Epidemiology

Osteoporosis is a silent disease, which in itself causes no symptoms.

• 2 million Australians have an osteoporosis related condition
• 1.5 million are women.
• 0.5 million are men
   
• Currently osteoporosis affects 10% of the Australian population
• By 2021, osteoporosis will affect 13% of the Australian population 

For more information go to Epidemiology

Definition

The World Health Organisation (WHO) Working Group defines osteoporosis according to measurements of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA).

• Osteoporosis is defined as a bone density T score at or below 2.5 standard deviations (T score) below normal peak values for young adults.

A clinical definition of osteoporosis was developed in 2001 by the National Institutes of Health (NIH) Consensus Development Panel on Osteoporosis.

• Osteoporosis is defined as a skeletal disorder characterised by compromised bone strength predisposing a person to an increased risk of fracture.

For more information go to Definition

Pathogenesis

The human skeleton is comprised of a mixture of collagen (type 1), non-collageneous matrix proteins and minerals; mainly calcium and phosphate, but also magnesium.

Bone structurally needs to be stiff in order to allow for mechanical loading, but also flexible enough to absorb energy during impact loading and muscle contraction.

When the balance between bone stiffness and flexibility is exceeded, fracture results.

For more information go to Pathogenesis

Content updated February 20, 2006