Diabetic Kidney Disease (Diabetic Nephropathy)

Protecting one's kidneys from diabetic nephropathy is important to living a healthy life. Besides cleansing the blood by removing waste products, the kidneys also release three important hormones:

• renin (REE-nin), which regulates blood pressure;
• erythropoietin (eh-RITH-ro-POY-eh-tin), or EPO, which stimulates the bone marrow to make red blood cells;
• calcitriol (kal-suh-TRY-ul), the active form of vitamin D, which helps maintain calcium for bones and for normal chemical balance in the body;

Diabetes is the leading cause of end-stage renal disease (kidney failure), accounting for 44% of all new cases. In 2001, 42,813 people in the U.S. began treatment for end-stage renal disease and 142,963 people with end-stage renal disease were living on chronic dialysis or with a kidney transplant.

Uncontrolled glucose levels over a period of time—including high blood pressure—damage the kidneys. If not corrected, elevated glucose levels and/or high blood pressure will impair and destroy the kidneys’ filtering system. When too many nephrons are destroyed, the only solution is dialysis or kidney transplant.

Your Kidneys

The kidneys are bean-shaped organs, each about the size of your fist. They are located near the middle of your back, just below the rib cage. Every day, your kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and extra water. The waste and extra water become urine, which flows to your bladder through tubes called ureters. Your bladder stores urine until you go to the bathroom.

The wastes in your blood come from the normal breakdown of active tissues and from the food you eat. Your body uses the food for energy and self-repair. After your body has taken what it needs from the food, waste is sent to the blood. If your kidneys did not remove these wastes, the wastes would build up in the blood and damage your body.

The actual filtering occurs in tiny units inside your kidneys called nephrons. Every kidney has about a million nephrons. In the nephron, a glomerulus—which is a tiny blood vessel, or capillary—intertwines with a tiny urine-collecting tube called a tubule. A complicated chemical exchange takes place, as waste materials and water leave your blood and enter your urinary system.

At first, the tubules receive a combination of waste materials and chemicals that your body can still use. Your kidneys measure out chemicals like sodium, phosphorus, and potassium and release them back to the blood to return to the body. In this way, your kidneys regulate the body’s level of these substances. The right balance is necessary for life, but excess levels can be harmful.

Preventing or Delaying Diabetic Nephropathy

The book includes several topics for discussion with your physician about protecting one's kidneys.

Kidney Failure

The only treatment for end stage renal disease (kidney failure) is dialysis or transplant. The most common dialysis—hemodialysis—is performed by a machine which mechanically filters the blood. This process is performed every 3 days and the dialysis process requires 3 to 5 hours or longer.

Hemodialysis cleans and filters blood using a machine to temporarily rid the body of harmful wastes, extra salt, and extra water. Hemodialysis helps control blood pressure and helps the body keep the proper balance of important chemicals such as potassium, sodium, calcium, and bicarbonate.

Hemodialysis uses a special filter called a dialyzer that functions as an artificial kidney to clean the blood. During treatment, blood travels through tubes into the dialyzer, which filters out wastes and extra water. Then the cleaned blood flows through another set of tubes back into the body. The dialyzer is connected to a machine that monitors blood flow and removes wastes from the blood. The needles used for dialysis are very large—typically 15 gauge; however, some people require the use of even larger 14 gauge needles. As a comparison, the smallest insulin syringe needles are 31 gauge.

Kidney Transplants

Kidney transplantation surgically places a healthy kidney from another person into the recipient's body. The donated kidney does the work that two failed kidneys used to do.

A surgeon places the new kidney inside the lower abdomen and connects the artery and vein of the new kidney to an artery and vein. Blood flows through the donated kidney, which makes urine, just like the original kidneys did when they were healthy. The new kidney may start working right away or may take up to a few weeks to make urine. Unless the original kidneys are causing infection or high blood pressure, they are left in place.

Kidney transplants require the use of lifelong anti-rejection drugs which prevents the body's immune system from destroying the newly transplanted kidney. Anti-rejection drugs are known to increase the risk of developing certain cancers.