7/11/2014

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Proteinuria
Digestive and Kidney Diseases (NIDDK). NIDDK is part of the
‘National Institutes of Health under the U.S. Department of Health and
Human Services. Established in 1987, the clearinghouse provides
information about diseases of the kidneys and urologic system to
people with kidney and urologic disorders and to their families, health
care professionals, and the public. NKUDIC answers inquiries;
develops, reviews, and distributes publications; and works closely with
professional and patient organizations and Government agencies to
coordinate resources about kidney and urologic diseases.

Publications produced by the clearinghouse are carefillly reviewed for
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NIH Publication No. 00-4732
May 2000

e-text posted: June 2000

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For More
Information

Proteinuria

Proteinuria is a condition in which urine contains an abnormal
amount of protein.

Proteinuria may be a sign that your kidneys are damaged and
that you are at risk for end-stage renal disease.

Several health organizations recommend that people be
regularly checked for proteinuria so that kidney disease can
be detected and treated before it progresses.

Groups at risk for proteinuria and kidney failure include
African Americans, American Indians, Hispanic Americans,
Pacific Islander Americans, people who are older or
overweight, and people who have a family history of kidney
disease.

You may have proteinuria without noticing any signs or
symptoms. Testing is the only way to find out how much
protein you have in your urine.

Tf you have diabetes or hypertension, or both, the first goal of
treatment will be to control your blood sugar or blood
pressure.

American Kidney Fund

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Internet: www.akfinc.org

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Phone: (800) 62249010 or (212) 88982210
Email: info@kidney.org

Internet: www.kidney.org

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Emuil: National Kidney and Urologic Diseases
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The National Kidney and Urologic Diseases Information Clearinghouse
(NKUDIC) is a service of the National Institute of Diabetes and

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7/11/2014 Proteinuria

©NIDD

Publications * Introduction

¢ Who Is at Risk?

¢ What Are the Signs of Proteinuria and Kidney Failure?
¢ What Are the Tests for Proteinuria?

° How Is Proteinuria Treated?

¢ Hope Through Research

© Points to Remember

¢ For More Information

NIDDK Home

Introduction Proteinuria describes a condition in which urine contains an abnormal
amount of protein. Proteins are the building blocks for all body parts,
including muscles, bones, hair, and nails. Proteins in your blood also
perform a number of important functions: protecting you from infection,
helping your blood coagulate, and keeping the right amount of fluid
circulating through your body.

As blood passes through healthy kidneys, they filter the waste products
out and leave in the things the body needs, like proteins. Most proteins
are too big to pass through the kidneysi filters into the urine, unless the
kidneys are damaged. The two proteins that are most likely to appear
in urine are albumin and globulin. Albumin is smaller and therefore more
likely to escape through the filters of the kidney, called glomeruli.
Albuminis function in the body includes retention of fluid in the blood. It
acts like a sponge, soaking up fluid from body tissues.

Inflammation in the glomeruli is called glomerulonephritis, or simply
nephritis. Many diseases can cause this inflammation, which leads to
proteinuria. Additional processes that can damage the glomeruli and
cause proteinuria include diabetes, hypertension, and other forms of
kidney diseases.

Research shows that the level and type of proteinuria (whether the
urinary proteins are only albumin or include other proteins) strongly
determine the extent of damage and whether you are at risk for
developing progressive kidney failure.

Proteinuria has also been shown to be associated with cardiovascular
disease. Damaged blood vessels may lead to heart failure or stroke as
wellas kidney failure. If your doctor finds that you have proteinuria,
you will want to do what you can to protect your health and prevent
any of these diseases from developing.

Several health organizations recommend that some people be regularly
checked for proteinuria so that kidney disease can be detected and
AUTHENTICATED treated before it progresses. A 1996 study sponsored by the National

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7/11/2014

Who Is at Risk?

What Are the
Signs of
Proteinuria and
Kidney Failure?

What Are the
Tests for
Proteinuria?

Proteinuria

Institutes of Health determined that proteinuria is the best predictor of
progressive kidney failure in people with type 2 diabetes. The American
Diabetes Association recommends regular urine testing for proteinuria
for people with type 1 or type 2 diabetes. The National Kidney
Foundation recommends that routine checkups include testing for
excess protein in the urine, especially for people in high-risk groups.

People with diabetes, hypertension, or certain family backgrounds are
at risk for proteinuria. In the United States, diabetes is the leading cause
of end-stage renal disease (ESRD), the result of progressive kidney
failure. In both type 1 and type 2 diabetes, the first sign of deteriorating
kidney function is the presence of small amounts of the protein albumin
in the urine, called microalbuminuria. As kidney function declines, the
amount of albumin in the urine increases, and microalbuminuria
becomes full-fledged proteinuria.

High blood pressure is the second leading cause of ESRD. Proteinuria
in people with high blood pressure is an indicator of declining kidney
function. If the hypertension is not controlled, the person can progress
to full renal failure.

African Americans are more likely than white Americans to have high
blood pressure and to develop kidney problems from it, even when
their blood pressure is only mildly elevated. In fact, African Americans
ages 25 to 44 are 20 times more likely than their white counterparts to
develop hypertension-related kidney failure. High blood pressure is the
leading cause of kidney failure among African Americans.

Other groups at risk for proteinuria are American Indians, Hispanic
Americans, Pacific Islander Americans, older people, and overweight
people. People who have a family history of kidney disease should also
have their urine tested regularly.

Large amounts of protein in your urine may cause it to look foamy in
the toilet. Also, because the protein has left your body, your blood can
no longer soak up enough fluid and you may notice swelling in your
hands, feet, abdomen, or face. Alternatively, you may have proteinuria
without noticing any signs or symptoms. Testing is the only way to find
out how much protein you have in your urine.

To test for proteinuria, you will need to give a urine sample. A strip of
chemically treated paper will change color when dipped in urine that
has too much protein. A more sophisticated chemical analysis is needed
to find smaller amounts (microalbuminuria). The most dependable
measure of proteinuria requires you to collect your urine for 24 hours.
You will be given a

special container and

instructions for starting

and stopping the

collection and for

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How Is
Proteinuria
Treated?

Hope Through
Research

Proteinuria

storing the container.

Your doctor will also
want to test a sample
of your blood for
creatinine and urea
nitrogen. These are
waste products that
healthy kidneys remove
from the blood. High
levels of creatinine and
urea nitrogen in your
blood indicate that
kidney function is
impaired.

Containers for collecting urine.

Tf you have diabetes, hypertension, or both, the first goal of treatment
will be to control your blood sugar and blood pressure. If you have
diabetes, you should test your blood sugar often, follow a healthy eating
plan, take your medicines, and get plenty of exercise. If you have
diabetes and high blood pressure, your doctor may prescribe a
medicine froma class of drugs called ACE (angiotensin-converting
enzyme) inhibitors. These drugs have been found to protect kidney
function even more than other drugs that provide the same level of
blood pressure control.

People who have high blood pressure and proteinuria but not diabetes
may also benefit from taking an ACE inhibitor. The National Heart,
Lung, and Blood Institute recommends keeping blood pressure below
125/75 mm Hg for people with proteinuria greater than | gram per 24
hours.

In addition to blood sugar and blood pressure control, the National
Kidney Foundation recommends restricting dietary salt and protein.
Your doctor may refer you to a dietitian to help you follow a healthy
eating plan.

In recent years, researchers have learned much about kidney disease.
The National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK) sponsors several programs aimed at understanding kidney
failure and finding treatments to stop its progression.

NIDDKis Division of Kidney, Urologic, and Hematologic Diseases
(DKUHD) supports basic research into normal kidney function and the
diseases that impair normal function at the cellular and molecular levels,
including diabetes, high blood pressure, glomerulonephritis, and other
diseases marked by proteinuria.

Points To Remember

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