Bergström J, Fürst P, Alvestrand A, Lindholm B
Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
Kidney Int. 1993 Nov;44(5):1048-57. doi: 10.1038/ki.1993.347.
The aim of this investigation was to analyze factors which influence the dietary protein intake (DPI), the energy intake and the utilization of ingested protein, and to determine the relationship between various types of nitrogen losses in stable continuous ambulatory peritoneal dialysis (CAPD) patients. We performed 23 nitrogen balance (NB) studies of 6 to 11 days duration in 12 CAPD patients. One study was performed in all patients 3.4 +/- 1.2 months after starting CAPD (early studies). The study was then repeated in nine patients after 12.1 +/- 2.6 months, and two of these patients were studied again after 16 and 24 months, respectively (late studies). Before each NB study, the dietary intakes prior to the study were assessed in diaries and interviews. During a few days preceding the NB periods and during the NB periods each patient received an individualized diet composed so as to resemble the patients' spontaneously chosen diet regarding DPI and dietary energy intake (DEI). Total nitrogen, protein, urea and creatinine were analyzed in the dialysate and urine collected daily. Total nitrogen was also analyzed in the feces, collected over the whole NB period. Total nitrogen appearance (TNA), non-protein nitrogen appearance (NPNA) and urea nitrogen appearance (UNA) were calculated by correcting total nitrogen output, non-protein nitrogen output, that is, TNA minus the total protein losses (PL) and urea nitrogen output for changes in total body urea nitrogen. Glucose was determined in the collected dialysate and the daily glucose absorption was calculated. DPI varied between 0.62 and 2.09 g/kg/day, DEI between 21 and 42 kcal/kg/day and the peritoneal energy (glucose) intake (PEI) between 4 and 13 kcal/kg/day. DPI (but not DEI) correlated with Kt/V(urea) and Kt/VCr and with total and renal clearances for urea and creatinine. NB (not corrected for "unmeasured" nitrogen losses) was positive in most studies, and it correlated with DPI and the total energy intake (TEI) in the early studies, but only with TEI in the late studies. DPI correlated with TNA, NPNA, UNA, non-protein-non-urea nitrogen loss and fecal nitrogen loss. UNA was highly correlated with TNA and NPNA (r = 0.95). We used data from 33 NB studies in CAPD patients (our present data combined with data from the literature) to calculate regression equations describing the relationship between TNA and NPNA, respectively, and UNA.(ABSTRACT TRUNCATED AT 400 WORDS)
本研究的目的是分析影响膳食蛋白质摄入量（DPI）、能量摄入量和摄入蛋白质利用率的因素，并确定持续性非卧床腹膜透析（CAPD）患者各种氮损失类型之间的关系。我们对12例CAPD患者进行了23项为期6至11天的氮平衡（NB）研究。在所有患者开始CAPD后3.4±1.2个月进行了一项研究（早期研究）。然后在9例患者12.1±2.6个月后重复该研究，其中2例患者分别在16个月和24个月后再次接受研究（后期研究）。在每次NB研究前，通过日记和访谈评估研究前的饮食摄入量。在NB期之前的几天以及NB期内，每位患者都接受了个性化饮食，其组成与患者自发选择的关于DPI和膳食能量摄入量（DEI）的饮食相似。每天收集的透析液和尿液中分析总氮、蛋白质、尿素和肌酐。在整个NB期收集的粪便中也分析总氮。通过校正总氮输出、非蛋白质氮输出（即TNA减去总蛋白质损失（PL））以及全身尿素氮变化的尿素氮输出，计算总氮出现量（TNA）、非蛋白质氮出现量（NPNA）和尿素氮出现量（UNA）。测定收集的透析液中的葡萄糖，并计算每日葡萄糖吸收量。DPI在0.62至2.09 g/kg/天之间，DEI在21至42 kcal/kg/天之间，腹膜能量（葡萄糖）摄入量（PEI）在4至13 kcal/kg/天之间。DPI（而非DEI）与Kt/V（尿素）和Kt/VCr以及尿素和肌酐的总清除率和肾清除率相关。在大多数研究中，NB（未校正“未测”氮损失）为正值，在早期研究中它与DPI和总能量摄入量（TEI）相关，但在后期研究中仅与TEI相关。DPI与TNA、NPNA、UNA、非蛋白质非尿素氮损失和粪便氮损失相关。UNA与TNA和NPNA高度相关（r = 0.95）。我们使用来自CAPD患者33项NB研究的数据（我们目前的数据与文献数据相结合）来计算分别描述TNA与NPNA以及UNA之间关系的回归方程。（摘要截断于400字）
