Objective: To explore the impact of dietary sodium-intake on residual renal function in patients undergoing peritoneal dialysis (PD).
Methods: Thirty-three patients on PD with stable dialysis were regularly followed up for 12 months. The daily sodium intake of the patients was calculated based on the 3-day dietary record. Based on the mean daily sodium intake, the patients enrolled were divided into low-salt group (sodium intake≤3.0 g/day, 19 patients) and high-salt group (sodium intake>3.0 g/day, 14 patients). The baseline data of the patients were recorded, and the indicators of residual renal function and peritoneal function were regularly tested. The patients were followed-up at 3-month intervals, and their urine volume, peritoneal ultrafiltration volume and other clinical indicators were recorded and the biochemical indexes were detected to evaluate the changes in the residual renal function and peritoneal function.
Results: There was a positive correlation between the total sodium excretion and dietary sodium intake in these patients (r=0.536, P=0.0013), and sodium excretion by dialysis was positively correlated with their sodium intake (r=0.901, P=0.000). Regression analysis suggested that the total sodium excretion was correlated with dietary sodium intake (β=0.416, 95% CI: 0.170-0.666; P < 0.0018); sodium excretion by dialysis was associated with dietary sodium intake (β=0.489, 95% CI: 0.395-0.582; P < 0.001). The residual renal function was reduced by 17.48±11.22 L /(w·1.73 m2) in the low-salt group, as compared to 30.20±18.30 L /(w·1.73 m2) in the high-salt group (P=0.032). The reduction in the residual renal function was correlated with sodium intake in the PD patients (r=0.409, P=0.018). Multivariate regression analysis showed that sodium intake was an independent factor contributing to the reduction of residual renal function (β=14.646, 95% CI 7.426-21.866, P < 0.001).
Conclusions: Sodium excretion by PD in patients with continuous ambulatory PD is positively correlated with their dietary sodium intake, which contribute to the decrease of residual renal function. A high dietary sodium intake may accelerate the reduction of residual renal function in these patients.
目的: 探讨腹膜透析患者摄钠量与残余肾功能之间的关系。
方法: 对33例稳定透析、规律随访的腹膜透析患者进行12月的随访观察。以3 d饮食记录计算患者的日摄盐量，以平均日摄钠量为依据，将患者分为低盐组（摄钠量≤3.0 g/d，19例）和高盐组（摄钠量>3.0 g/d，14例）。记录患者基线资料，检测患者残余肾功能、腹膜功能等指标。按1次/3月进行规律随访。记录尿量、腹透超滤量等临床指标，检测患者生化指标，评估患者残余肾功能、腹膜功能的变化情况。
结果: 钠排泄总量与腹透患者钠摄入量呈正相关（r=0.536，P=0.0013）；腹透清除钠的总量与腹透患者钠摄入量呈正相关（r=0.901，P=0.000），而残余肾的钠排泄量与腹透患者钠摄入量无明显相关关系。回归分析发现，钠排泄总量、腹透液钠的排泄均与钠的摄入相关（β=0.416，95%CI：0.170~0.666，P < 0.0018；β=0.489，95%CI：0.395~0.582，P < 0.001）。腹透患者残余肾功能的下降值，低盐组为17.48±11.22 L/（w·1.73 m2），高盐组为30.20±18.30 L/（w·1.73 m2），差异有统计学意义（P=0.032）。患者残余肾功能的下降与摄钠量之间存在相关关系（r=0.409，P=0.018），多因素回归分析显示摄钠量是残余肾功能下降的独立影响因素（β=14.646，95%CI：7.426~21.866，P < 0.001）。
结论: 腹透患者腹透清除钠的总量与患者钠摄入量呈正相关；腹透患者残余肾功能的下降和摄钠量相关，高钠饮食可使残余肾功能下降更快。
Keywords: dietary sodium intake; peritoneal dialysis; residual renal function.