Topic Overview
What is diabetic nephropathy?
Nephropathy means
kidney disease or damage. Diabetic nephropathy is damage to your kidneys caused
by
diabetes. In severe cases it can lead to kidney
failure. But not everyone with diabetes has kidney damage.
What causes diabetic nephropathy?
The kidneys have
many tiny blood vessels that filter waste from your blood. High blood sugar
from diabetes can destroy these blood vessels. Over time, the kidney isn't able
to do its job as well. Later it may stop working completely. This is called
kidney failure.
For reasons doctors don't yet understand, only
some people who have diabetes get kidney damage. Out of 100 people with diabetes,
as many as 40 will get kidney damage.1
Certain things make you more likely to get diabetic nephropathy. If you
also have
high blood pressure or high cholesterol, or if you smoke, your risk is
higher. Also, Native Americans, African Americans, and Hispanics (especially
Mexican Americans) have a higher risk.2
What are the symptoms?
There are no symptoms in
the early stages. So it's important to have regular urine tests to find kidney
damage early. Sometimes early kidney damage can be reversed.
The
first sign of kidney damage is a small amount of protein in the urine, which is
found by a simple urine test.
As damage to the kidneys gets worse,
your blood pressure rises. Your
cholesterol and
triglyceride levels rise too. As your kidneys are less
able to do their job, you may notice swelling in your body, at first in your
feet and legs.
How is diabetic nephropathy diagnosed?
The problem
is diagnosed using simple tests that check for a protein called
albumin in the urine. Urine doesn't usually contain
protein. But in the early stages of kidney damage—before you have any
symptoms—some protein may be found in your urine, because your kidneys aren't
able to filter it out the way they should.
Finding kidney damage
early can keep it from getting worse. So it's important for people with
diabetes to have regular testing.
- If you have type 1 diabetes, get a urine test
every year after you have had diabetes for 5 years.
- If your child
has diabetes, yearly testing should begin when your child is 10 years old and has had diabetes for 5 years.
- If you have
type 2 diabetes, start yearly testing at the time you are diagnosed with
diabetes.
How is it treated?
The main treatment is medicine
to lower your blood pressure and prevent or slow the damage to your kidneys.
These medicines include:
- Angiotensin-converting enzyme inhibitors,
also called ACE inhibitors.
- Angiotensin II receptor blockers, also
called ARBs.
You may need to take more than one medicine, especially
if you also have high blood pressure.
And there are other steps
you can take. For example:
- Work with your doctor to keep your blood
pressure down, usually below 130/80.
- Work with your doctor to
keep your cholesterol level as close to a healthy level as you can. You may need to take
medicines for this.
- Keep your heart healthy by eating a low-fat
diet and exercising regularly. Preventing heart disease is important, because
people with diabetes are 2 to 4 times more likely to die of heart and blood
vessel diseases. And people with kidney disease are at an even higher risk for
heart disease.
- Watch how much protein you eat. Eating too much is
hard on your kidneys. If diabetes has affected your kidneys, limiting how much
protein you eat may help you preserve kidney function. Talk to your doctor or
dietitian about how much protein is best for you.
- Watch how much salt you eat. Eating less salt helps keep high
blood pressure from getting worse.
- Don't smoke or use other
tobacco products.
How can diabetic nephropathy be prevented?
The
best way to prevent kidney damage is to keep your blood sugar in your target range and your blood pressure at a target of less than 130/80 mm Hg. You do this by staying at a healthy weight, exercising regularly, and
taking your medicines as directed.
At the first sign of protein in
your urine, you can take high blood pressure medicines to keep kidney damage
from getting worse.
Frequently Asked Questions
Learning about diabetic nephropathy: | |
Being diagnosed: | |
Getting treatment: | |
Living with diabetic nephropathy: | |
Symptoms
There are no symptoms in the early stages of
diabetic nephropathy. The only sign of kidney damage
may be small amounts of protein leaking into the urine (microalbuminuria).
Normally, protein is not found in urine except during periods of high fever,
strenuous exercise, pregnancy, or infection.
In people with
type 1 diabetes, diabetic nephropathy usually develops
5 to 10 years after the onset of diabetes. People with
type 2 diabetes may find out that they already have a
small amount of protein in the urine (microalbuminuria) at the time diabetes is
diagnosed, because they may have had diabetes for several years.
As diabetic nephropathy progresses, your kidneys cannot do their job as well.
They cannot clear toxins or drugs from your body as well. And they cannot balance the chemicals in your blood very well. You may:
- Lose more protein in your urine (macroalbuminuria, also known as
overt nephropathy).
- Have higher blood pressure.
- Have
higher
cholesterol and
triglyceride levels.
You may have symptoms if your nephropathy gets worse. These
symptoms include:
- Swelling (edema), first in the feet and legs and later throughout
your body.
- Poor appetite.
- Weight
loss.
- Weakness.
- Feeling tired or worn
out.
- Nausea or vomiting.
- Trouble sleeping.
If the kidneys are severely damaged, blood sugar levels may drop because
the kidneys cannot remove excess
insulin or filter oral medicines that increase insulin
production, such as glipizide (Glucotrol) or glyburide (for example,
Micronase).
Exams and Tests
Diabetic nephropathy is diagnosed using tests that check for a protein (albumin)
in the urine, which points to kidney damage. Your urine will be
checked for protein (urinalysis) when you are diagnosed with
diabetes.
Microalbumin urine tests can detect
very small amounts of protein in the urine that cannot be detected by a routine
urine test, allowing early detection of nephropathy. Early detection is
important, to prevent further damage to the kidneys. The results of two tests,
done within a 3- to 6-month period, are needed to diagnose nephropathy.
When to begin checking for protein in the urine depends on the type of
diabetes you have. After testing begins, it should be done every year.1
Microalbumin testing| Type of diabetes | When to begin yearly
testing |
|---|
Type 1 diabetes | After you have had diabetes for
5 years |
Type 2 diabetes | When you are diagnosed with
diabetes |
Diabetes present during
childhood | After age 10 and after the child has had diabetes for 5 years |
A microalbuminuria dipstick test is a simple test that can
detect small amounts of protein in the urine (microalbuminuria, also called
proteinuria). The strip changes color if protein is present, providing an
estimate of the amount of protein. A spot urine test for microalbuminuria is a
more precise lab test that can measure the exact amount of protein in a
urine sample. Either of these tests may be used to test your urine for protein.
You will also have a
creatinine test done every year. The creatinine test
is a blood test that shows how well your kidneys are working.
If
your doctor suspects that the protein in your urine may be caused by a disease
other than diabetes, other blood and urine tests may be done. You may have a
small sample of kidney tissue removed and examined (kidney biopsy).
Other tests
It is important to check your blood
pressure regularly, both at home and in your doctor's office, because blood
pressure rises as kidney damage progresses. About one-third of people with type
2 diabetes have
high blood pressure at the time diabetes is diagnosed.
The American Diabetes Association recommends a target blood pressure of less
than 130/80 millimeters of mercury (mm Hg).1 The level
recommended by other organizations may vary. Talk with your doctor about what
your target blood pressure level should be. Keeping your blood pressure at or
below this target can prevent or slow kidney damage.
Blood levels
of
cholesterol and
triglycerides also should be checked regularly to see
whether diabetes,
nephrotic syndrome, or other factors are raising your
blood cholesterol level.
High cholesterol can increase the risk of hardening of
the arteries (atherosclerosis), possibly leading to heart disease,
peripheral arterial disease, and stroke.
Treatment Overview
Diabetic nephropathy is treated with medicines that lower blood pressure and
protect the kidneys. These medicines may reverse kidney damage and are started
as soon as any amount of protein is found in the urine (microalbuminuria). The
use of these medicines before nephropathy occurs may also help prevent
nephropathy in people who have normal blood pressure.
If you have
high blood pressure, two or more medicines may be
needed to lower your blood pressure enough to protect the kidneys. Medicines
are added one at a time as needed. The American Diabetes Association recommends
a target blood pressure of less than 130/80 millimeters of mercury (mm
Hg).1 The level recommended by other groups may
vary. Talk with your doctor about what your target blood pressure level should
be.
If
you take other medicines, avoid ones that damage or stress the kidneys,
especially
nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs include ibuprofen and naproxen.
It is also important to keep your blood sugar within your target range. Maintaining blood sugar levels within your target range prevents
damage to the small blood vessels in the kidneys.
Limiting the
amount of salt in your diet can help keep your high blood pressure from
getting worse. You may also want to restrict the amount of protein in your
diet. If diabetes has affected your kidneys, limiting how much protein you eat
may help you preserve kidney function. Talk to your doctor or
dietitian about how much protein is best for you.
People who have diabetes are 2 to 4 times more likely than people who
don't have diabetes to die of heart and blood vessel diseases. Eating a low-fat diet can help prevent heart attack,
stroke, and other large blood vessel disease (macrovascular disease).3
Initial treatment
Medicines that are used to treat
diabetic nephropathy are also used to control blood
pressure. If you have a very small amount of protein in your urine, these
medicines may reverse the kidney damage. Medicines used for initial treatment
of diabetic nephropathy include:
- Angiotensin-converting enzyme (ACE) inhibitors, such
as captopril, lisinopril, ramipril, and enalapril. ACE
inhibitors can lower the amount of protein being lost in the urine. Also, they
may reduce your risk of heart and blood vessel (cardiovascular) disease.
- Angiotensin II receptor blockers (ARBs), such as candesartan cilexetil, irbesartan, losartan potassium,
and telmisartan. You may be given both an ACE inhibitor and an ARB. The
combination of these medicines may provide greater protection for your kidneys
than either medicine alone.
If you also have high blood pressure, two or more
medicines may be needed to lower your blood pressure enough to protect your
kidneys. Medicines are added one at a time as needed. The American Diabetes
Association recommends a target blood pressure of less than 130/80 millimeters
of mercury (mm Hg).1
If you take other
medicines, avoid ones that damage or stress the kidneys, especially
nonsteroidal anti-inflammatory drugs (NSAIDs).
It is also important to keep your blood sugar within a target range to prevent damage to the small blood vessels in the kidneys. The
American Diabetes Association recommends that you keep your blood sugar levels
at:1
- 70 mg/dL to 130 mg/dL before meals and 110 mg/dL to 150 mg/dL
at bedtime.
- Less than 180 mg/dL 1 to 2 hours after meals.
Ongoing treatment
As
diabetic nephropathy progresses, blood pressure
usually rises, making it necessary to add more medicine to control blood
pressure and keep it less than 130/80 mm Hg.
Your doctor
may advise you to take the following medicines that lower blood pressure. You
may need to take different combinations of these medicines to best control your
blood pressure. By lowering your blood pressure, you may reduce your risk of
kidney damage. Medicines include:
- A combination of
angiotensin-converting enzyme (ACE) inhibitors and
angiotensin II receptor blockers (ARBs). A combination
of these medicines may be more effective in controlling blood pressure than
either used alone.
- Calcium channel blockers lower blood pressure by
making it easier for blood to flow through the vessels. Examples include
diltiazem (such as Cardizem SR, Dilacor XR, or Tiazac), verapamil (such as
Calan SR or Isoptin SR), amlodipine (such as Norvasc), and nifedipine (such as
Adalat or Procardia XL).
- Diuretics. Medicines such as
chlorthalidone, hydrochlorothiazide, or spironolactone help lower blood
pressure by removing sodium and water from the body.
- Beta-blockers lower blood pressure by slowing down
your heartbeat and reducing the amount of blood pumped with each heartbeat.
Examples include atenolol (Tenormin), carvedilol (Coreg), or metoprolol (such
as Lopressor).
Continue to avoid other medicines that may damage
or stress the kidneys, especially
nonsteroidal anti-inflammatory drugs (NSAIDs). And it is still important to keep your blood sugar within your target range, limit salt in your diet, restrict the amount of protein you eat, keep your cholesterol at a healthy level, eat a low-fat diet, get regular exercise, and not smoke.
Treatment if the condition gets worse
If damage to
the blood vessels in the kidneys continues,
kidney failure eventually develops. When that occurs,
it is likely that you will need
dialysis treatment (renal replacement therapy)—an
artificial method of filtering the blood—or a kidney transplant to survive. To
learn more, see the topic
Chronic Kidney Disease.
What to think about
Diabetic nephropathy can
get worse during pregnancy and can affect the growth
and development of the fetus. If your nephropathy is not severe, your kidney
function may return to its prepregnancy level after the baby is born. If you
have severe nephropathy, pregnancy may lead to permanent worsening of your
kidney function.4
If you have
nephropathy and are pregnant or are planning to become pregnant, talk with your
doctor about which medicines you can take. You may not be able to take some
medicines (for example, angiotensin-converting enzyme [ACE] inhibitors, such as
captopril, lisinopril, ramipril, or enalapril) during pregnancy, because they
may harm your developing baby.
Prevention
Prevention is the best way to avoid
kidney damage from
diabetic nephropathy.
- Keep your blood sugar levels within a target range.
Manage your blood sugar by eating a balanced diet, taking your medicines
(insulin or oral medicines), and getting regular exercise. The American
Diabetes Association recommends that you keep your blood sugar levels
at:1
- 70 mg/dL to 130 mg/dL before meals and
110 mg/dL to 150 mg/dL at bedtime.
- Less than 180 mg/dL 1 to 2 hours after meals.
Your doctor will want you to check your blood sugar several
times each day. - Have yearly testing for protein in your urine.
- If you have type 1 diabetes, begin urine
tests for protein after you have had diabetes for 5 years.
- Children with type 1 diabetes should begin yearly urine protein
screening when they are 10 years of age and have had diabetes for 5 years.
- If you have type 2 diabetes, begin
screening at the time diabetes is diagnosed.
- Keep your blood pressure at less than 130/80
mm Hg with medicine, diet, and exercise. Learn to check your blood pressure at
home.
- Stay at a healthy weight. This can help you
prevent other diseases, such as high blood pressure and heart disease.
- Follow the nutrition
guidelines for hypertension (including the
Dietary Approaches to Stop Hypertension, or DASH, diet).
- Do not smoke or use other tobacco products.
If you already have diabetic nephropathy, you may be able
to slow the progression of kidney damage by:
- Avoiding
dehydration by promptly treating other conditions—such
as diarrhea, vomiting, or fever—that can cause it. Be especially careful during
hot weather or when you exercise.
- Reducing your risk of heart
disease. Lifestyle changes such as eating a low-fat diet, quitting smoking , and
getting regular exercise can help reduce your overall risk of developing heart
disease and stroke.
- Treating other conditions that may block the normal flow of
urine out of the kidneys, such as
kidney stones, an
enlarged prostate, or bladder
problems.
- Not using
medicines that may be harmful to your kidneys,
especially
nonsteroidal anti-inflammatory drugs (NSAIDs). Be sure
that your doctor knows about all prescription, nonprescription, and herbal
medicines you are taking.
- Avoiding X-ray tests that require IV
contrast material, such as angiograms, intravenous
pyelography (IVP), and some CT scans. IV contrast can cause further kidney
damage. If you do need to have these types of tests, make sure your doctor
knows that you have diabetic nephropathy.
- Avoiding situations where
you risk losing large amounts of blood, such as unnecessary surgeries. Do not
donate blood or plasma.
- Lowering your blood pressure, because high
blood pressure can make kidney damage even worse.
- Checking with
your doctor to find out if it is safe for you to drink alcohol. If you do drink
alcohol, have no more than 1 drink a day. Limiting alcohol can lower your blood
pressure and lower your risk of kidney damage.
Home Treatment
If you have
diabetes, work with your doctor to keep your blood
sugar levels within your target range. By managing your blood sugar, you
can reduce the chances of developing
nephropathy, or you can slow the disease if you
already have it.1 Your doctor will want you to check
your blood sugar several times each day.
Other steps you can take include the following:
- Check your blood pressure often, and also have it checked at your
doctor's office. The American Diabetes Association recommends a target blood
pressure of less than 130/80 millimeters of mercury (mm Hg).1 The level recommended by other groups may vary. Talk with
your doctor about the target blood pressure that is right for you.
- Be sure to take your blood pressure medicines as
prescribed.
- Don't take medicines that damage or stress the
kidneys, especially
nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs include ibuprofen and naproxen.
- Follow the nutrition guidelines for hypertension
(including the
Dietary Approaches to Stop Hypertension, or DASH, diet).
- Stay at a healthy weight for your height and age
by eating a well-balanced diet and exercising regularly. A low-fat diet and
regular exercise also will lower your risk of heart and blood vessel
(cardiovascular) disease. A healthy weight is one that is right for your body type and height
and is based on your
body mass index (BMI) and the size of your waist (waist circumference).
- Do not smoke or use other tobacco products. People with diabetes
who smoke raise their risk of nephropathy, cardiovascular disease, and other
complications of diabetes.
- Eat a moderate amount of protein. If you have nephropathy, your
doctor may recommend limiting protein. Limiting how much protein you eat may
help you preserve kidney function. Talk to your doctor or
dietitian about how much protein is best for
you.
- Limit salt. Your doctor may recommend that you cut back on
salt, because salt may make your high blood pressure worse.
What to think about
If your diabetic nephropathy
becomes worse and kidney failure develops, you may need to follow a specific
diet. A dietitian can help you understand the requirements of this diet and
help you make healthy choices.
Other Places To Get Help
Organizations
| American Diabetes Association (ADA) |
| 1701 North Beauregard Street |
| Alexandria, VA 22311 |
| Phone: | 1-800-DIABETES (1-800-342-2383) |
| Email: | AskADA@diabetes.org |
| Web Address: | www.diabetes.org |
| |
The American Diabetes Association (ADA) is a national organization
for health professionals and consumers. Almost every state has a local office.
ADA sets the standards for the care of people with diabetes. Its focus is on
research for the prevention and treatment of all types of diabetes. ADA
provides patient and professional education mainly through its publications,
which include the monthly magazine Diabetes Forecast,
books, brochures, cookbooks and meal planning guides, and pamphlets. ADA also
provides information for parents about caring for a child with diabetes. |
|
| National Diabetes Education Program
(NDEP) |
| 1 Diabetes Way |
| Bethesda, MD 20814-9692 |
| Phone: | 1-800-438-5383 to order materials
(301) 496-3583 |
| Email: | ndep@mail.nih.gov |
| Web Address: | http://ndep.nih.gov |
| |
The National Diabetes Education Program (NDEP) is
sponsored by the U.S. National Institutes of Health (NIH) and the U.S. Centers
for Disease Control and Prevention (CDC). The program's goal is to improve the
treatment of people who have diabetes, to promote early diagnosis, and to
prevent the development of diabetes. Information about the program can be found
on two Web sites: one managed by NIH (http://ndep.nih.gov) and the other by CDC
(www.cdc.gov/team-ndep). |
|
| National Diabetes Information Clearinghouse
(NDIC) |
| 1 Information Way |
| Bethesda, MD 20892-3560 |
| Phone: | 1-800-860-8747 |
| Fax: | (703) 738-4929 |
| TDD: | 1-866-569-1162 toll-free |
| Email: | ndic@info.niddk.nih.gov |
| Web Address: | http://diabetes.niddk.nih.gov |
| |
This clearinghouse provides information about research
and clinical trials supported by the U.S. National Institutes of Health. This
service is provided by the National Institute of Diabetes and Digestive and
Kidney Disease (NIDDK), a part of the National Institutes of Health (NIH).
|
|
| National Kidney and Urologic Diseases Information
Clearinghouse |
| 3 Information Way |
| Bethesda, MD 20892-3580 |
| Phone: | 1-800-891-5390 |
| TDD: | 1-866-569-1162 |
| Fax: | (703) 738-4929 |
| Email: | nkudic@info.niddk.nih.gov |
| Web Address: | www.kidney.niddk.nih.gov |
| |
The National Kidney and Urologic Diseases Information
Clearinghouse (NKUDIC) provides information about diseases of the
kidneys and urologic system to people with these problems and to
their families, to health professionals, and to the public. NKUDIC answers
inquiries; develops, reviews, and distributes publications; and works closely
with professional and patient groups and government agencies to
coordinate resources about kidney and urologic diseases. NKUDIC, a federal agency, is a service of the National
Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). NIDDK is part
of the National Institutes of Health under the U.S. Department of Health and
Human Services. |
|
| National Kidney Foundation |
| 30 East 33rd Street |
| New York, NY 10016 |
| Phone: | 1-800-622-9010 |
| Phone: | (212) 889-2210 |
| Fax: | (212) 689-9261 |
| Web Address: | www.kidney.org |
| |
The National Kidney Foundation works to prevent kidney
and urinary tract diseases and help people affected by these conditions. Its
website has a lot of information about adult and child conditions. The site
has interactive tools, donor information, recipes for kidney disease patients,
and message boards for many kidney topics. Free materials, such as brochures
and newsletters, are available. |
|
References
Citations
- American Diabetes Association (2012). Standards of medical care in diabetes—2012. Diabetes Care, 35(Suppl 1): S11–S63.
- American Diabetes Association (2004). Nephropathy in
diabetes. Clinical Practice Recommendations 2004. Diabetes Care, 27(Suppl 1): S79–S83.
- Van Dam RM, et al. (2002). Dietary patterns and risk
for type 2 diabetes mellitus in U.S. men. Annals of Internal Medicine, 136(3): 201–209.
- American Diabetes Association (2004). Preconception
care of women with diabetes. Clinical Practice Recommendations 2004.
Diabetes Care, 27(Suppl 1): S76–S78.
Other Works Consulted
- American Diabetes Association (2012). Standards of medical care in diabetes—2012. Diabetes Care, 35(Suppl 1): S11–S63.
- Brownlee M, et al. (2011). Complications of diabetes mellitus. In S Melmed et al., eds., Williams Textbook of Endocrinology, 12th ed., pp. 1462–1551. Philadelphia: Saunders.
- Molitch ME, Genuth S (2006). Complications of diabetes
mellitus. In DC Dale, DD Federman, eds., ACP Medicine,
section 9, chap. 3. New York: WebMD.
- Parving H, et al. (2008). Diabetic nephropathy. In BM
Brenner, ed., Brenner and Rector's The Kidney, 8th ed.,
vol. 2, pp. 1265–1298. Philadelphia: Saunders Elsevier.
- Shlipak M (2010). Diabetic nephropathy: Preventing progression, search date November 2009. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
|---|
| Specialist Medical Reviewer | Tushar J. Vachharajani, MD, FASN, FACP - Nephrology |
|---|
| Last Revised | March 7, 2011 |
|---|