What is osteoporosis?
Osteoporosis is a condition in which bones become fragile and brittle, leading to an increased risk of fracture. Osteoporosis is common in Australia, affecting over 1 million Australians.
Bone is a living tissue made up of minerals such as calcium and phosphorus. The body continually remodels and rebuilds bones to keep them strong. However, in osteoporosis, bones break down faster than they rebuild. Although bones remain the same size, the loss in bone mineral density makes them more porous and more brittle. The lower your bone mineral density, the higher your risk of fractures.
As people age, their bone mineral density (BMD) decreases, leading to an increased risk of osteoporosis.
Osteopenia is a condition where you have lower than normal bone mineral density, so your bones are weaker than normal, but you haven’t yet progressed to osteoporosis.
By 2022, an estimated 6.2 million Australians older than 50 years will have osteoporosis or osteopenia.
For many people, the first sign of osteoporosis is when they have a bone fracture. But other people may have signs and symptoms earlier, such as back pain, a stooped posture and loss of height.
The most common fractures due to osteoporosis are in the spine. They are called vertebral compression fractures. If you have multiple osteoporotic fractures in your spine, it will lose its normal curvature, and you may have the appearance of your back being hunched forwards. This can develop very slowly, and you may not notice. If you have lost more than 3 cm in height, you may have undiagnosed vertebral fractures.
Often a person will not feel these vertebral compression fractures, but sometimes when a vertebra fractures, a person may have sudden and intense back pain. Vertebral fractures can occur spontaneously or as a result of a seemingly trivial movement.
Osteoporosis is diagnosed by measuring your bone mineral density (BMD), usually at the hip and the spine. This is most often done by a special X-ray scan called DXA or DEXA (dual-energy X-ray absorptiometry). A DEXA scan can determine the mineral content of your bones, indicating how dense and strong they are.
Bone density scans compare your bone density with that of a young healthy adult (T score) and that of a healthy adult of the same gender and age as you (Z score). The resulting scores show whether you have normal bone density, slightly reduced bone density or osteoporosis.
Heel ultrasounds and bone tests offered in pharmacies are not recommended as suitable tests to accurately measure your bone density and assess your risk.
Risk factors for osteoporosis
Most people reach their peak bone mass by their early 20s. Then bone density declines every year after that. However, there are some risk factors which can accelerate the process of bone loss or make it more likely. Some of these risk factors can’t be changed, but some are lifestyle choices. Remember, the more bone mass you have accumulated when you’re young and the slower you lose it, the lower your risk of osteoporosis.
Risk factors you can’t change
Being female. Women tend to be more at risk of osteoporosis than men, with a relatively rapid loss of bone mineral density (BMD) in the first 5 to 7 years after menopause. Women who have a premature menopause (before age of 45) are at higher risk, and women who have had their ovaries removed before the age of 45 may also be at increased risk.
Age. Osteoporosis is more likely the older you get.
Small frame. Being small or light-framed increases the risk of osteoporosis, as you start off with less bone to draw on when the inevitable bone loss starts. Potentially at risk are very lean athletes, gymnasts or dancers, particularly if their periods have stopped.
Family history. Bone health may be inherited, so having a history of osteoporosis in your family may put you at increased risk, particularly parents who ‘lost height’ in older age, developed a humped back or had a hip fracture.
Ethnic background. White and Asian women seem to be at highest risk of osteoporosis. Black Afro-Caribbean people are at the lowest risk, as their bones seem to be bigger and stronger.
Medicines and diseases. Some medical conditions and medicines predispose people to secondary osteoporosis. These include:
- long-term or frequent use of steroid medicines, such as prednisone and cortisone
- some anti-convulsant medicines
- hyperthyroidism (overactive thyroid) or taking too much thyroid hormone replacement for an underactive thyroid
- conditions leading to malabsorption of nutrients from the bowel, such as inflammatory bowel disease or coeliac disease
- some cancer treatments that cause lowering of oestrogen may increase risk of osteoporosis
- depot medroxyprogesterone acetate – a form of hormonal contraception injection (brands include Depo-Provera and Depo-Ralovera).
Lifestyle risk factors for osteoporosis
Drinking excess alcohol. Alcohol can interfere with the body’s ability to absorb calcium, so high alcohol intake increases the risk of osteoporosis.
Low physical activity. Weight-bearing exercise, such as walking, running, and strength training helps to build strong bones, so people who sit a lot, or who have low levels of physical activity are at greater risk of osteoporosis.
Smoking. Smoking tobacco has been shown to contribute to weak bones.
Inadequate diet. Eating a diet low in calcium increases your risk of osteoporosis. If you don’t eat sufficient calcium when you’re young, your bone density will be diminished, and you will start to lose bone early and be at increased risk of fractures.
People with anorexia are also at higher risk of osteoporosis because their restrictive diets lead to low calcium intake, and for women, their periods can stop, which leads to low oestrogen.
Surgery for weight loss or to remove parts of the intestine can reduce the amount of calcium absorbed and so increase risk of osteoporosis.
Vitamin D. Your body needs vitamin D to absorb calcium. This vitamin is made by your skin when it is exposed to sunlight. People who cover their bodies for religious reasons and people who don’t get outside enough are at risk of vitamin D deficiency and so have increased risk of osteoporosis.
You can aim to prevent osteoporosis by modifying your lifestyle while you are still young to give your bones the best opportunity to be as dense as possible. Bone density peaks in the early 20s. After that, bones start to lose density slowly.
Continued calcium intake, adequate vitamin D and a healthy lifestyle are important to maintain bone mass and help reduce the loss. For these reasons, you should stop smoking, avoid excessive alcohol, undertake weight-bearing and resistance training exercise, and ensure that your diet contains enough calcium. Throughout life, the types of exercise to maximise your bone health will change.
For women, once they reach menopause, bone mineral density is lost rapidly for the next 5 to 7 years, so it is important to take action to try to maintain BMD for as long as possible after that.
There are also medicines that can be used to help prevent osteoporosis in certain at-risk people.
Because osteoporosis increases your risk of bone fractures, reducing your risk of falling is also important.
Lifestyle measures to help prevent osteoporosis
There are several simple lifestyle measures that can reduce your risk of developing osteoporosis and help maintain healthy bones well into old age.
Eat lots of calcium-containing foods
Low calcium intake is associated with low bone mass. Appropriate calcium intake can help reduce the rate of bone loss.
|Recommended dietary intakes of calcium|
|Group||Calcium RDI (Recommended Dietary Intake)|
|Women 19 to 50||1000 mg per day|
|Women over 50||1300 mg per day|
|Men 19 to 70||1000 mg per day|
|Men over 70||1300 mg per day|
|Source: Australian Government Department of Health and Ageing and NHMRC. Nutrient Reference Values for Australia and New Zealand. Updated 9 April 2014.|
Good sources of calcium include milk, yoghurt, cheese, almonds, dark green leafy vegetables, such as broccoli, and fish with bones (e.g. sardines and salmon).
Dairy foods are the best source of calcium, so aim for at least 3 serves of dairy products each day.
Remember, if there isn’t enough calcium in your food, your body will take it from your bones.
Your doctor may recommend taking a calcium supplement (e.g. Caltrate, Cal-Sup, Citracal) to boost your calcium intake, but there may be risks as well as benefits. Calcium supplements are usually only recommended if your dietary intake is inadequate. Doses of 500 mg to 600 mg elemental calcium per day are usually recommended.
Remember that supplements based on calcium carbonate should be taken with or after food as they need gastric acidity to help increase their absorption, and not to rely on supplements at the expense of a good diet. Calcium supplements may cause constipation and bloating.
Vitamin D, which is synthesised in the skin through exposure to sunlight, plays an important role in helping to absorb calcium and also in the general health of bone.
The amount of sun exposure needed to make adequate vitamin D for healthy bones depends on your skin type, the season, where you live in Australia and the amount of skin you have exposed.
Many Australians have low vitamin D levels, particularly in winter and early spring.
To maintain adequate vitamin D levels during winter and when the UV Index is below 3, many Australians need to spend some time outdoors in the middle of the day with some skin uncovered.
The Cancer Council advises that for most people, adequate vitamin D levels are reached through regular incidental exposure to the sun. When the UV Index is 3 or more, just a few minutes outdoors on most days of the week will be enough for most people. Sensible sun protection behaviour should not put you at risk of vitamin D deficiency.
The UV index is given by the Bureau of Meteorology website, or you can get it from the Cancer Council’s SunSmart app for mobile phones.
Older people who live in nursing homes, people who spend little time outdoors, those with naturally dark skin and those who cover their skin for cultural reasons, are most at risk of vitamin D deficiency.
People with low vitamin D levels may need vitamin D supplements – sometimes these are combined with calcium – talk to your doctor for advice on testing and supplements. Vitamin D supplements may also be recommended to prevent osteoporosis in people taking corticosteroid medicines.
Some foods, such as fatty fish (e.g. salmon, mackerel, and herring), eggs, liver, and foods fortified with vitamin D (e.g. margarine and some milks), also contain vitamin D. However, dietary intake alone is unlikely to provide adequate vitamin D to maintain healthy bones.
Bone is living tissue which gets stronger when extra strain or impact is imposed on it. Two types of exercise can help improve your bone health – weight-bearing exercise and strength training.
Weight-bearing exercise means exercise done on your feet, so you are carrying your own body weight. Examples are walking, hiking, running, jogging, aerobics, dancing and tennis. The higher the impact each time your foot hits the ground, the more stress on your bones, which results in your bones maintaining or increasing their strength. The strength of your bones and your stage of life determines what osteoporosis prevention exercises are safe.
Exercises like swimming or cycling, where you do not carry your body weight do not have much or any impact on your bone density.
Strength or resistance training (e.g. lifting weights with your arms or legs) also helps improve bone health.
For healthy adults, incorporating at least 30 minutes of a variety of these types of activities (weight-bearing and strength-training exercises), 3 to 5 times a week, is what’s recommended by Osteoporosis Australia.
For post-menopausal women and middle-aged men, Osteoporosis Australia recommends a varied exercise regime which includes moderate to high impact weight-bearing exercise and high-intensity progressive resistance training, at least 3 times per week.
For older adults and people at risk or who already have osteoporosis, the recommendations are different.
The earlier you start building an exercise programme into your life, the larger your bank of bone mass will be, making you less susceptible to osteoporosis later on.
Weight-bearing exercise can slow the rate of bone loss, and even increase bone mineral density in the spine and hips in women who have been through menopause.
You are never too old for exercise because it will also help you build muscle, and improve your posture and balance, which may prevent falls when you are older.
Maintain a healthy body weight
Low body weight is a risk factor for osteoporosis. Women who lose so much weight that their periods stop, such as those with eating disorders like anorexia, do not have sufficient circulating oestrogen to maintain bone density. Having your periods stop for more than 6 months before the age of 45, other than during pregnancy, is a risk factor for getting osteoporosis.
Drink alcohol only in moderation
Alcohol interferes with calcium absorption, so high alcohol intake increases the risk of osteoporosis. The draft National Health and Medical Research Council’s guidelines say that for both healthy men and women, limiting alcohol to no more than 10 standard drinks per week reduces the risk of alcohol-related harm.
Smoking may affect your ability to absorb calcium from your diet — it certainly does contribute to weak bones.
Manage your medicines
Long-term use of some medicines, including anti-convulsants, heparin, corticosteroids and some diuretics, can contribute to bone loss. You should talk to your doctor about whether any of your medicines may contribute to your risk of osteoporosis.
Medicines to prevent osteoporosis
Some people may need to take medicines to reduce their risk of developing osteoporosis. If you have low bone density, your doctor may suggest you take medicines to strengthen your bones. This includes some women after menopause, some people taking long-term corticosteroid medicines and some people who have had a fracture after minimal trauma.
Bisphosphonates are a group of medicines that can slow bone loss, improve bone density and reduce the risk of fractures. They are used in the treatment of osteoporosis, but some bisphosphonates can also be used in prevention of osteoporosis. Bisphosphonates can be used in prevention of osteoporosis in men and women with low bone mass and to preserve bone mass in certain people who take corticosteroids long term. They are mainly given as tablets.
- alendronic acid (brand name Adronat, Fosamax);
- risedronate (e.g. Actonel); and
- zoledronic acid (brand names include Aclasta, Osteovan) which is given as a once-yearly infusion.
Bisphosphonates should be taken on an empty stomach with plain water, as food and other drinks reduce their effect if taken at the same time. You must wait for 30 minutes after taking the tablet before you eat or drink. Also, people are advised to stay upright for 30 minutes after taking risedronate and alendronic acid, as these medicines can sometimes irritate the oesophagus (gullet). Once-weekly bisphosphonate formulations are available (e.g. Adronat) which reduce the risk of gastrointestinal side effects.
Certain people may be able to take a dose of risedronate once a month (Actonel 150 mg Once a Month Tablets), which may be more convenient.
Other side effects of bisphosphonates may include musculoskeletal pain and fatigue.
Bisphosphonates can – rarely – cause osteonecrosis (death of bone) in the jaw. This risk is generally confined to people with underlying cancers taking large doses.
Denosumab (Prolia) is given as a 6-monthly injection. It is available on the PBS to increase bone mineral density for certain groups of people. These include those who are over 70 and at greater risk of fracture because of low bone density, and people at risk due to long-term use of corticosteroids.
Side effects of denosumab include eczema, increased cholesterol and for men, muscular pain.
Raloxifene (brand names Evifyne, Evista) belongs to a class of medicines called selective oestrogen receptor modulators (SERMs). Raloxifene can prevent post-menopausal bone loss and has been shown to reduce spine (backbone) fractures. It is only for use by women after the menopause.
Raloxifene may make hot flushes worse and may cause leg cramps and increase the risk of blood clots. There is evidence that it may reduce the risk of breast cancer.
Menopausal Hormone Therapy (MHT)
Menopausal hormone therapy (previously known as HRT or hormone replacement therapy) is effective for the prevention of osteoporosis and fractures in post-menopausal women.
However, because of the risks associated with long-term MHT use, including breast cancer and thrombosis (blood clots), MHT is not recommended for routine osteoporosis prevention.
MHT may be used to prevent osteoporosis in certain women younger than 60 years who are at high risk of osteoporosis and are considering taking MHT in the short term to relieve menopausal symptoms.
Women over 60 are not generally recommended to take MHT for osteoporosis because of the risk of cardiovascular problems. The risks and benefits of taking MHT need to be assessed on an individual basis for each woman and vary depending on age, the type of MHT and other factors. Your doctor will be able to advise you on whether it is right for you.
There may be other medicines that are available for the prevention of osteoporosis. Talk to your doctor about your options.
Reduce your risk of falling
If you are older or already have osteoporosis, having a fall and breaking a bone can have a dramatic effect on your quality of life, so it is important you try to avoid this.
Weight-bearing exercise will improve your muscle strength, and exercises such as Tai Chi or yoga can improve your balance.
You should ensure your house is free from loose mats, badly placed power cords and uneven surfaces that could cause you to trip over. Also, check that the lighting in your home is sufficient throughout and that any rails or steps are securely fixed.
Make sure too that you minimise the chance of falls by having your eyesight checked and that your eyeglasses, if you wear them, are adequate.
Some medicines, such as sedatives, antihistamines and blood pressure medicines, can make you dizzy or interfere with your balance, so it is important that your doctor reviews all of your medications regularly.
If you are diagnosed with osteoporosis, your doctor will advise what medicines for osteoporosis may be suitable for you.
What type of doctor deals with osteoporosis?
Your GP may refer you to an Endocrinologist or a specialised bone centre for treatment. They may also suggest you see a physiotherapist or occupational therapist for a specific exercise programme suitable for osteoporosis. There are exercise classes available specifically for people with osteoporosis and osteopenia – search online or ask your doctor.