Leung Simon, McCormick Brendan, Wagner Jessica, Biyani Mohan, Lavoie Susan, Imtiaz Rameez, Zimmerman Deborah
Division of Endocrinology, Department of Medicine, Ottawa Hospital, Ottawa, ON, Canada.
Division of Nephrology, Department of Medicine, Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
BMC Nephrol. 2015 Dec 9;16:205. doi: 10.1186/s12882-015-0205-3.
Removal of phosphate by peritoneal dialysis is insufficient to maintain normal serum phosphate levels such that most patients must take phosphate binders with their meals. However, phosphate 'counting' is complicated and many patients are simply prescribed a specific dose of phosphate binders with each meal. Therefore, our primary objective was to assess the variability in meal phosphate content to determine the appropriateness of this approach.
In this prospective cohort study, adult patients with ESRD treated with peritoneal dialysis and prescribed phosphate binder therapy were eligible to participate. Participants were excluded from the study if they were unable to give consent, had hypercalcemia, were visually or hearing impaired or were expected to receive a renal transplant during the time of the study. After providing informed consent, patients kept a 3-day diet diary that included all foods and beverages consumed in addition to portion sizes. At the same time, patients documented the amount of phosphate binders taken with each meal. The phosphate content of the each meal was estimated using ESHA Food Processor SQL Software by a registered dietitian. Meal phosphate and binder variability were estimated by the Intra Class Correlation Coefficient (ICC) where 0 indicates maximal variability and 1 indicates no variability.
Seventy-eight patients consented to participate in the study; 18 did not complete the study protocol. The patients were 60 (± 17) years, predominately male (38/60) and Caucasian (51/60). Diabetic nephropathy was the most common cause of end stage kidney disease. The daily phosphate intake including snacks ranged from 959 ± 249 to 1144 ± 362 mg. The phosphate ICC by meal: breakfast 0.63, lunch 0.16; supper 0.27. The phosphate binder ICC by meal: breakfast 0.68, lunch 0.73, supper 0.67.
The standard prescription of a set number of phosphate binders with each meal is not supported by the data; patients do not appear to be adjusting their binders to match the meal phosphate content. An easy to use phosphate counting program that assists the patient in determining the appropriate amount of phosphate binder to take may enhance phosphate control.
腹膜透析清除磷酸盐不足以维持正常血清磷酸盐水平，因此大多数患者必须在进餐时服用磷酸盐结合剂。然而，计算磷酸盐含量很复杂，许多患者只是每餐被规定服用特定剂量的磷酸盐结合剂。因此，我们的主要目标是评估餐中磷酸盐含量的变异性，以确定这种方法的适当性。
在这项前瞻性队列研究中，接受腹膜透析并规定了磷酸盐结合剂治疗的成年终末期肾病（ESRD）患者有资格参与。如果参与者无法给出同意书、患有高钙血症、有视力或听力障碍或预计在研究期间接受肾移植，则被排除在研究之外。在提供知情同意书后，患者记录一份为期3天的饮食日记，其中包括所有食用的食物和饮料以及份量。同时，患者记录每餐服用的磷酸盐结合剂的量。每餐的磷酸盐含量由注册营养师使用ESHA Food Processor SQL软件估算。餐中磷酸盐和结合剂的变异性通过组内相关系数（ICC）进行估算，其中0表示最大变异性，1表示无变异性。
78名患者同意参与研究；18名未完成研究方案。患者年龄为60（±17）岁，以男性为主（38/60），白种人（51/60）。糖尿病肾病是终末期肾病最常见的病因。包括零食在内的每日磷酸盐摄入量为959±249至1144±362毫克。餐中磷酸盐的ICC：早餐0.63，午餐0.16；晚餐0.27。餐中磷酸盐结合剂的ICC：早餐0.68，午餐0.73，晚餐0.67。
数据不支持每餐固定服用一定数量磷酸盐结合剂的标准处方；患者似乎没有根据餐中磷酸盐含量调整其结合剂的服用量。一个易于使用的计算磷酸盐含量的程序，可帮助患者确定合适的磷酸盐结合剂服用量，可能会增强对磷酸盐的控制。
