What is microalbuminuria and how is it managed?

What is Microalbuminuria?

Microalbuminuria is a small but abnormal amount of protein (albumin) leaking into your urine, which serves as an early warning sign that your blood vessels—particularly in your kidneys—are being damaged. 1, 2

Understanding the Basics

• Normal kidneys act like filters that keep important proteins like albumin in your bloodstream while removing waste products. 1
• When blood vessels become damaged, these filters start to leak, allowing small amounts of albumin to escape into your urine—this is microalbuminuria. 1, 3
• The term "microalbuminuria" is actually misleading because it suggests minor damage, when in reality it signals significant vascular problems throughout your body. 1

What the Numbers Mean

Your urine test measures the albumin-to-creatinine ratio: 1

• Normal: Less than 30 mg/g creatinine
• Microalbuminuria: 30-299 mg/g creatinine
• Macroalbuminuria (more severe): 300 mg/g creatinine or higher

Because albumin levels can vary day-to-day, your doctor needs to confirm abnormal results with 2 out of 3 tests over a 3-6 month period before making the diagnosis. 1, 2

Why This Matters to Your Health

Microalbuminuria is not just about your kidneys—it's a red flag for problems throughout your cardiovascular system. 1, 3

Kidney Risk

• In people with diabetes, microalbuminuria predicts progression to kidney failure if left untreated. 1, 4
• Without intervention, 20-40% of people with type 2 diabetes and microalbuminuria will develop kidney failure. 1

Heart and Blood Vessel Risk

• Microalbuminuria signals that blood vessels throughout your body are damaged, dramatically increasing your risk of heart attacks, strokes, and early death. 1, 3
• This vascular damage exists whether or not you have diabetes. 5, 6

How It's Managed

First-Line Treatment

Your doctor should start you on an ACE inhibitor medication (or an ARB if you can't tolerate ACE inhibitors), even if your blood pressure is normal. 1, 2 These medications protect your kidneys and heart beyond just lowering blood pressure. 4

Blood Pressure Control

• Target blood pressure is less than 130/80 mmHg for anyone with microalbuminuria. 2, 3
• Additional blood pressure medications may be needed if the ACE inhibitor alone doesn't achieve this goal. 2

Blood Sugar Control (if you have diabetes)

• Tight glucose control (keeping your HbA1c below 7%) is essential to slow kidney damage. 1, 4

Dietary Changes

• Reduce protein intake to 0.8 grams per kilogram of body weight daily (roughly 10% of your daily calories). 2
• Limit salt intake to help control blood pressure. 3

Lifestyle Modifications

• Stop smoking immediately—smoking accelerates kidney and vascular damage. 1, 3
• Lose weight if overweight, targeting a BMI under 30. 3
• Control cholesterol levels, keeping LDL below 100 mg/dL if you have diabetes. 3

Monitoring Your Progress

• Your urine albumin will be rechecked every 3-6 months to see if treatment is working. 2
• A reduction of 30% or more in albumin levels indicates successful treatment. 2
• Blood tests for kidney function (creatinine) and potassium will be monitored at least annually, as ACE inhibitors can affect these levels. 1, 2

Important Caveats

• Avoid vigorous exercise for 24 hours before urine testing, as it can temporarily elevate albumin levels and give false results. 1
• Infections, fever, uncontrolled blood sugar, and menstruation can also temporarily increase albumin excretion. 1
• If you're pregnant or planning pregnancy, ACE inhibitors and ARBs must be stopped as they can harm the developing baby. 2
• Referral to a kidney specialist (nephrologist) is warranted if your kidney function declines significantly (GFR below 60) or if blood pressure and albumin levels don't improve with treatment. 2, 7