Osteoporosis and age-related fracture syndromes.

Osteoporosis is one of the most important age-related diseases. Each year in the United States it causes at least 1.2 million fractures and costs 7 to 10 billion dollars. The main cause of the fractures is increased bone fragility due to low bone density, although in the elderly an increase in the frequency of falls and in the trauma produced by the falls also contributes to fractures. Low bone density in osteoporosis has multiple causes which can be grouped into the categories of low initial bone mass and bone loss due to ageing, menopause, and sporadic factors. Given the magnitude of the problem, prevention is the only cost-effective approach. Enough is known about causes of bone loss leading to osteoporosis that an effective programme of prevention can be designed. Its implementation in the population should substantially reduce the incidence of this major public health problem.