Effects of SERMs on bone health. Effects of raloxifene and bisphosphonate on bone quality in osteoporosis: collagen cross-links, mineralization, and bone strength

Abstract

Selective Estrogen Receptor Modulators (SERMs) such as raloxifene are characterized as anti-bone resorptive agent as well as bisphosphonate. Recently, bone mass and quality affect bone strength independently. Oxidative stress induced by hyperhomocysteinemia deteriorates bone quality in terms of collagen enzymatic and non-enzymatic cross-links such as pentosidine (Saito M, Osteoporos Int [REVIEW], 2010). Such deterioration of bone quality also exist in osteoporotic patient with mildly elevated plasma homocysteine (Saito M, Calcif Tissue Int, 2006). Such detrimental cross-link formation in bone was ameliorated by raloxifene treatment (Saito M, Osteoporos Int, 2009, May 30, in press). In contrast. bisphosphonate treatment increases degree of mineralization, collagen maturity, and pentosidine. The treatment had no effect on the total amount of enzymatic cross-link formation (Saito M, Osteoporos Int, 2008). Based on these results, osteoporotic patients with hyperhomocysteinemia had better take raloxifene, while patients with severe low bone mineral density should take bisphosphonate.