According the National Institutes of Health’s National Institute of Diabetes and Digestive and Kidney Diseases, to date, diabetes affects 25.8 million people of all ages in the United States, and around 40 percent of people who have diabetes may eventually develop kidney disease (CKD). This accounts for 44 percent of all the new cases of kidney failure each year. The main reasons for kidney disease are as follows:
• 1.4 percent urologic diseases
• 2.3 percent cystic kidney
What is eGFR?
T he term eGFR stands for estimated glomerular filtration rate, or flow rate in the kidneys.
Doctors will often use the eGFR when assessing kidney damage, including in people who have diabetes and may have symptoms of kidney disease.
For example, an eGFR of less than 60 milliliters per minute is often indicative of kidney disease.
Doctors may also use other tests, such as looking for protein in the person’s urine, as even a small amount may indicate trouble with the kidneys (although everyone is different in terms of protein in the system, which is why other tests are used).
• 6.6 percent glomerulonephritis (or glomerular disease, an acute inflammation of the kidney’s tiny filters called glomeruli, which remove excess fluid, electrolytes, and waste from the blood and pass them into the urine)
• 17.6 percent other reasons
• 28.4 percent high blood pressure (the second major cause of kidney failure; it is important since many people with diabetes also find controlling blood pressure to be a major problem. For more about high blood pressure, see the chapter “How Diabetes Affects the Circulatory System.”)
• 43.7 percent diabetes
How is it determined that a person with diabetes has kidney disease?
There are five stages of kidney disease, with kidney failure the final and most severe stage.
Certain numbers are associated with kidney disease, called the glomerular filtration rate, or GFR.
This is a reflection of how the kidneys are filtering fluid per minute.
The lower the number, the less efficiently the kidneys are working.
It is estimated that if a person has a GFR of around 60 milliliters per minute, it could be indicative of kidney disease.
And if a person has a GFR of 15 milliliters per minute or less, he or she is a candidate for renal-replacement therapy, or, in other words, either a kidney transplant or some type of kidney dialysis.
What is kidney failure?
Kidney failure is a condition in which the kidneys fail to rid the body of waste products. It is also considered to be end-stage kidney disease (ESRD, or end-stage renal disease). It is most often treated with a kidney transplant (if a kidney can be found and/or the patient is strong enough for a transplant) or dialysis, a blood-filtering treatment (see below). Each year in the United States, more than 100,000 people are diagnosed with kidney failure.
What are the symptoms of kidney failure?
There are several symptoms of kidney failure, including excess fluid buildup (most often seen in the legs) and a buildup of salt in the body.
This is because the kidneys cannot excrete enough water and salt (in urine) from the body.
This causes an increase in blood pressure, which often leads to hypertension.
An indirect symptom of kidney failure is anemia owing to the decreased production of erythropoietin, a hormone secreted by the kidney that increases the rate of red blood cell production in response to falling levels of oxygen in the body’s tissues.
Without adequate red blood cells, a person will have fatigue and shortness of breath, two major symptoms of anemia.
What is kidney dialysis?
Kidney dialysis is a procedure that uses a special machine to eliminate wastes, salt, and excess fluids from the blood.
Dialysis is usually done because the kidneys are not functioning properly, either because of disease or injury.
One of the major causes of kidney failure that leads to dialysis is diabetes, owing to high blood glucose levels.
This excess amount of glucose damages the millions of nephrons, the small filtering units in the kidneys.
A person usually needs dialysis when he or she develops end-stage kidney failure, or has lost about 85 to 90 percent of their kidney function.
When a patient’s kidneys fail and they have not been able to get a transplant, dialysis is really the only option left. Typically, patients require three treatments a week.
Is there any way doctors can potentially identify kidney disease in a person with diabetes?
Yes, there are ways in which doctors can potentially identify kidney disease in a person with diabetes.
They use what are called markers, or chemicals produced by the body that help determine possible problems with the kidneys.
In particular, doctors look at A1c values to see whether a person who has diabetes has been controlling his or her blood glucose levels in the long term.
They also can assess damage to blood vessels of the kidneys (and the heart) by checking on advanced glycation end products (AGEs).
Doctors also check on the kidney levels themselves, including the glomerular filtration rate (GFR) and serum albumin.
Doctors are also using several new markers to determine possible kidney disease in people with type 1 and type 2 diabetes. For example, neutrophil gelatinase-associated lipocalin (NGAL) is a protein that is produced in response to a decrease in blood flow to the kidneys or a trauma to the kidneys. Another is the enzyme N-acetyl-beta-D-glucosaminidase (NAG). An increase in activity of this enzyme may be connected to uncontrolled diabetes.
DIABETES AND URINE
What is a ureter?
There are two ureters, which are tubes extending from the kidney into the urinary bladder. Each ureter is 10 to 12 inches (25 to 30 centimeters) long. They begin in the kidneys as thin, hollow, narrow tubes and widen to 0.5 inches (1.7 centimeters) as they enter the bladder. Urine is transported to the bladder via the two ureters.
Where is the urinary bladder located?
The urinary bladder is located in the abdominal cavity. In males, it is behind the rectum and above the prostate gland. In females, it is located much lower, behind the uterus and upper vagina.
How much urine can the urinary bladder hold?
The urinary bladder is highly distensible and can vary in its capacity. As urine fills the bladder, at moderate capacity, it expands to about 5 inches (12 centimeters) long and hold 1 pint (473 milliliters) of urine. The bladder can expand to twice that capacity if necessary. It usually accumulates 0.63 to 0.85 pints (300 to 400 milliliters) of urine before emptying, but it can expand to hold 1.27 to 1.69 pints (600 to 800 milliliters).
How does the urethra differ in males and females?
Urine is transported to the outside through the urethra, which is a thin, muscular tube that extends from the urinary bladder to the exterior of the body.
The length and structure of the urethra differ between males and females.
In males, the urethra is about 8 inches (20 centimeters) long and extends from the urinary bladder to the exterior.
It has the dual function of transporting semen as well as urine out of the body.
The female urethra is only about 1.5 inches (3 to 4 centimeters) long and extends from the bladder to the exterior opening.
What is urea, and where is it produced?
During the process of metabolizing proteins, the body produces ammonia. Ammonia combines with carbon dioxide to form urea. Urea is the major organic component in the urine; it is eliminated by the kidneys. Humans generate about 0.75 ounces (21 grams) of urea each day.
What is the composition of human urine?
Human urine is composed mostly of water containing organic wastes as well as some salts. The composition of urine can vary according to diet, time of day, and diseases, but overall, it is mostly water (95 percent) and organic waste products (5 percent), such as urea, uric acid, and creatinine, along with some other organic chemicals.
How are urine tests used in diabetes diagnoses?
U rine tests were once used to detect glucose in a person’s body.
In addition, many doctors would taste a person’s urine for sweetness, an indication of diabetes (the excess glucose, or sugar, eliminated in the urine), or pour the urine into sand to see whether it was sweet enough to attract insects.
Now most health care professionals rely on blood tests, which are much more accurate to determine diabetes.
That being said, urine tests do have a place in diabetes diagnoses.
For example, tests for protein in the urine may be conducted if a person with diabetes is suspected to have kidney damage.
Tests for ketones in the urine may indicate hyperglycemia, too.
Is urine always yellow in color?
Normally, dilute urine is nearly colorless. Concentrated urine is a deep yellow; colors other than yellow are not normal. Food pigments can make the urine red, and drugs can produce colors such as brown, black, blue, green, or red. Urine may also be brown, black, or red owing to disorders or diseases such as severe muscle injury or melanoma. Cloudy urine suggests the presence of pus, due to a urinary tract infection, or salt crystals from uric acid or phosphoric acid.
Is frequent urination one of the signs of diabetes?
Yes, among other symptoms, frequent urination is often one of the signs of type 1 and type 2 diabetes. It is a symptom of high blood sugar, or hyperglycemia, or an overall rise in blood (or plasma) glucose. (For more information about the fasting plasma glucose test to measure glucose levels, see the chapter “Coping With Diabetes.”)
Is there a connection between high uric acid levels and diabetes?
Uric acid is a chemical that is created when the body breaks down substances known as purines.
These are found in some foods and drinks, including liver, seafood, dried beans and peas, and beer.
In people without high uric acid problems, the uric acid dissolves in the blood and travels to the kidneys, and most of it is excreted in the urine.
But often, the body produces too much uric acid or the kidneys don’t excrete enough, causing uric acid to build up in the blood.
This buildup can create sharp crystals that eventually form in joints, causing pain and inflammation. (If a person has an excess of uric acid in the body, it is called hyperuricemia, with a blood uric acid level greater than 7 considered to be uncontrolled.) One of the more common results of such a buildup is gout.
Recent studies have shown that people who have problems with uric acid in the blood also have a nearly 20 percent increased risk of developing diabetes, along with a more than 40 percent increased risk of developing kidney disease (also often associated with diabetes). The studies do not prove that uncontrolled uric acid levels cause these health problems, but there seems to be an association between high uric acid levels and the risk of developing these two diseases.
Diabetics are more prone to urinary tract infections, which occur when bacteria contaminate the bladder, ureters, or kidneys.
What is a urinary tract infection?
A urinary tract infection, or UTI, is caused by different types of bacteria (usually E. coli ), most often from the bowels.
The bacteria often travel up the urethra to the bladder, the most commonly affected organ.
If the infection is in the bladder, it is called cystitis (a lower urinary tract infection), and if it is in the kidneys and ureters, it is called pyelonephritis (an upper urinary tract infection).
Symptoms include a burning sensation when urinating, strong-smelling urine, fever or chills, a pain in the back or abdomen, and cloudy, dark, or bloody urine.