Lupus Site - a guide for lupus patients and their families

Many lupus patients take steroids, and one of the major side effects is osteoporosis. This article is based on a talk given to the Lancashire & Cheshire Lupus Group, by Dr Kilmiuk, consultant rheumatologist.

Osteoporosis is a decrease in bone mass, which causes an increased susceptibility to bone fractures. It is most common in postmenopausal women, but patients who are on steroids are at a greater risk at any age.

However steroid treatment in lupus is often lifesaving, and shouldn't be stopped just because there is an increased risk of osteoporosis. There are things that can be done to reduce your risk of getting osteoporosis, which we will look at later.

The definition of osteoporosis is a condition that affects the skeleton, with thinning of the bone, accompanied by an architectural change in bone structure.

The most common sites of fracture in osteoporosis patients are the vertebrae, hip and wrist. Although any bone in the body can be fractured as a result of osteoporosis. In the UK, there are 250,000 fractures to due osteoporosis annually, 50,000 of which are hip fractures. Hip fractures are the ones with the most severe consequences, and are most associated with mortality. If you have one vertebral fracture, there is a 50% risk that you will have another within a year. If you sustain more than one vertebral fracture, curvature of the spine can occur. 20% of those that suffer hip fractures will die due to complications.

Corticosteroids are live-saving drugs, and are used widely for many conditions, including lupus. An estimated 140,000 people in the UK are taking steroids, and have double the risk of a hip or vertebral fracture due to osteoporosis. 80% of those people don't take any preventative treatments. You need to take over 7.5mg of prenisone/prednisolone a day for more than six months before it has an adverse affect on the bones.

Throughout our lives, our bones are alive and have a blood supply, they may stop growing, but they are still living. We replace our whole skeleton every seven years! Cells in the body eat holes in bones, which are usually replaced by new bone.

However, in osteoporosis more bone is eaten away than is replaced, and we are left with a lower bone density. In our early 20s we stop growing, and the skeleton goes through a resting phase. The in our late 30s, we slowly start to lose bone. When we reach the menopause, our oestrogen levels drop, and there is a rapid decline of bone mass. Then, after 10 years, the rate of bone loss evens out and is equal to the level of bone loss in men.

Risk factors for osteoporosis include: being female; being Caucasian; a family history of osteoporosis; smoking; heavy alcohol intake.

So how is osteoporosis diagnosed? X-rays can't measure bone density, so a DEXA machine is used. DEXA machines don't deliver high-dose radiation like x-rays do, and they can measure the bone density. There is no need to scan the whole body, only a small part, as bone density should be the same throughout the body. The most useful areas to scan are the lumbar spine & the hip.

The key to preventing osteoporosis is to enhance the amount of bone we have in the growing period. We can then afford to lose the bone when we reach the menopause. It is better to start preventative measures when we are children, but later is better than never! You should eat a good balanced diet that includes plenty of calcium-rich foods. Dairy produce is the best source of calcium, and skimmed milk contains as much calcium as whole-fat milk. A good vitamin D intake is also needed, as vitamin D helps the body to absorb calcium. Exercise is also very important, bones need constant weight-bearing exercise.

HRT can help, as it replaces oestrogen, which in turn stops the bone loss. After 10 years of taking HRT there is an increased risk of breast cancer, although this is thought to be an acceptable risk compared to the high possibility of a fatal bone fracture. Plant derived oestrogens do exist, but have not been proven to provide enough oestrogen.

The use of HRT in lupus patients is controversial, as oestrogen is thought to play a part in triggering lupus flares. However, all HRT does is replace the natural level of oestrogen in the body that was there prior to the menopause. So you have no more oestrogen in your body than you did before the menopause. There is no scientific evidence to say that HRT makes lupus worse.

A group of drugs called Bisphosphonates can be used to treat osteoporosis & improve bone mass. One such drug is called alendronate.