Can osteoporosis be prevented?

Post-menopausal women who start hormone replacement therapy (HRT) soon after the menopause substantially reduce their risk of osteoporosis. In addition, many of the disruptive symptoms of the menopause (such as flushing, depression, irritability, palpitations and tiredness to name but a few) are lessened. It also helps to restore the protective effect on the cardiovascular system that HRT has, lost to women after the menopause. HRT is still useful if commenced late on but it may not be as well tolerated in older women.

Lifestyle changes apply to both sexes. Taking regular exercise, reducing alcohol and caffeine intake and stopping smoking reduce the risk of osteoporosis, as well as providing a host of other health benefits. Ensuring an adequate calcium and vitamin D intake also helps to maintain bone mass.

Screening

It is clear that osteoporosis is a major problem, affecting a large number of people with serious consequences. The inevitable conclusion is therefore that this costs the NHS a great deal of money. Why therefore do we not have a national screening program designed to detect this disease early to prevent people going on to develop complications which cost so much to treat?

The answer lies in the difficulty in diagnosing osteoporosis. As described elsewhere, bone mineral density is measured using the DEXA technique which involves a large, expensive, immobile machine scanning the spine and hip. It would be too expensive to get people to come in to the specific centres that have such machines for screening (in contrast to the newly developed breast screening units with cheaper simple X ray machines).

Portable machines have been developed to measure bone mass in peripheral bones (e.g. in the heel and forearm). These are cheaper and portable. However there are several problems. Bone mineral density varies throughout the skeleton and the way in which this varies is in itself variable between different people, particularly in the younger population. Studies have shown a significant variation in the diagnosis of osteoporosis when measuring at central vs peripheral sites, suggesting the potential for large scale mis-diagnosis. Until a more robust method can be found this technique will be of limited use.

In addition there is considerable variation in the absolute values of bone mineral density measured by different machines. This obviously needs to be addressed if such devices are to be used in widespread practice.

The conclusion is therefore that we need to develop cheap portable DEXA machines that are standardised with each other. In addition, which sites should be scanned to give the best predictive value must be determined before screening can be postulated. Unfortunately we are still some way from completing these tasks.