Kidney Disease - March 3, 2009 Newsletter

March is National Kidney Month

EHE Newsletter, Volume 9, Number 5
March 3, 2009

What do the kidneys do?

The kidneys are two bean–shaped organs, each about the size of your fist, that are located near the middle of your back, just below your rib cage. The kidneys are vital organs that perform many functions to keep your blood clean and chemically–balanced. Healthy kidneys act as a filtering system for your blood. As blood passes through your kidneys, it is filtered, and waste products and excess fluid are removed. This filtering occurs in tiny units called nephrons. Each kidney has about one million nephrons which process blood, waste products, and extra water. The waste and extra water become urine which flows to your bladder where it is stored until you urinate. If the kidneys do not remove these wastes, the wastes will build up in your blood and damage your body.

In addition to removing wastes, healthy kidneys also balance the chemicals in your blood and produce hormones to control blood pressure and maintain healthy blood cells and bones.

Kidney Disease

Most kidney diseases occur as a result of damage to the nephrons, which cause them to lose their filtering capacity. The damage usually occurs gradually over many years, without any obvious symptoms. Gradual loss of kidney function is called chronic kidney disease (CKD) or chronic renal insufficiency. CKD, in time, may lead to kidney failure which requires dialysis treatment or a kidney transplant to maintain life. Early detection and treatment can prevent or delay these complications.

The two most common causes of kidney disease in the United States are diabetes and high blood pressure. These conditions may also speed up the progression of chronic kidney disease in someone who is already affected.

  • Diabetes: Diabetes is the leading cause of chronic kidney disease and accounts for 45 percent of new cases of kidney failure. Diabetes occurs when a person’s body does not produce enough insulin or cannot use the insulin that it produces. Insulin is a hormone that regulates the amount of sugar (glucose) in the blood. When someone has diabetes, his or her body cannot process glucose adequately and it builds up in the bloodstream. Over time, these high sugar levels in the blood can cause blood vessels to become narrow and clogged. Without enough blood, kidneys become damaged and albumin (a type of protein) will pass through the nephrons and collect in the person’s urine. As kidney function worsens, the amount of albumin and other proteins in the urine increases.
  • High Blood Pressure: High blood pressure, or hypertension, is a condition in which the force of blood against the walls of the arteries is too strong. High blood pressure places additional stress on blood vessels throughout the body and also places stress on nephrons. As a result, the kidneys may stop removing wastes and extra fluid from the blood. The extra fluid in blood vessels may build up and raise blood pressure even more. If uncontrolled, or poorly–controlled, high blood pressure can be a leading cause of chronic kidney disease as well as heart attacks and strokes.

There are several other risk factors for kidney disease:

  • cardiovascular disease
  • a mother, father, sister, or brother who has had kidney disease
  • an ethnic background that is African American, Native American, or Hispanic
  • obesity
  • autoimmune diseases
  • urinary tract infections and systemic infection

If you have ANY of these risk factors, talk to your health care provider about getting tested for kidney disease.

Tests for Kidney Disease

Early kidney disease, like high blood pressure, is a silent problem. Kidney disease can become kidney failure with little or no warning, and is often discovered just before the kidneys fail. Most people affected are over the age of 40, but kidney failure can also occur in children and young adults. Early detection, education and awareness are crucial. If you have any of the risk factors, discuss testing for early signs of kidney disease with your doctor.

The National Kidney Foundation recommends three simple tests to screen for kidney disease: a blood pressure measurement, a spot check for protein or albumin in the urine, and a calculation of glomerular filtration rate (GFR).

  • High blood pressure can lead to kidney disease. It can also be a sign that your kidneys are already impaired. Detection and early treatment of high blood pressure is key in slowing or preventing kidney damage. Be sure to have your blood pressure checked.
  • An estimate of your "filtering rate" is determined by a blood test called a blood creatinine test which measures the amount of a waste product (creatinine) in your blood. It is the most effective test used in measuring your level of kidney function and determining your stage of kidney disease. This test, along with your age, body size, and gender, gives your doctor an estimate of glomerular filtration rate (GFR). GFR is a calculation of how efficiently your kidneys are filtering wastes from your blood.
  • A urine test measures the amount of protein in your urine. Protein can leak into your urine when your kidneys are not working well. The first sign of kidney deterioration is a condition known as microalbuminuria in which tiny amounts of albumin are detected in your urine. As kidney function worsens, the amount of albumin and other proteins in your urine increases, resulting in a condition called proteinuria.

Prevention and Treatment

According to the National Kidney and Urologic Diseases Information Clearinghouse, if your doctor finds that you have kidney disease, there may be a number of ways to help slow down the disease; to help you feel better; and to help you make better medical decisions. By taking steps to control your diabetes and high blood pressure now, you can keep your kidneys healthy for a longer period of time.

  • If you have diabetes, control your blood glucose levels. Studies show that keeping tight control of blood glucose can delay or prevent kidney failure.
  • If you have high blood pressure with CKD, keep your blood pressure below 130/80 mm Hg. Blood pressure medicines called ACE (angiotensin-converting enzyme) inhibitors and ARBs (angiotensin receptor blockers) may protect your kidneys better than other medicines. You may need a combination of two or more drugs to keep your blood pressure below 130/80. In many cases, a medicine that lowers blood pressure by increasing urination (a diuretic), should also be part of the plan.
  • If you have CKD, do not eat too much protein. Protein breaks down into waste products that your kidneys must excrete. Reducing these waste products by eating less protein means that your kidneys will not have to work too hard. Eating too little protein, however, can lead to poor nutrition. Work with a dietitian to make sure you get the right amounts of protein and other nutrients.
  • Stay at a healthy weight. This can help you prevent other diseases, such as diabetes, high blood pressure, and heart disease.
  • Maintain healthy levels of fats (lipids), such as cholesterol and triglycerides.
  • Do not smoke or use other tobacco products. Smoking can lead to atherosclerosis, which reduces blood flow to the kidneys and increases blood pressure.

Recent studies indicate that 26 million American adults suffer from CKD and that most are completely unaware of their condition. National Kidney Month is the perfect time to raise awareness of this condition and to get serious about prevention. Chronic kidney disease is common, has treatable components, and its progression can be slowed substantially.

MEDICAL DISCLAIMER: The information is not intended to constitute medical advice and is not a substitute for consultation with a physician or other health care provider. Individuals with specific complaints should seek immediate consultation from their personal physicians.