Question 1

Why is a first-morning urine preferred for ACR?

Accepted Answer

First-morning urine minimises the effect of orthostatic (postural) proteinuria and provides the most reproducible ACR value. If a first-morning sample is not possible, a random spot sample is still acceptable, but an abnormal result should be confirmed with a first-morning specimen.

Question 2

What factors can falsely elevate urine albumin?

Accepted Answer

Acute illness, fever, vigorous exercise within 24 hours, urinary tract infection, menstrual contamination, congestive heart failure, and poorly controlled hypertension can transiently elevate ACR. Confirm with a repeat test when the patient is clinically stable.

Question 3

How is ACR used alongside eGFR in CKD staging?

Accepted Answer

KDIGO CKD staging uses a heat map matrix: eGFR category (G1–G5) on one axis and ACR category (A1–A3) on the other. The combination determines the risk of progression, monitoring frequency, and referral urgency (e.g., G3aA3 has higher risk than G3aA1).

Question 4

Should I use ACR or PCR (protein-creatinine ratio)?

Accepted Answer

ACR is more sensitive for detecting early glomerular disease (especially diabetic nephropathy). PCR is acceptable for monitoring nephrotic-range proteinuria or when ACR is not available. Both can be used on the same spot sample.