Bone Turnover Markers and Sphingosine-1-phosphate levels among the Chinese Community in Selangor, Malaysia and its Correlation with Bone Density

ABSTRACT

@#Introduction: Prevention of osteoporotic fracture requires identification of individuals at high risk. Bone mineral density(BMD) is commonly used to estimate fracture probability despite inadequate predictive discrimination ability. Sphingosine-1-phosphate(S1P), a new marker of bone metabolism and bone turnover markers(BTM) such as procollagen-type-1 amino-terminal propeptide(P1NP) and C-terminal telopeptide of type I collagen(CTX) may complement current assessment. The study determined P1NP, CTX and S1P levels and their correlation with BMD, 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone(PTH) in selected subjects. Method: A cross-sectional study involving Malaysian Chinese men and women aged 50-90 years old from Puchong and Kajang, Selangor. Each subject had BMD determined by dual-energy x-ray absorptiometry and blood samples taken for 25(OH)D, PTH, P1NP, CTX and S1P. Results: A total of 131 subjects [45(34.4%) males and 86(65.6%) post-menopausal women] with median age of 65(IQR=17) were recruited. P1NP and CTX were significantly higher in post-menopausal women (P1NP=61.71 ng/ml, CTX=0.489 ng/ml) compared to men (P1NP=46.94 ng/ml, CTX=0.381 ng/ml). P1NP and CTX differed significantly according to BMD categories with values highest in osteoporosis. S1P between men (2.12±0.75 µmol/L) and post-menopausal women (1.96±0.68 µmol/L) did not differ significantly and did not differ according to BMD categories. S1P did not correlate with BMD, P1NP, CTX and 25(OH)D. P1NP and CTX negatively correlated with BMD at all measured sites but not 25(OH)D. Conclusion: CTX and P1NP, but not S1P negatively correlated with BMD. CTX and P1NP were highest in those with osteoporosis. In this group of Malaysian Chinese subjects, CTX and P1NP rather than S1P reflects bone health.