What Blood Test Is Used To Detect Increased Bone Destruction?

At a glance

Also known as

Bone Resorption Markers; Bone Formation Markers; Os Turnover Tests; Due north-telopeptide; NTx; Crosslinked C-telopeptide; CTx; Deoxypyridinoline; DPD; Pyridinium Crosslinks; Tartrate-resistant Acid Phosphatase; Bone-specific Alkaline Phosphatase; Osteocalcin; Procollagen Type 1 N-Final Propeptide;

Why get tested?

Bone markers are used to help evaluate and monitor the rate of bone resorption and formation; to monitor some metabolic bone diseases such as osteoporosis; to discover Paget disease

When to get tested?

When a bone mineral density scan indicates reduced bone density; before and periodically during treatment for os loss to evaluate effectiveness, to decide if the rate of loss has decreased or the charge per unit of bone formation has increased

Sample required?

A blood sample drawn from a vein in your arm or a urine sample

Test preparation needed?

Fasting may be required before testing; samples are typically collected in the morn

What is being tested?

Os is the rigid, hard connective tissue that comprises the majority of the skeleton in humans. It is a living, growing tissue that turns over at a rate of about x% a year. Os markers are blood and urine tests that detect products of bone remodelling to help determine if the rate of bone resorption and/or formation is abnormally increased, suggesting a potential bone disorder. The markers can be used to help determine a person's risk of bone fracture and to monitor drug therapy for people receiving treatment for skeletal disorders including osteoporosis.

Os is fabricated up largely of type-I collagen, a protein network that gives the os its tensile strength and framework, and calcium phosphate, a mineralised complex that hardens the skeletal framework. This combination of collagen and calcium gives bone its hardness, and yet bones are flexible enough to bear weight and withstand stress. More than 99% of the body's calcium is contained in the bones and teeth. Most of the remaining 1% is found in the blood.

Throughout a person's lifetime, os is constantly being remodelled to maintain a salubrious bone structure that conforms to the person's needs. At that place are two major types of cells within os: osteoblasts and osteoclasts. Osteoblasts are the cells that lay downwardly new os, but they first initiate bone resorption past stimulating osteoclasts, which dissolve small amounts of bone in the area that needs strengthening using acrid and enzymes to dissolve the protein network.

Osteoblasts so initiate new os germination by secreting a variety of compounds that assistance form a new poly peptide network, which is then mineralised with calcium and phosphate. This on-going remodelling procedure takes place on a microscopic scale throughout the body to go along bones alive and sturdy.

During early on childhood and in the teenage years, new bone is added faster than one-time os is removed. As a result, bones become larger, heavier, and denser. Os germination happens faster than bone resorption until a person reaches their summit bone mass (maximum os density and force) between the ages of 25 and xxx years. After this peak flow, os resorption occurs faster than the rate of os germination, leading to net os loss. The age at which an private begins to feel symptoms of bone loss depends on the corporeality of bone that was developed during their youth and the charge per unit of bone resorption. Traditionally, women exhibit these symptoms earlier than men considering they may not have developed as much bone during the peak years and, after menopause, rate of bone loss is accelerated in some women.

Several diseases and atmospheric condition tin can cause an imbalance between bone resorption and formation, and bone markers tin can be useful in detecting the imbalance and os loss. Most often, the markers have been studied in the evaluation and monitoring of osteoporosis, including historic period-related osteoporosis or secondary osteoporosis, which is bone loss due to an underlying condition. Os loss may result from atmospheric condition such as rheumatoid arthritis, hyperparathyroidism, Cushing affliction, chronic kidney disease, multiple myeloma, or from prolonged apply of drugs such as anti-epileptics, glucocorticoids, or lithium.

Below is a list of some os resorption and formation markers measured in claret and/or urine samples. Enquiry is ongoing for new biomarkers that can predict abnormal bone loss in various affliction states. For many of these markers, caution is required in interpreting test results equally they can be affected by nutrition, exercise, and fourth dimension of day the sample is collected.

The International Osteoporosis Foundation (IOF) and the International Federation of Clinical Chemistry & Laboratory Medicine (IFCC) recommend ii blood tests for evaluating bone turnover:

A claret test for C-telopeptide (C-concluding telopeptide of type i collagen (CTx), Crosslaps) every bit a marker for os resorption
A blood examination for P1NP (Procollagen type ane N-concluding propeptide) equally a marker for bone formation

Other bone marker tests that may sometimes exist used include:

Northward-telopeptide (N-terminal telopeptide of type 1 collagen (NTx))
Deoxypyridinoline (DPD)
Pyridinium Crosslinks
Tartrate-resistant acid phosphatase (TRAP) 5b
Bone-specific alkaline metal phosphatase (ALP)
Osteocalcin (bone gla protein)

For further discussion of these tests, see the Test section/How is information technology used?

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm. Sometimes, a random or timed urine sample is collected in a clean container provided by the laboratory.

Notation: If undergoing medical tests makes y'all or someone you lot care for broken-hearted, embarrassed, or even difficult to manage, y'all might consider reading one or more of the following articles nether: Coping with Discomfort and Feet.

Another article, Follow a sample, provides a glimpse at the collection and processing of a blood sample.

Is any test training needed to ensure the quality of the sample?

Information technology may be necessary to fast prior to testing. Many of the bone markers vary in the blood and urine depending upon the fourth dimension of day (diurnal variation), and then sample timing can exist important. Advisedly follow any instructions given for the timing of sample drove. For case, you may be asked to collect urine from the 2d time you pass urine in the morning (a '2d morning void').

The Exam

How is information technology used?

One or more of the bone marker tests may be used to assist decide if a person has increased rates of bone turnover (resorption and/or germination). Bone markers are sometimes used as an adjunct to bone mineral density (BMD) testing (due east.g., by DEXA scan) to help evaluate os loss and detect some os diseases. They often are used to monitor response to anti-resorptive therapy for bone disease, primarily osteoporosis, and to help a medico determine if the dose of the drug a person is receiving is constructive.

These tests tin discover response to anti-resorption or bone edifice therapies in a much shorter time flow than BMD testing (three to vi months versus one to ii years). This mode, therapy tin can be adjusted or altered in a more timely manner if a person is not responding as expected.

The International Osteoporosis Foundation (IOF) and the International Federation of Clinical Chemistry & Laboratory Medicine (IFCC) recommend two claret tests for evaluating os turnover:

C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx), Crosslaps) – a marker for bone resorption. Information technology is a peptide fragment from the carboxy terminal stop of the collagen protein; used to monitor anti-resorptive therapies, such as bisphosphonates and hormone replacement therapy, in postmenopausal women and people with depression bone mass (osteopenia)
P1NP (Procollagen blazon 1 Northward-terminal propeptide) – a marker for bone germination. It is formed by osteoblasts; reflects rate of collagen and bone germination; may be ordered forth with bone resorption marker such as C or Northward-telopeptide; near sensitive marker of os formation and particularly useful for monitoring os formation therapies and anti-resorptive therapies; it is recommended that the test be performed at baseline before starting osteoporosis therapy and once again 3 to 6 months later.

Other urine or claret tests used less ordinarily for bone resorption include:

North-telopeptide (N-terminal telopeptide of blazon 1 collagen (NTx)) – a peptide fragment from the amino terminal stop of the poly peptide matrix; another marker used to monitor therapy.
Deoxypyridinoline (DPD) – a collagen breakdown production with a ring structure.
Pyridinium Crosslinks – a group of collagen breakup products that includes DPD; used to monitor therapy response; not equally specific for os collagen as the telopeptides.
Tartrate-resistant acid phosphatase (TRAP) is the version of acid phosphatase produced by osteoclasts, the cells that deliquesce small amounts of os, during bone resorption.

Other os formation blood tests that may sometimes be used include:

Bone-specific alkaline phosphatase (ALP) – one of the isoenzymes (types) of ALP; it is associated with osteoblast cell function, the type of cell involved in os formation. It is thought to have a role in bone mineralization; information technology is recommended that the test be performed at baseline earlier starting osteoporosis therapy and again 3 to 6 months afterwards; results may be affected by the level of liver ALP.
Osteocalcin (bone gla poly peptide) – a protein formed by osteoblasts; office of the not-collagen portion of the bone structure; some of it besides enters the bloodstream; the level of osteocalcin in the claret reflects the rate of bone germination, thus it is a useful indicator of the function of osteoblasts. This test may be affected by utilise of the drug warfarin (Coumadin®).

When is it requested?

Testing may be performed forth with other tests such as a calcium, vitamin D, thyroid testing, and parathyroid hormone when bone loss is detected during a bone mineral density test (diagnostic imaging) and/or when a person has a history of unexpected bone fracture.

One or more than bone marker tests may be performed prior to anti-resorptive or bone germination therapy then typically iii to 6 months later to monitor the effectiveness of treatment.

What does the examination result mean?

A loftier level of i or more bone markers in urine and/or blood suggests an increased rate of resorption and/or germination of bone, but it does not indicate the cause (it is not diagnostic). An elevated level of bone markers may be seen in weather such equally:

Osteoporosis
Paget disease
Cancer that has spread to the bone (metastatic os disease)
Hyperparathyroidism
Hyperthyroidism
Osteomalacia in adults and rickets in children—lack of bone mineralisation, frequently due to vitamin D or calcium deficiency
Chronic kidney failure (renal osteodystrophy)
Excess use or loftier doses of glucocorticoids or Cushing syndrome

A low or normal level suggests no excessive bone turnover.

When used to monitor anti-resorptive therapy, decreasing levels of the bone resorption markers over time reverberate a response to therapy.

About Reference Intervals

Is in that location anything else I should know?

Samples must be consistently collected, and exam results must be interpreted with caution. In that location is both twenty-four hour period-to-day variability in bone marker concentrations and diurnal variation (changes throughout the twenty-four hours). Virtually os mark concentrations volition be the highest in the morning, and some, in detail, C-telopeptide, are affected by eating.
Concentrations of bone markers are affected by a variety of factors, particularly during childhood development. These include age, sex activity, growth velocity, nutritional status, and puberty. Therefore, interpretation of bone marker results requires utilize of advisable reference intervals.

Most people with os loss are not enlightened of it. The condition may not cause any symptoms until a person has an unexpected bone fracture.

At that place are limitations to the clinical utility of many of these bone markers, but researchers continue to explore ways to improve their clinical use. Their main use is to gauge the effectiveness of the therapies used to treat metabolic os disease and to properly arrange the dose for maximal result.

Mutual Questions

Should anybody take bone marker testing performed?

Bone marker testing is typically merely indicated in those who have been diagnosed with or are at risk of bone loss. The tests are not intended to be used to screen the general public. They offering additional information to the doctor but do non accept the place of os mineral density screening.

Volition I have all or just some of these os markers tested?

Typically, no one will have all of the tests done that are described here. Most doctors apply one or a few particular bone markers, including 1 or two that evaluate bone resorption and one or ii that evaluate os formation. The option of bone markers volition depend on many factors, including your medical history, signs and symptoms, and physical examination, and these all vary from person to person. Your doctor will make the pick based on the usefulness of the tests for your status. In general, if a examination is ordered as a baseline prior to therapy, then the same examination will exist ordered subsequently so that the 2 results can be compared.

Can testing exist performed in my doctor'due south part?

In general, no. While a blood or urine sample may exist collected in your md'southward office, the sample will be sent to a laboratory for testing. Bone marker testing is not offered by all laboratories and volition often exist sent to a reference laboratory.

What can I practise to increment or decrease bone marker results?

People can and should take steps to maintain os health throughout their life, but os markers themselves are non affected by lifestyle changes. If you have bone loss, work with your healthcare practitioner to determine the all-time treatment for you.

How is osteoporosis treated?

Hormone replacement therapy (HRT) and related drugs such every bit raloxifene can assist maintain bone density in women after the menopause. Bisphosphonates, such as alendronate, too aid to maintain bone density and forbid fractures, and the hormone calcitonin tin be used to preclude bone resorption. Alternative treatments such as strontium ranelate taken as a daily drink increase bone mass, zoledronic acid given as a one time yearly infusion and denosumab given as a six monthly injection, are as well constructive treatments. The most appropriate selection will need to be discussed with your doc.

How prevalent is osteoporosis?

The condition may affect upwardly to 2 million people in Australia but many will non know they take the disease. Of the people with osteoporosis, 80% are women.