Related Experiment Videos
Quantitation of microalbuminuria using random urine samples
1Section of Pediatric Nephrology, Rush Medical College, Rush Children's Hospital, Chicago, IL 60612, USA. fassadi@rush.edu
Abstract:
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.
Insights
A random urine microalbumin-creatinine ratio (U(MA)/U(Cr)) accurately monitors microalbuminuria in diabetic patients. This simple method may replace cumbersome 24-hour urine collections for assessing kidney disease risk.
Area of Science:
- Nephrology
- Diabetology
- Clinical Chemistry
Background:
- Microalbuminuria is a key indicator of diabetic kidney disease and cardiovascular complications.
- Traditional 24-hour urine collection for microalbuminuria is inconvenient and prone to errors.
- A simpler, reliable method for monitoring microalbuminuria is needed.
Purpose of the Study:
- To evaluate the correlation between the microalbumin-creatinine ratio (U(MA)/U(Cr)) in random urine samples and 24-hour microalbumin excretion.
- To determine if U(MA)/U(Cr) can serve as a practical alternative to timed urine collections for microalbuminuria assessment in pediatric patients with type 1 diabetes.
Main Methods:
- A study involving 124 urine samples from 97 pediatric patients with type 1 diabetes.
- Comparison of U(MA)/U(Cr) in a random morning voided urine sample against microalbumin quantity in a 24-hour urine collection.
- Statistical analysis to determine the correlation coefficient (r) and significance (P-value).
Main Results:
- An excellent correlation (r=0.89, P<0.001) was observed between random U(MA)/U(Cr) and 24-hour microalbumin excretion.
- Patients with >30 mg/24h microalbumin excretion consistently showed U(MA)/U(Cr) >20 microg/mg.
- U(MA)/U(Cr) <20 microg/mg suggested the absence of significant microalbuminuria.
Conclusions:
- Measurement of U(MA)/U(Cr) in a random second morning voided specimen is a simple and reliable method for monitoring microalbuminuria.
- This approach may obviate the need for 24-hour urine collections in diabetic patients.
- The findings support the use of random urine U(MA)/U(Cr) for routine screening and management of diabetic nephropathy.