Osteoporosis risk factors

Osteoporosis is a condition in which bones become fragile and brittle, leading to an increased risk of fracture.

Bone is a living tissue made up of minerals such as calcium and phosphorus. The body constantly remodels and rebuilds bones to keep them strong. However, in osteoporosis, bones break down faster than they rebuild. Although bones remain the same size, they become more porous and more brittle, leading to a loss in bone mineral density. The lower your bone mineral density, the higher your risk of fractures.

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 had a hysterectomy before normal menopause also have an increased risk.

Age

Osteoporosis is more likely the older you get.

Small frame

Being small or light-framed increases 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 lowest risk, as their bones are seem to be bigger and stronger.

Lifestyle factors

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, 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.

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.

What you can do

Osteoporosis is a ‘silent’ medical condition — there are no symptoms or pain until there is a fracture. You should aim to prevent osteoporosis by modifying your lifestyle while you are still young. Bones stop growing in the early 20s, but continued calcium intake and a healthy lifestyle are important to maintain bone mass.

Bone calcium loss increases markedly from about 50 years onwards, although lifestyle and adequate calcium intake helps reduce the loss. For these reasons you should stop smoking, avoid excessive alcohol, undertake weight-bearing exercise, and ensure that your diet contains enough calcium.

Last Reviewed: 29 July 2013
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References

1. Mayo Clinic. Osteoporosis risk factors. Updated June 2013. http://www.mayoclinic.com/health/osteoporosis/DS00128/DSECTION=risk-factors (accessed July 2013).
2. Osteoporosis Australia. Risk factors for osteoporosis. Last updated April 2013. http://www.osteoporosis.org.au/about/about-osteoporosis/risk-factors/ (accessed July 2013).
3. International Osteoporosis Foundation. Who’s at risk? http://www.iofbonehealth.org/whos-risk (accessed July 2013).
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