What is Diabetic Nephropathy?

Diabetic nephropathy is a type of progressive kidney disease that occurs in people who have type 1 or type 2 diabetes. The University of Washington estimates that 20 to 40 percent of people with diabetes will get diabetic nephropathy at some point in their lives (UW, 2012). People who have type 1 diabetes are more likely to develop end-stage renal failure (ESRD) than people who have type 2 diabetes.

There are five stages of diabetic nephropathy. The fifth and final stage is ESRD. Diabetic nephropathy progresses slowly. According to the University of Rochester Medical Center, the average time it takes to progress from the beginning stage of kidney failure to the fifth stage is 23 years (URMC, 2012). However, not everyone progresses to stage five of the disease.

How Are the Kidneys Damaged?

Each of your kidneys has about one million nephrons. Nephrons are small structures that filter waste from your blood. Diabetes can cause the nephrons to thicken and scar, which makes them less able to filter waste and remove fluid from the body. This causes them to leak a type of protein called albumin into your urine, leading to diabetic nephropathy.

The exact reason this occurs in people with diabetes is unknown, but high blood sugar levels and high blood pressure are thought to contribute to diabetic nephropathy. Persistently high blood sugar or blood pressure levels can damage your kidneys, making them unable to filter wastes and remove water from your body.

Certain factors have been shown to increase your risk of getting diabetic nephropathy, such as:

  • being African-American, Hispanic, or American Indian
  • developing type 1 diabetes before you are 20 years old
  • smoking

What Are the Symptoms of Diabetic Nephropathy?

The early stages of kidney damage are often unnoticeable. This means they are not detected. You may not experience any symptoms until your kidney disease progresses to ESRD.

Symptoms of ESRD may include:

  • fatigue
  • a general overall unwell feeling
  • loss of appetite
  • headache
  • itchy and dry skin
  • nausea or vomiting
  • swelling of your arms and legs

How Is Diabetic Nephropathy Diagnosed?

Your doctor will mostly likely perform yearly blood and urine tests on you to check for early signs of kidney damage. Common tests include:

Microalbuminuria Urine Test

A microalbuminuria urine test checks for albumin in your urine. Normal urine does not contain albumin, so the presence of the protein in your urine is a sign of kidney damage.

BUN Blood Test

A BUN blood test checks for the presence of urea nitrogen in your blood. Urea nitrogen forms when protein is broken down. Higher than normal levels of urea nitrogen in your blood may be a sign of kidney failure

Serum Creatinine Blood Test

A serum creatinine blood test measures creatinine levels in your blood. Your kidneys remove creatinine from your body by sending creatinine to the bladder, where it is released with urine. If your kidneys are damaged, they cannot remove the creatinine properly from your blood. High creatinine levels in your blood may mean that your kidneys are not functioning correctly.

Kidney Biopsy

If your doctor suspects that you have diabetic nephropathy, but is not sure, he may perform a kidney biopsy. A kidney biopsy is a surgical procedure where a small sample of one or both of your kidneys is removed, so it can be viewed under a microscope.

What Are the Treatment Options?

There is no cure for diabetic nephropathy, but treatments can delay or stop the progression of the disease. Treatments consist of keeping blood sugar levels under control and blood pressure levels down through medications and lifestyle changes. Your doctor will also recommend a special diet for your kidneys. If your kidney disease progresses to ESRD, you will require more invasive treatments.

Medications

Regularly monitoring your blood sugar levels and using the proper dosages of insulin, as directed by your doctor, can keep your blood sugar levels under control. Your doctor may prescribe ACE inhibitors, angiotensin receptor blockers (ARBs), or other blood pressure medications to keep your blood pressure levels down.

Lifestyle Changes

Your doctor or dietitian will help you plan a special diet that is easy on your kidneys. Kidney diets are often low in fat, sodium, potassium, phosphorus, protein, and fluids. Your doctor may also recommend an exercise plan for you to help keep your blood pressure low and your kidneys healthy.

ESRD Treatment

If you have ESRD, you will need dialysis or a kidney transplant, in addition to treatments for earlier stages of kidney disease, to stay alive. Dialysis is a procedure in which a special machine filters the waste out of your blood. Many people require dialysis treatments three times a week for four hours a day. You may need less or more frequent treatments. The other option for treatment is a kidney transplant. For a kidney transplant, a kidney from a donor will be placed into your body. The success of dialysis and kidney transplants differs with each person.

Long-Term Outlook

If and how fast the disease progresses is dependent upon the person and at what point the condition is diagnosed. Following a treatment plan can reduce the disease progression. In some cases, diabetic nephropathy can cause eye damage and heart disease. In cases where the disease has progressed to ESRD, it can be deadly.