Kidney and Metabolic Bone Diseases Vol.22 No.3(2)

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
Publish Date 2009/07
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.
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