The peak bone mass concept.

Peak bone mass (PBM), i.e. the bone mass developed after growth in early adult life, is a major determinant for bone mass in the senescence, resp. for the risk of osteoporosis. Individual differences among young adults are so important that a person with a high PBM has a relatively low risk for osteoporosis, even if its annual bone loss is fast. PBM is conditioned by genetic, hormonal, and nutritional factors, and by physical activity, the latter two offering possible impact for preventive measures. Preservation of PBM through the early, resp. premenopausal life, can be favoured by adequate nutrition and physical activity, both together being capable of postponing the appearance of osteoporosis by several years. But various parts of the skeleton decrease constantly through life, starting already in the twenties; even when absorptiometry shows no loss of bone density until menopause, resp. during early adult life, there is a constant decrease of the mechanical properties of the bone with age. Therefore, the development of an optimal PBM is probably more effective in preventing osteoporosis than the measures for preservation of bone.