What are the other Names for this Test? (Equivalent Terms)
- Bone Turnover Markers
What is Bone Markers Test? (Background Information)
- The Bone Marker test is used to detect and measure the presence of certain biochemicals in blood and/or urine. This helps determine if there is either an excess of bone formation, or an excess of bone destruction (called resorption)
- This information helps predict the risk of bone fracture, diagnose conditions like osteoporosis, help make a treatment decision, and also serve as a baseline to measure the effectiveness of a future treatment
- The human bone is in a constant state of remodeling, even after the body growth stops. New bone is continuously being formed, while old bone continuously being absorbed in the body. This process is termed as ‘bone turnover’
- Formation of new bone is carried out by specialized bone cells called osteoblasts. The absorption of old bone occurs with the help of another special type of bone cells called osteoclasts. This ‘bone turnover’ is important for the normal bone health and helps in repair and response to stress (such as fractures)
- Normally, the bone formation and bone resorption processes are usually in a state of balance. However, during a disease (involving the bone), either of these processes may be affected causing imbalances in the overall bone health
- Bone Markers, a group of biochemicals, can be determined in blood and/or urine with special techniques, such as high performance liquid chromatography (HPLC) and immunoassay. The test can determine two different categories of markers; first category of markers for bone formation and the second category of markers for bone resorption
- Bone Markers test is mainly used in addition to other tests, like Bone Density Testing, to predict risk of fracture in individuals with osteoporosis, or those at an increased risk of developing osteoporosis
- The use of this test is also being researched for diseases such as Paget’s disease, primary hyperthyroidism, and renal osteodystrophy, which involves a high bone turnover. Its usefulness is also being studied for breast cancer and prostate cancer, which may have spread to the bone
- However, it should be noted that the detection of Bone Markers in blood and/or urine, may not be necessarily related to bone disease. In some cases, even though the bone resorption may be increased (showing an increase in that category of Bone Markers), if it is balanced by an equivalent bone formation increase, no net bone loss will occur
What are the Clinical Indications for performing the Bone Markers Test?
- Currently the use of Bone Markers test is limited to evaluating and estimating fracture risk in individuals having osteoporosis, or those at high risk of developing osteoporosis in the future. Bone Markers test is used along with Bone Density testing in these cases
- Bone Markers are also measured to evaluate the response to treatment. They are able to provide immediate assessment of the response to treatment (within 3-6 months of the start of therapy), compared to bone density tests (that show changes only after a minimum of 2 years)
It should however be noted that further research is underway to study the utility of Bone Markers. Due to a lack of sufficient evidence, it is not reliable to use Bone Markers to study the response to treatment. So this test is currently used only as an adjunct with other tests (such as Bone Density testing), to diagnose and manage osteoporosis. These tests are also helpful for other diseases associated with a high bone turnover.
How is the Specimen Collected for Bone Markers Test?
Sample required: Blood
Process: Insertion of needle into a vein (arm)
Preparation required: None; however, some laboratories may ask you to observe overnight fasting before the test.
What is the Significance of the Bone Markers Test Result?
- Presence of Bone Markers in blood and/or urine, signifies either an increased bone formation or an increased bone resorption, depending on the type of markers detected
- The Bone Markers cannot indicate the reason for increased bone formation/resorption. Other tests and investigations are usually ordered by the healthcare provider to arrive at a definitive diagnosis
- Bone Markers are also used to monitor a patient’s response to treatment. Decreasing levels of Bone Markers, as the therapy progresses, indicates an effective response to treatment
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
Markers for bone formation, in blood include:
- Serum bone-specific alkaline phosphatase
- Serum osteocalcin
- Serum C1NP or P1NP (type 1 procollagen C-terminal/N-terminal propeptide)
Markers for bone resorption, in blood and/or urine include:
- Serum and urinary hydroxyproline
- Urinary total pyridinoline (PYD)
- Urinary free deoxypyridinoline (DPD)
- Urinary collagen type 1 cross-linked N-telopeptide (NTX)
- Urinary or serum collagen type 1 cross-linked C-telopeptide (CTX)
- Tartrate-resistant acid phosphatase (TRAP) 5b
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.