[The diagnosis of postmenopausal osteoporosis]

Post-menopausal osteoporosis is a metabolic bone disease which is histologically characterised by a reduction of bone mass with normal mineral content of the remaining bone tissue. In clinical term, the symptoms of disease include pain in the bones, pathological fractures (of the vertebra, femur, wrist) and consequent deformations of the skeletons. X-ray is still the most efficient diagnostic tool, although it is only capable of revealing osteopenia when bone has lost more than 40% of its mineral content. Bone densitometry is an important stage in the diagnosis and study of osteoporosis. It is first performed at the distal extremity of the forearm, then at the lumbar vertebra and head of the femur. Bone mineralometry is also currently used to study the skeleton as a whole (total body absorptiometry). This method, which has a high level of precision and no positioning problems, is able to provide extremely reliable measurements of bone mineral content, in particular during monitoring. It is worth underlining, however, that other bone metabolic diseases, namely osteomalacia, are also characterised by reduced bone density: the level of bone density should therefore not be considered as an expression of bone mass. In biochemical terms, post-menopausal osteoporosis leads to minimum modifications of the phospho-calcium metabolism: only during stages of accelerated bone turnover is it possible to observe a small increase in calciuria, hydroxyprolinuria and serum osteocalcin levels. A prime factor for the diagnosis of post-menopausal osteoporosis is the intestinal calcium absorption test: post-menopausal osteoporosis is characterized by insufficient intestinal calcium transport.(ABSTRACT TRUNCATED AT 250 WORDS)