Osteoporosis: not just a women's disease

Osteoporosis – a progressive metabolic bone disease characterised by low bone mineral density (BMD) –results in decreased bone strength, increased bone fragility and increased risk of minimal trauma fracture.¹ (A minimal trauma fracture is one that occurs after a fall from standing height or less, or from a minor force that would not normally cause a fracture in a healthy younger person.)

A previous minimal trauma fracture doubles a person's subsequent risk of fracture.² However, osteoporosis remains under-recognised and undertreated, even in people who present with minimal trauma fracture.^3,4

Men, in particular, are undertreated. A large epidemiological study of elderly Australian men found only 10% of those eligible for PBS-subsidised treatments were taking a bisphosphonate medicine.⁵

While osteoporosis is more common in women,⁶ the risk of death from minimal trauma fractures is greater in men.^7-9

The Dubbo Osteoporosis Epidemiology Study examined mortality rates following minimal trauma fracture.⁷ In the first 5 years post-fracture, the study found that approximately 26% of women and 37% of men died.⁷

If a repeat fracture occurred within the same timeframe, the mortality risk increased dramatically to 75% for men and 50% for women. The total 5-year mortality rate was 39% in women and 51% in men.⁷

It has also been reported that after a hip fracture, the fatality rate for those aged > 75 years was 20.7% in men compared with 7.5% in women.⁹

In both genders, a previous minimal trauma fracture is strongly associated with an increased risk of repeat fractures.^3,10 Up until 80 years of age, a previous minimal trauma fracture is the strongest risk factor for hip fractures and non-hip fractures.¹¹

In addition to previous minimal trauma fracture, other risk factors for osteoporosis include:^3,10

• age
  
• low BMD
  
• smoking
  
• alcohol consumption
  
• low BMI (body mass index)
  
• physical inactivity
  
• inadequate dietary calcium intake and vitamin D levels.^3,10
  

For a comprehensive list of risk factors see RACGP Clinical guideline for osteoporosis.

Up to 50% of osteoporosis in men can be attributed to an underlying or secondary cause, including predisposing medicines or conditions and lifestyle factors.^9,10 The major causes of secondary osteoporosis in men are hypogonadism, long-term corticosteroid use and excessive alcohol consumption.⁹

Other risk factors that can increase the likelihood of osteoporosis in men include:^3,9,10,12

• decreased testosterone and other sex hormone levels due to ageing
  
• androgen deprivation therapy in patients with prostate cancer.
  

Click here for more information on assessing patients for risk of osteoporosis.

Evidence on whether osteoporosis medicines reduce fracture risk in men is limited by small patient numbers. However, when compared with placebo, osteoporosis medicines increase BMD to a similar degree in both men and women.^10,13-18

For more information on the pharmacological management of osteoporosis, including a decision pathway for PBS-subsidised osteoporosis medicines, see our clinical topic Osteoporosis.

For a summary of the guideline recommendations on lifestyle changes to improve bone health, see Managing osteoporosis.

GP-mediated resources such as the Bone Health Action Plan can help facilitate discussion about modifiable risk factors, and medicine effectiveness and safety for patients taking osteoporosis medicines.