不同腹膜透析液对钙磷代谢的影响

Calcium and phosphonium metabolism in peritoneal dialysis patients with different dialysates

目的:观察不同含钙离子浓度的腹膜透析液对腹膜透析(PD)患者钙、磷代谢的影响。方法:将74例终末期肾衰行PD治疗患者分为三组。组1:采用标准腹膜透析液(BaxterPD2,SCD)治疗,并口服碳酸钙;组2:采用SCD,但不服碳酸钙;组3:采用低钙透析液(BaxterPD4,LCD,钙离子浓度1.25mmol/L),并服碳酸钙。入组筛选时,血钙、血磷均在正常范围者进入组2,其余患者随机进入组1和组3。透析液剂量为1000ml/d的整数倍,碳酸钙片剂量为2.25g/d。每3个月进行一次临床随访,评估血钙、血磷和甲状旁腺素(iPTH)变化情况。部分组1、组3患者还在随访基线和研究终点时检测iPTH值。三组患者随访时间均>12个月,选取0～12个月为观察范围。结果:随访基线三组患者基本临床特点无差别。三组患者腹膜平衡试验状态多以高平均、低平均转运两型为主。血钙变化情况:随访基线三组患者血钙水平相当,观察终点组1患者血钙水平较前明显上升[(2.49±0.31)vs(2.10±0.26)mmol/L,P<0.01];组2、组3患者血钙相对平稳;三组患者在观察终点低钙血症发生率相当(6.5%,8.3%,3.2%,组间比较P>0.05)。血磷变化情况:随访基线组1和组3患者血磷水平明显高于组2患者,观察终点时,组3血磷水平下降最为明显,与基础值比较有显著统计学差异[(1.41±0.51)vs(1.82±0.48)mmol/L,P<0.05];组1患者血磷仅轻度下降,组2患者血磷水平反而上升;观察终点,组3患者高磷血症发生率明显低于前两组(P<0.05)。钙磷乘积变化情况:随访基线组1和组3两组患者钙磷乘积水平>40mg2/dl2,观察终点,组1和组2组患者钙磷代谢乘积均不同程度升高,组3患者钙磷乘积下降,且明显低于组1[(36.91±10.76)vs(51.80±11.27)mg2/dl2,P<0.01],也低于组2,但无统计学差异。iPTH变化情况:随访基线,组1患者iPTH水平高于组3患者,治疗后,前组数值明显下降,而后组相对稳定;两组iPTH数值在随访基线和观察终点时组间比较均无统计学差异。结论:不同含钙浓度腹膜透析液对机体钙磷代谢的影响是不同的,使用碳酸钙片可以预防和纠正高磷血症的发生;采用低钙透析液治疗,能有效防止高钙血症,降低钙磷乘积,并不会增加低钙血症发生的风险,碳酸钙可长期大剂量应用。

Objective：To investigate the effect of standard calcium dialysate （SCD; calcium： 1.75 mmol/L） and low-calcium dialysate （LCD; calcium： 1.25 mmol/L）, and oral calcium carbonate on the metabolism of calcium and phosphonium in patients with peritoneal dialysis （PD）. Methodology：Seventy-four patients with PD were divided into three groups. They were normal serum [ Ca^2＋ ] and serum [ P^3＋ ] in group 2 （n = 12）, received the treatment of SCD. Another two groups were both received calcium carbonate and randomized to receive SCD or LCD, who were in group 1 （ n=31 ） and group 3 （n=31 ）. The biochemical data and treatment were evaluated every 3 month. The levels of parathyroid hormone（PTH） were detected on some patients in group 1 and group 3 at baseline and at 12 months. The levels of serum [ Ca^2＋] and [ P^3＋], value of [ Ca^2＋ ]×[ P^3＋], and levels of PTH were compared. Results ： All of the patients completed the study. At baseline, the levels of serum [ Ca^2＋] were approximation in three groups. After one year with PD treatment, the levels of serum [ Ca^2＋ ] were significantly increased from （2.10 ±0. 26） to （2.49±0. 31 ） mmol/L （P 〈0.01 ） in group 1, but it was not markedly different in the other two groups. The percentage of hypocalcemia were similar in three groups （6. 5% ,8.3% ,3.2% ,P 〉 0. 05）. At the baseline, the levels of serum [ P^3＋ ] were higher group 1 and group 3than that in group 2. After one year with PD, the levels of serum [ p^3＋ ] were decreased significantly from （ 1.82 ±0. 48） to （ 1.41 ±0. 51 ） mmol/L （ P 〈 0.05） in group 3. At the baseline, the values of [ Ca^2＋]×[ P^3＋] of group 1 and group 3 were more than 40 mg^2/dl^2. One year later, the values of [ Ca^2＋ ]×[ P^3＋ ] in groups 3 were significantly lower than that in group 1, and also lower than that in group 2 while no significant difference. In group 1 and group 3, the levels of PTH were lower at 12 month after PD treatment than that at baseline, however, the cases of PTH in the limit of 150-300 pg/ml were more in group 3. Conclusion：Oral calcium carbonate can prevent and treat hyperphosphatemia. LCD can prevent hyperealeemia, decrease the value of [ Ca^2＋]×[ P^3＋ ], and didnt increase the risk of hypoealeemia.