Wang Angela Yee-Moon, Woo Jean, Sea Mandy Man-Mei, Law Man-Ching, Lui Siu-Fai, Li Philip Kam-Tao
Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Am J Kidney Dis. 2004 Apr;43(4):712-20.
Hyperphosphatemia is an important predictor for mortality in hemodialysis patients. This study evaluated significant factors associated with hyperphosphatemia in peritoneal dialysis (PD) patients.
We estimated residual renal function (RRF), dialysis adequacy, and normalized protein equivalent nitrogen appearance (nPNA), together with simultaneous measurement of serum phosphorus levels in 252 prevalent Chinese continuous ambulatory peritoneal dialysis (CAPD) patients.
Average serum phosphorus level was 5.2 +/- 1.5 mg/dL (1.68 +/- 0.48 mmol/L). Serum phosphorus levels were 5.6 mg/dL or greater (> or =1.81 mmol/L) in 44.0% of anuric patients (n = 116) versus 28.7% of patients with RRF (n = 136; P = 0.012). Patients with RRF maintained serum phosphorus levels at or less than the median value (< or =5.1 mg/dL [< or=1.65 mmol/L]), with a total creatinine clearance (CCr) of 72 +/- 25 L/wk/1.73 m2 and nPNA of 0.94 +/- 0.19 g/kg/d in contrast to a total CCr of 63 +/- 22 L/wk/1.73 m2 (P = 0.031) and nPNA of 1.03 +/- 0.22 g/kg/d (P = 0.011) in patients with serum phosphorus levels greater than the median value. Among anuric patients, total CCrs were 46 +/- 9 and 42 +/- 7 L/wk/1.73 m2 (P = 0.005) and nPNA values were 0.89 +/- 0.17 and 0.98 +/- 0.18 g/kg/d (P = 0.010) for patients with serum phosphorus levels at the median value or less and greater than the median value, respectively. Multiple regression analysis showed that residual glomerular filtration, despite an average of less than 2 mL/min/1.73 m2, was independently associated with phosphorus control in PD patients. nPNA, PD CCr or urea clearance, body mass index, and parathyroid hormone level were other important correlates of serum phosphorus levels in patients with and without RRF.
Hyperphosphatemia is a frequent complication in Chinese CAPD patients. Our study not only shows the importance of RRF in maintaining serum phosphorus levels in PD patients, but also the limitations of PD alone to achieve adequate phosphorus control in anuric patients.
高磷血症是血液透析患者死亡的重要预测指标。本研究评估了腹膜透析（PD）患者中与高磷血症相关的显著因素。
我们评估了252例中国维持性持续性非卧床腹膜透析（CAPD）患者的残余肾功能（RRF）、透析充分性和标准化蛋白相当氮出现率（nPNA），同时测量血清磷水平。
血清磷平均水平为5.2±1.5mg/dL（1.68±0.48mmol/L）。无尿患者（n = 116）中44.0%的血清磷水平≥5.6mg/dL（≥1.81mmol/L），而有RRF的患者（n = 136）中这一比例为28.7%（P = 0.012）。有RRF的患者血清磷水平维持在或低于中位数（≤5.1mg/dL[≤1.65mmol/L]），总肌酐清除率（CCr）为72±25L/周/1.73m²，nPNA为0.94±0.19g/kg/天；相比之下，血清磷水平高于中位数的患者总CCr为63±22L/周/1.73m²（P = 0.031），nPNA为1.03±0.22g/kg/天（P = 0.011）。在无尿患者中，血清磷水平在中位数及以下和高于中位数的患者，其总CCr分别为46±9和42±7L/周/1.73m²（P = 0.005），nPNA值分别为0.89±0.17和0.98±0.18g/kg/天（P = 0.010）。多元回归分析显示，尽管平均肾小球滤过率低于2mL/分钟/1.73m²，但残余肾小球滤过与PD患者的磷控制独立相关。nPNA、PD的CCr或尿素清除率、体重指数和甲状旁腺激素水平是有和无RRF患者血清磷水平的其他重要相关因素。
高磷血症是中国CAPD患者常见的并发症。我们的研究不仅表明RRF在维持PD患者血清磷水平方面的重要性，也表明仅靠PD在无尿患者中实现充分磷控制的局限性。
