This information is for anyone with axial spondyloarthritis (axial SpA) including people with ankylosing spondylitis (AS)
People with axial SpA are at higher risk of osteoporosis
Osteoporosis is a condition that weakens bones, making them fragile and more likely to break.
Recent research shows that axial SpA patients have a higher prevalence of both osteoporosis and osteopenia. High disease activity and hip involvement are risk factors for bone loss in axial SpA.
What is osteoporosis?
During childhood, bones grow and repair very quickly, but this process slows as you get older. Bones stop growing in length between the ages of 16 and 18, but continue to increase in density until you’re in your late 20s. You gradually start to lose bone density from about 35 years of age. Women lose bone rapidly in the first few years after the menopause.
Losing bone is a normal part of the ageing process, but for some people it can lead to osteoporosis and an increased risk of fractures. People with inflammatory conditions such as axial SpA are at higher risk of developing osteoporosis.
Osteoporosis is often referred to as the ‘silent disease’ because, although almost 3 million people in the UK are estimated to have osteoporosis, few know they have it until they break a bone.
Your GP can use an online programme such as the Fracture Risk Assessment Tool to help assess your risk of fracture. They may also refer you for a bone mineral density scan, known as a DXA scan.
A DXA scan is a quick, safe and painless procedure that usually takes about five minutes, depending on the part of the body being scanned. The scan measures your bone mineral density and compares it to the bone mineral density of a healthy young adult and someone who’s the same age and sex as you.
The difference between the density of your bones and that of a healthy young adult is calculated as a standard deviation (SD) and is called a T score. A T score of:
- above -1 SD is normal
- between -1 and -2.5 SD is defined as decreased bone mineral density compared with peak bone mass
- below -2.5 is defined as osteoporosis
There are medications that can help strengthen bones.
- Calcium and vitamin D supplements
- Bisphosphonates slow the rate bone is broken down in your body. This maintains bone density and reduces the risk of fracture. There are a number of different bisphosphonates, including alendronate, ibandronate, risedronate and zoledronic acid. They’re given as a tablet or injection
- Selective oestrogen receptor modulators (SERMs) are medications that have a similar effect on bone as the hormone oestrogen. They help to maintain bone density and reduce the risk of fracture, particularly of the spine. Raloxifene is the only type of SERM available for treating osteoporosis. It’s taken as a daily tablet
- Parathyroid hormone (teriparatide) are used to stimulate cells that create new bone (osteoblasts). They’re given by injection. They can increase bone density but are only used where bone density is very low and when other treatments aren’t working
- Hormone replacement therapy (HRT) has been shown to maintain bone density and reduce the risk of fracture during treatment.
How can I help myself?
- Exercise. Your bones will be stronger if you do regular weight-bearing exercise. This is any kind of physical activity where your feet and legs bear the weight of your own body. Brisk walking is ideal. For most benefit you should exercise regularly, aiming for 30 minutes at least 5 times a week. Muscle strengthening exercises are also important as they will help give strength to the supporting muscles around bones
- Food and diet. Calcium is important for maintaining strong bones. Adults need 700mg a day, which you should be able to get from your daily diet. Calcium-rich foods include leafy green vegetables, dried fruit and yoghurt. Vitamin D is also important for good bone health. Your body needs a good supply of vitamin D in order to absorb the calcium you are eating and drinking. Vitamin D can be found in eggs, milk and oily fish. Vitamin D is also made by your body after exposure to the sun
- Smoking and drinking. Smoking is associated with an increased risk of osteoporosis. It’s another good reason to try to give up. Enjoying the odd drink is fine but drinking too much alcohol can damaging your bones and increases your risk of fracture
Learn more about osteoporosis and axial SpA
With Sarah Leyland, Specialist Osteoporosis Nurse and Clinical Advisor to the Royal Osteoporosis Society
The Royal Osteoporosis Society have lots of resources to help you manage osteoporosis and look after your bones.
You can also contact their specialist nurse-led Helpline on 0808 800 0035 (0900-1300 and 1400-1700, Monday to Friday).