| Theme |
Beyond bone mineral density : roles of collagen and its related mineral quality in bone fragility in osteoporosis, diabetes, and renal dysfunction |
| Title |
Role of collagen cross-link formation as determinants of bone strength |
| Author |
Mitsuru Saito |
Department of Orthopaedic Surgery, Jikei University School of Medicine |
| [ Summary ] |
Collagen cross-link formation in bone plays an important role in bone strength and the proper biological function of bone. Thus, collagen cross-links are thought to be a determinant of bone quality at a material level. A moderately increased plasma content of homocysteine (Hcys) in the general population may indicate a risk of fracture that is independent of bone mineral density (BMD). McKusick first proposed that hyperhomocysteinemia may interfere with normal enzymatic collagen cross-link formation. This proposed mechanism was confirmed indirectly in homocystinuric patients. We reported, in a case-controlled study, a significant reduction in the actual amount of enzymatic cross-links and a marked increased in AGEs cross-link, pentosidine, in the bone from patients with post-menopausal osteoporotic hip fractures and hyperhomocysteinemia. These results suggest that reductions in enzymatic cross-links and excessive formation of pentosidine may play an important role in explaining poor bone quality in osteoporosis. |