低蛋白大米联合低磷乳清蛋白改善血液透析患者高磷血症的自身对照研究

Low protein rice plus low phosphorus whey improves hyperphosphatemia in maintenance hemodialysis patients:a self-controlled study

目的探讨低蛋白大米联合低磷乳清蛋白改善血液透析患者高磷血症的有效性和安全性。方法自身对照研究,选择连续3个月透析前平均血磷≥1.78 mmol/L的患者,先给予4周低磷饮食指导作为基线,然后将饮食中的主食换成等重低蛋白大米,两者蛋白质含量之差用等量低磷乳清蛋白补充,干预10周后再恢复到普通饮食观察8周。分析干预前后血磷、血钙、全段甲状旁腺激素(intact parathyroid hormone,iPTH)、血清白蛋白及营养状态的变化。研究过程中透析方案不变,口服磷结合剂、维生素D或拟钙剂根据血钙、血磷、iPTH结果调整,并记录进行分析统计。结果29例患者完成研究全过程,入组前患者血磷(2.15±0.28)mmol/L,经过4周的低磷饮食指导后基线血磷下降,但无显著性差异。低蛋白大米联合低磷乳清蛋白与基线时比较干预2周后,患者磷摄入、血磷显著降低(t值分别为5.132,-2.200;P值分别为<0.001,0.037),热量、蛋白摄入无显著差异,且血磷维持低水平至干预第10周(与基线比t=-2.011,P=0.048)。恢复普通饮食8周后,尽管热量、蛋白摄入较低蛋白大米联合低磷乳清蛋白干预2周时无显著差异,但磷摄入显著增加(t=-2.577,P=0.016),血磷较干预10周时显著升高(t=2.979,P=0.006),与干预前无显著差异。此外,干预10周时血白蛋白较基线显著增加(t=5.376,P<0.001)。研究过程中,血钙,iPTH,透析方案和磷结合剂使用强度无显著性差异,无明显不良事件。结论低蛋白大米联合低磷乳清蛋白可以在保证患者热量、蛋白摄入的基础上有效降低磷的摄入和血磷水平,并提高血清白蛋白。

Objective To study the efficacy and safety of low protein rice plus low phosphorus whey on hyperphosphatemia in hemodialysis patients.Methods The hemodialysis patients who had average serum phosphorus of≥1.78 mmol/L for three consecutive months were enrolled in this self-controlled trial.Patients received low phosphorus diet instruction for 4 weeks as baseline,followed by change of the staple foods to the same amount of low protein rice for 10 weeks.The difference of protein intake between the low protein rice and staple foods was replaced by low phosphorus whey.Then the patients reverted to staple foods for 8 weeks.Serum phosphorus,calcium,intact parathyroid hormone(iPTH),serum albumin and nutritional status before and after dietary changes were observed and analyzed.Throughout the trial,dialysis treatment remained unchanged;appropriate adjustment of oral phosphorous binding agent,active vitamin D or calcimimetic treatment based on the results of calcium,phosphorus and iPTH were allowed.The changes of these medications were recorded and analyzed.Results A total of 29 patients completed the study.Serum phosphorus at the beginning was 2.15±0.28 mmol/L.After 4 weeks of low phosphorus diet instruction,serum phosphorus decreased but without statistical significance.After 2 weeks of low protein rice plus low phosphate whey,there were no significant differences in calorie and protein intake,while phosphorus intake was significantly reduced(t=5.132,t=-2.200,P<0.001,P=0.037,respectively);serum phosphorus reduced to 1.82±0.45 mmol/L,which was significantly lower than the baseline value(t=-2.200,P=0.037).This effect continued until the end of 10 weeks(t=-2.011,P=0.048,compared to baseline value).After reverted to staple foods for 8 weeks in which calorie and protein intake had no significant differences,phosphorus intake increased significantly(t=-2.577,P=0.016);serum phosphorus increased significantly compared to that during food intervention at 10th week(t=2.979,P=0.006)and had no significant difference from baseline value.In addition,serum albumin increased significantly(t=5.376,P<0.001).There were no changes in serum calcium and iPTH levels,dialysis regimen and phosphorus-binding agents throughout the study.Conclusion For hemodialysis patients,low protein rice plus low phosphorus whey can effectively reduce phosphorus intake,decrease serum phosphorus level,and improve serum albumin on the basis of enough calorie and protein intake.