Osteoporosis: The risk and management of fragile bones

A few years ago, as part of Osteoporosis Week, I was offered the chance to have a free bone density test. I jumped at the chance – not least because I was convinced it would affirm my belief that I had the strongest bones on the planet. After all, I am a big fan of dairy products, walk at every opportunity and don't smoke. Sadly, I was proven wrong, and the test confirmed that I am at significant risk of developing osteoporosis as I age.

Osteoporosis (OP) is a condition that causes our bones to become increasingly thin and weak. As our bones become more fragile, the risk of fractures greatly increases. OP is slowly progressive, and "silent" – there are usually no symptoms at all until the first fracture occurs.

OP affects around 50% of women over the age of 60, and 33% of men in this age range too. Risk factors include:

·    Age – incidence rises with age

·    Previous osteoporotic fracture – most commonly the hip, wrist or spine

·    A family history of OP

·    Early menopause – the drop in oestrogen levels for women after the menopause contributes significantly to the risk of OP; so the earlier you go through the menopause, the greater your risk

·    Petite build – a BMI of under 19 is thought to increase your risk of OP

·   White/Asian ethnicities

·    Low levels of dietary calcium

·    Smoking

·    Heavy use of alcohol

·    Immobility – it is well recognised that regular weight-bearing exercise helps strengthen your bones, and the reverse is true too – periods of immobility, even if they are temporary, can lead to a dramatic reduction in your bone density

·        Less than 30 minutes of sunlight per day

·        Long term use of steroids, e.g. prednisone in asthmatics.

As a result of OP, around 4000 people will fracture a hip every year in New Zealand. Of those 4000, a horrifying 25% will die as a result, and approximately 1/3 will never live independently at home again. The estimated cost of OP each year is over $300million.

Unfortunately, once it is fully established, OP can be difficult to treat – medications aim to preserve bone density, but may not always be able to improve it. However, preventing OP before it develops is possible, and is a much more desirable option.

Identifying "at risk" people can be done using bone density imaging, called a DEXA scan. This test tells if you have normal bone density, low bone density (osteopenia, which is a precursor to OP) or osteoporosis. The lower your bone density, the greater the risk of breaking a bone. A DEXA scan can help you and your doctor:

·        Find out if you have OP before you break a bone

·        Predict your future risk of breaking a bone

·        Monitor your bone density over time

·        Assess how well an osteoporosis medication is working.

The scan is simple, pain-free and takes less than 15 minutes. It takes only tiny amounts of radiation (about the same as you would absorb from the environment in an average day), and is a highly precise test. The best results are obtained if the same machine is used each time you need a DEXA scan.

If a DEXA scan shows you are at risk of OP, your doctor will talk to you about appropriate management. Depending on the level of risk, the options might include:

·        Lifestyle changes – altering diet, exercise, smoking status and alcohol intake can improve your bone density

·        Vitamin D – using vitamin D supplements, especially over winter, can have a positive effect as well, especially in people who don't get much daily sunlight exposure

·        Falls prevention – if you have OP, reducing your risk of falls (via programmes such as Tai Chi or Pilates) is an important part of management

·        Medication – oral or intravenous drugs are available that can maintain or even improve your bone density.

If you fall into a "high risk" category, or have already had a "low-impact" fracture (i.e. a broken bone after a fairly minimal injury), I would strongly suggest you consider getting a bone density scan. Unfortunately, at present, it is almost impossible to get a free scan – something I would dearly love to see the Ministry of Health reconsider. The cost is around $150 – unaffordable for many - but when compared to the $300 million it costs the government to currently treat the effects of OP, I would have thought the cost-benefit ratio of a funded, targeted screening programme was hard to argue.

For more information, or to book a DEXA scan, talk to your doctor, or visit www.osteoporosis.org.nz .