Glossary
Parathyroid hormone (PTH)
PTH is a substance produced by four tiny glands in the front of the neck called the parathyroid glands. The hormone PTH helps to control blood levels of calcium.
When kidneys fail blood calcium levels can become low. The body compensates by producing more PTH. Due to this overstimulation of the glands large quantities of PTH are produced. In order to keep up the calcium levels high the PTH takes calcium out of the bones, so that calcium levels excessively rise. High PTH levels are common in patients with chronic kidney failure and this extra PTH aggravates renal bone disease (renal osteodystrophy).
Peritoneal dialysis
Cleaning the blood by using the lining of the abdominal cavity as a filter. A cleansing liquid, called dialysis solution, is drained from a bag into the abdomen. Fluids and wastes flow through the lining of the cavity and remain "trapped" in the dialysis solution. The solution is then drained from the abdomen, removing the extra fluids and wastes from the body.
Phosphate
Phosphate is an essential mineral in the diet and - together with calcium - a major component of bone. Phosphate is also found in the blood, muscles, nerves, and teeth. It is a component of adenosine triphosphate (ATP), the primary energy source in the body.
In chronic kidney disease the kidneys are no longer able to excrete excess phosphate into the urine. High levels of phosphate (hyperphosphataemia) cause e.g. itching. The treatment is to reduce phosphate levels by diet, dialysis and medication (phosphate binders).
Studies have determined high phosphate levels to be a risk factor for severe cardiovascular events.
Phosphate binders
Failing kidneys are no longer able to get rid of excess phosphate from the body. Kidney failure also results in excess PTH production, which further disrupts the balance between blood levels of calcium and phosphate. As a result, excess phosphate starts to build up in the blood.
Phosphate binders help to pass excess phosphate out of the body in the stool, thus reducing the blood phosphate levels. These medicines bind the phosphate in the digestive tract by forming a non-absorbable compound. Phosphate binders are usually taken with every meal in order to avoid the absorption of too much dietary phosphate. There are three common types of phosphate binding medicines: aluminium-based, calcium-based and aluminium- and calcium-free phosphate binders. The application of phosphate binders is a relevant part in the treatment of patients with severe kidney disease undergoing dialysis.
Potassium
The major positive ion (cation) found inside of cells. An increase of potassium is called hyperkalaemia.
Chronic kidney disease is one of the major causes of hyperkalaemia. If the Glomerular Filtration Rate is only 5 ml/min or less, hyperkalaemia may result, particularly when high-potassium foods are consumed. Depending on the increase of potassium in the blood disorders of the heart beat or symptoms of the nervous system can result. Severe hyperkalaemia can lead to fatal cardiac arrhythmias or even cardiac arrest.
Potassium binders
In patients with kidney failure excess potassium could no longer be excreted via the kidneys. As diet and dialysis alone sometimes are not able to eliminate the necessary amount of potassium, potassium binders give further support to control blood potassium levels. The medication binds dietary potassium in the intestinal passage so that gastrointestinal excretion is increased while blood concentration of potassium is decreased to a normal level.
Proteinuria
A condition in which the urine contains large amounts of protein, a sign and an indicator that the kidneys are not functioning properly.


