諾魯月報第三十八版-營養專欄 Kidney disease, not kidding!－My Way, My Life

May 2013
諾魯月報-第三十八版封面

The Nutrition Corner

Kidney disease, not kidding!

The kidneys are pair bean-shaped, fist-sized organs that are located below the rib cage near the middle of the back. Most people know that a major function of the kidneys is to remove waste products and excess fluid from the body. These waste products and excess fluid are removed through the urine. The production of urine involves highly complex steps of excretion and re-absorption. This process is necessary to regulate the amount of water and electrolytes in the body such as sodium, potassium and phosphorous. In adults they filter around 190 liters of blood every day to remove waste products that result from the normal activities of tissues in the body.

Chronic kidney disease (CKD) is defined as having some type of kidney abnormality, or "marker", such as protein in the urine and having decreased kidney function for three months or longer. There are many causes of chronic kidney disease. The kidneys may be affected by diseases such as diabetes and high blood pressure whilst in Nauru diabetes is the leading cause of CKD, which accounting around 90%.

What Are Main Causes of Chronic Kidney Disease?

Diabetes is a disease in which your body does not make enough insulin or cannot use normal amounts of insulin properly. This results in a high blood sugar level, which can cause problems in many parts of your body. In the kidneys, millions of tiny blood vessels (capillaries) with even tinier holes in them act as filters. As blood flows through the blood vessels, small molecules such as waste products squeeze through the holes. These waste products become part of the urine. Useful substances, such as protein and red blood cells, are too big to pass through the holes in the filter and stay in the blood. Diabetes can damage this system. High levels of blood sugar make the kidneys filter too much blood. All this extra work is hard on the filters. After many years, they start to leak and useful protein is lost in the urine. Having small amounts of protein in the urine is called microalbuminuria.

High blood pressure, also known as hypertension, is another common cause of kidney disease and other complications such as heart attacks and strokes. High blood pressure occurs when the force of blood against your artery walls increases. High blood pressure makes the heart work harder and, over time, can damage blood vessels throughout the body. If the blood vessels in the kidneys are damaged, they may stop removing wastes and extra fluid from the body. The extra fluid in the blood vessels may then raise blood pressure even more. It's a dangerous cycle. When high blood pressure is controlled, the risk of complications such as chronic kidney disease is decreased.

How is Chronic Kidney Disease detected?

Early detection and treatment of chronic kidney disease are the keys to keeping kidney disease from progressing to kidney failure. Some simple tests can be done to detect early kidney disease. They are:

Blood pressure measurement
A test for protein in the urine. An excess amount of protein in your urine may mean your kidney's filtering units have been damaged by disease. One positive result could be due to fever or heavy exercise, so your doctor will want to confirm your test over several weeks.
A test for blood creatinine. Your doctor should use your results, along with your age, race, gender and other factors, to calculate your glomerular filtration rate (GFR). Your GFR tells how much kidney function you have. To access the GFR calculator, click here.

It is especially important that people who have an increased risk for chronic kidney disease have these tests. You may have an increased risk for kidney disease if you:

are older
have diabetes
have high blood pressure
have a family member who has chronic kidney disease

If you are in one of these groups or think you may have an increased risk for kidney disease, ask your doctor about getting tested. Once kidneys fail, dialysis (have regular blood-cleansing treatments) is necessary. The person must choose whether to continue with dialysis or to get a kidney transplant.

Diet

When you have chronic kidney disease, you need to make changes in your diet, including:

Limiting fluids
Eating a low-protein diet (this may be recommended)
Restricting salt, potassium, phosphorous, and other electrolytes
Getting enough calories if you are losing weight

Your recommended diet may change over time if your kidney disease gets worse, or if you need dialysis. Just remember to screen for kidney disease once a year.