- 18.2 mg and U(MA)/U(Cr) ranged from 5 to 59 microg/mg with a mean of 39.4 +/- 11.3. An excellent correlation was found between the microalbumin excretion measured in 24-h urine collections and the random urine U(MA)/U(Cr) specimens (r=0.89, P<0.001). All patients who excreted more than 30 mg microalbumin in the 24-h specimen also had a U(MA)/U(Cr) of more than 20 microg/mg in the randomly voided sample. Microalbuminuria was unlikely if the U(MA)/U(Cr) was below 20 microg/mg. The results of this study indicate that the measurement of U(MA)/U(Cr) in a second voided morning specimen is a simple and reliable method for monitoring microalbuminuria in diabetic patients and may replace the need to assess quantitative microalbumin excretion on 24-h urine collections.
Assadi
Farahnak K
FK
Section of Pediatric Nephrology, Rush Medical College, Rush Children's Hospital, Chicago, IL 60612, USA. fassadi@rush.edu
D000293:Adolescent; D000419:Albuminuria / Q000652:urine*; D002648:Child; D003404:Creatinine / Q000652:urine; D003922:Diabetes Mellitus, Type 1 / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D011897:Random Allocation; D013048:Specimen Handling / Q000379:methods
D003404:Creatinine