Microalbuminuria can either be detected by:
- checking the albumin concentration or the albumin/ creatinine ratio in the first voided urine sample.
- or, making a timed collection and checking the albumin concentration.
The diagnosis of microalbuminuria cannot be made in the presence of an acute metabolic crisis. As far as is practicable, the best possible metabolic control of diabetes should be achieved before investigating patients for microalbuminuria. Patients should not be screened during intercurrent illness (1).
Notes (2):
- use of early morning urines to measure albumin creatinine ratio (ACR) gives a more accurate estimate of 24h urine albumin, though random samples have acceptable performance
- additionally, early morning urines allow the exclusion of orthostatic proteinuria. In orthostatic proteinuria significant urinary protein is excreted when erect, but when recumbent the urinary protein is completely normal. This usually occurs in young adults, and has no long-term consequences
- for the diagnosis of microalbuminuria 2 abnormal results from 3 specimens are required
Reference:
- The Renal Association (May 2006).UK CKD Guidelines
- UK Renal Association (2011). Detection, Monitoring and Care of Patients with CKD