Diabetic Nephropathy

What is diabetic nephropathy?

 Diabetic nephropathy is a complication of diabetes that is caused by uncontrolled high blood sugar. High blood sugar damages the filtering system of the kidneys (nephron). Over time, the damage can lead to kidney failure. Diabetic nephropathy is the most common cause of kidney failure in the United States.

Preventing or slowing kidney damage is most important in managing this disease. Keeping blood sugar and blood pressure as near to normal as possible and eating a healthy diet can reduce your risk of developing this condition or progressing to kidney failure.

What causes diabetic nephropathy?

Persistently high blood sugar levels caused by diabetes can, over time, damage the blood vessels in your kidneys, resulting in diabetic nephropathy.

What are the symptoms?

There are no symptoms in the early stages of diabetic nephropathy. A small amount of protein in the urine (microalbuminuria) is the first sign of kidney damage. As damage to the kidneys progresses, larger amounts of protein spill into the urine (macroalbuminuria) and blood pressure rises. Your triglyceride levels will increase as well. As kidney function declines, you may notice swelling in your body, at first in your feet and legs.

Regular checkups with your health professional are important to detect early signs of diabetic nephropathy and begin efforts to prevent further kidney damage.

What increases my risk for diabetic nephropathy?

For reasons doctors don't yet understand, only some people with diabetes develop nephropathy. Diabetic nephropathy eventually occurs in up to 40% of people who have diabetes.

If you have both diabetes and high blood pressure, you have an even greater risk of developing nephropathy. Other risk factors for the disease include smoking and a high cholesterol level. In addition, people of Native American, African-American, or Hispanic (especially Mexican-American) descent have a greater-than-average risk.

How is it diagnosed?

As the kidney becomes less able to filter wastes, proteins from the blood spill into the urine. One protein, albumin, helps control the fluid balance in the body. Early in diabetic nephropathy, before other symptoms are present, the kidneys are still able to filter waste and function normally. The only sign of kidney disease may be an increase in albumin in the urine. Urine tests for albumin can detect early kidney disease.

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. Yearly urine tests for protein are recommended for all people with diabetes.

• If you have type 1 diabetes, you should have a microalbumin test every year after you have had diabetes for 5 years.
• If your child has diabetes, yearly testing should begin at puberty.
• If you have type 2 diabetes, you should begin yearly testing at the time you are diagnosed with diabetes.

How can it be prevented?

Diabetic nephropathy can be prevented or its progress slowed by carefully keeping your blood sugar levels as close to normal as possible. You can do this by maintaining a healthy weight, taking your medications as prescribed, checking your blood sugar level frequently, and exercising regularly. At the first sign of too much protein in your urine, there are high blood pressure medications that you can take to slow the progression of nephropathy.

How is it treated?

Medications that lower blood pressure and prevent or slow the development of diabetic nephropathy are recommended for all people who have diabetes and have a high risk for nephropathy. Examples of these medications are angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs). You may need to take more than one medication, especially if you also have high blood pressure. Treatment to control blood pressure and blood sugar levels can reduce kidney failure caused by diabetes by 50%.