Pyridinoline and deoxypyridinoline are the stable crosslinks used to measure the bone resorption rate in the human body.
Deoxypyridinoline is a type I collagen or protein that is present in bones and is generally excreted from the system through the urine without going through a metabolic stage. The level of bone collagen in urine clearly indicates the degree or extent of bone degeneration as bone minerals from bone fluid are released into the blood and then, in turn, are excreted through urine.
The level of Urinary Deoxypyridiinoline is measured through a urine test called deoxypyridinoline urine test, when a doctor suspects that a patient’s bones are breaking down due to the onset of degenerative conditions like osteoporosis or metabolic bone disease, and to access the bone resorption rate in an individual. The use of the procedure is primarily to determine the amount of collagen that is excreted from the body, thereby leading to a calculation of the approximate loss of bone material, and degeneration of the skeletal system. In addition, deoxypyridinoline crosslinks are measured through the calculation of protein in various samples of dentin and bone matter, leading to a calculation of the age of a person, and the estimated percentage of degeneration of the bone. Since undergoing numerous bone scans to determine the extent of bone degeneration is an expensive affair, a urine test to check the level of deoxypyridinoline being flushed out of the body is a more cost effective method of checking the same. On the basis of the findings, doctors can ascertain the necessary mode of action for treating the condition.
The deoxypyridinoline levels in the urine follow a circadian rhythm wherein the levels of excretion are higher in the night and may vary from day to day as well. The first urine of the day is not taken into consideration for the test and therefore a patient is advised to discard this urine and the second urine is usually used. Besides, the method of renal collection and handling plays a vital role. The urine should not be contaminated in anyway and making sure that the genital area is thoroughly cleansed before collection is essential.
The urine has to be collected in a properly sterilized container. The urine sample is then sent to the laboratory where the deoxypyridinoline and pyridinoline levels are measured and the levels indicate the level of bone resorption.