Skeletal and cardiovascular consequences of a positive calcium balance during hemodialysis

Abstract Patients on hemodialysis are exposed to calcium via the dialysate at least three times a week. Changes in serum calcium vary according to calcium mass transfer during dialysis, which is dependent on the gradient between serum and dialysate calcium concentration (d[Ca]) and the skeleton turnover status that alters the ability of bone to incorporate calcium. Although underappreciated, the d[Ca] can potentially cause positive calcium balance that leads to systemic organ damage, including associations with mortality, myocardial dysfunction, hemodynamic tolerability, vascular calcification, and arrhythmias. The pathophysiology of these adverse effects includes serum calcium changes, parathyroid hormone suppression, and vascular calcification through indirect and direct effects. Some organs are more susceptible to alterations in calcium homeostasis. In this review, we discuss the existing data and potential mechanisms linking the d[Ca] to calcium balance with consequent dysfunction of the skeleton, myocardium, and arteries.

摘要 接受血液透析（hemodialysis）的患者每周至少会通过透析液（dialysate）接触钙三次。血清钙的变化随透析过程中的钙传质（calcium mass transfer）而改变，而钙传质水平取决于血清与透析液钙浓度差（d[Ca]）以及影响骨骼摄取钙能力的骨转换（skeleton turnover）状态。尽管该因素未得到足够重视，但透析液钙浓度差可能引发正钙平衡，进而导致全身器官损伤，包括与死亡率、心肌功能障碍、血流动力学耐受性、血管钙化（vascular calcification）及心律失常（arrhythmias）相关的不良结局。此类不良反应的病理生理学机制包括血清钙变化、甲状旁腺激素（parathyroid hormone）抑制，以及通过间接与直接途径引发的血管钙化。部分器官对钙稳态（calcium homeostasis）失衡更为易感。在本综述（review）中，我们将探讨现有研究数据及潜在机制，阐明透析液钙浓度差与钙平衡之间的关联，以及由此引发的骨骼、心肌及动脉功能异常。