Overmodification of collagen I in osteopenia

Abstract

Possible abnormalities of the collagenous matrix in osteoporosis might provide important informations on the pathogenesis of this common disorder. Furthermore, observations from osteogenesis imperfecta suggest that alterations in collagen modification may cause problems in fibril formation and hence mineralization. In particular, several studies on this inherited disease revealed alterations in the collagenous composition (Brenner et al. 1989a) and both changes in the primary structure as well as overmodification of the collagen molecule (Prockop et al. 1989; Kirsch et al. 1981). A transient overmodification of lysine residues has also been found in hyperplastic callus tissue (Brenner et al. 1989b) and is seen during fetal development (Kirsch et al. 1981; Brenner et al. 1989b). Therefore, we wondered whether similar abnormalities can be found in the collagenous bone matrix of adult patients with osteopenia. For this purpose, we performed a combined biochemical and morphometric study.