Published by Bupa's Health Information Team, December 2011.
This factsheet is for people who have microalbuminuria, or who would like information about it.
Microalbuminuria is when very small amounts of a protein called albumin pass through your kidneys and into your urine. This can be a sign of underlying conditions such as kidney disease or cardiovascular disease.
Your blood contains cells and proteins that your body requires, as well as waste products that it needs to get rid of. Your blood is filtered by your kidneys, and waste products are removed from your body in your urine. Usually, cells and proteins stay in your blood, but sometimes a small amount of protein is lost into your urine along with other waste products.
Albumin is a protein that is produced in your liver. If your kidneys are working properly, very little albumin will be lost in your urine. However, if you have microalbuminuria, the blood vessels involved in filtering waste products in your kidneys are damaged and your kidneys begin to lose their ability to filter proteins out of your urine.
Microalbuminuria is defined as losing 30 to 300 milligrams of albumin in your urine per day. If you lose more than this, you may have a condition called proteinuria, which is when the levels of protein in your urine are higher than 300 milligrams per day.
Microalbuminuria can often be the first sign of kidney damage or kidney disease. People with type 1 and type 2 diabetes may develop kidney damage as a complication of their diabetes. If you have diabetes and microalbuminuria is detected early, there are treatments that may slow down any further damage to your kidneys.
Microalbuminuria can also be a sign of more widespread damage to your blood vessels, including those of your heart. Microalbuminuria can be a sign that you're at an increased risk of heart disease, particularly if you have type 2 diabetes.
If you have microalbuminuria, you won’t have any symptoms. The only way you will know if you have microalbuminuria is to have a test. See our diagnosis of microalbuminuria section for more information.
Microalbuminuria is a possible complication of type 1 or type 2 diabetes. As well as diabetes, there are several other risk factors that make you more likely to develop microalbuminuria. These include:
If your GP thinks you may be at risk of having microalbuminuria, he or she may ask you to do a urine test. He or she may also ask about your medical history.
Your urine sample will usually be sent to a laboratory for testing. There are several ways to diagnose microalbuminuria.
Your urine may be tested for its albumin to creatinine ratio – this measures how well your kidneys are working. You may be diagnosed as having microalbuminuria if your albumin to creatinine ratio is:
If your GP thinks you have microalbuminuria, you may be asked to collect more than one urine sample on several occasions to confirm the diagnosis.
Your GP may ask you to collect all of your urine over a set amount of time (such as over four hours, overnight, or even over a 24-hour period). This is because the levels of protein can vary throughout the day and night so it will help to give a more accurate measurement of how much albumin you lose in your urine.
If you’re asked to collect your urine over a set amount of time, it will be tested for its level of albumin instead of its albumin to creatinine ratio. If you have 30 to 300 milligrams of albumin in your urine, you will be diagnosed with microalbuminuria. However, the test results can be affected by:
Tell your GP or nurse if you have any health problems or if any of the other factors above apply to you. If you have exercised within a day of being due to start collecting your urine, the test can be rearranged for another day.
If you have microalbuminuria, your GP will monitor your condition and may refer you to a specialist. You will usually be asked to have a urine test at least once a year and your doctor will discuss the different types of treatment available.
Diet and exercise play a key role in controlling your blood sugar levels and reducing your weight, blood pressure and cholesterol level – in turn preventing any further kidney damage. Your GP may advise you to:
If you develop kidney disease, you may need to change your diet to prevent a build-up of waste products in your kidneys and prevent further kidney damage. You may need to limit the amount of certain foods you eat, such as those that contain high levels of protein, sodium, potassium or phosphate. If you need to do this, your GP can refer you to a dietitian for advice.
Medicines called angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) can help to slow down kidney damage. These medicines can also help to reduce your blood pressure.
Having microalbuminuria can be a sign of cardiovascular disease, so your GP may prescribe a cholesterol-lowering medicine called a statin if you're over 40, or if you're younger and have other cardiovascular risk factors, such as high blood pressure or diabetes. Your GP may advise you to take 75 milligrams of aspirin daily if you're particularly at risk of heart attack or stroke, especially if you've already had one or the other in the past. See our common questions for more information.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.
Publication date: December 2011
Get checked out with Bupa Health Assessments