Stage Five Chronic Kidney Disease and Protein Intake
by Jim Duffy
Chronic kidney disease (CKD) is one of the many diseases and conditions that can affect the kidneys. These two small organs (each about 4 inches long and they weigh less than a pound altogether) filter the blood at a rate of about eighteen gallons per hour. Over half of all of the fluid in the body will also be filtered by the kidneys at some point, removing waste products and sending those to the bladder to be excreted via urine. By the end of the day, the body will have created and excreted about two quarts of urine (more or less, depending on liquid intake) (Source: The National Kidney and Urologic Disease Information Clearinghouse).
Chronic kidney disease may be slow to develop, while acute kidney disease can develop very quickly and can be very dangerous. Because the kidneys are important to the body, any symptom that could indicate problems should be investigated by a doctor. Acute kidney diseasecan lead to a rapidly progressing loss of renal function. Symptoms of acute kidney disease can include decreased urinary output, bodily fluid disturbances and electrolyte imbalances. CKD may have no initial symptoms at all.
Additional symptoms of progressing kidney disease include increased urea in the blood, vomiting, diarrhea which can lead to dehydration, weight loss, increased nocturnal urination, foamy or bubbly urine, and increased frequency or increased amounts of urine, typically with very pale color. (Alternately, the symptoms can include decreased frequency and amounts with very dark colored urine.) Blood in the urine, a sense of pressure and difficult urination are also indicative of advanced kidney disease.
As the body's fluid and electrolyte imbalance becomes even more unbalanced, there will be increasing levels of phosphates in the blood, itching skin, bone damage and muscle cramps as a result of the low levels of calcium in the blood. A buildup of potassium (hyperkalemia) can lead to abnormal heart rhythms and eventual muscle paralysis. Kidney disease may also cause swelling of the legs, ankles, feet, face and hands as well as shortness of breath.
Protein and the Kidneys
When protein is digested in the body, it is first broken down into amino acids which are used to create other amino acids, hormones, and enzymes for a variety of functions and uses. After the protein is completely broken down, it will generate waste products which travel through the digestive tract walls and out into the bloodstream, where they will be filtered and removed by the kidneys.
A healthy kidney has millions of nephrons which work to filter these and other waste products out of the blood stream, however, an unhealthy kidney is not able to filter these wastes which are then allowed to not only build up in the kidney but to back up into the blood stream as well.
Chronic kidney disease is rated by the doctor in stages (I through V) based on the glomerular filtration rate (GFR), which is the rate of filtration of the blood through the kidneys. The test rates actual filtration through the glomerulus of the renal capillaries to the fluid in Bowman's capsule. Bowman's capsule is the small cup-shaped part of the kidney that removes liquid from the blood and converts it to urine before it is sent to the bladder. The rate of this conversion is typically about 120 mL per minute (Source: The New American Pocket Medical Dictionary).
Using the GFR, the doctor can not only diagnose chronic kidney disease but can diagnose its stage as well. Of course, the stage refers to the severity of the disease. Stages and the scores for the GFR are as follows:
Stage GFR Score
Stage One 90 or above (normal GFR, abnormal amount of protein noted in urine)
Stage Two 60-89
Stage Three 30-59
Stage Four 15-29 (Typically final stage before dialysis becomes necessary)
Stage Five End Stage Renal Disease Below 15, dialysis is necessary, kidney transplant is considered
During the first four stages of CKD, as well as with other types of kidney disease, the need to restrict protein intake is important. Excess protein can cause nausea and vomiting, a loss of appetite, weakness, some taste changes and skin itching which may be intense, all because the body cannot handle the waste products created from digesting protein.
Restricting the amount of protein as well as sticking to certain types of protein can reduce a number of these symptoms and allow the kidneys to function better so that the progression of the disease can be slowed. The amount of protein that is typically suggested for stages one through three is only slightly less than in the typical diet (12-15% of daily calories should be protein as opposed to 15-30%). In stage four, however, it is typically further reduced to around ten percent.
The most important aspect for these stages of the disease is control: control of the blood sugar and control of the protein intake. Diabetics must also control their blood sugar as well. Plant based protein, the basis of the vegetarian diet, may slow down some of the progression ofchronic kidney disease and can give the body the protein that it needs while lessening some of the waste product which can build up in the system (Source Brookshyer RD, CSR).
In stage five of chronic kidney disease, the kidneys are working at only ten percent of their normal capacity. Instead of filtering about 18 gallons of blood per hour, it may only manage to filter 2. The patient will need to use a machine to filter the blood stream in a process called dialysis. While dialysis does remove the waste products from the bloodstream, it is not as efficient as the kidneys because it also removes the amino acids that the body actually needs. In this stage of the disease, the body must be given additional amounts of protein not only to meet basic needs but to ensure that the lost amino acids are made up for as well. The added protein works to ensure that there is no muscle loss and also works to help the body fight infection.
While increasing the protein intake at this time, the patient will have to watch for the increased levels of phosphorous which are found in a number of common protein food sources, including halibut, nonfat yogurt, salmon, skim milk, chicken breast, oatmeal, and extra lean ground beef. Phosphorous is needed for many of the chemical reactions that occur in the body, including as part of the regulation of energy production in the body. It binds with calcium to help form strong bones and teeth. 85% of the body's phosphorous is located in the bone. Too much phosphorus coupled with a high protein diet equals a loss of calcium, which in turn equals osteoporosis (Source: Feinstein 1996).
The goal for the diet in stage five is to increase calories and increase protein intake to keep the strength up, to maintain lean muscle mass and to make sure that the immune system is able to continue doing its work. If the body does not have enough protein available, it will turn to the muscles and start breaking them down, which is one of the major reasons why it is important for elite athletes to refuel after an intense workout. To preserve lean muscle mass, the protein intake for stage five may be as high as two grams per kilogram of dry weight (weight minus fluid retention), or double the average intake. About 25% of this protein should be eaten at each meal, and most people will also need protein supplements and snacks to reach this level of intake (Source: Maree 2002).
There are a number of different kinds of protein supplements that you can choose from. Protein powders (whey, soy, rice and egg) supply high quality protein and can be either single protein or a combination of two or more. Protein bars may give a high level of protein but may also have high sugar content, a problem for those who have weakened immune systems. Profect, from Protica, is a liquid protein supplement which has zero sugars or fats but supplies a good amount of high quality protein - 25 grams per serving in a very small size (2.9 fluid ounces).
About the Author:
Protica Research (Protica, Inc.) specializes in the development of Capsulized Foods. Protica manufactures Profect, IsoMetric, Pediagro, Fruitasia and over 100 other brands, including Medicare-approved, whey protein liquid for bariatric surgery patients. You can learn more atProtica Research - Copyright