Can bisphosphonates make your bones weaker?
28 Aug 2020
A recent headline about research published in the journal Scientific Reports suggests that bisphosphonates taken to treat osteoporosis may make bones less flexible and more likely to break. But if you are taking bisphosphonate medications, be reassured that you do not need to change treatment based on this small pilot study.
The study looked at 30 samples of bone from three groups of donors: those who had never broken a bone; those who had broken a hip and never taken bisphosphonates; and those who had broken a hip and taken bisphosphonates.
The researchers used a novel technique to look at the molecular structure of the bone samples. They found that donors who hadn’t broken a bone had a more flexible bone structure than those with the broken hips. The researchers suggested that less flexible bones cannot absorb impact so well, making them more likely to break.
The donors who had taken bisphosphonates appeared to have the lowest bone strength and flexibility of the three groups.
How reliable are these results?
This was a small study, involving single bone samples from 30 donors. The results do suggest that reduced bone flexibility is linked to an increased risk of hip fracture. But the small number of donors and limited clinical information make it difficult to draw any other firm conclusions.
The donors taking bisphosphonates had been prescribed this medication for osteoporosis, meaning they were already known to have poor bone strength. This may explain the differences observed in this group’s bone structure and why they had a higher risk of breaking bones.
Unfortunately, we don’t have any other information about the two donor groups with a history of broken bones – such as their bone density measurements and their risk factors for osteoporosis. This means we can’t know whether the differences in bone structure between these two groups were caused by a difference in their underlying bone health, or if the bisphosphonate treatment also had an effect.
Can I have my bone flexibility tested?
The technique used to measure bone flexibility in this study is a research tool that cannot currently be used in clinical practice.
In clinical practice, dual energy X-ray absorptiometry (DEXA) is the main test used to measure bone strength. DEXA scans give us a very good assessment of a person’s risk of breaking bones, especially when used alongside information about their lifestyle and medical history.
But because DEXA scans simply measure the amount of calcium in bone, they can’t give much information about the other properties that may contribute to bone strength.
This preliminary study provides us with more information and shows that changes in bone structure may cause differences in bone strength.
This is an exciting development. Further advances in the techniques used in this research may help us to develop more sophisticated ways of measuring bone strength, so we can better identify people who are most at risk of breaking a bone.
Should I be worried about taking a bisphosphonate treatment?
No – these treatments have been in clinical use for many years and have been carefully assessed in very large research trials. These trials have consistently shown that bisphosphonate treatments reduce the risk of breaking a bone – including fractures of the spine and hip. So, even if these treatments lead to some loss of bone flexibility over time, this is outweighed by the positive effects on the skeleton.
If you are taking bisphosphonates, you should be regularly reassessed to minimise any risks – usually after five years of treatment. This is to consider whether you should have some time off treatment, also known as a ‘drug holiday’. If your risk of breaking a bone is higher than any risk of continuing treatment, you will usually be advised to carry on with your bisphosphonate treatment for up to 10 years.
Nicola Peel, chair of our clinical committee, says:
“We often hear from people who are concerned about the wider effects of their osteoporosis treatments, so we welcome this research into the effects of bisphosphonate medications on bone structure and flexibility.
“But although this is an important preliminary study that adds to our understanding, it has its limitations and further research is needed to understand why some people are at higher risk of breaking bones than others.
“We are very hopeful that research like this, which was supported by the ROS, will lead to the development of new tests and treatments to reduce the impact of osteoporosis and, eventually, lead to a cure.
“If you are taking bisphosphonates, rest assured that they are still a safe and effective treatment option for osteoporosis, as long as they are used appropriately and you are monitored by your healthcare professional.”
If you have concerns or want to discuss your osteoporosis treatment, you can contact our specialist nurses – no question is too small. Call our free Helpline on 0808 800 0035 or email email@example.com.