Supplementary Material for: Serum sclerostin levels and mortality in hemodialysis patients: An 8-year prospective study

Introduction: Sclerostin is an osteocyte-derived inhibitor of bone formation and is increased in kidney failure. Sclerostin might be involved in the pathogenesis of vascular calcification, but few studies have examined the association between sclerostin and mortality in hemodialysis patients. Methods: We analyzed a prospective cohort of 654 patients undergoing maintenance hemodialysis. The primary exposure variable was the baseline serum sclerostin level measured at study enrollment. The primary outcome was 8-year all-cause mortality. Mortality risk was assessed using Cox regression models adjusted for potential confounders. Results: During a median follow-up of 7.6 years (IQR, 4.1-8.0 years), 229 of the 654 participants died. In univariate analysis, serum sclerostin levels were not associated with mortality (HR per doubling, 0.94; 95% CI, 0.76-1.17). This result was unchanged after adjustment for age, sex, dialysis vintage, diabetes, prior cardiovascular disease, and, body mass index (HR per doubling, 0.92; 95% CI, 0.72-1.17). Similar results were obtained for cardiovascular mortality. Conclusion: Serum sclerostin levels were not associated with mortality in maintenance hemodialysis patients. Further research is required to determine the role of sclerostin in vascular calcification and cardiovascular disease in kidney failure.引言：骨硬化蛋白（Sclerostin）是一种骨细胞源性骨形成抑制剂，在肾衰竭患者体内其水平可升高。骨硬化蛋白可能参与血管钙化的发病过程，但目前鲜有研究探讨血液透析（hemodialysis）患者中骨硬化蛋白与死亡率之间的关联。 方法：本研究对654例行维持性血液透析的患者开展前瞻性队列研究。主要暴露变量为研究入组时检测的基线血清骨硬化蛋白水平；主要结局为8年全因死亡率。采用校正潜在混杂因素的Cox回归模型评估死亡风险。 结果：中位随访时长为7.6年（四分位间距IQR：4.1~8.0年），654名参与者中有229例死亡。单因素分析显示，血清骨硬化蛋白水平与死亡率无显著关联（每倍增的风险比HR=0.94；95%置信区间CI：0.76~1.17）。在校正年龄、性别、透析龄、糖尿病、既往心血管疾病及体质量指数后，该结果未发生改变（每倍增的风险比HR=0.92；95%置信区间CI：0.72~1.17）。心血管死亡率的分析结果与此一致。 结论：维持性血液透析患者的血清骨硬化蛋白水平与死亡率无显著关联。未来仍需开展进一步研究，以明确骨硬化蛋白在肾衰竭患者血管钙化及心血管疾病中的作用。