Clinical Significance and Pathogenesis of Osteoporosis

作者：B. E. C. Nordin · 发表于：BMJ · 年份：1971 · DOI：10.1136/bmj.1.5749.571 · 被引用次数：159 · 研究领域：Bone health and osteoporosis research、Bone health and treatments、Bone Metabolism and Diseases

The development of osteoporosis with advancing age in man is a widespread if not a universal phenomenon. The average loss between youth and old age amounts to about 15% of the skeleton but involves a much larger proportion of trabecular than of cortical bone.THE PRINCIPAL CLINICAL MANIFESTATION OF OSTEOPOROSIS IS FRACTURE, AND THREE OSTEOPOROTIC FRACTURE SYNDROMES CAN BE DEFINED: the lower forearm fracture, which predominantly affects women between the ages of 50 and 65; the fracture of the proximal femur, which affects both sexes over the age of 70; and the relatively rare vertebral crush fracture syndrome, which may present at any age but is most common in elderly women.The lower forearm fracture rate is inversely related to the mean normal lower forearm x-ray "density" of the wrist, which falls by about 30% in the 15 years following the menopause. This process, which is associated with corresponding trabecular bone loss elsewhere in the skeleton, is associated with a corresponding rise in the fasting urinary calcium excretion. Some degree of negative calcium balance, and consequent bone resorption, probably occurs in everyone during the later part of the night because calcium absorption is completed within about three to five hours of a meal. In postmenopausal women, however, the sensitivity of the bone to parathyroid hormone appears to be increased, and their nocturnal negative calcium balance therefore comes to exceed the positive balance which can be achieved during the...