Bone quality is thought to encompass the structural and material properties of bone that are affected by turnover rate. The concept of bone quality is included in Japanese Guideline for
Osteoporosis prevention and treatment. Evidence has accumulated that
collagen cross-links play important roles in bone strength. We have demonstrated that the quantitative and qualitative deterioration of
lysyl oxidase controlled and non-enzymatic cross-links (
Advanced glycation end products, AGEs,
Pentosidine) of
collagen in patients with osteoporotic
femoral neck fracture cases might be affected by
hyperhomocysteinemia (Saito M, Calcif Tissue Int, 2006), oxidative stress,
vitamin B status (Saito M, Osteoporos Int, 2006) . Recently, Shiraki et al. demonstrated that a functional polymorphism in
methylenetetrahydrofolate reductase (MTHFR) polymorphism, T allele (C677T), may be a risk factor for future fracture in addition to the traditional risk factors (Shiraki M, Saito M, et al., J Bone Miner Metab, in press). In addition, we have reported that a higher urinary
pentosidine was an independent risk factor, for vertebral fracture in a 5-year prospective study in Japanese women (Shiraki M, Saito M, et al., J Bone Miner Metab, 2008). If confirmed in large, prospective trials, measurement of serum
homocysteine and serum or urinary excretion of
pentosidine might be characterized as markers reflecting bone
collagen deterioration.