Have You Had Your Bone Turnover Markers Checked Lately?
Some of us taking osteoporosis medications have to wait for our next DXA to find out if the drugs we are taking are working to prevent fractures and increase bone density. For most of us this waiting just isn't practical. Do we want to subject ourselves to 1 to 2 years of any given treatment and it's cost before we can find out if the drug we are taking is working? There are simple blood or urine tests that can be performed on bone resorption or formation markers that will tell you if your treatment is effective without having to wait. If your doctor isn't ordering one of these tests, maybe you should ask about it?
What Are These Markers and How Are They Produced?
In the article Bone Loss...The Cost to Your Health the author explains that "Bone resorption osteoclasts excavate small pits into the bone. Fragments of excavated bone collagen are released into bodily fluids. Bone formation osteoblasts deposit new collagen to fill the excavated pits. When resorption and formation are in balance there is no net change in bone mass (Georgia Reproductive Specialist, 2007)." Since these fragments of collagen and osteocalcin can be measured we know how our osteoporosis treatment is working on our bones.
Measuring These Markers-Which Test?
There are two different types of tests that can be ordered to evaluate our remodeling process; bone resorption markers and bone formation marker tests. Your doctor will decide which of these tests is best for the type of treatment you are on for osteoporosis.
Listing of formation and resorption markers from the University of Washington
My doctor orders the 24 hour urine N-telopeptide (NTx) test several times a year so she knows how her patient's treatment regimes are progressing. Your doctor may opt for a different test based on their personal preference, or on the type of treatment you are on. Regardless of the drug you are taking, this test can be ordered, however different classes of drugs produce different results.
Who Pays For This Test?
Most insurance companies pay for this test, since it's considerably less expensive than a DXA, and can provide important information on bone status within the first three months after treatment is initiated. Currently Medicare pays for this test, but the number of tests permitted annually should be confirmed in the Medicare National Coverage Detail Booklet. Check with your individual insurance provider for information on the coverage of these tests.
Who Performs This Test?
Your local lab can perform these tests, but confirm this with your lab prior to arrival for the test.
Preparation For This Test?
Your doctor's office or nurse will give you a printed list of instructions to follow for these tests. Instructions vary depending on which type of test your doctor chooses. If you have a blood test there will be individual instructions for that, and if they decide on a urine test you will also receive information on collecting the sample, and how to store it until it reaches the lab. If you are having the urine test, pick up the collection equipment 24 hours prior to the start of the 24 hour collection.
What Will The Test Results Tell You and Your Doctor?
This test won't give you a t-score, nor is it a replacement for a DXA, but it will give the clinician an idea on bone density increases which correlate into fracture risk and will tell your Doctor if the current drug regime is working properly.
ASBMR: Blood Test Predicts Risk of Fracture