By Jan Chait
Special to the Tribune-Star
TERRE HAUTE
November 21, 2007 07:29 pm
—
Make a fist. That’s about the size of one of your kidneys. Chances are you have two of the bean-shaped organs, sitting on either side of your spine at the lowest level of the rib cage.
Two kidneys are actually more than you need. Some people are born with only one kidney. Many others donate one of their kidneys to a family member or friend whose kidneys don’t work. People with one healthy kidney live normal, healthy lives.
However, even two kidneys in end stage renal disease aren’t enough. In 2004, 45 people in Clay, Parke, Sullivan, Vermillion and Vigo counties died from kidney disease, making it the eighth-leading cause of death in this area.
Counted another way, deaths from kidney disease could be higher on the list, says Terre Haute nephrologist Manish Gera, M.D. “If you exclude causes like motor vehicle accidents, Alzheimer’s disease and flu, it is fifth on the list after heart disease, cancer, stroke and diabetes,” he says, adding: “Also, the ranking does not justify the burden. A person who has even moderate kidney disease has a much higher risk of cardiac events and stroke.”
Most of the time, kidney disease is asymptomatic — that is, it has no symptoms — until function is less than 30 to 40 percent. Dialysis or a kidney transplant is needed when kidney function is less than 10 to 15 percent.
“Unfortunately, the main problem is that most of the time loss of kidney function is irreversible and, since it is asymptomatic, patients come to attention late in the course, Gera says.
Why is kidney function so important? Most of us are aware that our kidneys have a role in urine production. Your kidneys process about 200 quarts of blood to sift out about two quarts of waste products and extra water every day.
But that’s not all these vital organs do. According to the National Kidney Foundation, they also:
• 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
Most of the time, kidneys fail when the nephrons are attacked. According to units of the National Institutes of Health, a nephron is a filtering unit of tiny blood vessels called a glomerulas. Blood enters the glomerulas, where it is filtered. The remaining fluid goes to the tubule, where chemicals and water are either added or removed according to the needs of our bodies. The final product is the urine we secrete.
The two most common causes of kidney disease? Diabetes and high blood pressure, or hypertension.
“Diabetes causes kidney disease by both direct and indirect ways, Gera says. “High sugar gets attached to components of the … glomeruli and causes damage over time. Indirectly, it causes infections [urinary tract infection], nerve damage which results in an inability to empty the bladder and subsequent back pressure on kidneys, arteriosclerosis [hardening and loss of elasticity of the arteries] and heart failure resulting in poor kidney perfusion.” When you have heart problems or poor blood supply to the kidneys, they sustain damage due to poor blood supply, Gera explains. Therefore, they cannot expel water and waste, which results in chronic kidney disease, Gera explains.
“Hypertension, on its own, is the second most common cause of end-stage renal failure, next to diabetes,” Gera says. “Hypertension causes damage to blood vessels, by high pressure.” The microscopic blood vessels known as glomeruli “… get damaged by persistent high blood pressure and, over time, get scarred. Also important to note is that kidney problems are both an effect and a cause of hypertension,” Gera says, explaining that not only can for while hypertension, or high blood pressure, cause kidney disease, kidney disease in return also can cause high blood pressure. “Approximately 80 percent of chronic kidney disease patients develop hypertension at some point,” he adds.
Some lessening of kidney function is normal. “We are born with a kidney function of around 120-150 [ml per minute of glomerular filtration rate],” Gera says. “In simple terms, glomerular filtration rate is the amount of fluid extracted from the blood to make urine. It is the best and most sensitive way of knowing one’s kidney function. We lose one mililiter per year from birth, which is the normal aging process. If we have diabetes, we can lose up to 3-5 mililiters per year and, in 10 years, we can lose 30 to 50 mililiters of glomerular filtration.”
“If a patient is 50 years of age and starts with kidney function of 70 at the onset of diabetes, he will have a function of 10 left at 65 years and will need dialysis.”
And what about dialysis? It may be a life-saver, but it’s hardly a bed of roses.
First of all, Gera says, dialysis comes packaged with a number of other problems, “whether it’s your mental function, exercise capacity, strength, heart health, blood pressure, appetite. etc. Everything receives a severe beating.”
In addition, life expectancy is reduced. One of every four people who are on dialysis and have diabetes will die in one year, Gera says, adding that “a 30-year-old person on dialysis has the same risk of dying as a 90-year-old normal person.
“Although maintenance dialysis prevents death from uremia, patient survival remains an important issue. Once renal replacement therapy is initiated, the range of the expected remaining life span in the United States Renal Data System report was 7 to 11 years [depending on race] for dialysis patients aged 40 to 44, and four to six years for those 60 to 64 years of age.”
There are two dialysis centers in Terre Haute, with a combined capacity of 200 patients.
However, the treatment of choice for kidney failure is a kidney transplant, with living-donor transplants preferred. “A living kidney transplant can be even given by a non-related donor, Gera says. “The average waiting period for deceased-donor kidney transplant is three to five years, depending upon geographical location.”
But the best thing is to avoid getting kidney disease in the first place. Gera says current preventive care practices for lowering your risk are:
• Maintaining stringent control of blood pressure. The National Heart, Lung, and Blood Institute recommends a target of no higher than 130/80 mm Hg for people with diabetes and those with impaired renal function, even if they don’t have diabetes.
• Blood pressure medicines known as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers not only reduce blood pressure, but protect the kidneys better than other blood-pressure medications, according to information from the National Institutes of Health.
• Maintain careful blood-glucose control if you have diabetes. The A1C test is used to determine the overall level of blood-glucose control. The American Association of Clinical Endocrinologists recommends an A1C level of 6.7 percent or lower.
• Follow a low-protein diet.
“Additional reports indicate that treating dyslipidemia [high lipid levels], quitting smoking and managing anemia may also help to delay progression of early CKD,” Gera says. “Maintaining ideal body weight also helps.”
Causes of Chronic Kidney Disease
Chronic kidney disease is defined as having some kind of kidney abnormality, such as protein in the urine, and having decreased kidney function for three months or longer. Causes of CKD include:
• Diabetes: A condition in which your body either fails to make insulin or cannot use it properly. Poorly controlled diabetes results in high blood-glucose levels, which can damage the nephrons — the part of the kidneys that filter waste.
• High blood pressure: Occurring when the force of blood against your artery walls increases, high blood pressure can damage the small blood vessels in your kidneys and render them unable to filter wastes from your blood.
• Glomerulonephritis: Several different types of kidney disease are grouped together under this heading, but all attack the tiny blood vessels inside the kidney. The first signs of the disease are protein, blood or both in the urine. It can develop suddenly, such as after strep throat, or it may develop slowly over several years.
• Polycystic kidney disease: The most common inherited kidney disease, it is characterized by the formation of kidney cysts that enlarge over time and may cause serious damage or even kidney failure.
• Kidney stones: Causes include having an inherited disorder that causes too much calcium to be absorbed from foods and urinary tract infections or obstructions. Medication and diet sometimes can prevent recurring stone formation.
• Urinary tract infections: While these infections generally affect the bladder, they can sometimes spread to the kidneys and could cause fever and pain in your back.
• Drugs and toxins: Products that combine aspirin, acetaminophen, and other medicines such as ibuprofen have been found to be the most dangerous to the kidneys. If you take painkillers regularly, check with your doctor to make sure you are not putting your kidneys at risk. Certain other medications, toxins, pesticides and "street" drugs such aas heroin and crack can also cause kidney damage.
SOURCE: National Kidney Foundation
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