Voormolen Nora, Noordzij Marlies, Grootendorst Diana C, Beetz Ivo, Sijpkens Yvo W, van Manen Jeannette G, Boeschoten Elisabeth W, Huisman Roel M, Krediet Raymond T, Dekker Friedo W
Department of Clinical Radiology, Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, The Netherlands.
Nephrol Dial Transplant. 2007 Oct;22(10):2909-16. doi: 10.1093/ndt/gfm286. Epub 2007 May 21.
Hyperphosphataemia is associated with increased mortality in patients with chronic kidney disease (CKD) stage IV or on dialysis. Furthermore, in animal studies, elevated plasma phosphate has been shown to be associated with an accelerated decline in renal function. The aim of this study was to determine the association of plasma phosphate with renal function loss and mortality in CKD stage IV-V pre-dialysis patients with GFR <20 ml/min/1.73 m(2).
Incident pre-dialysis patients were included between 1999 and 2001 in the multi-centre PREPARE study, and followed until 2003 or death. Rate of decline in renal function for each patient was calculated by linear regression using the Modification of Diet in Renal Disease (MDRD) formula to estimate GFR (eGFR).
A total of 448 patients were included [mean (SD) age 60 (15) years, eGFR 13 (5.4) ml/min/1.73 m(2), decline in renal function 0.38 (0.95) ml/min/month]. Phosphate concentration at baseline was 4.71 (1.16) mg/dl, calcium 9.25 (0.77) mg/dl and calcium-phosphate product 43.5 (10.9) mg(2)/dl(2). For each mg/dl higher phosphate concentration, the mean (95% CI) decline in renal function increased with 0.154 (0.071-0.237) ml/min/month. After adjustment, this association remained [beta 0.178 (0.082-0.275)]. Seven percent of the patients died. Crude mortality risk was 1.25 (0.85-1.84) per mg/dl increase in phosphate, which increased to 1.62 (1.02-2.59) after adjustment.
High plasma phosphate is an independent risk factor for a more rapid decline in renal function and a higher mortality during the pre-dialysis phase. Plasma phosphate within the normal range is likely of vital importance in pre-dialysis patients.
高磷血症与慢性肾脏病（CKD）4期患者或透析患者的死亡率增加相关。此外，在动物研究中，血浆磷酸盐升高已被证明与肾功能加速下降有关。本研究的目的是确定血浆磷酸盐与CKD 4-5期透析前肾小球滤过率（GFR）<20 ml/min/1.73 m²患者的肾功能丧失和死亡率之间的关联。
1999年至2001年，多中心PREPARE研究纳入了初诊透析前患者，并随访至2003年或死亡。使用肾脏病饮食改良（MDRD）公式估算GFR（eGFR），通过线性回归计算每位患者的肾功能下降率。
共纳入448例患者[平均（标准差）年龄60（15）岁，eGFR 13（5.4）ml/min/1.73 m²，肾功能下降0.38（0.95）ml/min/月]。基线时磷酸盐浓度为4.71（1.16）mg/dl，钙为9.25（0.77）mg/dl，钙磷乘积为43.5（10.9）mg²/dl²。磷酸盐浓度每升高1 mg/dl，肾功能平均（95%CI）下降增加0.154（0.071-0.237）ml/min/月。调整后，这种关联仍然存在[β 0.178（0.082-0.275）]。7%的患者死亡。磷酸盐每升高1 mg/dl，粗死亡率风险为1.25（0.85-1.84），调整后增加至1.62（1.02-2.59）。
高血浆磷酸盐是透析前阶段肾功能更快下降和更高死亡率的独立危险因素。正常范围内的血浆磷酸盐对透析前患者可能至关重要。
