Osteoporosis: a silent disease

Osteoporosis is defined as a reduction in the strength of bone that leads to an increased risk of fractures. Osteoporosis results from bone loss due to age related changes in bone remodelling as well as extrinsic and intrinsic factors that accelerate the process.

Increased sex hormones at puberty is required for skeletal maturation, which reaches maximum mass and density in early adulthood. The sex dimorphism in skeleton size becomes obvious after puberty, although true bone density remains similar between the sexes. Nutrition and lifestyle also play an important role in growth, though genetic factors primarily determine peak skeletal mass and density.

Osteoporosis is the most common bone disease. It has been estimated that more than 8.9 million fractures occur annually worldwide and most of these occur in patients with osteopenia or osteoporosis. About one-third of all women and one-fifth of all men aged 50 and above suffer from fractures at some point in life.

The burden of osteoporosis-related fractures is predicted to increase by two to three fold by 2050 on a worldwide basis, due to ageing of the population.

Fractures in patients with osteoporosis can affect any bone, but the common sites are the forearm (Colles fracture), spine (vertebral fracture), shoulder (humerus) and hip (femur). All of these fractures become more common with increasing age. Hip fractures are the most serious. Treatment of hip fracture accounts for majority of the health care cost associated with osteoporosis. The trouble with osteoporosis is that there are no symptoms prior to a fracture. However, once a person has broken a bone, their risk of a second fragility fracture increases significantly.

The risk factors for osteoporosis are well recognised. The key risk factors for fractures are non-modifiable and potentially modifiable. Non-modifiable risk factors of osteoporosis includes advanced age (> 50 years), female, white and Asian ethnicity, family history of osteoporosis and dementia. Potentially modifiable risk factors are smoking, low body weight (< 58 kg), recurrent fall, inadequate physical activity, oestrogen deficiency, alcohol consumption, early menopause, prolonged premenopausal amenorrhoea, androgen and calcium deficiency, poor health etc.

Osteoporosis should be treated not only by drugs but also with advice on lifestyle, nutrition, exercise and measures to reduce fall. Ensuring adequate calcium and vitamin D status, with supplements that should be given if required, may help to reduce the risk of osteoporosis.

The writer is a Consultant at the Cardicare Heart and General Hospital.