Bone health has been a topic of a lot of discussions and controversies in the past few years. With new treatment medication options, conflicting reports about calcium supplementation, questionable effects of fosamax and such drugs, it can be quite overwhelming! This post is dedicated to teach patients about the basics of bone density to get a better understanding of what we are looking for.
Strong and healthy bones are very important because it is our bones that keep us strong, mobile, and upright! Weak and unhealthy bones can truly affect the quality, as well as the quantity of our lives. When we talk about “healthy” or “strong” bones we are referring to their mass and density. You can have normal bones, Osteopenia (“thinning” bones) or Osteoporosis (“brittle” bones). Low bone mass/density can put you at high risk for fractures. The density of our bones is measured by a radiological x-ray test called BONE DENSITY (DEXA SCAN)—Dual Energy X-ray Absorptiometry. These DEXA scans give us a number called T-score which has helped standardize our discussion about bones–so when you talk to one doctor about your T-score, another physician knows exactly what you are saying and the health of your bones! T-score is your bone mass compared to normal healthy young adult. There is another number called the Z-score, which is your score compared to patients of your age/gender/ethnicity group. We make our treatment decisions based on the T-score. Although all bones in our body can weaken, we measure the bones in our lower spine and hips. Sometimes if patients have a lot of arthritis in their spine or an artificial hip, we check the arm to measure bone density.
The radiation levels involved in a DEXA scan is very low—almost negligible. The technician doing the test does not need to wear protective shields. For safety reasons, it is recommended the technician sit 3 feet away from the table when a patient is being scanned.
There can be significant difference in technologies used by different manufacturers and sometimes different models of the DEXA machines; therefore, it is very important for you to go to the same facility each time you have a bone density scan to get more consistent readings. Of course if you move out of town due to relocation or can no longer go to the facility due to insurance reasons, then you need to start at a new one.
Decision to treat low bone density is quite individualized. Not everyone necessarily needs prescription medicines. The World Health Organization released an algorithm to help physicians decide which patient will benefit from treatment and which can be monitored. The algorithm is called “FRAX” score. It is an algorithm that takes into account your Age, Gender, Weight, Height, Ethnicity, Smoking status, Prior fractures, Family History of fractures, Alcohol use, use of steroid medicines, T-score, and history of autoimmune arthritis to help decide if you will benefit from medicines to help with Osteopenia or Osteoporosis. You should speak with your physician to see if you need treatment.
There are many causes of low bone density including family history, low body weight, ethnicity, loss of estrogen for women in menopause, low testosterone in men, medications like steroids and antacids, calcium and vitamin D deficiency, hyperthyroidism (overactive thyroid) to name just a few.
To read more about prevention options, please read “What Can I Do To Help My Bones?”