When you have RA, you are at a higher risk for developing osteoporosis. Other aspects of living with this disease may also contribute to the risk: a sedentary lifestyle, taking steroids and being low on vitamin D. If you're taking certain stomach medications to deal with side effects from your RA meds, you can add another risk factor. All of these contribute to lowering your bone density, i.e., how thick or heavily packed with minerals your bones are. The higher your bone density, the stronger your bones are and this makes them less likely to break. Being aware of the state of your bones can help you prevent bone loss or treat any bone loss you may already be experiencing.
DXA stands for Dual-energy X-ray Absorptiometry. It uses very low dose x-rays, about 1/10 the radiation you get in a chest x-ray. The US Preventative Services Task Force currently recommends bone density tests or DXA scan for all women over the age of 65. If you are younger and have not yet entered menopause, certain risk factors can indicate that you may need one sooner. As people living with RA, we have a higher risk. The sooner you have a conversation with your doctor about maximizing your bone health and preventing bone loss, the better. Even if your bone density is fine, getting a DXA scan now will help you establish a baseline that can be used in the future.
A DXA scan is noninvasive and quick. It involves lying on your back on a cushioned exam table while the scanning contraption moves along your body. It will scan your hip and the lower vertebrae in your spine. These scans provide your T-score, a measure of how strong your bones are. Sounds easy, right? For people with normal mobility, it's a snap. However, the pain and limited mobility that can be part of having RA may affect your ability to do this scan.
The first scan of your hip requires your foot to be held by a strap to achieve a rotation of the hip to see the femoral area. The second scan of your lower back is done while you place your legs on the box so your hips and knees are in more or less a 90° angle (PJ Hamel's post on getting a DXA scan includes photos of these positions).
As with so many other things in our lives, sometimes it can be necessary to do things that can lead to a bit of a flare and temporary pain. Taking painkillers before your DXA scan can make the process easier and reduce your experience of pain. However, some people can't physically do the positions required for this scan or it might cause unmanageable pain for them. I spoke to Pam Flores, the Community Leader for our Osteoporosis site, about alternatives.
Alternatives to DXA Scan
The DXA scan, is the "gold standard" for bone density testing. However, if you can't rotate your hip in the position required or can't put your legs on a box, there are a number of other options. As well, certain factors can make your bones look denser than they are and therefore given an inaccurate reading. These complication factors include scoliosis, arthritis and titanium hardware in your hip or lower back from surgery.
One alternative is to scan another area of your body, such as the bones in your wrist. You can sit next to the scanning table and place your hand on it while the machine scans. Another option is peripheral DXA scans. This is a smaller machine that scans the bones in your wrist, fingers, leg or heel. Peripheral DXA machines are usually found in doctor's offices, pharmacies and health fairs. They do not yet have a uniform reference standard and the results may therefore be less reliable. As well, they're not ideal sites to monitor the effectiveness of treatment, but if it's the only option you have, work with what you've got.
The Quantitative Ultra-sound (QUS) is a new test using a much smaller machine and can be done in doctor's offices. The ultrasound wand is applied to your heel and the test is completely noninvasive and radiation-free. It is also quite reasonable in cost and can be a good alternative to establish a baseline or indicate whether further testing is necessary. The QUS received FDA approval last year and availability may therefore be limited.
Another option is a Quantitative Computed Tomography test (QCT). This can also be used if you have titanium in the area is scanned by the DXA, such as hip replacements or hardware along your spine from back surgery. A regular CT scanner with bone density software is used in this test. It has the benefit of being able to read around the titanium, although it may overestimate your score. However, CT scans expose you to a very high level of radiation and are more expensive than the DXA scans.
Talk to your doctor about the different options available to you and what would give you the best result giving your individual needs and limitations.
Prevention is Key
With so many potential risk factors there can be with RA, you might feel a bit daunted by what it will take to prevent or manage osteoporosis. However, there are a number of things you can do. A diet rich in calcium and vitamin D is an essential part of making sure your bones are as healthy as possible. Weight-bearing exercise is also crucial in building strong bones and this can be a challenge when you have RA. You don't have to do a high-impact exercise for it to have an effect. Lower impact types of exercise such as walking, tai chi and walking in shallow water can also be effective in building your bone. The key is to do what you can. Talk to your doctor about the best exercise for you, or ask for a referral to a physical therapist who can help you design an exercise program that protect your joints.
This post is part of my series on preventative health care for people living with RA. Previous posts include Pap tests and mammograms, endoscopy and colonoscopy and heart health.
Lene is the author of the award-winning blog The Seated View