Osteoporosis literally means porous bone and is characterised by low bone mass and poor bone quality.
As our bones become more porous and fragile, the risk of fracture is greatly increased. The loss of bone often occurs silently and progressively. Generally there are no symptoms until your first fracture occurs.Osteopenia is when your bones are weaker than normal but they are not likely to break easily, unlike osteoporosis.
Bone is divided into cancellous (or trabecular) bone and cortical bone. Cancellous bone is more metabolically active and is formed by interconnecting latticework. Cancellous bone is surrounded by the less delicate cortical bone.
Bone is remodelled (or turned over) throughout adult life by discrete remodelling units of osteoclasts (cells that resorb bone) and osteoblasts ( cells that lay down new bone).
After about 50 years of age, the volume of bone resorbed is greater than the volume formed in each remodelling unit. This process accelerates during menopause. This is because decreasing oestrogen levels enhances the rate of bone resolution. This continues in old age (ie over 70 years of age).
Risk Factors For Osteoporosis:
- Family history (of osteoporotic fracture)
- Increasing age
- Low Calcium and Vitamin D levels
- Medical history–hormonal and metabolic factors-in women: delayed puberty, early menopause , in men: low testosterone , thyroid conditions:, conditions leading to malabsorption (eg coeliac disease), chronic diseases eg liver or kidney disease
- Medications– corticosteroids ( commonly used for asthma, rheumatoid arthritis)
- Lifestyle factors– low levels of physical activity, smoking, excessive alcohol intake, weight (over or under weight).
Osteoporosis prevalence increases with age , but usually has no symptoms until a fracture occurs.
Prevent the Next Fracture
Exercise and bone maintenance are inextricably linked. Exercise helps to build and maintain strong bones and prevent falls and fractures by improving balance, co-ordination, muscle strength and agility. To have an effect on bone and maximise bone adaptation, exercise needs to be
- REGULAR (at least 3x/week),
- PROGRESSIVE ( becomes more challenging over time),
- FAIRLY VIGOROUS,
- VARIED and performed in SHORT INTENSE BURSTS.
- Exercise should be WEIGHT-BEARING (ie performed whilst on your feet) and STRENGTH ENHANCING.
Rapid, short bursts of high intensity and/or high impact activities such as jogging, jumping and rope skipping are more stimulating to bone cells than sustained, low impact activity such as walking,
Lifting heavy weights, particularly when lifted rapidly seems more effective than lifting light weights.
Novel forces, such as changing directions and different heights of jumps are more stimulating than repetitive force patterns.
Exercising in shorts bouts with rest periods seems to be more effective than continuous, long periods of exercise.
Continuous progression of the weight moved, balance exercise difficulty and jump height is the most critical element of the exercise prescription for bone health. If the progression stops, so does the adaptation in the bone and muscle.
Did You Know:
- Approximately every 8 minutes someone is admitted to an Australian hospital with an osteoporotic fracture.
- 30-50% of Australian women and 15-30% of men will develop osteoporotic fractures.
- Of all reported osteoporotic fractures, 46% are vertebral, 16% are hip and 16% are wrist fractures.
- Wrist fractures are the most common in peri-menopausal women and increase rapidly after menopause.
- Approximately 50% of all patients with a fracture due to osteoporosis will go on to have another: called the “cascade effect”.
- Hip fracture reduces life expectancy. More than 20% of people who suffer a hip fracture die within 12 months. 50% need long term help with activities of daily living and 15-25% require full time nursing home care.
- Available therapies can reduce the risk of osteoporotic fractures by approximately 50% within a year of beginning treatment.
- Treatment therapies include medication, nutrition (vitamin D and calcium), and exercise.