[A histomorphometric study of normal iliac trabecular bones. Part I: Age related changes and the values of tissue-leveled static parameters].

Trans-iliac bone biopsies were performed on 142 normal Japanese subjects (55 males, 87 females, mean age: 44.8 years) and were evaluated particularly for the indices of tissue-leveled static parameters: volume and thickness of bone/osteoid, and surface measurement of formation, resorption and inert surface. The results were in general agreement with previous studies, but some discrepancies were found regarding osteoid indices: 1) The osteoid (formation) surface, especially osteoblastic osteoid surfaces, increased significantly at the ages from 50 to 60 years in females, 2) osteoid volume and relative osteoid volume were also found to have increased at this age range in females, 3) osteoid thickness decreased or had a rather constant value in females, and 4) the values of these 3 parameters decreased in males with the advance of age after young adulthood. From these results, at least at tissue level, the bone formation rate seemed to increase from the 6th to the 7th decade of life in women making a clear contrast to men in whom the formation rate appeared to decrease within the same age range.