Melamed M L, Eustace J A, Plantinga L, Jaar B G, Fink N E, Coresh J, Klag M J, Powe N R
Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Kidney Int. 2006 Jul;70(2):351-7. doi: 10.1038/sj.ki.5001542. Epub 2006 May 31.
Elevated bone mineral parameters have been associated with mortality in dialysis patients. There are conflicting data about calcium, parathyroid hormone (PTH), and mortality and few data about changes in bone mineral parameters over time. We conducted a prospective cohort study of 1007 incident hemodialysis and peritoneal dialysis patients. We examined longitudinal changes in bone mineral parameters and whether their associations with mortality were independent of time on dialysis, inflammation, and comorbidity. Serum calcium, phosphate, and calcium-phosphate product (CaP) increased in these patients between baseline and 6 months (P<0.001) and then remained stable. Serum PTH decreased over the first year (P<0.001). In Cox proportional hazards models adjusting for inflammation, comorbidity, and other confounders, the highest quartile of phosphate was associated with a hazard ratio (HR) of 1.57 (1.07-2.30) using both baseline and time-dependent values. The highest quartiles of calcium, CaP, and PTH were associated with mortality in time-dependent models but not in those using baseline values. The lowest quartile of PTH was associated with an HR of 0.65 (0.44-0.98) in the time-dependent model with 6-month lag analysis. We conclude that high levels of phosphate both at baseline and over follow-up are associated with mortality in incident dialysis patients. High levels of calcium, CaP, and PTH are associated with mortality immediately preceding an event. Promising new interventions need to be rigorously tested in clinical trials for their ability to achieve normalization of bone mineral parameters and reduce deaths of dialysis patients.
骨矿物质参数升高与透析患者的死亡率相关。关于钙、甲状旁腺激素（PTH）与死亡率的数据存在矛盾，且关于骨矿物质参数随时间变化的数据很少。我们对1007例新进入血液透析和腹膜透析的患者进行了一项前瞻性队列研究。我们研究了骨矿物质参数的纵向变化，以及它们与死亡率的关联是否独立于透析时间、炎症和合并症。这些患者的血清钙、磷和钙磷乘积（CaP）在基线至6个月之间升高（P<0.001），然后保持稳定。血清PTH在第一年下降（P<0.001）。在调整炎症、合并症和其他混杂因素的Cox比例风险模型中，使用基线值和时间依赖值时，最高四分位数的磷与风险比（HR）为1.57（1.07 - 2.30）相关。在时间依赖模型中，钙、CaP和PTH的最高四分位数与死亡率相关，但在使用基线值的模型中则不然。在进行6个月滞后分析的时间依赖模型中，PTH的最低四分位数与HR为0.65（0.44 - 0.98）相关。我们得出结论，基线和随访期间的高磷水平与新进入透析患者的死亡率相关。高钙、CaP和PTH水平与事件发生前即刻的死亡率相关。有前景的新干预措施需要在临床试验中进行严格测试，以检验其使骨矿物质参数正常化并降低透析患者死亡的能力。
