Posts Tagged ‘diet and exercise and its relationship to kidney disease’

Kidney Disease: The Importance of Diet and Exercise

Part I

I am initiating a two-part series on the importance of diet and exercise and their impact on Kidney Disease. In Part I the reader will come to understand where the kidneys are located in our body, the basic functions of a kidney, prevalence of kidney disease, epidemiological facts, and the causes, detection, treatment and warning signs of chronic kidney disease. Where applicable, I will provide definitions of medical terms. Finally, I will discuss my own experience as a kidney cancer survivor.

In Part II I will describe current research findings regarding the relationship of diet and exercise to kidney disease. Diet and exercise has an important role in the prevention and treatment of this disease. It’s important to discuss diet and exercise because that is at least something everyone can have some control over.

Where are the Kidneys?

There are two kidneys, each about the size of a fist, located on either side of the spine at the lowest level of the rib cage. They are bean shaped and weigh about one-third of a pound.

Basic Functions of a Kidney

The kidneys perform their life-sustaining job of filtering and returning to the bloodstream about 200 quarts of fluid every 24 hours. About two quarts are removed from the body in the form of urine, and about 198 quarts are recovered. The urine we excrete has been stored in the bladder for anywhere from 1 to 8 hours.

Each kidney contains up to a million functioning units called nephrons. A nephron consists of a filtering unit of tiny blood vessels called a glomerulus attached to a tubule. When blood enters the glomerulus, it is filtered, and the remaining fluid then passes along the tubule. In the tubule, chemicals and water are either added to or removed from this filtered fluid according to the body’s needs, the final product being the urine we excrete.

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 maintain a stable balance of body chemicals.

The critical regulation of the body’s salt, potassium and acid content is performed by the kidneys. The kidneys also produce hormones that affect the function of other organs. For example, a hormone produced by the kidneys stimulates red blood cell production. Other hormones produced by the kidneys help regulate blood pressure and control calcium metabolism.

To Summarize the kidneys are powerful chemical factories that perform the following basic functions:

  • remove waste products from the body
  • remove drugs from the body
  • balance the body’s fluids
  • release hormones that regulate blood pressure
  • produce an active form of vitamin D that promotes strong, healthy bones
  • control the production of red blood cells


Prevalence of Kidney Disease

Kidney disease statistics for the United States convey the burden of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Based on these statistics, researchers can estimate the size of the ESRD population in years to come and gauge the need for resources such as dialysis and transplant clinics to treat the growing ESRD population.

Over time, kidney disease statistics show trends and movement. For example, statistics show which ethnic and age groups and geographical regions have the highest incidence of kidney disease. This demographic information helps direct targeted programs to the people who need them most. Statistics can later help measure progress in preventing and treating kidney disease. With the knowledge provided by statistics, researchers and health care providers can make great gains in the fight against kidney disease.

Unless otherwise noted, the following statistics are from the United States Renal Data System’s 2010 Annual Data Report and 2011 Annual Data Report.

One in 10 American adults, more than 20 million, has   some level of CKD.Source: Centers for Disease Control and Prevention

Chronic kidney disease (CKD): any condition that causes reduced kidney function over a period of time. CKD is present when a patient’s glomerular filtration rate remains below 60 milliliters per minute for more than 3 months or when a patient’s urine albumin-to-creatinine ratio is over 30 milligrams (mg) of albumin for each gram (g) of creatinine (30 mg/g).

End-stage renal disease (ESRD): total and permanent kidney failure. When the kidneys fail, the body retains fluid. Harmful wastes build up. A person with ESRD needs treatment to replace the work of the failed kidneys.

Acute kidney injury (AKI): sudden, temporary, and sometimes fatal loss of kidney function

Incidence: the number of new cases of a disease in a given time period

Prevalence: the number of existing cases of a disease at a given point in time

Epidemiological Facts

  • The incidence of CKD is increasing most rapidly in people ages 65 and older.
    • The incidence of recognized CKD in people ages 65 and older more than doubled between 2000 and 2008.
    • The incidence of recognized CKD among 20- to 64-year-olds is less than 0.5 percent.
    • The prevalence of CKD is growing most rapidly in people ages 60 and older.
  • Between the 1988–1994 National Health and Nutrition Examination Survey (NHANES) study, and the 2003–2006 NHANES study, the prevalence of CKD in people ages 60 and older jumped from 18.8 to 24.5 percent.
  • During that same period, the prevalence of CKD in people between the ages of 20 and 39 stayed consistently below 0.5 percent.

As said above, more than 10% of people, or more than 20 million, aged 20 years or older in the United States have CKD.

  • CKD is more common among women than men.
  • More than 35% of people aged 20 years or older with diabetes have CKD.
  • More than 20% of people aged 20 years or older with hypertension have CKD.


Causes and Treatment of CKD

Chronic kidney disease 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. Some kidney conditions are inherited (run in families).

Others are congenital; that is, individuals may be born with an abnormality that can affect their kidneys. The following are some of the most common types and causes of kidney damage.

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. Diabetes is the leading cause of kidney disease.

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. When high blood pressure is controlled, the risk of complications such as chronic kidney disease is decreased.

Glomerulonephritis is a disease that causes inflammation of the kidney’s tiny filtering units called the glomeruli. Glomerulonephritis may happen suddenly, for example, after a strep throat, and the individual may get well again. However, the disease may develop slowly over several years and it may cause progressive loss of kidney function.

Polycystic kidney disease is the most common inherited kidney disease. It is characterized by the formation of kidney cysts that enlarge over time and may cause serious kidney damage and even kidney failure. Other inherited diseases that affect the kidneys include Alport’s Syndrome, primary hyperoxaluria and cystinuria.

Kidney stones are very common, and when they pass, they may cause severe pain in your back and side. There are many possible causes of kidney stones, including an inherited disorder that causes too much calcium to be absorbed from foods and urinary tract infections or obstructions. Sometimes, medications and diet can help to prevent recurrent stone formation. In cases where stones are too large to pass, treatments may be done to remove the stones or break them down into small pieces that can pass out of the body.

Urinary tract infections occur when germs enter the urinary tract and cause symptoms such as pain and/or burning during urination and more frequent need to urinate. These infections most often affect the bladder, but they sometimes spread to the kidneys, and they may cause fever and pain in your back.

Congenital diseases may also affect the kidneys. These usually involve some problem that occurs in the urinary tract when a baby is developing in its mother’s womb. One of the most common occurs when a valve-like mechanism between the bladder and ureter (urine tube) fails to work properly and allows urine to back up (reflux) to the kidneys, causing infections and possible kidney damage.

Drugs and toxins can also cause kidney problems. Using large numbers of over-the-counter pain relievers for a long time may be harmful to the kidneys. Certain other medications, toxins, pesticides and “street” drugs such as heroin and crack can also cause kidney damage

Detection of Kidney Disease

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:

  1. Blood pressure measurement
  2. 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.
  3. 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.
  4. 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
  • Are an African American, Hispanic American, Asians and Pacific Islander or American Indian.

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.

Kidney Treatment

Many kidney diseases can be treated successfully. Careful control of diseases like diabetes and high blood pressure can help prevent kidney disease or keep it from getting worse. Kidney stones and urinary tract infections can usually be treated successfully. Unfortunately, the exact causes of some kidney diseases are still unknown, and specific treatments are not yet available for them. Sometimes, chronic kidney disease may progress to kidney failure, requiring dialysis or kidney transplantation.

Treating high blood pressure with special medications called angiotensin converting enzyme (ACE) inhibitors often helps to slow the progression of chronic kidney disease. A great deal of research is being done to find more effective treatment for all conditions that can cause chronic kidney disease.

Kidney failure may be treated with hemodialysis, peritoneal dialysis or kidney transplantation. Treatment with hemodialysis (the artificial kidney) may be performed at a dialysis unit or at home. Hemodialysis treatments are usually performed three times a week. Peritoneal dialysis is generally done daily at home. Continuous Cycling Peritoneal Dialysis requires the use of a machine while Continuous Ambulatory Peritoneal Dialysis does not. A kidney specialist can explain the different approaches and help individual patients make the best treatment choices for themselves and their families.

Kidney transplants have high success rates. The kidney may come from someone who died or from a living donor who may be a relative, friend, or possibly a stranger who donates a kidney to anyone in need of a transplant.

Warning Signs of Kidney Disease

Kidney disease usually affects both kidneys. If the kidneys’ ability to filter the blood is seriously damaged by disease, wastes and excess fluid may build up in the body. Although many forms of kidney disease do not produce symptoms until late in the course of the disease, there are six warning signs of kidney disease:

  1. High blood pressure.
  2. Blood and/or protein in the urine.
  3. A creatinine and Blood Urea Nitrogen (BUN) blood test, outside the normal range. BUN and creatinine are waste that builds up in your blood when your kidney function is reduced.
  4. A glomerular filtration rate (GFR) less than 60. GFR is a measure of kidney function.
  5. More frequent urination, particularly at night; difficult or painful urination.
  6. Puffiness around eyes, swelling of hands and feet.

My Experience with Kidney Cancer

 I’m basically a “tough old bird with attitude.” In May 2004, at the age of 61, I was diagnosed with kidney cancer. The tumor was very large, 8 inches long by 4 inches wide. While tests were being performed to see if the cancer had spread, I didn’t know whether I had Stage I or Stage 4 cancer. Surprisingly, I discovered that, during my wait for clarification, I had a very positive attitude about the cancer and was quite philosophical about the situation I found myself in. In fact, I was more concerned about what loved family members were feeling than what I was feeling. In early June I was told that, despite the very large tumor, I appeared to have Stage I cancer.

On June 9, 2004 I underwent a 3+ hour operation in which surgeons removed the tumor and one of my kidneys. The operation was a success and my stay was only 4-5 days in the hospital. Because of the way a body works (shutting down the digestive track after an operation) I wasn’t allowed to eat any food or drink water. I used a lemon swab to keep my lips moist; after the third day I was allowed to sit up in a chair and eat crushed ice. It was unexpected, but eating crushed ice was incredibly refreshing.

By the fourth day I was allowed to eat soft foods—one bite at a time. The next day I was released from the hospital and went home. What I didn’t know was that my appetite would not return to normal for another two weeks. Needless to say, I had lost more than 25 pounds from the experience. And yes folks, over time I gained all my weight back.

Now I was living with just one kidney, and filtration was just below 60. Before the operation my kidney function was normal; post the operation I now had stage 3 CKD. Fortunately for me, my filtration rate has remained pretty much the same these last nine years. On June 9, 2014 I will be a ten-year kidney cancer survivor. And yes, I get up every morning and am very glad I am alive. I feel I mostly have control over my lifestyle. As you know, there are no guarantees in life; however, two areas you do have control over are diet and exercise related to developing and maintaining a healthy lifestyle.

In Part II ahead I will share with you the latest research findings on diet and exercise that relates to the health of your kidneys. If you are one who possesses any of the risk factors for kidney disease, it will be important next month to tune in again to my Blog—The Reasoned Society.


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