Effect of dialysate glucose load on plasma glucose and glucoregulatory hormones in CAPD patients

The effect of a dialysate exchange with both 1.5 and 4.25% glucose solutions on plasma levels of glucose, insulin, gastric inhibitory polypeptide (GIP), and glucagon has been investigated in 5 continuous ambulatory peritoneal dialysis (CAPD) patients. Only in the case of the 4.25% solution did plasma glucose levels rise above 100 mg/dl. 4 of the 5 patients responded to this change with a marked insulin secretion. Employing the 1.5% solution, plasma glucose remained stable and only a slight insulin stimulation was observed in 2 patients. It is concluded that provided the 4.25% dialysates are used only occasionally, there will be no continuous stimulation of the pancreatic beta-cells due to absorption of glucose from the dialysate alone during CAPD treatment. GIP levels are highly elevated in CAPD patients. A dialysate exchange with either a 1.5 or a 4.25% glucose solution had no effect on this gastrointestinal hormone. Hyperglucagonemia was also observed in this collective. An initial suppression of glucagon levels occurred in 4 of the patients after a 4.25% dialysate exchange. The 5th patient demonstrated an initial rise followed by a later decrease in glucagon, a response similar to that reported in adult onset diabetes after an oral glucose tolerance test.     

Diabetic Glomerulopathy May be Preventable

Variation in blood glucose levels throughout the day was assessed in six diabetic maintenance hemodialysis patients and six diabetic renal transplant recipients. None of the twelve studied patients had good control. Glucose levels greater than 300 mg/dl were noted in four of six dialysis patients and five of six transplant recipients. A regimen of self blood glucose measurement and multiple insulin doses was instituted for four transplant and three dialysis patients. Each patient achieved the desired glucose range of 60 to 120 mg/dl most of the time, with a resultant fall in mean hemoglobin A_lc concentration from 10.3% to 7.9%. It is suggested that a long term trial of self glucose monitoring might prove beneficial to treated uremic diabetics.     

Icodextrine and Insulin Resistance in Continuous Ambulatory Peritoneal Dialysis Patients

Insulin resistance is commonly observed in uremic patients. Glucose-based peritoneal dialysis solutions have long-term metabolic complications like hyperinsulinemia, hyperlipidemia, and obesity. The purpose of this study was to examine the insulin resistance in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) with standard glucose and icodextrin containing solutions. The entire non diabetic CAPD patients of our center were studied: forty-four patients in all who were on CAPD treatment for 36.2 ± 23.7 months. Twenty-seven of them (11 male and 16 female) with a mean age of 46 ± 16 years were treated with standard glucose solutions (glucose group). The other 17 patients (10 male and 7 female) with a mean age of 49 ± 16 years were treated with standard glucose solutions during the day and icodextrin dwell during the night, for a median of 12 ± 6.3 months (icodextrin group). Morning fasting serum insulin levels were 20.59 ± 17.86 in the glucose group and 10.15 ± 6.87 in the icodextrin group (p = 0.0001).

Homeostasis Model Assessment Method scores of the glucose group were significantly higher (4.8±4.1 vs 2.3± 1.7; p = 0.025) than the icodextrin group. A significant positive correlation of HOMA score with insulin, fasting plasma glucose, and triglyceride levels were found in HOMA (IR+) patients. Twenty patients of the icodextrin group (74%) and 15 patients of the glucose group (88%) were hypertensive, but there was no statistically significant difference between the two groups (p = 0.13). The groups showed no significant differences for body mass index and serum levels of glucose, total cholesterol, LDL cholesterol, VLDL cholesterol, HDL cholesterol, triglyceride, intact parathyroid hormone (iPTH), and fibrinogen. In conclusion, the use of icodextrin in the long nighttime dwell can reduce serum insulin levels and increase insulin sensitivity in CAPD patients.     

The Effect of Colchicine on the Peritoneal Membrane

Peritoneal dialysis (PD) is a treatment modality for patients with renal failure. Peritoneal fibrosis is one of the most serious complications after long-term continuous ambulatory peritoneal dialysis (CAPD). Histological studies in both humans and animals show that chronic peritoneal dialysis results in fibrosis of the peritoneal membrane. In our study, we investigated the effect of colchicine on peritoneal alterations induced by hypertonic PD solution in rats. Sprague-Dawley rats intraperitoneally received saline (control group) once daily, for 28 days, or 3.86% glucose (PDF group), or 3.86% glucose plus colchicine (colchicine group). Animals from each group were sacrificed after 28 days with anesthetized ketamine (60 mg/kg BW). For the PD fluid assessment, 1 h before the sacrifice of animals, 10 mL PD fluid of 2.27% glucose was given, and this fluid was obtained after the sacrifice. The levels of transforming endothelial growth factor β (TGF-β), tumor necrosis factor α (TNF-α) and albumin were investigated both in the peritoneal dialysate and blood, and the levels of malondialdehyde (MDA) were investigated only in peritoneal dialysate. The peritoneal membrane was evaluated histologically by light microscopy. When groups were compared in terms of body weight change, the colchicine group significantly lost weight compared to controls and PDF group (?4.7% ± 4.5, 3.5% ± 7.2, 3.0% ± 1.3, respectively, p = 0.018). Also, the blood albumin level was significantly lower for these in the colchicine group compared to those in the PDF group (2.7 ± 0.35 versus 3.2 ± 0.3 g/dL, respectively, p = 0.048). The blood TGF-β level was significantly lower in the control group, and no difference was observed between the PDF and colchicine groups (294.4 ± 67.5 versus 787.4 ± 237.4 versus 615.3 ± 235.1 pg/mL, respectively, p = 0.004). The mesothelial thickness found in groups was as follows: control group 102 ± 18.9 µm, PDF group 128.33 ± 33.1 µm, colchicine group 117 ± 35.6 µm (p = 0.34). In conclusion, a rat model for peritoneal dialysis associated peritoneal derangement without fibrosis could be induced. Colchicine could not prevent peritoneal derangement in this model.     

Intermediary metabolism and glycemic control in insulin-dependent diabetic uremic patients treated by continuous peritoneal dialysis

The effect on metabolic control and on intermediate metabolism of continuous ambulatory peritoneal dialysis (CAPD) was evaluated in 6 insulin-dependent diabetic uremic patients treated by CAPD, in 6 nondiabetic uremic patients in CAPD and in 6 normal subjects. During the study, 4 dialysis exchanges with 1.36 g/dl dextrose concentration were performed daily; regular insulin was added to the bags in diabetic patients. Our data show a well-controlled mean blood glucose in CAPD diabetic patients by intraperitoneal insulin administration as well as higher insulinemic levels in comparison with those of normal subjects. Plasma lactate and serum glycerol levels were higher and butyrate levels were lower reflecting a continuous ketogenesis inhibition.     

Glucose concentration in the dialysate does not contribute to lipid profiles in patients undergoing CAPD

The aim of this study was to investigate lipid profiles in patients with end-stage renal disease receiving hemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD), or no dialysis (nondialytic treatment group, NT), and to analyze the association between dyslipidemia in CAPD patients with glucose-containing dialysate dosages. Lipid profiles were determined in 64 NT patients, 62 HD patients, and 180 CAPD patients at a single time point. NT patients' samples were collected following hospitalization due to renal failure. HD and CAPD patients' samples were collected after 3 months of dialysis. The association between lipid profiles of 180 CAPD patients and glucose-containing dialysate was analyzed using Pearson methods; 76.56% of NT patients, 66.13% of HD patients, and 72.22% of CAPD patients had dyslipidemia. Compared with NT patients, CAPD patients had significantly altered levels of cholesterol, triglycerides, high-density lipoprotein, apolipoproein (Apo)-A1, and Apo-E (p < 0.05), but unchanged levels of low-density lipoprotein or Apo-B. There was no correlation between the three different concentrations of glucose in the dialysate with the lipid profile of CAPD patients. We concluded that patients on CAPD exhibit dyslipidemia, and that different concentrations of glucose in the dialysate do not affect lipid profiles in these patients.     

Ten years experience of CAPD in diabetics: comparison of results with non-diabetics

CAPD outcomes were compared between a group of 301 diabeticpatients (mean age±SD, 58.9±12.7 years, 55.8%males) and a group of 1689 non-diabetic patients (mean age±SD57.8±14.8 years, 55.9% males) treated in 30 centres participatingin the Italian Cooperative Peritoneal Dialysis Study Group from1980 to 1989, with follow-up observation periods of 444 years(mean±SD, 1.48± 1.24) and of 3502 years (mean±SD,2.07± 1.91) respectively. CAPD was the first modality for 87.2% of diabetics and 78.1%of non-diabetics (P<<0.001). The percentage of patientswho needed a partner for CAPD was 45.9% in diabetics and 30.2%in non-diabetics (P<0.00l). In diabetics compared with non-diabetics, cardiovas cular diseasesand cachexia were nearly twice and infections other than peritonitismore than three times as frequent in causing death. In diabetics,survival was significantly worse (P<0.0001) and the relativerisk of death 2.13 times higher (P<0.001). The technique survival and the relative risk of drop out werenot significantly different in the two groups. Clinical problemswere the most important cause of drop-out among diabetics. Theprobability and relative risk of drop-out due to peritonitis,as well as of the first peritonitis episode, were not significantlydifferent between the two groups and between diabetics usingor not using intraperitoneal insulin. Days per patient year of hospitalization, excluding the first,were 18.4 in diabetics and 14.3 in non diabetics. CAPD-relatedproblems caused hospitalization in a similar way in the twogroups. In conclusion, compared to non-diabetics on CAPD, diabeticson the same treatment showed more clinical problems that accountfor a higher need of partner, death, and hospitalization andare the first reason for technique failure; on the other hand,problems closely related to the CAPD technique seem to occurwith the same frequency in the two groups.     

Nonenzymatically glucosylated serum proteins in patients with end-stage renal disease

We report here abnormally elevated levels of nonenzymatically glucosylated whole-serum proteins in nondiabetic, as well as diabetic patients with end-stage renal disease (ESRD). Increased glucosylation of serum proteins and structural proteins has been documented in patients with diabetes mellitus, but not previously in ESRD. Increased levels of hemoglobin A1 have been reported in patients with ESRD, but appear to be due to carbamylation of hemoglobin rather than glucosylation. Using an assay that does not detect carbamylation, the present study demonstrates abnormally elevated levels of nonenzymatically glucosylated whole-serum proteins in all the chronic hemodialysis and continuous ambulatory peritoneal dialysis (CAPD) patients studied. Further, we found no change in levels of these abnormal proteins when patients were changed from hemodialysis with a dialysate that contained no glucose to one that did, or to CAPD in which large amounts of glucose are absorbed from the dialysate. The mode of dialysis does not appear to affect glucosylated protein levels in ESRD.     

终末期肾衰竭腹膜透析患者的转归及其危险因素分析

目的:探讨影响终末期慢性肾衰竭连续性不卧床腹膜透析患者死亡危险因素及其防治对策.方法:对1999年8月～2003年8月期间我院52例慢性肾衰竭腹膜透析患者的资料进行回顾性临床分析.其中死亡组22例、存活组30例,分析其死亡原因和影响因素.结果:(1)52例腹膜透析患者死亡组的22例中,死于心血管病变13例(占59.1%),腹膜炎3例(占13.6%),肺部感染2例(占9.1%),严重营养不良2例(占9.1%),其他2例(占9.1%).(2)死亡组年龄、性别分布与存活组比较无统计学差异(P＞0.05);与存活组比较,死亡组的体重、平均动脉压明显升高,血浆白蛋白明显降低,均有统计学差异(P＜0.05).(3)死亡组的透析龄、透析液总剂量、腹腔超滤量、尿量及液体总清除量与存活组比较均无统计学差异(P＞0.05);然而死亡组的水肿发生率明显高于存活组,分别为68.2%及43.3%(P＜0.05).(4)死亡组透析初始时的尿素氮、肌酐、肌酐清除率、血色素、总胆固醇、甘油三酯与存活组相比无统计学差异(P＞0.05).(5)糖尿病腹膜透析患者的水肿发生率和病死率均明显高于非糖尿病患者(P＜0.05),16例糖尿病患者有11例死亡,非糖尿病患者36例中有11例死亡(病死率分别为68.8%VS 30.6%).结论:心血管疾病是终末期肾衰竭腹膜透析患者最主要的死亡原因.容量超负荷、糖尿病、控制不良的高血压、营养不良以及透析时机过迟都是影响终末期肾衰竭患者心血管病死亡的主要危险因素.积极维持体液平衡、控制血压及糖尿病合并症,并根据患者的残余肾功能、临床症状、合并症情况和营养状态综合考虑,及时开始CAPD治疗,将有助于改善患者的预后.     

Comparison between continuous subcutaneous insulin infusion and multiple injections of insulin. A one-year prospective study

Twenty insulin-dependent diabetic patients participated in a 1-yr prospective randomized cross-over study comparing multiple subcutaneous injections (MSI) and continuous subcutaneous insulin infusion (CSII) complemented by home blood glucose monitoring. While 4 patients dropped out early, 16 patients completed the study. Patients had severe insulin deficiency documented by absent C-peptide response to glucagon stimulation. A marked improvement in control was observed when mean blood glucose and glycosylated hemoglobin A1 were compared with conventional therapy. No significant differences in the degree of metabolic control achieved, as measured by mean fasting, preprandial, and postprandial capillary blood glucose (CBG), M values, glycosylated hemoglobin A1 concentration, cholesterol and triglyceride levels were seen between MSI and CSII in the sixteen patients who completed the study. However, individual comparisons showed that fasting CBG and M-values were lower under CSII than MSI in seven patients (P less than 0.05). In contrast, two patients exhibited lower M values under MSI than under CSII (P less than 0.01), while for the remaining seven patients the results were similar. After completion of the study, two patients went back to conventional insulin therapy, seven patients remained on the pump, and seven patients chose to stay on MSI. In conclusion, on a long-term basis, the two methods can produce comparable levels of blood glucose and glycosylated hemoglobin in ambulatory insulin-dependent diabetics.     

Recombinant human erythropoietin dosage in children undergoing hemodialysis and continuous ambulatory peritoneal dialysis

The efficacy of erythropoietin (EPO) in 11 children on hemodialysis (HD) and 8 on continuous ambulatory peritoneal dialysis (CAPD) (mean age 11.8 years) was compared. The initial EPO dose was 50 U/kg s.c. once a week; the time of observation was 24 weeks. In the CAPD group, the mean hemoglobin (Hb) level increased from 7.7±0.2 to 11.2±0.6 g/dl (P< 0.001) and hematocrit (Hct) from 22.3±1.0 to 32.6±1.4% (P<0.001), while in the HD group the mean Hb rose from 7.7±0.6 to 9.3±0.8 g/dl (P<0.001) and mean Hct from 22.7±2.3 to 27.6±2.8% (P<0.001) after 12 weeks of observation. An increase in Hb to over 10 g/dl was obtained in 87.5% of children on CAPD but in only 10% on HD after 8 weeks of EPO treatment. After 12 weeks of treatment, all children on CAPD had the target Hb level of more than 10 g/dl, while 7 children on HD required increased doses of EPO (100 U/kg per week). We conclude that the EPO dose of 50 U/kg given s.c. once a week is effective for children with anemia on CAPD but is insufficient for children on HD. Received June 17, 1996; received in revised form January 24, 1997; accepted March 4, 1997     

Pharmacokinetics of recombinant human erythropoietin in children with chronic renal failure

Basal erythropoietin (Epo) levels and single dose-pharmacokinetics of recombinant human erythropoietin (rhuEpo) were investigated in 8 predialysis (PD) patients (mean age 11.6±1.4 years) and in 8 patients on continuous ambulatory peritoneal dialysis (CAPD) (mean age 12.7±0.6 years). Basal Epo levels were found to be 1.0±0.0 mu/ml in PD group, 1.6±0.7 mu/ml in CAPD group and 8.5±1.8 mu/ml in control group. Following administration of 50 μ/kg rhuEpo (s.c.) serum Epo concentration (C_max) was 23.2±2.5 mu/ml in 18.5±2.6 hours (t_max) in PD patients and 9.9±0.8 mu/ml in 26.8±7.7 hours in CAPD patients. Mean elimination half-lives (t_1/2) were 13.3±1.9 hours and 13.5±3.0 hours in PD patients and CAPD patients, respectively. The volume of distribution (Vd) was 840.0±100.0 ml/kg; the clearance (Epo Cl) was 37.0±5.5 ml/kg/hour in PD patients. These values were significantly lower in PD patients than in CAPD patients (p<0.05) (Vd; 1500±240.0 ml/kg; Epo Cl 110±30.0 ml/kg/hour). During the course of CAPD, more efficient clearance of uraemic toxins that inhibit erythropoiesis and more rapid extraction of erythropoietin by erythroid precursors may cause higher Vd in CAPD patients than in PD patients.     

Intraperitoneal pressure and hernias in children on peritoneal dialysis

Abdominal wall hernias have been increasingly recognized in patients on continuous ambulatory peritoneal dialysis (CAPD). They are also more frequent in children than in adults. The aim of this study was to determine the influence of intraperitoneal pressure (IPP) on the development of hernias in children on CAPD, and if there was a difference between IPP in children and adults. We studied 14 children aged 11.2±3.2 years, body weight 31.1±9.4 kg, who had undergone CAPD for 16.2±14.4 months. Also, 10 adults were studied, aged 48±18 years, body weight 62.4±13.9 kg, on the CAPD program for 35±27 months. The IPP was measured via a column of dialysate in the peritoneal dialysis line, immediately before the drainage of the peritoneal cavity. The pressure was measured with the patients in the supine position, at the level of the umbilical cicatrix with the zero point located on the mean axillary line. IPP was measured at inspiration and at expiration, and the mean of these two measurements was calculated. The children were divided in two groups : group 1 (n=7) without hernias and group 2 (n=7) with hernias (5 umbilical and 2 inguinal). The IPP of all children was 9.5±2.9 cm H₂O. The IPP was 8.1±2.6 and 10.9±2.6 cm H₂O in groups 1 and 2, respectively (P=0.003). The instilled volume for test was similar in both groups. The IPP of the adults was 13.8±2.8 cm H₂O, which was significantly greater than that of the children (P=0.001). In conclusion, hernia is a common complication in children on CAPD and its prevalence is affected by IPP. Other associated factors may be the presence of anatomically weak sites in the abdominal wall of the children, since IPP is lower in children than in adults. Received: 20 July 1998 / Revised: 26 January 1999 / Accepted: 26 January 1999     

Plasma concentrations and transperitoneal transport of native insulin and C-peptide in patients on continuous ambulatory peritoneal dialysis

The insulin and C-peptide response to glucose (50 g), given intraperitoneally or enterally, and the elimination rate of these compounds has been studied in five nondiabetic patients on continuous ambulatory peritoneal dialysis (CAPD). The fasting C-peptide concentrations were three to ten times the normal values, whereas the fasting plasma insulin concentrations were within normal limits. After intraperitoneal glucose administration, a more marked hyperglycemia (P less than 0.05) and a more long lasting hyperinsulinemia (P less than 0.05) were found than after the enteral glucose load. The relative change in plasma C-peptide was slower and less pronounced in both experiments. Estimated total body clearance (Kt) for insulin was higher than for C-peptide (P less than 0.01), but dialysis clearance (Kd) for C-peptide was higher than for insulin in both experiments (P less than 0.01). The markedly elevated fasting C-peptide concentrations in plasma can be explained only partly by the absence of normal kidney function and suggests a continuously increased production of C-peptide during CAPD treatment. This was not reflected by the fasting plasma insulin concentrations. C-peptide measurements in plasma and dialysate during CAPD could be helpful in evaluating the beta-cell function in patients in need of exogenous insulin.     

Effect of peritonitis on insulin and glucose absorption during peritoneal dialysis in diabetic rats

The intraperitoneal route is frequently used for the administration of insulin in diabetic continuous ambulatory peritoneal dialysis patients. However, there is conflicting evidence as to whether the dosage of intraperitoneal insulin should be increased or decreased during peritonitis in these patients. Glucose and insulin absorption and glycaemic control were evaluated in 2-hour exchanges using 15 ml of 2.5% dextrose dialysis solution in diabetic rats with (group 1) and without (group 2) peritonitis. Fasting blood glucose values at the beginning of the study exchanges were mean +/- SD 17.9 +/- 3.3 mmol/l in group 1 and 18.2 +/- 3.5 mmol/l in group 2. Even though group 1 had a higher percentage absorption of dialysate glucose (65 +/- 19 vs. 47 +/- 7%; p less than 0.05) and higher percentage absorption of dialysate insulin (49 +/- 12 vs. 44 +/- 14%; p less than 0.1), the hypoglycaemic response to the standard intraperitoneal dose of insulin was similar in each group. Plasma C peptide levels remained very low in both groups, thus excluding significant endogenous release of insulin. These data indicate that peritonitis per se does not change intraperitoneal insulin requirements during standardized peritoneal dialysis exchanges in diabetic rats. Insulin requirements may also be unaltered during peritonitis in diabetic continuous ambulatory peritoneal dialysis patients, provided that dialysate glucose load and oral carbohydrate intake are kept constant.     

Adsorption of insulin to the surface of peritoneal dialysis solution containers

Continuous ambulatory peritoneal dialysis (CAPD) is becoming widely used in diabetics with end-stage renal disease. One of the proposed advantages of this technique is the ability to administer insulin intraperitoneally. The administration of insulin by this route provides acceptable plasma glucose control with no need for subcutaneous injections. Because adsorption of insulin to glass and polyvinyl chloride (PVC) surfaces is known to occur with intravenous fluid systems, this study was conducted to measure insulin adsorption to dialysis fluid systems. The effects of time, temperature, heparin concentration, dextrose concentration, and insulin concentration in 2-L glass and PVC dialysis solution containers were studied. While all factors significantly affected adsorption to the PVC containers, the effects of heparin and dextrose were considered to be clinically unimportant. The percentage of insulin adsorbed to the PVC surface increased with increasing time and temperature and decreased with increasing insulin concentrations. Under the conditions studied, 7.1% to 9.6% of insulin added to PVC containers was lost within the first minute. Since 15 to 30 minutes is required by most CAPD patients to prepare and instill the dialysate, 10% to 20% of added insulin may be adsorbed to the PVC bad. The adsorption of insulin to the glass surfaces was rapid with 39.6% to 42.8% being lost within the first minute. All factors studied significantly affected adsorption to the glass, but the effects of time, temperature, dextrose, and heparin were considered to be of minor clinical importance.(ABSTRACT TRUNCATED AT 250 WORDS)     

小剂量日间非卧床腹膜透析对残肾功能较好的糖尿病终末期肾病患者的疗效

目的　研究小剂量日间非卧床腹膜透析（DAPD）和小剂量持续非卧床腹膜透析（CAPD）对残肾功能较好的糖尿病终末期肾病（ESRD）患者的疗效。 方法 病情稳定、残肾功能较好（rGFR≥5 ml/min,且尿量≥750 ml/d）的40例糖尿病ESRD患者入选。按数字随机法分为小剂量DAPD组20例和小剂量CAPD组20例。DAPD组透析处方为1.5 L或2 L,3次/d,每次留腹3～4 h,夜间干腹。CAPD组透析处方为1.5～2 Ｌ,3次/d,或1.5 L,4次/d,夜间留腹。在研究开始及6个月后,分别计算两组腹膜尿素氮清除率（Kt/V）、残肾Kt/V、每周总Ｋt/V、Ccr、rGFR等指标;测定24 h尿蛋白量、24 h腹透液蛋白、血清白蛋白、空腹血糖、糖化血红蛋白及胰岛素剂量;用改良主观综合性营养评估法（SGA）评估患者营养状况。 结果 共35例患者完成研究。两组患者年龄、性别、体质量指数、透析龄、透析液肌酐/血肌酐（D/Pcr）等基线值差异无统计学意义。6个月后,CAPD组胰岛素剂量和24 h腹透液丢失蛋白明显高于DAPD组,分别为（33.6±10.9） U/d 比（20.6±6.2） U/d（P < 0.05）和（11.13±4.95） g比（5.66±2.88） g（P < 0.01）,而血清白蛋白明显低于DAPD组[（29.7±4.2） 比（36.5±3.9） g/L,P < 0.05]。DAPD组与CAPD组相比,24 h净超滤量为（554±187） ml比（309±177） ml,24 h尿量为（1090±361） ml比（750±258） ml,rGFR为（8.21±2.40） ml/min比（4.88±2.11） ml/min,DAPD组均显著高于CAPD组（均P < 0.05）。 结论 对于残肾功能较好的糖尿病ESRD患者,小剂量DAPD较小剂量CAPD能更好地控制血糖,改善营养状态及保护残肾功能。     

Increased risk of Staphylococcus epidermidis peritonitis in patients on dialysate containing 1.25 mmol/L calcium.

Peritoneal macrophage function is decreased in vitro in the presence of dialysate with 1.25 mmol/L calcium compared with that containing 1.75 mmol/L calcium. Theoretically, patients using this dialysate may have a higher risk of peritonitis. Nineteen patients on continuous ambulatory peritoneal dialysis (CAPD) or continuous cycling peritoneal dialysis (CCPD) were converted from dialysate with 1.75 mmol/L calcium (mean time, 33 +/- 26 months) to that with 1.25 mmol/L calcium, for some or all exchanges (mean time, 10 +/- 4.7 months). Peritonitis rates were compared with 19 control patients who remained on dialysate with 1.75 mmol/L calcium. The two groups were matched for the proportion of diabetics, sex, age, use of the Y-set, and dialysis modality (CAPD, CCPD). Peritonitis rates were similar in the study patients before conversion to 1.25 mmol/L calcium dialysate and in the control patients (0.49 v 0.58 episodes/patient-year, respectively). After conversion to dialysate with 1.25 mmol/L calcium, the peritonitis rate was 0.82 episodes/patient-year contrasted to 0.58 episodes/patient-year in the control patients (P = 0.09). The peritonitis rate due to Staphylococcus epidermidis was 0.51 episodes/patient-year when 1.25 mmol/L calcium dialysate was used, and 0.19 episodes/patient-year for the comparable period in the control patients on 1.75 mmol/L calcium dialysate (P = 0.005). The proportion of peritonitis episodes due to S epidermidis increased from 20% to 61% after conversion to 1.25 mmol/L calcium (P = 0.01). The increased risk of peritonitis due to S epidermidis in patients using dialysate with 1.25 mmol/L calcium is consistent with a previous study demonstrating that clearance of S epidermidis by peritoneal macrophages is less effective with a decrease in the dialysate calcium content.(ABSTRACT TRUNCATED AT 250 WORDS)