Saturday, January 12, 2008

Nutrition for renal disease

By Sudipa Sarkar


Renal system is defined as a portion of the metabolic system which is responsible for the regulation and maintenance of the body fluids by removing the surplus water and electrolytes, and waste products generated by food metabolism. The renal system comprises of all the organs implicated in the formation and excretion of urine. It incorporates the kidneys, ureters, bladder and urethra. Renal disease is characterized by such a condition when kidneys fail to perform in a proper manner on their part of actions. In physiology, such state is described as a reduction in glomerular filtration rate – which is marked by high level of serum creatinine. In some cases, depending on the type of the disease, it may result a fatal consequence. This paper focuses on the aspect of nutritional supplement for the patient suffering from renal disease in association with a thorough discussion about the treatment of this disease concerning the nutrient management as a whole.

Types of Renal Disease

The renal disease is, in general, categorized into two broader groups –

1. Chronic Renal Failure (CRF): It is developed very slowly. At the onset of this disease, the symptoms are hardly found. Gradually it can be manifested into diseases like IgA nephritis, glomerulonephritis, chronic pyelonephritis and urinary retention, for example. This ultimately leads to the condition known as End-stage renal failure (ESRF), where either dialysis or donor for renal transplantation is needed.
2. Acute Renal Failure (ARF): It is usually characterized by the situation of rapid progression in the renal failure. The situation is comprised of a condition known as oliguria, a state with decreased rate of urine production, imbalance in the ratio of body fluid and body water along with electrolyte management. In this case, the underlying cause of the disease must be identified in order to control the progression of the disease; hence, meanwhile, the dialysis is needed.

Pathophysiology of Renal Disease

The chronic renal failure is defined by The Kidney Disease Outcomes Quality Initiative (K/DOQI) of the National Kidney Foundation (NKF) as either kidney injure or a reduced rate of kidney glomerular filtration rate (GFR) of less than 60 mL/min/1.73 m2 for three or more months. More than 1millions of nephron comprising in each kidney contribute to GFR and with an injury in kidney, the successive reduction in nephron cause the kidney to maintain the GFR level by employing the method hyper-filtration as well as compensatory hypertrophy of the rest of the healthy nephrons. This residual nephron hyper-filtration and hypertrophy is considered as a key cause of progressive or chronic renal dysfunction. Various factors causing chronic renal injury may involve the followings –

· Systemic hypertension

· Proteinuria

· Increased rate of renal ammoniagenesis with interstitial damage

· Hyperlipidemia

· Hyperphosphatemia with calcium phosphate disorder

· Acute invective from nephrotoxins or reduced perfusion

· Decline in the levels of nitrous oxide

The pathophysiology of acute renal failure involves vascular, glomerular and tubular dysfunction. This is particularly dependent on the actual offending stimulus and it varies in the severity and time of onset. Ischemia is considered to be the major cause of acute renal failure (ARF) in the adult population. In clinical diagnosis, a decline in glomerular filtration rate (GFR) resulting to condensed renal blood flow can reproduce prerenal azotemia or acute tubular necrosis (ATN).

Salient Symptoms of Renal Disease

At its onset, acute renal failure does not produce any significant symptoms that can be considered a good signal. However, the most common symptom includes reduced level of urine secretion, prevalent in almost 70% of the cases. Other non-significant symptoms may involve –

Quick heart rate
Feeling puzzled, anxious and restless, or sleepy
Swelling, especially in leg area and below
Feeling of dizziness
Loss of appetite, nausea, and vomiting
Dry mouth syndrome

It is hard to diagnose or identify at the onset of chronic renal failure (CRF) because of its slow progression. In a common practice, CRF usually fabricates symptoms when renal function, measured as the glomerular filtration rate (GFR), come below 30 ml per minute, which is about 30% of the normal value, and the amount of urea in blood is found this time. But when the GFR level is below 15 ml/min, it makes people more and more symptomatic. This may involve cognitive impairment, personality change, nausea, vomiting, and food distaste, anaemia, lung fluid, breathing difficulties and few more.

Various Causes of Renal Disease

For Chronic Renal Failure (CRF), the most common cause is various kinds of diseases which may damage the functionality of kidney. These diseases may include high BP, diabetes mellitus, obstructions of the urinary tract, polycystic kidney disease, glomerulonephritis, few types of cancers, autoimmune disorders for instance systemic lupus erythematosus, and heart or lungs diseases.

In case of Acute Renal Failure (ARF), an acute raise of the serum creatinine level from baseline is considered as one of the important cause. Acute renal failure may be developed by Cephalosporins and trimethoprim-sulfamethoxazole, as a result of interstitial infection. The other causes of acute renal failure may furnish acute tubular necrosis, blood vessel disease, acute interstitial nephritis, glomerular disease.

Treatments for Renal Disease

Considering the progressive nature of the failure, the chronic renal failure is more serious that that compared to acute renal failure, as the symptoms are lacking till the kidneys get severely damaged. Hence, chronic renal failure may worsen the condition if it is not diagnosed properly and of course on time. The treatment for CRF mainly involves controlling the associated symptoms, minimizing complications, and slowing down the progression of the disease. In case of presence of diseases such as hypertension, cardiac problem, urinary tract infections, kidney stone, glomerulonephritis and other diseases need to be taken care as the first phase of the treatment. Blood transfusion and erythropoietin supplements are necessary in some of the cases. The amount of fluid intake needs to be controlled as well.

As there are various causes that may be involved with the onset of acute renal failure, so the primary goal of ARF should include correcting or treating the underlying cause of kidney failure. Next it comes with the process to facilitate the kidney with required support so that they might be healed and started working properly. After that, the measure should be taken to prevent or treat any complications that are developed as a consequence of renal failure. As because the treatment for ARF mainly depends on the causes of this disease, so the treatment policy greatly varies in individual cases, like, replacing blood fluids and restoring blood flow in kidney, promoting discontinuation of any medication (say, antibiotics) considered as a potential factor, treating kidney disease if any, using medicine to stop immune system from working (immunosuppressant), removing any blockage in urinary tract for example. However ARF is a reversible condition, it can take place in patients with CRF. Every attempt should be made to recognize reversibility, albeit development in renal function is marginal. By tracking the rate of deterioration of renal function is the best way to spot reversibility. If the rate of deterioration in renal function speeds up, the cause should be find out and treated.

Dialysis Procedure

Dialysis is a process that is used in renal disease in order to eliminate waste products from our body in an artificial method. There are mainly tow types of dialysis involved in the treatment process depending on the nature of requirement –

1. Peritoneal Dialysis

2. Hemodialysis

1. Peritoneal Dialysis: The goal of this dialysis is to replace the role of kidney. During peritoneal dialysis, a sterilized combination of sugar and minerals liquefied in water flows through the catheter. This catheter is attached into the abdomen by gravity from either a container fixed to a rod and located higher than head level or it may be positioned by cycler. At the time of osmosis, the high density of sugar in the solution draws wastes, chemicals and additional water from blood vessels in the peritoneal membrane into the solution.

2. Hemodialysis: In homeodialysis, the blood circulation is allowed to continue, in a little amount, artificially with the help of a machine to eliminate the excess fluid from the body and waste products as well. Following this method, the body becomes free from any harmful wastes or extra fluids, but it is always recommended to maintain the proper schedule to apply the method on a regular basis. This method of dialysis can be used in home setup as well.

Food Supplements in Renal Disease

The renal system plays an important role in the growth and development of a child. Apart from keeping our body waste free and providing fluid homeostasis, it is also responsible for interaction among various nutrients found from food, such as calcium, phosphorus, and vitamin D. These, in turn, work as a necessary factor for growth. If the prevalence of the disease in child starts from his early ages, the doctor may recommend to do the proper dietary change and implement necessary food supplements to treat growth failure. The primary dietary changes involve imitating food high in phosphorus, such as milk, meat, poultry and fish.

Dietary Treatment for Renal Disease

Diet in Hemodialysis

Hemodialysis along with a proper diet helps lessen the wastes built up in blood. The essential factors while choosing appropriate diet in this condition, one must remember that

A balance amount of high-protein foods such as meat, chicken, and fish needs to undertake

The amount of potassium in food must be put in control, hence, some of the fruits like bananas, oranges, vegetables, and chocolates.

The amount of fluid intake needs to be controlled. Because, the lack of functionality in kidney leads to raise the level of water in body, thus, resulting fluid disturbance – this may lead to high BP or heart trouble as well.

The raw salt as well as cooked salt needs to be avoided as the salty substance causes thirst, hence lead in increasing the level of body water.

Phosphorus contained foods need to avoided such as milk, cheese, nuts, dried beans, and dark colas. The greater amount of in the blood stream causes calcium to be pulled from bones, leading an individual weak and brittle and can cause arthritis.

Diet in Peritoneal Dialysis

It is some how different from a hemodialysis diet.

In this method, an individual may need to have controlled the amount of salt and liquids, but quite lenient with more choice of food compared with hemodialysis. The diet must include more protein. The potassium may be restricted in few cases depending on the category of the disease. One may need to curtail on the number of calories you eat. There are calories in the dialysis fluid that may cause to gain weight.

Diet for Transplantation

In the case of transplant patients, the dietary restriction is more flexible than it is for dialysis patients. The diet will probably transform in accordance with the prescribed medicines, blood reports, weight, and blood pressure. One may not have allowed consuming much salt. The medications may lead the body to preserve sodium, leading to high blood pressure.

Nutritional Variation on Different Types

However, the ideology of dietary support for ARF, differ from those for patients with CRF, as because diets or infusions that gratify minimal requirements in CRF not necessarily plenty for patients having ARF.

In one study by Wilfred Druml to find out the dietary implication on acute renal failure, proposed that “Considering the dietary goals in patients with the acute renal failure or ARF, we can say that the goals of dietary intrusion in acute renal failure will differ from those in patients having chronic renal failure or CRF: Hence one must not offer a negligible ingestion of nutrients so as to reduce uremic toxicity or to slow down development of renal failure, as it is recommended for CRF, but to a certain extent an most favourable amount of nutrients should be given for alteration and preclusion of nutrient deficits and for stimulation of immunocompetence and injury healing in the mostly hyper-catabolic individuals with ARF”[ Wilfred Druml]

The main objective of the diet for individual having renal failure is to support adequate intake to promote health, especially in the case of children while considering the protein, sodium, phosphorus, and fluid, potassium, as needed. The other factors contributing the pattern of dietary restriction is dependent on age, level of renal failure, treatment type and medications.

Protein Restriction

Protein helps to construct new cells in our body, thus generates body waste products to certain extent. Due to the dysfunctional condition of renal system it is strictly recommended that the victim must avoid high consumption of protein - like meat (say beef, mutton for example), fish, seafood, dairy products like milk, cheese, ice-cream, pudding for example. If not avoided, it may produce a fatal condition by increasing the amount of destroyed cell in the body, and eventually causing imbalance in the level of waste product in the body.

Potassium Restriction

However, potassium is very important to our system, but too much amount of potassium is harmful for our blood. The situation may be worsening for an individual for non-restricted consumption of the potassium, if the renal condition is poor. Some foods like bananas, oranges, orange juice, prunes, potatoes, sweet potatoes, tomato. Most of the fruits and vegetables contain high amounts of potassium. If not restricted properly, the amount of potassium will be increased in the blood as the renal system has lost its fullest potentiality to keep the blood clean. It will cause harmful consequence for the victim.

Phosphorous Restriction

Kidney helps in filtering phosphorous from our body, so the patients suffering from renal failure should be restricted in their diet to refrain any extra amount of phosphorous in their system. Almost all the dairy products including milk, yogart, cheese, butter, custards, ice cream; meats, chicken, fish, turkey, dried beans, peas, pinto, lama, kidney, nuts, seeds, cereles, bread. Like potassium, however, phosphorous is essential to our body, but too much of condensation cause harmful effect in the system. Due to renal failure, kidney is unable to remove phosphorous from the blood stream properly, so, if not restricted properly, it will be increased in the blood stream, causing impairment to the whole system

Sodium and Fluid Restriction

Sodium and salt restriction needs to be induced in order to maintain the fluid level in the body of the patient suffering from renal failure. Sodium enhances the production of fluid in the body. As the kidney is not fully functional, so it becomes too heavy on the system to maintain the excess water level, so it needs to be restricted. The canned food comes for vegetables, meat, pasta, and the processed food like salami, hot dogs, sausage, and cheese, snack foods like chips, pretzel, pop corn, sauce, salad dressing, dried and canned soups, and salted nuts. If not restricted, it may enhance the development of fluid in our body and eventually it will lead to an imbalance in the fluid level, resulting in a great damage to the system.

We can see from the restrictions mentioned above that it is physically almost impossible to maintain for an individual. In that case, the patient is recommended to take corresponding nutrient binder by the physician, which will help the individual to intake food without the nutrient being absorbed in the body. By using this process, the individual can freely intake at least some amount of delicious food without being much concerned about the dreadful consequences.


Renal failure is a fatal and dismal condition where the victim becomes almost helpless. The disease itself is a manifestation of so many other types of disease that sometimes its vastness even cannot be measured by proper means. As prevention is always better than cure, so, at its prevention level few basic measures can be employed in accordance with proper and healthy diet. Those are ‘quit smoking’, ‘avoid using anti-inflammatory drugs’, ‘do regular exercise’ and ‘regular health check up’ to help an individual to live a healthier life.

The status of all of these articles is sold. I am here submitting these articles in order to build my virtual portfolio. That means, it is here used for sample purpose only. The bibliography section is intentionally not provided with any of these academic articles. Please do not use any portion of these articles for any purpose. Thanks for your kind co-operation.


Unknown said...

The article is very good. why can't you review few more articles on the same topic from various journals and write another good one?

The style of writing I liked very much. Keep writing...

Anonymous said...

Hi, the article is very useful. I have a question, though. Would someone who drinks milk urinates more, or someone who drinks water? and why? Does it have to do anything with osmolarity?

Subscribe Now: standard