The diagnosis and management of osteoporosis have advanced in the last decade. Many clinicians practising today were not taught about bone cell biology, the epidemiology of osteoporosis or the methods of treatment. Consensus groups, meetings and conferences to sort out issues in osteoporosis management have become a world-wide phenomenon.
The Australian consensus group met in Canberra in October 1996.1 The conference format involved experts in the prevention and management of osteoporosis presenting their views to a consensus panel which consisted of other experts and representatives of various health care provider groups. The consensus panel then selected the views it liked and incorporated them into a set of responses to specific questions. The result is a document that is a bit like the 'Hitch Hikers Guide to the Galaxy': having got the answers you wonder a bit about the questions. However, it is possible to extract useful and detailed advice in a variety of areas.
There was agreement that osteoporosis is a major health problem for Australians, especially in old age. It affects 60% of women and 30% of men over the age of 60. The principal impact is on quality rather than quantity of life. Although hip fracture kills as many women as breast cancer, it cripples many more. What can be done? As opposed to the situation only a few years ago, there are now a number of effective treatments that reduce future fracture rates. They include calcium, oestrogen, bisphosphonates and calcitriol, so there is now no place for not actively managing the problem in your patients.
The questions then are:
– are there groups of patients that should be the targets of intervention?
– how should their treatment be individualised?
For premenopausal amenorrhoeic women, the answers included adequate nutrition and oestrogen replacement, if necessary. The answers for early postmenopausal women were oestrogen and calcium for those with low bone mass. For the older postmenopausal women, the answer was oestrogen if they tolerate it and bisphosphonates (etidronate or alendronate) or calcitriol if they cannot. Calcium supplements are required with oestrogen and bisphosphonates.
In men, secondary causes of osteoporosis, especially hypogonadism, were emphasised as common problems. In the absence of clear-cut causes, other treatments such as bisphosphonates and calcitriol may be effective. Research in this area was supported.
In older housebound or institutionalised patients, vitamin D deficiency, which is rampant in nursing homes, should be treated with ergocalciferol as well as calcium. In both sexes, specific causes such as hypogonadism, alcoholism and myeloma should be considered and treated. Finally, glucocorticoid-treated patients are at high risk and need preventive treatment with sex steroids when deficient, and calcitriol or bisphosphonates when not.
Treatment should be seriously considered for patients with fractures of the spine, arms or legs due to falls or smaller degrees of trauma (minimal trauma fractures). These patients are at very high risk of more fractures in the future. Similar treatments should be offered to patients with low bone mass if they wish to have a higher degree of protection against future fracture than that provided by calcium supplements alone.
When to treat
Implicit within the consensus document was the concept that the treatment decision is determined by the future fracture risk. If the risk is low, simple lifestyle interventions are appropriate. If the risk is high, more aggressive interventions are appropriate.
Calculation of risk, as always, is a complex process. In addition to bone density, the panel suggested that increasing age, family history, falls and low body weight were other factors which should be considered, but did not explain how these factors should be added together. The panel supported the importance of prior fracture in increasing future risk, the implication being that all subjects with minimal trauma fractures should be considered for treatment to prevent further fractures.
Bone densitometry2 is not the only way to make treatment decisions. It helps to stratify risk: the lower the bone density, the higher the risk. The risk calculation used in the consensus document relates fracture risk to the bone density of subjects in their twenties. For each standard deviation below the mean of these young normal controls, the relative risk approximately doubles (the normal range is the mean plus or minus two standard deviations), so when a patient is getting to the lower part of the young normal range, their risk begins to rise unacceptably. Most 70 year olds are below this young normal range; the question is whether they all need medication. The answer depends on what degree of fracture protection they want with what degree of adverse effects.
The panel supported lifestyle advice on adequate nutrition, increased exercise and avoidance of skeletal toxins (cigarettes and excessive alcohol) as playing a role in osteoporosis prevention. Increasing calcium intake to a total of 1.5 g/day in oestrogen-deficient women was supported, as was exercise in pre-pubertal children and early adulthood. Exercise may play a role in a multi factorial approach to falls prevention. However, these interventions should not be overrated as the only answers to the osteoporosis problem in the absence of community-based studies to support them.
The panel considered that we need further research. Basic research on the causes of osteoporosis, anabolic agents and the mechanisms of genetic effects should be supported. Research on better ways of assessing risk, perhaps using genetic markers or new methods of measuring bone strength such as ultrasound, was also supported. More studies on community-based lifestyle interventions, including dietary and exercise studies, and new and better treatment regimens of safe and effective drugs, individually and in combination, also made the list.
The contributions to overall thought and the approach presented in the consensus statement1 are second to none and should provide a viable blueprint for many countries, including Australia, to follow for some years to come.
Individual practitioners should read this document as a logical and well-argued basis for medical practice in the area into the twenty-first century.
- Consensus statement. The prevention and management of osteoporosis. Australian National Consensus Conference 1996. Med J Aust 1997;167(Suppl):1S-15S.
- Wark JD. Bone density measurement. Aust Prescr 1992;15:62-5.