[Pathophysiology and epidemiology of osteoporosis]

The international consensus definition characterizes the osteoporosis by low bone mass and microarchitectural deterioration. New genetic aspects of the pathogenesis of osteoporosis underline these characteristics. In the younger age, a reduced bone mineral density and a reduction of the bone structure are predictors of a genetically caused osteoporosis. The short-term maximal mechanical load of the bone structure by Frost (4) was pointed out to be an important pathophysiological element for the balance of the bone metabolism. Sex hormones and other calcium regulating hormones determine the effect of this biomechanical signal. The deficiency of the osteoblast's activity in the older age is caused by a reduced proliferating cell pool of bone tissue. The epidemiologic data of the osteoporosis were derived from incidence of the hip fractures. A densitometrical osteoporosis screening test analyzes only the bone density but not the organisation of the bone structure. There is too little informations about the disease of osteoporosis. It is to hope that, in the future, the European-Vertebral-Osteoporosis-Study will give additional knowledge about osteoporosis.