Can random UAC detect microalbuminuria in diabetic patients?

For microalbuminuria screening in patients with diabetes, measuring urinary albumin concentration (UAC) in random urine samples offers sensitivity and specificity similar to those of the albumin-to-creatinine ratio (ACR), reports a study in JAMA Internal Medicine.

A meta-analysis was performed with the use of data on 2078 patients from 14 studies evaluating UAC and ACR in random urine samples. All studies included 24-hour urine collections as the criterion standard for diagnosis of microalbuminuria.

In bivariate random-effects models, the two tests offered similar diagnostic performances. Pooled sensitivity in detecting microalbuminuria was 0.85 for UAC and 0.87 for ACR. Specificity was 0.88 for both tests; diagnostic odds ratios were similar as well. Performance was similar by timing of sample as well as on analysis of seven studies in which patients underwent both UAC and ACR.

Measuring ACR in random urine samples has some disadvantages as a screening test for microalbuminuria, including the higher cost of urinary creatinine measurement. Studies comparing ACR with UAC for this purpose have yielded conflicting results.

The new meta-analysis suggests that UAC and ACR have similarly good performances for microalbuminuria screening in diabetic patients. With the rising incidence of diabetes and limited health care resources in many countries, the authors conclude, “UAC of random urine samples may become the screening tool of choice for the population with DM” [Wu H-Y, et al. Diagnostic performance of random urine samples using albumin concentration vs ratio of albumin to creatinine for microalbuminuria screening in patients with diabetes mellitus: a systematic review and meta-analysis. JAMA Intern Med, published online May 05, 2014. doi:10.1001/jamainternmed.2014.1363].