PEAK BONE MASS AND PEAK BONE-DENSITY

The bone mass in elderly persons depends on the rate of involutional bone loss and on the peak bone mass, i.e.: the bone mass present around the third decade of life. The factors relating to the attainment of peak bone mass include congenital factors, diet, hormones, physical activity, particular habits, drugs or diseases. A therapeutic intervention aimed at increasing peak bone mass is conceivable only by controlling factors such as estrogen status, dietary calcium intake and physical activity. Calcium intake appears to be relevant up to the so called intake threshold (1000 mg per day), but higher allowances do not seem to offer additive advantages. Exercise affects only the regions of the skeleton under mechanical stress. It is not clear whether these interventions are able to modify the peak bone mass or the peak of bone density. The first is under the control of mechanical forces throughout unknown factors. The latter appears to be constant over a wide range of age, equal in males and females and principally related to bone turnover at least in young healthy subjects.