Management of Microalbuminuria

Diagnosis and Confirmation

Microalbuminuria is defined as urinary albumin excretion of 30-299 mg/24h, 30-299 mg/g creatinine on a random spot urine sample, or 20-199 μg/min on a timed collection, according to the American Diabetes Association 3, 4
Confirmation requires 2 out of 3 abnormal specimens collected within a 3-6 month period due to significant day-to-day variability in urinary albumin excretion, as recommended by the American Diabetes Association 1, 4
First morning void samples are preferred to minimize effects of orthostatic proteinuria, which is common in adolescents, as suggested by the American Academy of Pediatrics 3, 2
Several factors can cause transient elevations in urinary albumin excretion that should be ruled out before confirming diagnosis, including exercise, acute infections, marked hyperglycemia, and marked hypertension, according to the American Diabetes Association 3, 4

For patients with confirmed microalbuminuria, treatment with an ACE inhibitor or ARB should be initiated even if blood pressure is normal, with the goal of normalizing microalbumin excretion to reduce progression to overt nephropathy and decrease cardiovascular risk, as recommended by the American Heart Association 1, 2
The American Diabetes Association recommends monitoring serum creatinine and potassium levels after starting ACE inhibitor or ARB therapy 1
Titration of medication to normalize microalbumin excretion is recommended if possible, according to the American Academy of Pediatrics 2, 1
Dietary modifications, including protein intake of approximately 0.8 g/kg body weight per day, are recommended by the American Diabetes Association 1
Smoking cessation is encouraged by the American Heart Association 2

ACE inhibitors/ARBs may cause acute kidney injury in patients with bilateral renal artery stenosis or advanced renal disease, as warned by the American Diabetes Association 1
ACE inhibitors and ARBs are contraindicated in pregnancy, according to the American College of Obstetricians and Gynecologists 1
Consider referral to nephrology when there is uncertainty about etiology, difficult management issues, rapidly progressing kidney disease, or eGFR <30 mL/min/1.73 m², as recommended by the American Diabetes Association 1

Microalbuminuria is an early marker of diabetic nephropathy and predicts progression to overt proteinuria and renal failure, according to the American Journal of Kidney Diseases 5
In patients with type 1 diabetes, GFR is stable at low-level microalbuminuria but decreases at 1-4 mL/min/year as albumin excretion increases, with more rapid decline in those with poorly controlled hypertension, as reported by the American Journal of Kidney Diseases 5, 6
Microalbuminuria is an independent marker of cardiovascular risk, indicating possible underlying vascular dysfunction, according to the American Heart Association 3