HRT and osteoporosis.

Osteoporosis is characterised by low bone mass, leading to an increased risk of fragility fracture, particularly in the femoral neck, vertebrae and radius. These fractures constitute a major public health problem in the Western world; the estimated annual cost to the health services of hip fracture alone is over 500 million pounds in the United Kingdom. Using population-based data from the USA, Cummings et al. have estimated that the lifetime risks of hip, vertebral and Colles' fractures in a 50 year old, white, postmenopausal woman are 16%, 32% and 15% respectively. Of these, vertebral fractures probably cause the most significant morbidity, since they occur at a younger age than hip fractures and may result in pain, deformity and disability for many years until death intervenes from other causes. Hip fractures occur most commonly in the eight and ninth decades of life and have a mortality at six months of around 15%, increased dependency occurring in the majority of survivors. Colles' fractures, although not usually associated with long-term morbidity, nevertheless cause considerable inconvenience and require hospital treatment.