Sphingosine-1-phosphate (S1P) is a significant regulator of bone metabolism. Recently, we found that a high plasma S1P level is associated with low bone mineral density (BMD), high levels of bone resorption markers, and a high risk of prevalent vertebral fracture in postmenopausal women. We investigated the possibility that S1P is a predictor of incident fracture. A total of 263 postmenopausal women participated in this longitudinal study and received follow-up for a mean duration of 3.5 years (untreated [n=79] or treated with bisphosphonate or hormone replacement therapy [n=184]). The baseline plasma S1P level and fracture occurrence during the follow-up period were assessed. A high S1P level was significantly associated with a higher rate of prevalent fracture after adjusting for femoral neck (FN) BMD and potential confounders (odds ratio [OR]=2.13; 95% confidence interval [95% CI] =1.08–4.22]. Incident fractures occurred more frequently in the highest S1P tertile (T3) than in the lower 2 tertiles (T1-2) after adjusting for confounders, including baseline FN BMD, prevalent fracture, antiosteoporotic medication, annualized changes in FN BMD, and potential confounders (hazard ratio [HR]=7.30; 95% CI =1.05–75.75). Insufficient response to bisphosphonate therapy occurred more frequently in T3 than T1-2 (OR=5.03; 95% CI=1.04–24.47). The plasma S1P level may be a potential predictor of fracture occurrence and insufficient response to bisphosphonate therapy in postmenopausal women.
14 - 17 May 2016
European Calcified Tissue Society