As we age, the underlying health of our bones begins to become important to us. The fear of a hip fracture scares most of us.
When it comes to bone density and testing for bone density, there are a few things you need to understand first.
The first aspect has to do with the time frames of osteoporosis and bone health in general. Osteoporosis does NOT begin as we get older. Rather, it starts in your teenage years. For this reason it remains critical for our teenage children to understand just how important it is for them to live a healthy lifestyle that is high in fruits, vegetables, exercise and vitamin D and low in stress.
The full discussion on what contributes to poor bone health and fractures is quite extensive, but you can begin to get an idea of the effects of inflammation, gut health, vitamin D, exercise and a good quality diet by reading through past posts.
The other aspect to understand is why we check bone density in the first place.
When you have your bone density checked by an X-ray machine called a DXA scan (checking either the forearm-my favorite-or hip or spine) we are trying to guess what your likelihood of having a fracture in the future may be. Only about 25% of your risk of fracture comes from what is found on one of these bone density tests. Doesn’t seem like such a good test, huh?
Other factors like your risk of falling play a role. This is why exercise, lower body strength, yoga and tai-chi can be so powerful at lowering your risk of fracture.
The dynamic strength of bone is generally contributed to by the medullary region of bone. This is the inside, mushier part of bone rather than the tough outer cortex that is checked with a DXA scan. The healthier this medullary bone and the less turnover we have in this region of the bone, the better off you will be.
For several decades, we have been able to check this region with urine tests referred to as CTX (C-telopeptide), and this gave us a pretty good idea of how fast you were turning over bone. It wasn’t the best, but when you combine a bone density DXA scan with the CTX you could get a reasonably good picture of bone health and trajectory.
In walks a relatively new compound discovered called sclerostin. This molecule is released by bone cells and basically stops bone formation. Not a good thing.
So can sclerostin help you determine whether you might be at increased risk of a fracture? This particular study suggests this may be the case. But just how well it predicts your risk of a fracture is jaw dropping…
- Those woman with the highest levels of sclerostin were more likely to have low bone density
- The highest levels of sclerstin led to a 340% increase risk of fracture
- However, those women with low bone density and the highest sclerostin levels had a whopping 2230% increased risk of a hip fracture
This is not quite a guarantee of a fracture, but it doesn’t really get any closer.
The bottom line is that bone density testing alone is not enough to fully determine your risk of fracture. It never has been. To make a treatment decision (which almost exclusively = drug treatment) without the entire picture is not in your best interest.