What is microalbuminuria?
Microalbuminuria is simply the presence of albumin (proteins) in urine. In a properly functioning body proteins are normally retained in the bloodstream by the kidneys. The blood vessels in the kidney filter waste products from the blood and this waste is expelled out in the form of urine. However if these blood vessels get damaged gradually due to high blood sugar levels, it may cause albumin protein to spell in the urine. This condition may be the first indication of ‘Diabetic nephropathy’. The level of urinary albumin is used to determine the extent and stage of nephropathy.
How is microalbuminuria test done?
Ideally, urine samples collected over 24 hours is the preferred specimen but a sample collected over a specific period of time such as 4 hours or 10 hours overnight collection is acceptable. Even a random collection is advisable. A urine sample collected over time such as 4-24 hours, gives the most accurate results. One should refrain from heavy exercises 24 hours before the test.
When is it recommended?
The National Kidney Foundation recommends that all patients with Type 1 diabetes older than 12 years and all patients with Type 2 diabetes less than 70 years should have their urine tested for microalbuminuria yearly when they are under stable glucose as well as blood pressure conrol. A repeat test should be done twice in next four months after the first positive test for microalbuminuria. If it is positive for 2 out of 3 times consider it positive.
What is reference range for microalbuminuria?
The readings are predicted as:
- Normoalbuminuria: <30 mg/day
- Microalbuminuria: 30-300 mg/day
- Macroalbuminuria or Proteinuria: >300 mg/day
Some of the doctors may advise for urine albumin creatinine ratio (UACR). UACR > 2.5 mg/mmol in male and >3.5 mg/mmol in women is suggestive of microalbuminuria.
What do the test results interpret?
If the results are in microalbuminuria range it might indicate incipient nephropathy (initial stage of development of nephropathy) and may predict the progression of diabetic kidney disease. This implies that patients need to take adequate measures in controlling their blood gucose, blood pressure and may at time indicate the necessity to start treatment. People with both type 1 and type 2 diabetes and microalbuminuria or macroalbuminuria have been found to have greater cardiovascular (heart disease) morbidity and mortality than those with urinary protein. Microalbuminuria is also associated with an increased risk of retinopathy (eye damage). Therefore, anyone who is positive for microlbuminuria screened for cardiovascular disease and eye disease yearly.
How to prevent microalbuminuria?
Maintaining a tight control over your blood glucose levels can prevent diabetics from microalbuminuria. Keeping high blood pressure under control is also effective in preventing kidney damage that leads to microalbuminuria. Research studies have shown that those having microalbuminuria can prevent it from worsening or may reverse it with good glycemic control and blood pressure control.