Diagnosing and managing osteoporosis in primary care

Medical Tribune August 2008 P15-16

Osteoporosis affects around a third of women aged 60 – 70 and two thirds of those aged 80 and above. The condition also affects men – approximately one in five of whom will suffer an osteoporosis-related fracture above the age of 50. Osteoporosis carries a significant burden in terms of hospitalization for fractures, and patients will typically experience increased morbidity, disability, and a reduction in independence.

Diagnosis

Osteoporosis is a silent epidemic, and overt signs are usually absent until a patient presents with a fracture. This is likely to be a fragility fracture caused by relatively low trauma – a sign that the bones have become weakened. Compression fractures of the vertebrae are a common presentation, while other types include Colles’ fractures of the wrist and hip fractures, both of which typically result from a fall.

There are several risk factors for osteoporosis that general practitioners (GPs) should be aware of, such as increasing age, frailty, a personal history of fractures and a family history of fractures (particularly on the maternal side). Loss of height is also common among patients, and suggests that the vertebrae are collapsing. Back pain may also be present – often signifying that the patient has an undiagnosed compression fracture.

It should also be noted that osteoporosis in men tends to have a later age of onset than in women. Consequently mortality from fractures is twice as high for men, so it is important that GPs retain a high suspicion for osteoporosis among their elderly male patients.

GPs can also encourage their elderly patients to use the Osteoporosis Self-Assessment Tool for Asians, which is applicable for post-menopausal women of Asian descent. This can help to identify patients at high risk, who can then visit their doctor for screening and further assessment.

The gold standard for diagnosis of osteoporosis is a bone mineral density (BMD) scan using dual energy x-ray absorptiometry, with osteoporosis defined as a T-score of minus 2.5 or lower. In the absence of any other cause, a fragility fracture can also be considered as a diagnosis for osteoporosis. Patients should also receive the relevant x-rays to fully document their fractures. It can be challenging for GPs to pinpoint osteoporosis in patients who have not experienced a fracture, as some patients might find the cost of the tests prohibitive. Access to BMD scanners can sometimes be problematic

Practice Guidelines

The Ministry of Health (MOH) in Singapore is currently revising its guidelines for osteoporosis, which were last published in 2002. The new version is expected to be available later this year. The Academy of Medicine of Malaysia also has its own guidelines for osteoporosis, the second edition of which was released in 2002.

Various guidelines and recommendations are also available from the International Osteoporosis Foundation (IOF) website, including IOF-endorsed guidelines published in 2008 by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). This comprehensive 30-page document covers the diagnosis and management of the condition in postmenopausal women.

Recommendations and other helpful documents for the secondary prevention of osteoporosis are available from the National Institute for Health and Clinical Excellence (NICE), UK.

Treatment

There are many factors to consider when treating osteoporosis, and it is important to decide carefully on an appropriate strategy for each patient before proceeding with treatment.
Drug treatments are available but the cumulative costs can be formidable. The first decision physicians should take after making a definite diagnosis of osteoporosis, therefore, is whether or not to treat the patient. This decision should be based on the patient’s 10-year fracture risk, which can be calculated using IOF guidelines. A 65-year old at low fracture risk, for example, might not warrant the same treatment approach as a high-risk 85-year-old. In some cases it may be best to postpone treatment following diagnosis, monitor the patient closely and review the decision at a later stage.

Before initiating drug therapy it is important to obtain a BMD scan. This will provide a baseline value for comparisons, so that the long-term efficacy of therapy can be monitored.

Bisphosphonates, such as alendronate and risedronate, are the first-line therapy for patients who do merit drug treatment. Doctors should make their patients aware that these drugs must be taken according to certain instructions. Tablets should be taken on an empty stomach first thing in the morning, and the patient should refrain from eating for an hour afterwards or consuming any caffeine-containing drinks or milk products in this time. Failure to do so can render the tablet ineffective – which may be an explanation in cases where BMD is not improving. Elderly patients may also forget to take the drugs, or take them but forget that they have done so and lie down shortly after, which can cause painful esophagitis.

Other drug treatments include strontium ranelate, raloxifene and parathyroid hormone injections (such as teriparatide).. Annual injections of zoledronic acid, a form of bisphosphonate, have also been shown to reduce the risk of fractures and the data in support of this option are promising. The injection can be expensive, however, and some patients might prefer treatments that spread the cost out over the year.

GPs should prescribe calcium supplements for patients who are deficient, which can be a common problem in Asian countries where dairy consumption is low. The recommended intake at different ages can be found in the guidelines. Boosting calcium levels can also serve as a prevention strategy, and GPs should also encourage the use of supplements in non-osteoporotic elderly patients who are at high risk.

Lifestyle management is also a key aspect of treating osteoporosis in the primary care setting. Ill-health can lower general nutrition, leading to further reductions in calcium levels, so a healthy diet should be promoted for all cases. Osteoporotic patients should be advised not to drink or smoke, and should also be encouraged to perform weight-bearing exercises at least three times per week for 50 – 60 minutes at a time in order to improve strength and co-ordination and reduce bone loss.

Disease management tools

Elderly patients living in the community have a roughly 30 percent chance of falling in a year, and fall prevention strategies are an important tool for reducing the risk of fractures among those with osteoporosis.

Falls typically result from a combination of several underlying causes. Risk factors such as poor gait, eyesight, and neurological comorbidities should be addressed where possible, which may require collaboration between different medical disciplines. Psychologically-altering medications such as antipsychotics and sleeping tablets can also increase the risk of falls, and may need to be adjusted accordingly.

Physicians may also need to consult with occupational therapists and physiotherapists, and in some cases might choose to encourage patients to make modifications to their home environment. Suggestions can include improving lighting, anchoring carpets and rugs, securing loose wires and applying non-slip mats to stairs and bathroom floors.

Further information on osteoporosis and home care solutions can usually be obtained from specialist centers and clinics, and GPs should refer their patients onwards for further advice and treatment where appropriate.

Conclusion

Managing osteoporosis in the primary care setting begins with an accurate diagnosis. GPs should remain vigilant for patients who have a history of fragility fractures or falls, and remember that men are also at risk for the condition. Once osteoporosis is identified, doctors should choose carefully from the range of available treatment options and select the strategy that is best suited to the patient.