高血压对持续腹膜透析患者残肾功能的影响

目的：观察不同血压控制状态对患者的残肾功能以及对临床效果的影响。方法：按照140／90mmHg为界,将患者分为血压控制良好组和血压控制不佳组,比较定期随访中两组残肾功能,秀析充分性指标,营养状况和临床结果的判别。结果：腹膜秀析（腹透）患者中高血压的发生率为94．7％,在54例高血压患者中,78．6％的患者联合使用两种以上的降压药物,血压控制正常者仅22例,血压控制较好的患者残肾功能和充分性保持较好,脑血管事件的发生少,结论：持续高血压会加速腹透患者残肾功能的丢失并增加并发症的产生,血压的控制在腹透阶段和非透析氮质血症阶段同等重要。     

腹膜透析患者残余肾功能与左心室质量的相关性分析

目的探讨腹膜透析患者残余肾功能与左心室质量及左心室质量指数的关系。方法选取我院接受持续不卧床腹膜透析治疗半年以上的慢性肾衰竭患者103例,将其根据残余肾肌酐清除率（Ccr）水平分为3组,A组31例：Cer为0～2ml·min-1·（1．73m2）-1;B组42例：Cer为2～4ml·min-1·（1．73m2）;C组30例：Ccr〉4ml·min-1·（1．73m2）-1。所有入选患者均检测残余肾Ccr、平均动脉压（MBP）、血钙、血磷、血清全段甲状旁腺素（iPTH）、左心室质量及左心室质量指数,并进行组间统计学分析。结果3组患者MBP和血钙水平差异无统计学意义（P〉0．05）;与A组相比,B组和C组患者血磷、钙磷乘积、iPTH、左心室质量及左心室质量指数降低（P〈0．01）;Pearson相关分析显示,Ccr与血磷（r=-0．384,P=0．000）、钙磷乘积（r=-0．344,P=0．000）及iPTH（r=-0．435,P=0．000）存在负相关关系;左心室质量及左心室质量指数与MBP（r=0．300,P=0．002;r=0．240,P=0．015）、血磷（r=0．332,P=0．001;r=0．241,P=0．014）、钙磷乘积（r=0．284,P=0．004;r=0．212,P=0．032）、iPTH（r=0．266,P=0．007;r=0．226,P=0．021）存在正相关关系。结论左心室质量及左心室质量指数增加与残余肾功能的丧失有一定的相关性,积极保护残余肾功能可以减少心血管疾病发生率和病死率。     

腹膜透析初透剂量对患者残余肾功能的影响

目的 探讨腹膜透析（腹透）初透剂量对患者残余肾功能的影响。 方法 追踪观察我院3个月内连续门诊随访的178例开始腹透的患者,测定24 h尿量。根据透析第1、3个月尿量的变化分为少尿组（LU,97例）、尿量减少组（DU,19例）、尿量正常组（NU,62例）,记录并分析其透析剂量、腹透液葡萄糖含量、超滤量、尿素清除指数（Kt/V）、体质量、水肿程度及尿量变化等的相关性。 结果 3组患者的年龄和性别比例差异无统计学意义。透析1个月后,DU组的体质量和水肿程度大于LU和NU组（P < 0.05）;腹透液总入量、腹透液葡萄糖含量、超滤量、残余肾尿素清除指数Kt/V（rKt/V）高于LU组,与NU组差异无统计学意义。透析3个月后,DU组的体质量和水肿程度有所下降（P < 0.05）,但仍高于LU和NU组（P < 0.05）;腹透液总入量、超滤量、尿量下降速度比LU组和NU组高（P < 0.05）;rKt/V 比腹透前显著下降（P < 0.05）。3组的血清白蛋白和tKt/V差异无统计学意义。 结论 开始腹透患者过度超滤可引起残余肾功能下降。对于有一定残余肾功能的患者要注意避免快速或过多超滤。     

依贝沙坦对维持性腹膜透析患者残存肾功能的保护作用

目的 探讨血管紧张素Ⅱ受体拮抗剂（ARB）依贝沙坦能否延缓腹膜透析患者残存肾功能（RRF）的丢失。 方法 将入选的48例病情稳定的维持性腹膜透析患者随机分为依贝沙坦组和对照组。依贝沙坦组予安博维300 mg/d。所有患者每3个月行残存肾功能测定（eGFR），研究前后检测Kt/V、肌酐清除率（CCL）、血钾、血红蛋白，并记录血压和24 h尿量。 结果 研究结束时，依贝沙坦组和对照组的收缩压和舒张压、血红蛋白、血钾水平差异均无统计学意义；依贝沙坦组CCL[单位：L&#8226;周-1&#8226;(1.73 m2)-1] 高于对照组 （63.0±16.9 比 59.0±14.8，P < 0.05）；两组24 h尿量均减少，但对照组较依贝沙坦组减少明显 [(663±312) 比(885±276) ml/d，P < 0.05]。前6个月两组eGFR都明显下降，而依贝沙坦组更明显，6个月后依贝沙坦组下降变缓，研究结束时依贝沙坦组eGFR较对照组高[（1.68±1.01）比（1.04±0.76）ml/min，P < 0.05]。 结论 长期使用依贝沙坦可以延缓腹透患者的残存肾功能的丢失     

A novel association between residual renal function and left ventricular hypertrophy in peritoneal dialysis patients

BACKGROUND: Left ventricular hypertrophy (LVH) and dialysis adequacy are both important predictors for mortality in dialysis patients. This study evaluated the association between residual renal function (RRF) and the severity of LVH in endstage renal failure (ESRF) patients undergoing long-term continuous ambulatory peritoneal dialysis (CAPD). METHODS: A cross-section study was performed with left ventricular mass index (LVMi), determined in 158 non-diabetic CAPD patients using echocardiography and its relationship with residual glomerular filtration rate (GFR), peritoneal dialysis (PD) and total weekly urea clearance (Kt/V) and other known risk factors for LVH was evaluated. RESULTS: Twelve patients had no LVH (group I). The remaining 146 patients were stratified [group II (lowest), III and IV (highest)] according to the LVMi (median 207 g/m2; range 103 to 512 g/m2). Across the four groups of patients with increasing LVMi, there was significant decline in GFR (2.27 +/- 1.98 vs. 1.49 +/- 1.58 vs. 1.61 +/- 1.91 vs. 0.80 +/- 1.42 mL/min/1.73 m2; P = 0.011) and total weekly Kt/V (1.98 +/- 0.44 vs. 1.96 +/- 0.38 vs. 1.92 +/- 0.42 vs. 1.71 +/- 0.42; P = 0.037); however, PD Kt/V was similar for all four groups. Patients with better-preserved residual GFR not only had significantly higher total Kt/V, but were less anemic and hypoalbuminemic and had a trend toward lower systolic blood pressure and arterial pulse pressure. Multiple regression analysis showed that other than age, gender, body weight, arterial pulse pressure, hemoglobin and serum albumin, known factors for LVH, residual GFR (estimated mean -7.94; 95% confidence interval -15.13 to -0.74; P = 0.031) was also independently associated with LVMi. CONCLUSIONS: Other than anemia, hypoalbuminemia and arterial pulse pressure, this study demonstrates an important, novel association between the degree of RRF and severity of LVH in ESRF patients undergoing long-term CAPD. Prospective studies are needed to define if indeed there is a cause-effect relationship between this association, to evaluate if a decline in residual GFR is independently associated with an increase in LVMi, and to determine whether treatment directed at preserving RRF will reduce the severity of LVH, improve cardiac performance and hence survival of these patients.     

Association between residual renal function, inflammation and patient survival in new peritoneal dialysis patients.

BACKGROUND: The recent ADEMEX study (Paniagua R, Amato D, Vonesh E et al. J Am Soc Nephrol 2002; 13: 1307-1320) indicates that peritoneal small solute clearance is not as critical for the survival of peritoneal dialysis (PD) patients as thought previously. On the other hand, low residual renal function (RRF), inflammation and an increased peritoneal transport rate (PTR) as evaluated by the peritoneal equilibration test (PET) are reported to be associated with increased mortality in PD patients, but the relationships between these factors and their separate and combined impact on the survival of PD patients are not clear. In this retrospective analysis, we evaluated possible relationships between RRF, inflammation and initial PTR in patients starting PD and the impact of these factors on patient survival. METHODS: A total of 117 patients with initial assessments for RRF, serum C-reactive protein (CRP) and PET at a mean period of 0.4+/-0.2 months (range 0.1-1.0 months) after start of PD were included in this study. Based on RRF (cut-off point, 4 ml/min/1.73 m(2)), serum CRP (cut-off point, 10 mg/l), and the dialysate to plasma creatinine ratio at 4-h of dwell (mean+1 SD), the patients were divided into different groups: low RRF and high RRF group, high CRP and normal CRP group and high PTR and other PTR group, respectively. RESULTS: Of 117 patients, 54 patients (46%) were in low RRF (<4 ml/min/1.73 m(2)) group, 36 patients (31%) were in high serum CRP (> or = 10 mg/l) group and 17 patients (15%) were in high PTR group. Forty-nine patients (42%) had one of these characteristics, 26 patients (22%) had two of these characteristics, two patients (2%) had three, and 40 patients (34%) had none of these characteristics. Patients with low RRF were older and had a higher prevalence of high CRP, lower normalized protein equivalent of total nitrogen appearance (nPNA), lower total Kt/V(urea) and lower total creatinine clearance (CCr) whereas patients with high CRP were older and had a higher proportion of men, lower serum albumin, lower nPNA, lower RRF and lower total CCr. Patients with high PTR had lower serum albumin, higher RRF and higher total CCr compared with patients with other PTR. Upon logistic multiple regression analysis, age and RRF were identified as factors affecting inflammation. Overall patient survival was significantly lower in the patients with low RRF, with high CRP, and in patients with more than two of the following: low RRF, high CRP and high PTR. In contrast, in patients with none of the discriminators low RRF, high CRP and high PTR, the 5-year survival was 100%. A high PTR was associated with decreased survival during the initial year on PD, but not thereafter. Patients who died during the follow-up period had a higher prevalence of high CRP and lower serum albumin, lower RRF, lower Kt/V(urea) and lower total CCr. Upon Cox proportional hazards multivariate analysis, age and RRF were predictors of mortality. CONCLUSIONS: These results indicate that in patients starting PD, low initial RRF is associated with inflammation, and low RRF and inflammation are both associated with high overall mortality. A high PTR was associated with higher mortality, but only during the initial year on PD, whereas Kt/V(urea) did not predict mortality. These results indicate the importance of RRF and inflammation as predictors of mortality in PD patients whereas the predictive power of PTR as such may lose its significance if these two parameters are taken into consideration.     

Benefits of preserving residual renal function in peritoneal dialysis

Residual renal function (RRF) is of paramount importance in patients with end-stage renal disease, with benefits that go beyond contributing to achievement of adequacy targets. Several studies have found that RRF rather than overall adequacy (as estimated from total small solute removal rates) is an essential marker of patient and, to a lesser extent, technique survival during chronic peritoneal dialysis (PD) therapy. In addition, RRF is associated with a reduction in blood pressure and left ventricular hypertrophy, increased sodium removal and improved fluid status, lower serum beta(2)-microglobulin, phosphate and uric acid levels, higher serum hemoglobin and bicarbonate levels, better nutritional status, a more favorable lipid profile, decreased circulating inflammatory markers, and lower risk for peritonitis in PD. As compared with conventional hemodialysis, PD is associated with a slower decrease in RRF. This highlights the usefulness of strategies oriented to preserve both RRF and the long-term viability of the peritoneal membrane. Several factors contributing to the loss of RRF have been identified and should be avoided. Renoprotective drugs and new glucose-sparing, more biocompatible PD regimes may prove useful tools to preserve RRF and peritoneal membrane function in the near future.     

The relationship among asymmetric dimethylarginine (ADMA) levels, residual renal function, and left ventricular hypertrophy in continuous ambulatory peritoneal dialysis patients

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial-based nitric oxide synthase. Its level is increased by end stage renal disease. However, most studies showing an increase in ADMA in dialysis patients have focused on hemodialysis. Results with peritoneal dialysis patients have been more inconclusive. Recent studies suggest that ADMA may be a new cardiovascular risk factor. The aim of the present study was to evaluate the relationship between ADMA levels, residual renal function, and left ventricular hypertrophy in peritoneal dialysis patients. Serum ADMA measurements and echocardiographic evaluations were performed in 54 peritoneal dialysis patients and 26 healthy volunteers. Residual renal function was measured in peritoneal dialysis patients by urea clearance from a urine collection. Thirty-two of the 54 peritoneal dialysis patients had residual renal function. ADMA levels of the peritoneal dialysis group were found to be significantly higher than those of healthy individuals (p = 0.03). Within the peritoneal dialysis group, ADMA levels of patients with residual renal function were significantly lower than those without residual renal function (p = 0.01), though they were still higher than the ADMA levels of the control group (p = 0.04). Serum levels of ADMA were positively correlated with left ventricular mass index (r = 0.29, p = 0.01) and negatively correlated with early mitral inflow velocity (Em) (r = -0.28, p = 0.01), Em/Late mitral inflow velocity (Am) (r = -0,32, p = 0.00), and isovolumetric relaxation time (r = -0.30, p = 0.01). In conclusion, increased ADMA levels seem to be associated with left ventricular hypertrophy in peritoneal dialysis patients, and residual renal function may lead to a reduction of serum ADMA levels.     

腹膜透析剂量与残余肾功能及透析质量的关系研究

目的观察慢性肾脏病5期患者应用非透析治疗、不同腹膜透析剂量治疗对肾功能的影响。方法选取慢性肾脏病5期的非糖尿病肾病患者,采用非透析保守治疗者20例,腹膜透析剂量4升／天者26例、6升／天者35例及8升／天者43例。随访观察1年,检查各项指标及肾功能的变化。结果随访1年后,非透析患者血压的控制较4升／天腹膜透析组差（P〈0．05）,血清白蛋白水平、血钙水平低于4升／天透析组,血磷及甲状旁腺素水平高于不同剂量透析组。各组尿量及残余肾功能均有不同程度的下降,其中腹膜透析各组尿量、肾功能及非透析组肾功能均较观察前具有统计学差异（P〈0．05）,而各组之间肾功能下降的幅度未见显著性差异（P〉0．05）。结论慢性肾脏病5期患者早期的腹膜透析治疗对患者钙磷代谢、蛋白质营养改善及血压的控制优于非透析治疗。腹膜透析治疗对残余肾功能的保护与非透析治疗相比未见明显优势,不同的透析剂量在1年的观察期内未显示对肾功能的影响。     

腹膜透析患者残余肾功能下降速率的相关影响因素分析

目的 探讨腹膜透析患者残余肾功能(RRF)下降速率的相关影响因素,以期为临床早期干预提供依据.方法 将纳入的95例患者按估算的肾小球滤过率(eGFR)水平分为A组[eGFR＜ 6mL·(min·1.73m2)-1]、B组[eGFR(6 ～10)mL·(min·1.73m2)-1]及C组[eGFR＞ 10mL·(min·1.73m2)-1],随访患者18个月或至终点事件发生,计算eGFR平均下降速率,并建立回归模型,分析各项指标与eGFR下降速率的关系.结果 95例患者eGFR下降速率平均为-0.156mL·(min·1.73m2)-1,其中A组为-0.091mL·(min·1.73m2)-1,B组为-0.153mL·(min·1.73m2)-1,C组为-0.251mL· (min·1.73m2)-1;共有37例(38.95％)eGFR丧失,其中A组18例(60.00％)、B组13例(40.63％),C组6例(18.18％);3组eGFR下降速率及eGFR丧失率组间比较均有显著差异(P ＜0.001).至终点时,3组死亡率、转HD治疗及行肾移植组间比较均无显著差异(P＞0.05).多因素回归分析显示,基线时eGFR、Hb、血清白蛋白、总胆固醇、NT-pro-BNP为为eGFR下降速率的独立影响因素.结论 腹膜透析患者eGFR下降速率与基线时eGFR、Hb、血浆白蛋白、总胆固醇及NT-pro-BNP水平等密切相关,临床上应识别并重视.     

Predictors of loss of residual renal function among new dialysis patients

Residual renal function (RRF) in end-stage renal disease is clinically important as it contributes to adequacy of dialysis, quality of life, and mortality. This study was conducted to determine the predictors of RRF loss in a national random sample of patients initiating hemodialysis and peritoneal dialysis. The study controlled for baseline variables and included major predictors. The end point was loss of RRF, defined as a urine volume <200 ml/24 h at approximately 1 yr of follow-up. The adjusted odds ratios (AOR) and P values associated with each of the demographic, clinical, laboratory, and treatment parameters were estimated using an "adjusted" univariate analysis. Significant variables (P < 0.05) were included in a multivariate logistic regression model. Predictors of RRF loss were female gender (AOR = 1.45; P < 0.001), non-white race (AOR = 1.57; P = <0.001), prior history of diabetes (AOR = 1.82; P = 0.006), prior history of congestive heart failure (AOR = 1.32; P = 0.03), and time to follow-up (AOR = 1.06 per month; P = 0.03). Patients treated with peritoneal dialysis had a 65% lower risk of RRF loss than those on hemodialysis (AOR = 0.35; P < 0.001). Higher serum calcium (AOR = 0.81 per mg/dl; P = 0.05), use of an angiotensin-converting enzyme inhibitor (AOR = 0.68; P < 0.001). and use of a calcium channel blocker (AOR = 0.77; P = 0.01) were independently associated with decreased risk of RRF loss. The observations of demographic groups at risk and potentially modifiable factors and therapies have generated testable hypotheses regarding therapies that may preserve RRF among end-stage renal disease patients.     

血清白蛋白水平对腹膜透析患者残余肾功能的影响

Objective To study the effect of serum albumin(Alb) levels on residual renal function (RRF) in peritoneal dialysis patients. Methods Fiftyfour patients accepting peritoneal dialysis were divided into two groups base- d on the serum levels of Alb,including group A (Alb≥35 g/L) and group B(Alb < 35g/L). The serum levels of Alb, creatinine, urea nitrogen, IL-6, TNFα were determined. 24 - hour urine and peritoneal dialysis fluids were remained and urea nitrogen, creatinine, RRF, and others were determined. The above mentioned marks and RRF were observed in follow- up visit. Results The proportion of diabetic nephropathy patients in group B was higher than in group A. Correlative analysis indicated that a negative correlation was found between the levels of Alb and mediators of inflammation IL - 6 and TNF - α. The de-crease in RRF is time- dependent in all selected patients. But the RRF in group B began to decline since peritoneal dialysis 6th month, there is lower compared with 1st month. After peritoneal dialysis 12th months the RRF in group A also significant declined, but the degree of declining in group B was greater. Correlative analysis indicated that the negative correlation was found between RRF and the levels of Alb, otherwise the positive correhtion was found between the RRF and mediators of inflammation IL - 6 and TNF - α. Conclusions The low levels of Alia resulted from malnutrition was one of the factors to decline RRF in per-itoneal dialysis patients. The high levels of mediators of inflammation accelerated the deterioration of the RRF.     

血清白蛋白水平对腹膜透析患者残余肾功能的影响

目的 研究血清白蛋白水平对腹膜透析患者残余肾功能的影响.方法 54例腹膜透析患者以血清白蛋白35 g/L为界,血清白蛋白≥35 g/L为A组,血清白蛋白<35 g/L为B组,测定血清白蛋白、血肌酐、血尿素氮,白细胞介素6、肿瘤坏死因α,留取24 h尿量及腹透液、记录总量并检测尿素氮、肌酐;残余肾功能等.随访过程中观察以上指标和残余.肾功能(RRF).结果 B组中糖尿病肾病患者的比例高于A组,相关分析结果显示血清白蛋白水平与炎症介质白细胞介素6及肿瘤坏死因α水平呈负相关(r分别=-0.48、-0.64,P均<0.05),随着透析时间的延长两组患者RRF均下降,而B组RRF自腹膜透析6个月时即开始下降,与透析初月比较差异有统计学意义(P<0.05),12个月时A组RRF与透析初月时比较差异有统计学意义(P<0.05),A、B组RRF比较差异也有统计学意义(P<0.05).相关分析结果显示残余肾功能下降绝对值(△RRF)与血清白蛋白水平呈负相关(r=-0.31,P<0.05),与白细胞介素6及肿瘤坏死因α水平呈正相关(r分别=0.45、0.58,P均<0.01).结论 营养不良导致低水平的血清白蛋白是促进腹膜透析患者残余肾功能下降的因素之一,高水平的炎症介质也加速了残余肾功能的恶化.     

Peritoneal transport rate,systemic inflammation,and residual renal function determine peritoneal protein clearance in continuous ambulatory peritoneal dialysis patients

Background

Peritoneal protein clearance (Pcl) is related to the mortality of patients on continuous ambulatory peritoneal dialysis (CAPD) as well as technique failure. In this prospective observational study, we aimed to investigate factors associated with the level of Pcl.

Methods

We prospectively enrolled 344 prevalent CAPD patients. A standard peritoneal equilibrium test was conducted for each patient. Baseline demographics, biochemistry, and Pcl were recorded.

Results

The average Pcl of the patients was 97.40 ± 54.14 mL/day. Peritoneal transport level, serum high-sensitivity C-reactive protein (hsCRP), and residual glomerular filtration rate (rGFR) were independently related to Pcl. The standard β values were 0.53, 0.17, and ?0.10, respectively. Moreover, compared with non-diabetic patients, diabetic patients had a non-significantly higher level of Pcl (104.90 ± 48.65 vs. 96.15 ± 54.97 mL/day; P = 0.06).

Conclusion

Continuous ambulatory peritoneal dialysis patients lose a high amount of protein through the peritoneum each day. The Pcl value is positively related to the level of peritoneal transport and hsCRP and negatively related to the rGFR.     

The importance of residual renal function in dialysis patients

Preserving residual renal function has always been the primary clinical goal for every nephrologist managing patients with chronic kidney disease. There is no reason why this important goal should not extend to patients with stage 5 chronic kidney disease receiving dialysis. Indeed, there is now clear evidence that preserving residual renal function remains important after the commencement of dialysis. Residual renal function contributes significantly to the overall health and well-being of dialysis patients. It not only provides small solute clearance but also plays an important role in maintaining fluid balance, phosphorus control, and removal of middle molecular uremic toxins, and shows strong inverse relationships with valvular calcification and cardiac hypertrophy in dialysis patients. Decline of residual renal function also contributes significantly to anemia, inflammation, and malnutrition in patients on dialysis. More importantly, the loss of residual renal function, especially in patients on peritoneal dialysis, is a powerful predictor of mortality. In addition, there is increasing evidence that residual renal and peritoneal dialysis clearance cannot be assumed to be equivalent qualitatively, thus indicating the need to preserve residual renal function in patients on dialysis. In this article, we will review evidence that residual renal function is important in dialysis patients (especially peritoneal dialysis) and outline potential strategies that may better preserve residual renal function in dialysis patients.     

Association of fetuin A,left ventricular function and residual renal function in peritoneal dialysis patients

Objective To investigate the relationship between fetuin A and left ventricular function and their influences on residual renal function(RRF) in peritoneal dialysis patients. Method Eighty patients recently initiating peritoneal dialysis were enrolled into this study and were divided into high fetuin A group and low fetuin A group accordin to the value of serum fetuin A concentration. Hemoglobin, high sensitive C reactive protein(hsCRP), calcium, phosphorus, albumin, lipoproteins and left ventricular myocardial performance index(LV-MPI) were examined. All these patients were followed up for 12 months, to discover the parameters’ differences between two groups and to investigate the association between fetuin A and left ventricular function and RRF. Results At the beginning of the study, there was no difference of hsCRP, calcium, phosphorus, albumin, lipoproteins and LV-MPI, estimated glomerular filtration rate (eGFR) between two groups; After 12 months follow-up, MPI was obviously shorter (P＜0.05) and RRF was obviously higher (P＜0.05) in high fetuin A group than thosein low fetuin A group. Compared with the beginning of the study, LV-MPI was significantly increased and eGFR was significantly decreased after 12 months follow-up (both P＜0.05) in low fetuin A group, but no obviously change of LV-MPI or eGFR was found in high fetuin A group after follow-up. Pearson correlation analysis discovered an obvious negative correlation between fetuin A and MPI (r=-0.680, P＜0.01). Multiple regression analysis indicated that eGFR had positive correlation with fetuin A (B=0.058, t=3.679, P＜0.01) and negative correlations with MPI (B=-0.511, t=-2.903, P=0.007), age(B=-0.144, t=-4.013, P＜0.01). Diabetes was risk factor to loss of RRF (B=-2.031, t=-2.759, P＜0.05). Conclusion Fetuin A has very close relationship with left ventricular function.Decreased serum fetuin A level and decreased left ventricular function are risk factors to the loss of the RRF in ERSD patients.     

Validation of cystatin C-based equations for evaluation of residual renal function among patients undergoing continuous ambulatory peritoneal dialysis

Objective To validate cystatin (Cys C)-based equations for evaluation of residual renal function （RRF） in patients on continuous ambulatory peritoneal dialysis (CAPD). Methods Fifty patients on CAPD from our department were enrolled in the study. Eight patients with residual urine volume ≤100 ml/d and 42 patients with residual urine volume ＞100 ml/d were enrolled into anuria group and non-anuric group respectively. The clinical and laboratory status of each group were compared and equations (Hoek’s, Yang’s and abbreviated MDRD equations) were validated in the non-anuric group by comparing with the arithmetic average of residual renal creatinine clearance rate and residual renal urea clearance rate which was considered as the golden standard for RRF. Results (1) Anuric group had significantly higher serum Cys C than the non-anuric group [(7.73±1.13) mg/L vs (6.46±1.15) mg/L, t＝2.39, P＝0.02)]. (2) RRF estimated by each equation was correlated well with measured RRF (r＝0.56, 0.56 and 0.39, all P＜0.05). (3) Yang’s equation [0.10 ml•min-1•(1.73 m2)-1] was least biased, followed by Hoek’s equation [-0.73 ml•min-1•(1.73 m2)-1] and abbreviated MDRD equation [3.15 ml•min-1•(1.73 m2)-1]. (4) The precision of Yang’s equation was equivalent to that of Hoek’s equation and both of them were better than abbreviated MDRD equation [6.2 and 6.1 vs 8.4 ml•min-1•(1.73 m2)-1]. (5) 50% accuracy according to Yang’s equation and Hoek’s equation revealed an elevated results in comparison to that according to abbreviated MDRD equation (59.5% and 54.8% vs 23.8%, respectively, all P＜0.01). Conclusions Serum Cys C-based prediction equations are better than the abbreviated MDRD equation in bias, precision and 50% accuracy. For patients undergoing CAPD, the use of Cys C-based equation to estimate RRF may be a clinically acceptable alternative.