Managing osteoporosis in older people with fractures

The World Health Organisation has compared osteoporosis to hypercholesterolaemia and hypertension, which are both asymptomatic conditions until an important tissue damaging event such as myocardial infarction or cerebrovascular accident occurs. Bone fracture, especially fracture with minimal trauma, is the feared endpoint of osteoporosis. Fractures of the wrist, hip, and vertebrae are well recognised consequences of the loss of mechanical strength that occurs as bone thins. These fractures are common in many countries, particularly among elderly people, and the burden they produce is expected to rise enormously in the next few decades. Pal’s article in this issue (p 500) underscores the hesitancy with which doctors currently approach this silent epidemic of osteoporosis.¹

The cost of osteoporosis is huge in both human and economic terms. Data on patients with hip fractures are the most complete, since nearly all such patients require hospital admission for treatment, whereas those with vertebral and wrist fractures do not, making data collection difficult. Although not all of Pal’s patients necessarily had an osteoporotic fracture, those with hip fracture might consider themselves lucky to be able to participate in his questionnaire study since a third of patients with osteoporotic hip fracture die as a direct result of their fracture. Awareness is growing about the morbidity associated with osteoporosis: a further third of patients require continuing institutionalised care and many of the remaining third suffer a significant loss in their independence and ability to perform daily tasks.² How much suffering occurs as a consequence of loss of vertebral height, with persisting mechanical back pain and other postural consequences, remains unknown.

The economic cost is also difficult to establish, but osteoporosis is undoubtedly an expensive business. In New Zealand (population 3 million) the combined total cost for caring for women in the two years after a hip fracture in 1994 was NZ$66 637 355 (£22 000 000).³ The estimated world wide annual cost of hip fracture alone will reach US$131.5bn (£82 000m) in the year 2050.⁴

Despite increasing media attention, it is disappointing that only 34 of 82 of the patients with recent fracture surveyed by Pal were aware of the condition of osteoporosis and that this knowledge came from doctors in only 29%. Effective treatments are available; these not only increase bone mineral density but also significantly reduce fracture rate. These treatments have been shown to be effective in all age groups. Bone mineral density increases of around 6% a year, as measured by dual energy x ray absorptiometry (DEXA) scanning, are achieved with agents such as oestrogen, vitamin D analogues, and bisphosphonates. All these have been shown to reduce the fracture rate by around 50%. There is also an increasing appreciation of the prevalence of vitamin D deficiency in elderly people, particularly those in institutional care.⁵ Measurement of serum 25-hydroxyvitamin D concentrations should be routine in elderly people, with vitamin D replacement therapy offered as necessary.

A major difficulty in managing patients with recent fracture and in identifying underlying osteoporosis is the availability of bone density measurement. Dual energy x ray absorptiometry has become the international standard tool, but it is not widely available, particularly to patients who cannot afford the test outside a publicly funded system. This is akin to trying to manage patients at risk of myocardial infarction or stroke without access to serum cholesterol concentrations or blood pressure measurements. Dual energy x ray absorptiometry can identify patients at high risk and allow prioritisation for treatment, thereby increasing the cost benefit ratio. In patients with a fracture a baseline measurement is required not so much to establish the diagnosis of osteoporosis as to document a baseline level with which to monitor treatment efficacy. The non-response rate to treatment seems to be about 15%, making progress monitoring essential. Without access to dual energy x ray absorptiometry management of osteoporosis must be speculative.

Papers p 500