OSTEOPOROSIS

What is it?

Bone is made up of both hard tissue, which gives it strength, and the much softer and weaker marrow. In osteoporosis the amount of hard bony tissue is reduced, and the bones become more fragile.

Who gets it?

Everyone loses bone as they get older and eventually everyone's skeleton will become weak enough to be at risk of fracture. However, after the menopause, the loss of oestrogen (the female hormone) is associated with very rapid bone loss, which makes elderly women particularly likely to suffer from osteoporosis. This problem is more serious in women who pass through the menopause relatively early (under 45 years), or who have had their ovaries removed surgically.

Osteoporosis is also more common in many women who had irregular periods, or where periods stop for a time before the menopause. Osteoporosis can also occur with:

• some other medical condition (e.g. thyroid disease, some gut disorders)
• treatment with some drug (especially steroids)
• poor nutrition
• smoking
• heavy alcohol consumption
• immobilisation and lack of exercise
• families with a history of osteoporosis
• slight build

It is not possible to replace the bone that has been lost. However, it is possible to stop further bone loss and prevent the condition getting worse.

What are the symptoms?

The weakness of the bones brought about by osteoporosis leads to increased risk of fracture. This occurs particularly at the wrist, in the vertebral bodies in the spine, and the hip. In addition to causing pain, fractures in the spine can cause loss of height and curvature (Dowager's hump).

The most serious fracture is that of the hip. This occurs in 20,000 people (mainly women) per year. It invariably needs treatment in hospital, often involving an operation, and many patients die as a result of this injury. It has been estimated that this fracture costs the country £500 million a year.

Unless you have already suffered from fractures, it is unlikely that osteoporosis will produce symptoms. There are a number of different machines available which measure the amount of bone in the skeleton.

How is it treated?

The best method to prevent osteoporosis in women is hormone replacement therapy (HRT). To be most effective, this should be given as soon as possible after the menopause, and be continued for at least five years.

Although calcium has no effect on the rapid bone loss that occurs at the menopause, it can reduce the gradual loss which occurs in both sexes throughout life. It is important that patients with osteoporosis have an adequate calcium intake of at least 1g or preferably 1.5g per day. The usual daily dietary intake is only 0.5g; the extra calcium can be obtained by eating extra dairy produce or by taking calcium supplements.

The following daily allowances for different age groups are recommended:

• young children, 800mg/day
• teenagers, 1200mg/day
• women aged 20 to 40, 1000mg/day
• men aged 20 to 60, 1000mg/day
• pregnant and nursing women, 1200mg/day
• pregnant and nursing teenagers, 1500mg/day
• women over 40 (i.e. before, during, and after the menopause) without HRT, 1500mg/day
• women over 40 with HRT, 1000mg/day
• men and women over 60, 1200mg/day

At the same time it is important to ensure that general nutrition is good. This also applies in the adolescent years, to ensure that adequate bone is laid down in the skeleton.

It is important to remove or treat as many of the risk factors of osteoporosis listed above as possible. Physical activity, as well as helping the heart and lungs, has also been shown to increase the strength of the skeleton. Other treatments such as bisphosphonate and fluoride are under investigation in specialist units.

In addition to trying to prevent the loss of bone due to osteoporosis, it is also important to try to prevent the falls that occur which lead to fracture. To do this:

• maintain fitness, balance and alertness
• regular exercise
• mental stimulation
• minimise sedation and other medication
• reduce alcohol intake
• consider walking aids if required
• attend to the feet regularly

In addition, maintain vision and hearing through regular check-ups with the doctor and optician. For general safety, avoid hazards (e.g. low obstacles, loose carpets, slippery floors, dangerous stairs, poor lighting, bath hazards, inadequate hand holds, slippery and uneven kerbs).