About Kidney Disease & Diabetes

Kidney Disease

Kidneys perform crucial functions, which affect all parts of the body. The kidney has three main functions: elimination of waste materials, regulation of blood pressure and production of the hormone erythropoietin. Erythropoietin is the hormone that regulates red blood cell production. Since your kidney is the major site of erythropoietin production, if you develop kidney failure (also called renal failure) then you may develop anemia. The anemia of chronic renal failure is caused primarily by damage to the areas within your kidney responsible for erythropoietin production. This results in a marked decrease in the amount of erythropoietin produced when needed. The production of red blood cells in people with renal failure is totally dependent upon the small amount of erythropoietin produced by the damaged kidney and other sites, such as the liver.

Diabetes

People with diabetes and hypertension can undergo a slow loss of kidney function, called nephropathy. Early diagnosis of kidney disease is essential in patients with diabetes.1

Commonly Asked Questions

Who is at risk for kidney problems?

*Because high blood pressure (hypertension) and diabetes are the two leading causes of renal insufficiency, those who suffer from one or both are among those most at risk for kidney problems.

What is anemia?

* When your body doesn't have enough red blood cells (RBCs), you can develop anemia. RBCs contain hemoglobin, which carries oxygen throughout your body. A lower than normal hemoglobin level indicates anemia.

What are the symptoms of anemia?

* The most common symptoms are fatigue (extreme tiredness), weakness and shortness of breath.

What does anemia have to do with my kidneys?

* Your kidneys maintain the proper water balance in your body, producing urine to get rid of waste products. They also control blood pressure and regulate red blood cell production. If your red blood cells decrease, anemia can develop.

How is anemia diagnosed?

* Your doctor will check your hemoglobin with a blood test called a Complete Blood Count (CBC). If your hemoglobin is below normal levels (140-180 g/L for men, 120-160 g/L for women), you might have anemia.

How can anemia be treated?

* If your anemia is due to vitamin or iron deficiency then modification of your diet may assist. However, if your anemia is not due to this, supplements and diet will not cure it. Blood transfusions are used to treat severe anemia.

* Your anemia can also be treated by a medication that stimulates RBC production. If more red blood cells are produced, more oxygen is carried through your body and your energy increases.

Anemia and Fatigue

All body tissues (for example: brain, muscle, heart, skin) need a constant supply of oxygen. The oxygen is carried to the tissues by the hemoglobin in the red blood cells. In a healthy individual, the number of functioning red blood cells is maintained at a constant level. Old red blood cells are continuously eliminated by the body and replaced by newly formed cells. Erythropoietin is a hormone produced in the kidneys which helps the body produce new red blood cells in the marrow.

Because people with chronic renal failure (called CRF or kidney disease) have kidneys that do not function normally, the amount of erythropoietin produced by their kidneys is diminished. As a result, people with kidney disease often have a low red blood cell count. The total hemoglobin in their blood is low, therefore their tissues do not receive enough oxygen. This condition is called anemia. Some of the symptoms of anemia include general fatigue and lack of energy. If your anemia is due to vitamin or iron deficiency then modification of your diet may assist. However, if your anemia is not due to this, supplements and diet will not cure it. One way to increase the number of red blood cells in the blood of people with anemia that have kidney disease is blood transfusions. Your doctor may also recommend a medication that stimulates red blood cell production. As the red blood cell count increases (and, therefore, the total hemoglobin increases), the problems caused by anemia can be alleviated or even eliminated. As a result, the quality of life for the majority of people with kidney disease will improve.

Reference 1. Canadian Medical Association Journal. 1998 clinical practice guidelines for the management of diabetes in Canada. Supplement to CMAJ 1998; 159 (8 Suppl): 973-978

About Diabetes and Kidney Disease

The number of Canadians diagnosed with diabetes is expected to reach 2.2 million by the year 2000 and 3 million by the year 2010.1 The two most common types of diabetes are Type 1 (insulin-dependent diabetes, or IDDM), when the pancreas cannot produce insulin, and Type 2 (non-insulin-dependent diabetes, or NIDDM), when the pancreas produces insulin but the body cannot properly use it. Type 1 is usually diagnosed during childhood; Type 2 is far more common. It is thought that kidney failure strikes both groups almost equally.2

Diabetes develops from two factors - a genetic predisposition and a "second event". In Type 1 diabetes, the second event could be a viral infection like chickenpox. In Type 2, the second event is usually obesity.2

Approximately 40% of people with Type 1 diabetes and 10% of people with Type 2 diabetes will eventually develop kidney disease leading to kidney failure.3

Because there is no cure for kidney disease, controlling and slowing it are crucial. Controlling hypertension (high blood pressure), the most important predictor of which people with diabetes will develop kidney disease, is extremely important, as are watching blood sugar levels and reducing dietary protein intake. Other control-oriented treatments used include preventing urinary tract infections, avoiding medications that might cause kidney damage, and weight loss.2

Signs that someone with diabetes might be developing kidney disease include:

• * High blood pressure (hypertension)
• *Protein in the urine
• *Increased need to urinate, particularly at night
• * Leg swelling or cramps
• *Abnormal blood tests (e.g., a rise in blood urea nitrogen)
• * Less need for insulin
• *Nausea and vomiting
• *Weakness, fatigue and anemia

References: 1. us Medical Association Journal. 1998 clinical practice guidelines for the management of diabetes in Canada. Supplement to CMAJ 1998; 159 (8 Suppl) pg: 973-978.

2. National Kidney Foundation website. "Ten Facts About Diabetes and Kidney Disease." http://www.kidney.org/general/news/diabetes.cfm

3. Diabetes and Kidney Disease. The Kidney Foundation of Canada website. http://www.kidney.ca/dia-e.htm

Diabetes, High Blood Pressure & Kidney Disease

People with diabetes and hypertension can undergo a slow loss of kidney function, called nephropathy. Early diagnosis of kidney disease is essential, since its progression can be slowed or even stopped with a type of drug known as ACE (angiotensin converting enzyme) inhibitors. These antihypertensive medications lower blood pressure, thus decreasing the loss of protein into the urine. They also are thought to protect clusters of blood vessels in the kidney called glomeruli.

Diabetes

Even those patients whose diabetes is well controlled are at risk for kidney disease; 20-30% of people with Type 1 or Type 2 diabetes develop kidney problems within 15 years of diagnosis. It starts with small amounts of protein in the urine, which usually appear after 10 years. If protein content in the urine reaches more then 300 mg/day, this is called nephropathy.1

The five stages of kidney disease in people with diabetes are:2

Stage I: Is marked by an increased blood flow through the glomeruli, which increases pressure in the kidneys and makes them appear enlarged. Many people with diabetes never advance beyond stage I.

Stage II: Defined as small amounts of albumin (a blood protein) leaking into the urine. This protein loss is known as microalbuminuria. People with diabetes can stay for many years in stage II.

Stage III: (Proteinuria, albuminuria, or overt diabetic nephropathy) Characterized by increased damage to the glomeruli. Some patients now also develop hypertension. Detecting albumin is done with a urine dipstick test. Blood tests will reveal higher creatinine and urea nitrogen levels, waste products that healthy kidneys would eliminate.

Stage IV: (Advanced clinical nephropathy) Blood levels in stage IV show even higher creatinine and urea nitrogen levels. Urine protein markedly increases as the glomeruli lose their blood-filtering capabilities. Hypertension is almost certain.

Stage V: In stage V, kidney function has fallen to less than 25% of normal. Stage V is considered End Stage Renal Disease (ESRD) when kidney function is 10% of normal and dialysis or kidney transplant is required. Diabetes and hypertension are the top two causes of ESRD.

Most people with diabetes and hypertension do not reach ESRD - approximately 3% of people with diabetes have ESRD. Managing blood pressure (120/80 is normal) and keeping blood glucose (sugar) levels close to normal (around 120 mg/dL, or milligrams per decilitve) are the keys to helping prevent ESRD.

Dialysis

When a patient with kidney failure (renal failure) does not respond to conservative medical treatment, some method of dialysis is performed to remove waste products. Dialysis refers to the movement or passage of particles (ions) across a semipermeable membrane. This membrane is a filter with pores large enough to allow certain particles to pass through but too small to allow the passage of larger particles.

Dialysis is used in renal failure to remove toxic substances and body wastes normally excreted by healthy kidneys. Methods of therapy include:

* peritoneal dialysis

* hemodialysis

References: 1. Johns Hopkins Intelihealth website. "Diabetes, Blood Pressure, and Kidney Disease." http://www.gdadm.com/intelihealth/

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