Bone Health Issues: Q&A with Dr. Richard Ward
May 6, 2014 – Your thalassemia nurse or physician is always reminding you how important it is to take the prescribed iron chelation medication every day, but there are other aspects of your health and wellbeing that are equally important to take care of if you or a loved one has thalassemia. This Q&A session with Dr. Richard Ward focuses on bone health, which is often not at the top of one’s list of priorities in living with thalassemia, and for many young patients may not seem important. Here’s some information as to why it deserves our attention.
CAF: In general, why do many people with thalassemia experience bone health issues? At what age do bone issues typically develop in thalassemia? What steps can those with thalassemia take to prevent bone health issues from developing? What can they do to address bone health issues?
Dr. Ward: Your body keeps your bones strong by continually removing old bone and making new bone. With thalassemia your bones can be affected in many different ways by interfering with this bone cycle. This includes the overgrowth of the bone marrow that is seen in thalassemia intermedia and sub-optimally transfused patients with thalassemia major. In addition, too much Desferal, as well as excess iron, can be harmful to the cells that are responsible for making new bone. Then there is the complex interplay of various hormone levels in the body that can be disturbed by deposition of iron in the brain’s pituitary and other hormonal glands. (These include: diabetes, growth hormone deficiency, delayed puberty, and hypothyroidism.) This occurs at a very young age and the pituitary gland seems particularly vulnerable to damage during puberty. Vitamin D deficiency is common too, and as a building block for the bones, a key element of bone health. All these interacting factors mean that most patients with thalassemia will have some problems with their bones, most commonly osteopenia/osteoporosis and short height. A final contributor to you or your child having lower bone mass is lack of exercise. Many patients do not exercise sufficiently, partly due to fear of any heart damage that may have occurred from iron overload or because of feeling lethargic from the chronic anemia. As well as being good for the heart muscle and our general wellbeing, exercise (particularly weight bearing) is beneficial to bone health.
Osteopenia/osteoporosis are the medical terms describing low bone mass, which can lead to risk of fractures in the future if not corrected. (More on this is explained in question 4.) It is thought to be one of the most common complications encountered in thalassemia major, affecting up to 70% of individuals. However, we don’t fully understand all the reasons why the bones are weaker, as it’s still a problem in about 40% of patients who are well transfused and chelated. Although the time at which you or your child may have their first DXA scan may vary depending on your local circumstances, we know that from early childhood the bones can be weakened. It is important to try and improve this early on as the main way to prevent having a future fracture is to maintain the bone strength as much as possible. This in turn depends on building the bones up as much as possible in childhood because the maximum bone mass is reached at the end of puberty. After this time, we can only try to slow down the natural weakening of bones that happens to everyone. The stronger the bones are and the slower they weaken, the lesser the chance of fractures as you get older.
As with many medical conditions, there are easy or simpler ways to help your bones, and some more complex choices that may require specialist opinions, such as from an endocrinologist or even an expert in osteoporosis. The latter are more commonly found in adult clinics as the general population is affected by osteoporosis in later life. So the first step is to be aware and educated that the bones are an issue if you have thalassemia. The next part of the puzzle is lifestyle changes that are often hard to achieve, especially on a consistent basis. Many of these recommendations also apply to someone who has weak bones but not from thalassemia. Depending on your age these may or may not be applicable: limit caffeine-containing drinks to one a day, quit smoking, take regular exercise (ideally weight bearing), ensure you’re getting enough calcium in the diet and that your vitamin D levels are measured and in the right range. There are many online tools and smartphone apps that can help guide you with the calcium intake, or you may have access to a dietician connected to your clinic.
The thalassemia part of the picture also needs addressing. This involves ensuring the height and weight are checked on a regular basis, being transfused enough blood to suppress the bone marrow from growing and weakening the bones, and taking the chelation medication as agreed with your healthcare team. For children who are on Desferal (deferoxamine) it’s important not to have too much drug as it can cause damage to the bones and cartilage, and affect growth. Exjade and Ferriprox probably do not have the same risks as Desferal, though data is still emerging on this. However, we also know that too much iron will lead to bone complications as well. Much of this is from the iron damaging the hormone glands of the body. If you remember that there are three key reasons to take the chelation treatment -heart, liver AND hormones/bones – you won’t forget ALL the benefits you can have from being well chelated!
If you or your child has, unfortunately, developed some hormone problems, the chances are that you will be referred to see an endocrinologist to help manage the issues. They will help you to decide which medications may be best depending on your individual circumstances. Options may include just watching and see what happens over time, growth hormone injections or estrogen/testosterone medication. Regardless, we do know that the bones will be healthier if any endocrine complications from your thalassemia are well managed.
For older patients with thalassemia, or if you have had a fracture, or are found to have very weak bones despite everything else being done for you, then it may be time to see a specialist in osteoporosis. Such specialists have the expertise to discuss the various bone strengthening medications that are available these days. The most widely used group of drugs are the bisphosphonates. They work primarily by stopping the cells that remove bone. These have been in use for longer than other drugs and so we are more informed of side effects than we are with some newer drugs recently made available. Although they are used widely in the general population with osteoporosis, there is actually much less data for their use in thalassemia. Not all the bisphosphonates have been shown to be beneficial, and due to the much younger age of thalassemia patients it is still not clear by how much they reduce the risk of fractures, though they can improve the DXA scan results and reduce associated back pain. However, it is important to think about what we are trying to do, which is to stop fractures, rather than simply improve a test result, and so they may not be the right choice for everyone.
As we have become more successful at looking after individuals with thalassemia, we are more aware these days of the possibility for successful pregnancies in women with thalassemia major. There is a slight concern that the bisphosphonates can stay in the bones for many years after taking the medication and then cross the placenta and potentially cause harm to the growing baby’s bones. We therefore try to avoid using them in women of child bearing age. There are several other types of medication that can be used to treat osteoporosis, and the options should be discussed with your healthcare team and specialists on an individual basis with a knowledge of your own DXA results and other risk factors for low bone mass. A final comment on this is directed at men: males have traditionally been not investigated or undertreated compared to women with osteoporosis. There has been some recent emerging data to suggest that men with thalassemia may actually also be at a higher risk of fractures than women. So if you are a male with thalassemia, please make sure you and your healthcare team are looking after your bone health too.
Is rapid joint destruction common in thalassemia, or is it more likely to be the result of thalassemia plus other co-existing conditions (such as arthritis and hypopituitarism)?
Low bone mass is thought to be due to different processes in thalassemia major (TM) and thalassemia intermedia (TI). The body is constantly making new bone and ridding itself of old bone, in a dynamic process of bone remodeling. In TM, there is thought to be high turnover of new and old bone, whereas in TI, it is more an issue with slower turnover of bone and the expansion of the bone marrow. Many patients with TM also have other hormonal complications, such as hypogonadism, hypothyroidism and diabetes. These can all play a role in the health of bones. It’s another reason why it’s so important to look after all aspects of your health if you have thalassemia, and not just the transfusions and chelation. This is described in more detail in the previous question. Destruction of joints, or arthritis, is not typically seen in thalassemia.
Can consumption of soda have a negative impact on bone mass? What are some foods/beverages that can have a positive or negative impact on bone mass?
Some carbonated drinks, particularly colas, can contain excess amounts of caffeine and also phosphorus acid. This chemical can potentially cause changes to the way the body handles calcium and have an effect on bone health. However, the evidence for this is weak and there is probably little harm from an occasional soda drink. There are, of course, other reasons to moderate carbonated drink intake. Soda water, specifically, is not harmful to the bones. Foods rich in calcium are good for the bones, and there exist many tools and calculators to see if you are getting enough in your diet. Such foods include dairy produce (though be careful with the fat content), green vegetables such as broccoli, legumes, some nuts, and bony fish such as sardines.
When undergoing a DXA scan, are the spine, hips and arm/hand usually all scanned? Are there other body parts which are typically involved in a DXA scan?
For adults, the spine and a hip are scanned. However, as children/adolescents under 19 years of age may still have growth in the hip or spine, total body scanning is more accurate. The forearm may be used as an alternative if there is a problem with the hip or spine, for example if you have received a hip replacement.
Bone density is often reported as a T-score which provides information as to how your bone strength compares to the general population and this is used to calculate the risk of having a fracture in the next 10 years. However, a T-score is used only if you are >50 years old, and the score for younger adults, the Z-score, does not have the same ability to predict risk of fracture. There are also no Z-scores for the total body BMD (bone mineral density) for Asians. The various scoring systems used to predict the risk of future fracture also involve collecting some medical information, so it’s not only the DXA scan result that is important. In fact, in recent years, there has been a move away from relying too much on the DXA scan result to guide physicians in how to treat patients with low bone mass.
Some hospitals employs IV magnesium in post-operative patients, which seems to result in improvement in bone density. Should IV magnesium, or another method of giving magnesium, be used regularly in patients with thalassemia?
Magnesium, like calcium and vitamin D, are all essential to help the bones grow healthily. However, there can be problems when taking too much of these and there is also no evidence that having additional amounts of magnesium beyond what a balanced diet will provide will be of benefit to the bones. There is no data that I am aware of to support the use of intravenous magnesium for patients with thalassemia.
Does prednisone have a negative impact on bone health? If so, are there other therapies that a thalassemia patient with a condition for which recommended treatment is prednisone (such as myasthenia gravis) can try that will not impact bone health?
Steroids, such as prednisone, definitely have a negative impact on your bone mass. The bones start to weaken within three to six months of starting steroid medication, even at doses of less than 7.5mg of prednisone daily. The risk of fracture is as high as 30-50% after three months of receiving steroids. It’s therefore recommended for all patients who will need prolonged steroid treatment, that they start calcium, vitamin D and bisphosphonate therapy at the beginning. Despite the side effects of steroids they can often be an essential part of managing many serious medical conditions, or even life-saving. It’s important for you to discuss the pros and cons of the various treatment options with the specialist you are seeing. If prednisone is recommended, then make sure you are doing all you can to help your bones from the start, including the lifestyle changes and vitamin supplements.
What else would you like to say about bone health in people with thalassemia?
With transfusions and chelation to think about, it can be hard to also focus on other aspects of your thalassemia health. For bones, especially, where lifestyle changes play a big role, it can be a struggle to make the necessary changes consistently. Also, it’s one of those complications that can be difficult to conceptualise if you are young and active. However, we know that the iron, anemia, hormones and bones are all inextricably linked and taking care to look after your body as a whole has many benefits. As more and more patients are living well and longer with their thalassemia, it’s vital that we ensure you are going to enjoy a good quality of life as you age. Looking after your bones is a major aspect of that.
There is great, easy to read information on www.osteoporosis.ca, including a calcium calculator to see if you are getting enough calcium in your diet, along with calcium rich recipes. Your clinic probably also has a wide range of information and resources, including child friendly material. As with many aspects of thalassemia care, it can be helpful to set realistic, stepwise goals to achieve good health. So, think about one change you can make after reading these Q&As and set yourself a target, be it taking vitamin D supplements more regularly, getting some daily exercise, improving your dietary calcium, or showing up for a DXA scan.
CAF extends its thanks to Dr. Ward for taking the time to participate in this Q&A session.