The urinary albumin:creatinine ratio is a useful measure of renal function
used in diabetic renal disease.
The urinary albumin:creatinine ratio is measured using the first morning urine
sample where practicable.
Microalbuminuria is defined as: albumin:creatinine ratio >2.5mg/mmol (men)
or >3.5mg/mmol (women) or albumin concentration >20mg/l.
Proteinuria is defined as: albumin:creatinine ratio >30mg/mmol or albumin
- NICE suggest that (2):
- all people with diabetes, and people without diabetes with a GFR
less than 60 ml/min/1.73 m^2, should have their urinary albumin/protein
excretion quantified. The first abnormal result should be confirmed on
an early morning sample (if not previously obtained)
- quantify by laboratory testing the urinary albumin/protein excretion
of people with an eGFR 60 ml/min/1.73 m2 or more if there is a strong
suspicion of CKD
- the Renal Association note that (3):
- 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