Microalbuminuria can therefore be a sign that your kidneys are not functioning optimally. Diabetes is the most common cause of microalbuminuria
Microalbuminuria is a condition in which there is an abnormally increased amount of a protein called albumin in your urine, between 30-299 mg/gram creatinine.
When your kidneys are healthy, they filter large molecules such as albumin and prevent them from being excreted in large quantities in urine. Microalbuminuria can therefore be a sign that your kidneys are not functioning optimally.
Diabetes is the most common cause of microalbuminuria in the U.S. Kidney damage can also be caused by conditions such as:
- Hypertension (high blood pressure)
- Obesity
- Metabolic syndrome (group of conditions that include increased blood pressure, high blood sugar, excess abdominal fat, and abnormal cholesterol or triglyceride levels)
- Inherited kidney diseases (such as polycystic kidney disease and Alport syndrome)
- Early stages of type I diabetes mellitus
Sometimes microalbuminuria has causes unrelated to kidney damage, such as high fever, extreme physical activity, or excessive protein intake. In such cases, the condition may reverse if the underlying cause is treated.
How is microalbuminuria detected?
Microalbuminuria is detected through a simple urine test. Normal albumin levels in urine should be less than 30 mg/gram per day.
Microalbuminuria is a laboratory diagnosis and is defined as urinary excretion of albumin between 30-300 mg of albumin per day. A value of more than 300 mg is called albuminuria, macroalbuminuria, or proteinuria and indicates severe kidney damage.
What additional tests may be done if you have microalbuminuria?
If you have three positive results over a few months, your doctor may order a blood test to estimate glomerular filtration rate (GFR). Your GFR number helps your doctor determine the status of your kidney functions. Other tests include
- Imaging tests (ultrasound or CT scan of the renal pelvis)
- Kidney biopsy (surgical removal of a small piece of the kidney for examination under a microscope)
Who should undergo regular urine testing for microalbuminuria?
People who are at an increased risk of developing kidney disease need to test their urine at regular intervals to check if they have microalbuminuria. These include people with conditions such as:
- Diabetes
- High blood pressure
- Polycystic kidney disease
- Family history of kidney failure
Other risk factors for kidney disease include:
- Age: 65 or older
- Ethnicity: African Americans, Hispanics, Asians, and American Indians
How is microalbuminuria treated?
If microalbuminuria is detected, your doctor will take your medical history and check if you:
- Have fever
- Exercised right before the test
- Are taking medications that cause excretion of albumin in urine
- Have a urinary tract infection
Your doctor will repeat the test the following day or sometime during the next few days. If the repeat test detects microalbuminuria again, it may indicate a problem with your kidneys. Your doctor will refer you to a nephrologist, who may recommend treatments that include:
- Medications to treat diabetes
- Medications to treat hypertension
- Lifestyle changes such as reducing excess weight, exercising regularly, and making changes to your diet