K - Kidneys
Kidneys are important to maintain homeostasis, meaning constancy of the internal environment of the body. A major function of the kidneys is to remove waste products and excess fluid from the body, via 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.
The kidneys are powerful chemical factories that perform the following functions:
removing waste products from the body
removing drugs from the body
balancing the body's fluids
releasing hormones that regulate blood pressure
producing an active form of vitamin D that promotes strong, healthy bones
controlling the production of red blood cells.
Kidney function is measured by a simple blood test in combination with a urine test. The level of a waste product in the blood called creatinine is converted into a measure of how efficiently the kidneys are filtering the blood this is called the estimated glomerular filtration rate (eGFR). The conversion formula takes into account the patient’s age, sex and ethnicity, as well as the creatinine itself. An eGFR of 100mls per minute is normal, or 100% efficient, while an eGFR of 50 means the kidneys are working at 50% efficiency, in other words, half as well as they should. An eGFR above 60 accompanied by raised levels of protein in the urine represents chronic kidney disease stages 1 – 2. An eGFR of between 59 and 30 regardless of the level of protein in the urine equates to stage 3 chronic kidney disease. An eGFR below 30, or a sustained decrease in eGFR of 25% or more, should trigger the GP to consider referral to a hospital specialist.
Failure can be acute (temporary) occurring in approximately 15% of Duchenne patients or chronic (permanent) kidney failure. Chronic k