不同钙浓度透析液对高磷血症血液透析患者钙磷代谢和血清胎球蛋白A水平的影响

Impacts of different dialysate calcium concentration on the calcium-phosphate metabolism and serum fetuin-A level in hemodialysis patients with hyperphosphatemia

目的:观察不同含钙离子浓度透析液与不同剂量碳酸钙联用对血液透析患者钙磷代谢和血清胎球蛋白A水平的影响。方法:63例维持性血液透析(MHD)患者随机分为3组,分别采用钙浓度(DCa)为1.75mmol/L(DCa1.75组)、1.50mmol/L(DCa1.50组)、1.25mmol/L(DCa1.25组)透析液透析。DCa1.75、DCa1.50组患者口服小剂量碳酸钙片或不服碳酸钙片,DCa1.25组患者口服碳酸钙片3g,每日3次。每组均透析9个月(为观察终点),每3个月检测血钙、血磷、血清全段甲状旁腺素(iPTH)和胎球蛋白A。结果:观察终点与初始值比较,DCa1.75组血钙、钙磷乘积和胎球蛋白A明显上升(P<0.05);DCa1.50组血磷轻度上升,iPTH均值和胎球蛋白A水平相对平稳;DCa1.25组血钙水平有所下降,血磷与钙磷乘积显著下降(P<0.05),iPTH均值和胎球蛋白A水平相对平稳,且发现iPTH在150～300ng/L间者所占百分比明显增多。结论:对合并高磷血症的MHD患者,使用高钙透析液可使钙磷乘积上升,钙化抑制物胎球蛋白A水平增高,增加了血管钙化的风险;对此采用低钙透析液联用较大剂量碳酸钙口服,不仅iPTH趋于理想范围,且胎球蛋白A水平相对稳定,可有效预防血管钙化的发生。

Objective To observe the impacts of different dialysate calcium concentrations, plus oral calcium carbonate, on the calcium-phosphate metabolism and serum fetuin-A level in hemodialysis patients with hyperphosphatemia. Methods Sixty-three maintenance hemodialysis （MHD） patients were randomly divided into three groups based on dialysate calcium concentration： （1） DCa 1.75 group, receiving 1.75 mmol/L Ca-contained dialysate, with or without lowdose oral calcium carbonate;（2） DCa 1.50 group, receiving 1.50 mmol/L Ca-contained dialysate, with or without low-dose oral calcium carbonate;（3） DCa 1.25 group, receiving 1.25 mmol/L Ca-contained dialysate, plus oral calcium carbonate of 3.0 g/d. All enrolled patients were treated for 9 months. Serum calcium and phosphate, intact parathyroid hormone （iPTH） and fetuin-A were detected every 3 month. Results Baseline characteristics among the three groups were similar. After 9 months of dialysis, the levels of serum calcium, [Ca^2＋]×[P^3＋] and fetuin-A were significantly elevated in Dca 1.75 group （P〈 0.05）. In Dca 1.50 group, the serum phosphate level was slightly elevated. There was no changes of iPTH and fetuin-A after dialysis. In Dca 1.25 group, the levels of serum phosphate and [Ca^2＋]×[P^3＋] were significantly declined（P〈0.05）, however, no obvious changes were observed in iPTH and fetuin-A levels and the patients with iPTH level of 150-300 ng/L were much more common in this group. Conclusions In hemodialysis patients with hyperphosphatemia, dialysate with high calcium concentration may increase serum [Ca^2＋]×[P^3＋] and fetuin-A, and increase the risk of vascular calcification. However, low-calcium dialysate and high-dose of oral calcium carbonate supplementation may maintain the optimal iPTH and fetuin-A levels, thus in turn prevent vascular calcification.