[Prevention of osteoporosis and role of densitometry]

Osteoporosis is a major public health problem in countries with aging populations, resulting in excess morbidity and mortality. Osteoporosis is defined as a systemic skeletal disease characterized by low bone mass and micro-architectural deterioration of bone tissue, with the consequent increase in bone fragility and susceptibility to fractures. Therefore, the bone loss that precedes fractures is a continuous process that is often mostly irreversible in the aging. The most efficient method of preventing fractures is the prevention of bone loss. The measurement of bone mass and other skeletal characteristics can effectively identify women at high risk for fractures. The measurement of bone mass which can be carried out by osteo-densitometry is now widely available. It is the only clinical data that can provide accurate assessment of individual fracture risk. Treatments exist that will preserve bone mass and presumably reduce fracture risk; therefore there is a place for screening of patients at high risk of fractures. Many studies have shown recently that a reduced bone mass (at least 1 standard deviation below normal) was associated with a more than 100% increased risk of fracture. Thus the initial assessment of bone mass can be used to estimate future fracture risk and to start prevention measures for high risk patients. Primary prevention can be initiated during the adolescence to optimize peak bone mass. Later in life, secondary prevention can prevent excessive bone loss and more specific treatments can prevent postmenopausal and age related bone demineralization. Strategies of prevention should be promoted and validated as general health care strategies.