The National Kidney Foundation (NKF) is a valuable resource organization that provides doctors, patients, and their families with up-to-date information and education regarding kidney disease. In an attempt to detect and eradicate kidney disease in its earliest phases, the NKF has developed a program called the Kidney Early Evaluation Program (KEEP), which allows for comprehensive screenings to be performed at local sites.
 |
| Stage 1 Kidney Disease |
The kidneys are the body's filters and are responsible for keeping all the other bodily systems in balance. Certain blood and urine tests, including the GFR and the urinalysis, are invaluable in helping your doctor determine if a kidney problem exists. Understanding the signs and symptoms of kidney disease, listening to your own body, and effectively communicating changes to your doctor are all very important to your kidney and overall health.
Once you have been told you have kidney disease, the next step involves understanding the extent of your kidney damage. To help you, a CKD (chronic kidney disease) staging system was developed. This system describes the severity of kidney disease and also helps doctors assess its progression and prescribe specific treatment plans.
There are five stages of kidney disease--ranging from stage one to stage five - each of which represents a level of declining kidney function. Stages one and two are defined as mild kidney disease; stage three, as moderate kidney disease; and stages four and five, as advanced disease.
Each stage is based on the GFR - or filter - performance, measured in milliliters per minute (ml/min). Remember that the GFR (glomerular filtration rate) is important in evaluating how well your kidneys are functioning as filters. The five stages are explained in terms of approximate percentage of kidney function, which will give you a clearer understanding of the GFR values at each stage. All of the stages have their own distinguishing features. You and your doctor should discuss what exactly should be done at each in order to maintain and possibly improve kidney function.
STAGE ONE
In stage one, kidney function is normal or near normal - around 90 percent - but proteinuria is present. The GFR is greater than 90 ml/min. (Normal GFR is in the range of 100 to 130 ml/min.) Left untreated, this condition can lead to a worsening of kidney disease in the future. Remember that protein in the urine is the single most important marker for predicting the future risk of worsening kidney function.
The Importance of Proteinuria
On an average day, your kidneys will reabsorb about 99 percent of the protein that you eat. Normally, about 150 to 200 milligrams (mg) of protein are eliminated daily in our urine. If the amount of protein excreted is above this level, it can be an early sign of kidney damage.
Imagine your kidneys as fishing nets that filter and capture most of the protein you eat each day. Now picture someone taking scissors and cutting small slots in the net, allowing some of the protein to leak through the holes. When this happens, the kidneys become bombarded by excess protein. It increases their workload, creating a vicious cycle - the more protein the kidneys have to break down and remove, the more work the kidneys have to do. This causes irreversible damage; the kidneys get "scarred up" and their function can worsen over time.
Proteinuria commonly happens with diabetes-related kidney disease. There is also some compelling evidence that proteinuria not only causes damage to the kidneys, but also may be an early sign of vascular disease. Many heart doctors will order urinary protein levels routinely, as high levels may predict future heart disease, as well.
Ways of Measuring Urinary Protein Levels
There are two methods that can be used to measure the amount of protein in urine. The first is a random urine sample, which involves urinating into a plastic cup one time. It is usually done at a local testing center or lab, and in most instances, this testing will be sufficient.
With this type of random test, the doctor will initially order the total amount of a special kind of urinary protein called albumin. This test is very sensitive and is a very early indicator of kidney disease. In addition, it may be an early predictor of future heart disease and vascular disease. If the levels of albumin in the urine, or albuminuria (al-bum-in-orea), are high, then the doctor will likely order another random urine sample to quantitate the total amount of protein in the urine. Under certain circumstances, however, your doctor may order a different type of urine test.
This second test consists of you urinating into a special plastic container every time you need to go over a twenty-four hour period. The lab will provide you with the container and directions to follow. There are two important tips to remember with this type of collection. First, plan to do it sometime when you will be home for the whole day. Second, the container needs to be kept cold, which is best done in the refrigerator. Before placing it in there, though, make sure you inform family members that its contents are not for drinking and keep it out of young children's reach.
The important point is this: Proteinuria is serious. Levels higher than normal require more investigation and will usually require referral to a kidney specialist. To find out more, you can check out Stage 1 Kidney Disease.