UACR Range in Diabetic Kidney Disease
Diabetic kidney disease commonly presents with UACR values ranging from normal (<30 mg/g) up to severely elevated levels (≥300 mg/g and beyond), with the disease spanning the entire spectrum of albuminuria categories. 1
Understanding the UACR Spectrum in DKD
Normal Range
- UACR <30 mg/g is defined as normal, though this does not exclude diabetic kidney disease, as reduced eGFR without albuminuria is increasingly recognized in both type 1 and type 2 diabetes 1
- Even within the "normal" range, higher values (particularly >8-10 mg/g) may predict future CKD progression in patients with type 2 diabetes 2
Moderately Increased Albuminuria (Category A2)
- UACR 30-299 mg/g represents moderately increased albuminuria, previously termed "microalbuminuria" 1
- This is an early indicator of diabetic kidney disease in type 1 diabetes and a marker for development in type 2 diabetes 1
- Approximately 30-40% of patients remain in this range without progressing to higher levels 1
Severely Increased Albuminuria (Category A3)
- UACR ≥300 mg/g defines severely increased albuminuria, previously termed "macroalbuminuria" or "overt nephropathy" 1
- This represents more advanced diabetic kidney disease with higher risk of progression 3
- There is no upper limit to UACR in diabetic kidney disease—values can extend well beyond 300 mg/g, with some patients presenting with UACR >1000 mg/g or higher 4
Clinical Presentation Patterns
Type 1 Diabetes
- Diabetic kidney disease typically develops after 10 years of diabetes duration 1
- Classical progression: normal UACR → moderately increased (30-299 mg/g) → severely increased (≥300 mg/g) over 5-15 years 3
- Rare to develop kidney disease without retinopathy 1
Type 2 Diabetes
- CKD may be present at diagnosis of diabetes 1
- More heterogeneous presentation: can have reduced eGFR without albuminuria or albuminuria without reduced eGFR 1
- Retinopathy is only moderately sensitive and specific for diabetic kidney disease 1
Important Clinical Caveats
Confirmation requires 2 of 3 abnormal specimens collected within 3-6 months due to high biological variability (>20%) in urinary albumin excretion 1, 5
Transient elevations can occur with:
- Exercise within 24 hours 1
- Infection or fever 1
- Congestive heart failure 1
- Marked hyperglycemia or hypertension 1
- Menstruation 1
The entire spectrum from <30 mg/g to >300 mg/g (and beyond) can be seen in diabetic kidney disease, as UACR is a continuous measurement where differences within both normal and abnormal ranges are associated with renal and cardiovascular outcomes 1