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 A Major Health Problem
Osteoporosis causes bones to become so porous and fragile that they break very easily. This is a disease which affects people of all ages and is now recognised as a major public health problem, causing pain, disability and premature death. Urgent action is needed to halt the increasing numbers of fractures it causes - more than 150,000 each year. In the UK, 1 in 3 women and 1 in 12 men are affected by it, breaking bones in the wrist, spine and hip. There are a number of factors that place men and women at higher risk of the disease including physical immobility and treatment with corticosteroids. Osteoporosis and Treatment with Steroids Corticosteroids (cortisone-like drugs often loosely referred to as 'steroids') are widely used in medicine. They have saved lives, prevented blindness and revolutionised the treatment of distressing skin disorders, multiple sclerosis and rheumatic diseases. But they have brought their own complications one of which is the bone disease osteoporosis. Long-term Treatment Whether given as pills or by injections or made up as ointments, all the currently available corticosteroids preparations (if given long-term in high enough dosage) can result in osteoporosis. This is due to corticosteroid action on cells called fibroblasts and osteoblasts which make the important collagen fibres and the micro-crystals of bone material attached to them. Like the steel bars in reinforced concrete, the fibres provide the strength and the mineral gives bone its hardness and rigidity. Bone is particularly rich in collagen fibres but corticosteroids shut down the ability of fibroblasts to make these fibres. As a result bones become less dense, more brittle and liable to fracture very easily. Short-term Treatment When the drugs are taken for a few days or a few weeks to help you 'ride over' a short-term illness or acute episode, such as those that are caused by infections or that occur in MS, they will not result in osteoporosis. If you are currently taking high amounts of corticosteroids it is important that the dose is slowly and carefully reduced. It is unsafe to stop corticosteroid drugs suddenly as the disease being treated may come back with a rush and the patient may have no effective response to the resulting deterioration. You may find that your doctor would make this slow reduction by changing the strength of some of your tablets so that over time the desired tapering down effect is achieved. The search continues for a more 'patient-friendly' drug and one being developed, called Deflazacort, is thought to retain the desired anti-inflammatory action of the existing drugs whilst being more 'bone-friendly'. It is not yet licensed in this country but it may be possible for a GP to provide it on what is known as a 'named-patient' basis, if he or she believes it might be suitable in a specific case. Reducing the Risk If you are taking corticosteroids or have been treated with them in the past, what can you do to reduce the risk of osteoporosis? Regular exercise within your personal capabilities, a calcium-rich diet and not smoking are key lifestyle steps that can be taken to maintain strong, healthy bones. Exercise may prove difficult for someone with arthritis, MS or other physically disabling condition but swimming and exercising in a warm pool can be very helpful in regaining some mobility. Hormone Replacement Therapy (HRT) HRT is strongly recommended for women at or after the menopause who are taking corticosteroids. HRT provides the oestrogen required to prevent the rapid loss of bone following the menopause when the ovaries no longer produce this female sex hormone. Taking HRT for 5-10 years can reduce the risk of painful fractures due to osteoporosis by some 60%. Approaches to Limitation and Prevention The dose of corticosteroids could be reduced to the minimum that is adequately effective in tackling the presenting condition, to minimise any harmful side effects. Where possible, as alternative to oral steroid could be used such as topical steroid inhaler or local injections which target tissues more directly and bypass general systematic distribution within the body. Another alternative to long-term corticosteroids is to use short-term, high dose 'booster' courses of megapulse intravenous infusions which will be followed by a period free of steroid intake. At present, only Deflazacort appears to be able to reduce inflammation without having adverse effects on bone. Counteractive Therapies Research on calcitonin, bisphosphonates, HRT and calcitriol shows that they are effective in preventing bone loss associated with steroid osteoporosis. It is suggested that by starting this type of preventative therapy at the onset of steroid treatment many fractures could be prevented. If in Doubt Raise the Question A conference in 1995 clarified various aspects of steroid treatment for a whole range of conditions, not just MS. Some of the other conditions need very high doses and for those patients the risk is real. What makes it appropriate to report these matters in relation to multiple sclerosis is that some people have restricted levels of activity and cannot take much physical exercise. It is understood that continuous inactivity, unavoidable as that might be, may increase the risk of osteoporosis in men as well as women. Where there is an opportunity to reduce or avoid the risk, it has to be good news. Multiple Sclerosis is often treated with courses of steroids which last a few days or perhaps weeks. Subject to dose levels, these are unlikely to be a serious threat but people should discuss their treatment with the GP about any possible enhancement to the risk of osteoporosis. To be fully confident, the question of counteractive therapy could be raised. Your doctor will know that he or she can obtain more detailed information on research results and therapeutic intervention from the National Osteoporosis Society and their medical advisers. Steroids as Balancing Agents Glucocorticoids influence many hormonal systems - the metabolism of carbohydrates, water balance, immune reaction, inflammatory response and insulin sensitivity, all systems which may be mobilised during injury, infection or trauma of any type. The function of glucocorticoids is to counterbalance these systems so that the body does not suffer from its defence structure being over-stimulated. Too much circulating glucocorticoid and our defence reactions do not respond so, for example we cannot kill micro-organisms, repair tissue damage or rebuild new bone correctly. Too little glucocorticoid and our defence reactions and our immune and inflammatory responses gain the upper hand. These substances therefore can be seen to play a vital role as balancing agents in the body. When used as a treatment for various disorders it is therefore important to look for steroids that can be selectively delivered, or look for dose regimes which minimise the types of response we do not want if this balance is not to be overly disturbed. Testing for Steroid Action One test is to put topical steroids on the skin to see if it blanches. This normally takes 6 to 18 hours to produce an effect. People who are resistant to steroids do not develop this blanching response. In those people who are very susceptible to them the response is enhanced. It is a simple, non-invasive test that is easy to measure. The Scale of the Problem of Corticosteroid Osteoporosis It is feared that fractures resulting from steroid use may occur in a large number of patients especially as very few are given any therapy to prevent bone loss. Bone loss can occur with this kind of treatment because the bone building cells are suppressed and calcium absorption from the gut is inhibited, most marked in the early stages of treatment. GP's must give a clear message to their patients that such treatments may result in osteoporosis and be aware of this themselves and of the counteractive therapies that can be offered. In brief: Up to 33% of people treated with long-term or high dose of corticosteroids are at risk of osteoporosis. Corticosteroids are mainly prescribed by GP's. The possible side effects of corticosteroid treatment, including bone damage, must be explained to patients before treatment commences. Bone loss resulting from steroid treatment can be reversed, if caught in time. Very few people are given counteractive therapy to halt bone loss at the start of treatment. Most bone loss occurs in the first six months so therapy is vital at that time. People being treated need to be regularly reviewed to assess the dose required and the effect on bone health.
Taken from a paper written for MSRC by the National Osteoporosis Society's Information Officer. Information and Advice If you are concerned about your risk of osteoporosis, consult your GP or write to the Osteoporosis Society's Helpline for information and advice. Further Information Contacting The National Osteoporosis Society The National Osteoporosis Society,
Camerton,
Bath.
BA2 0PJ Telephone: 0845 130 3076 (Monday to Friday 10am to 4pm) Email: info@nos.org.uk Website: http://www.nos.org.uk © Multiple Sclerosis Resource Centre
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