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BACKGROUND: The glomerular filtration rate (GFR) can be estimated from plasma creatinine according to the formula of Cockcroft and Gault (CG). When tubular secretion of creatinine is inhibited by cimetidine the mean difference between the Cockcroft-Gault clearance (CG(Cim) and GFR approximates zero, but there is still some interindividual difference, especially in type-2-diabetic patients. We studied during longitudinal follow-up, whether the discrepancies between CG(Cim) and GFR per patient are consistent in time in type-2-diabetic patients. PATIENTS AND METHODS: In 1996 and 1998 (interval 20-26 months) GFR was measured in 21 patients as the urinary clearance of continuously infused 125I-iothalamate. Plasma creatinine was analyzed with an enzymatic assay before and after oral cimetidine 800 mg t.i.d. during 24 hours. GFR estimations were calculated with the Cockcroft-Gault formula before (CG) and after cimetidine (CG(Cim)) and expressed as means +/- SEM. RESULTS: GFR deteriorated from 89.7 +/- 5.7 to 81.3 + 5.8 ml/min/1.73 m2 and CG(Cim) from 85.3 +/- 5.7 to 81.1 +/- 6.6 ml/min/1.73 m2, whereas CG decreased from 102.4 +/- 6.8 to 98.4 +/- 7.0 ml/min/1.73 m2. Changes in GFR and changes in CG(Cim) were correlated (r = 0.72, p < 0.001) and were not significantly different from each other. The discrepancy between CG(Cim) and GFR per patient in 1996 also correlated with the discrepancy between CG(Cim) and GFR in 1998 (r = 0.85, p < 0.001 ). CONCLUSIONS: In individual patients the discrepancies between the CG(Cim) and GFR are consistent in time and the change in GFR is reflected by the change in CG(Cim). This small variability means that CG(Cim), based on an enzymatic plasma creatinine assay, would be suitable for follow-up of GFR in type-2-diabetic patients, independent of albuminuria

The clearance of organic ions by the tubules may contribute to the removal of uremic waste products in dialysis patients. The renal excretion of an exogenous anion p-aminohippurate (PAH) was investigated in 10 peritoneal dialysis patients and 10 hemodialysis patients during one clearance period and compared with the clearance of creatinine (Ccr) and inulin (CIn). The clearance period was 24 hours in the peritoneal dialysis patients and one interdialytic interval of 3 days divided in 4 parts [CPA-D] in hemodialysis patients. In peritoneal dialysis patients the renal clearance of total PAH (median 14.3 ml/min, range 3.8-33.0) exceeded the CIN (median 3.2 ml/min, range 1.6-11.2, p < 0.005) and Ccr (median 4.0 ml/min, range 1.7-15.0, p < 0.005). A positive correlation was found between the tubular clearances of creatinine (cationic pathway) and of total PAH (anionic pathway, r: 0.72, p

Many patients treated with peritoneal dialysis (PD) are overhydrated. We investigated whether hypertension in PD patients is related to ultrafiltration-failure-induced fluid retention. Twenty-four-hour blood pressure measurements were performed in 10 normotensive and 9 hypertensive PD patients, aged 20 to 77 years, and treated with PD for 2 to 125 months. Antihypertensive medication had been discontinued for 3 weeks. Twenty-four-hour blood pressure was monitored with a Spacelabs 90207. Mean 24-hour systolic, mean, and diastolic pressure were calculated, together with the nighttime (23:00-07:00)/daytime (07:00-23:00) ratio. Ultrafiltration was determined separately during a standardized 4-hour peritoneal permeability analysis (SPA) with 1.36% glucose. Based on the SPA, patients were divided into a group with negative net ultrafiltration (NUF) and a group with positive net ultrafiltration (PUF). In 8 patients with NUF, systolic, mean, and diastolic pressures were 142 +/- 16 mmHg, 110 +/- 14 mmHg, and 95 +/- 13 mmHg, compared to 135 +/- 22 (ns), 99 +/- 14 (ns), and 81 +/- 11 (P < 0.05) in 11 patients with PUF. Net ultrafiltration during the test dwell correlated negatively with diastolic blood pressure (r = -0.53, P < 0.05). Diurnal blood pressure variations were not related to ultrafiltration capacity. In conclusion, hypertension in PD patients may in part be explained by fluid retention caused by impaired ultrafiltration

In some patients with renal disease 24-hour cimetidine aided creatinine clearances cannot equal GFR even after administration of the maximum daily dose of cimetidine. Short duration cimetidine aided creatinine clearances can equal GFR but are inconvenient for clinical use and can be inaccurate due to incomplete urine collection. We studied how accurately GFR can be estimated without the need to collect urine, by applying the Cockcroft and Gault formula (CCock) on a single plasma creatinine concentration, after oral administration of 3 x 800 mg cimetidine during the preceding 24 hours. GFR was measured as standard clearance, using continuous infusion of 125I-iothalamate. Nineteen patients with various renal diseases, plasma creatinine < 180 mumol/l and body mass index between 15 and 30 kg/m2 were included. After cimetidine administration, plasma creatinine values remained stable for 6 hours, despite rapidly decreasing plasma cimetidine values during the same period, in all 15 patients with GFR > 40 ml/min/1.73 m2. Tubular creatinine secretion was blocked completely in 14 of them. With cimetidine both accuracy and precision of the Cockcroft clearance improved: the mean (+/- SD) ratio of CCock to GFR decreased from 1.28 (+/- 0.21) to 0.98 (+/- 0.11) (p < 0.001) and the standard deviation of the difference (CCock-GFR) decreased from 9.23 to 7.07 ml/min/1.73 m2 (p < 0.05). With cimetidine the Cockcroft clearance correlated well with GFR (r = 0.974, p < 0.001) and this was as good as the correlation, between GFR and a 4-hour standard creatinine clearance (r = 0.972, p < 0.001). In conclusion, with a minimum of inconvenience, this method provides the clinician with accurate information on GFR for the outpatient follow-up of patients with a mild-to-moderate decrease in renal function, provided that no gross discrepancy between total bodyweight and muscle mass is present

Diurnal rhythms in proteinuria and selectivity index (SI) of proteinuria can vary from patient to patient with respect to phase and amplitude (A/M) and in some cases rhythms are absent. The aim of the present study was to relate this variability to a different pattern of diurnal rhythms in permselectivity of the glomerular capillary wall (GCW). Ten patients with nephrotic syndrome due to membranous nephropathy were studied. Diurnal rhythmicity in size-dependent permselectivity of the GCW was determined by measuring 3-h fractional clearances of dextrans (30-90 A) over a period of 1 day. Four types of rhythmicity could be recognized. Type I and II only differed in the magnitude of the diurnal variability in glomerular transport through large pores (r2) and shunt pathway (omega). Both had normal rhythms in clearance of proteins and SI, but all rhythms were more pronounced in the patients with normal renal function and mild histological abnormalities (type II). Although type III also had a normal GFR and minor histological lesions, only transport through omega (and not through r2) showed a significant diurnal rhythm, which implied that this type did not have a normal rhythm in SI. The patients with advanced renal failure and extensive interstitial lesions neither had a rhythm in permselectivity nor had normal rhythms for proteinuria and SI (type IV). The type of rhythmicity in glomerular permeability corresponds well with the presence and phase of rhythms in clearance of proteins and in SI of the proteinuria

To investigate whether or not a change in dialysate interleukin-8 (IL-8) concentration precedes the onset of clinically overt peritonitis and is significant in the recruitment of granulocytes during continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis.CAPD patients stored their overnight effluent at 4 degrees C, which was routinely thrown away after 2 days. If peritonitis developed, patients delivered their effluent of the preceding two nights and the peritonitis effluent for analysis. A control study was performed 1 to 3 months after recovery. Dialysate samples were analyzed for number of cells, differential cell count, IL-8 and elastase concentrations, and their neutrophil chemoattractive capacity. In addition, serum samples during peritonitis were analyzed for IL-8 concentrations.Ten peritonitis episodes in 7 patients were analyzed. Numbers of neutrophils and levels of dialysate IL-8 and elastase started to increase 4 to 12 hours before the first peritonitis effluent. The dialysate/serum IL-8 ratio was 423.5 during peritonitis and 7.0 in the postperitonitis controls. There was a significant correlation between the number of neutrophils and IL-8 concentration in the dialysate. The in vitro neutrophil chemotaxis was increased toward the peritonitis effluents, as compared to control effluents. Incubation of the peritonitis effluents with anti-IL-8 monoclonal antibody blocked the increase in neutrophil chemotaxis above control levels by an average of 26.7%.IL-8 is produced in the peritoneal cavity during CAPD treatment and may mediate part of the neutrophil recruitment and degranulation in the initial phase of a CAPD peritonitis.

BACKGROUND: Controversy exists as to whether electric charges of plasma proteins influence their transport across the peritoneal membrane during CAPD. Fixed negative charges in the peritoneal membrane are diminished during peritonitis in rats. METHODS: Peritoneal clearances of 10 proteins and their isoforms were used to establish the relationship between peritoneal clearance and molecular weight. The observed protein clearances were compared with the predicted clearances based on molecular weight. Clearances of proteins with different charge but identical size were compared. Stable patients and peritonitis patients were compared. Results. Only the peritoneal clearance of lipase, LDH 4/5 and IgG3 were significantly different from the predicted values (P

OBJECTIVE: To investigate whether or not a change in dialysate interleukin-8 (IL-8) concentration precedes the onset of clinically overt peritonitis and is significant in the recruitment of granulocytes during continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis. DESIGN: CAPD patients stored their overnight effluent at 4 degrees C, which was routinely thrown away after 2 days. If peritonitis developed, patients delivered their effluent of the preceding two nights and the peritonitis effluent for analysis. A control study was performed 1 to 3 months after recovery. Dialysate samples were analyzed for number of cells, differential cell count, IL-8 and elastase concentrations, and their neutrophil chemoattractive capacity. In addition, serum samples during peritonitis were analyzed for IL-8 concentrations. RESULTS: Ten peritonitis episodes in 7 patients were analyzed. Numbers of neutrophils and levels of dialysate IL-8 and elastase started to increase 4 to 12 hours before the first peritonitis effluent. The dialysate/serum IL-8 ratio was 423.5 during peritonitis and 7.0 in the postperitonitis controls. There was a significant correlation between the number of neutrophils and IL-8 concentration in the dialysate. The in vitro neutrophil chemotaxis was increased toward the peritonitis effluents, as compared to control effluents. Incubation of the peritonitis effluents with anti-IL-8 monoclonal antibody blocked the increase in neutrophil chemotaxis above control levels by an average of 26.7%. CONCLUSION: IL-8 is produced in the peritoneal cavity during CAPD treatment and may mediate part of the neutrophil recruitment and degranulation in the initial phase of a CAPD peritonitis

Differences have been reported in the decline of residual renal function in patients on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD), but it is unknown whether the urinary handling of water and solutes is similar in these patient groups. Ten CAPD patients with residual renal function were investigated during a clearance period (CP) of 24 hours, and 11 HD patients were investigated during one interdialytic interval of three days. In CAPD patients the urinary volume excretion was 0.65 +/- 0.31 mL/min (mean +/- SD), and the inulin clearance was 3.85 +/- 2.82 mL/min. A negative correlation was found between the peritoneal net ultrafiltration rate and both the urinary volume excretion rate (r = -0.80, p < 0.01) and the fractional sodium clearance (r = -0.69, p < 0.05). In HD patients the urinary volume excretion increased from 0.36 +/- 0.36 mL/min during the initial eight hours of CP (HD-A) to 0.64 +/- 0.29 mL/min during the last ten hours of CP (HD-D, p < 0.05), and the inulin clearance increased from 1.9 +/- 1.3 (HD-A) to 2.9 +/- 1.1 (HD-D, p < 0.005). The fractional sodium clearance increased from 8.5 +/- 5.7% (HD-A) to 14.4 +/- 9.0% (HD-D, p < 0.05). It can be concluded that the fractional excretion of volume and fractional clearance of solutes were similar in patients treated with CAPD and hemodialysis. The most important regulating factor seems to be the volume status influenced by volume removal by peritoneal net ultrafiltration in CAPD patients, and volume expansion during the interdialytic interval in hemodialysis patients

Mesothelial cells (MC) are able to produce interleukin-8 (IL-8) after stimulation with IL-1 beta or tumor necrosis factor alpha. The aim of our study was to investigate whether MC are able to produce IL-8 after direct stimulation with clinically relevant bacteria. We observed a significant IL-8 response by the MC which were directly stimulated with viable staphylococci

To analyze the effect of serum albumin using immunoturbidimetry, demographic, biochemical, and kinetic factors on survival of continuous ambulatory peritoneal dialysis (CAPD) patients. A review of prospectively collected data in a 2-year follow-up study of peritoneal transport kinetics. University medical center. Sixty-one patients, evaluated within 3 months after the start of CAPD. Covariables used in the survival analysis were plasma urea, and creatinine, albumin, hemoglobin, mass transfer area coefficient of creatinine, peritoneal albumin clearance, 4-hour peritoneal albumin loss, net ultrafiltration, age, blood pressure, body mass index, difference between actual and ideal bodyweight, and presence or absence of systemic disease. Overall survival was 64% at 2 years. Median serum albumin was 30.9 g/L, range 18.1-43.9 g/L. Patients with a serum albumin below the median had a lower survival rate than those higher than the median (2-year survival 49% vs 79%, p = 0.01). Using the Cox model, survival was related to systemic disease (p = 0.004), age (p = 0.02), hemoglobin (p = 0.03), and serum albumin (p = 0.1). The results confirm the strength of serum albumin as predictor of survival. However, in this study serum albumin merely reflected the presence of a systemic disease, which was the most important risk factor for patient survival

Within 6 months of a kidney transplantation the graft can be regarded as an organ deprived of its innervation. We analysed whether the transplanted kidney has a diurnal rhythm of its glomerular filtration rate (GFR) similar to the GFR rhythm that has been demonstrated in normal individuals and in patients with nephrotic syndrome. GFR was measured by inulin clearances every 3 h during 1 day of bed-rest and identical food and fluid intake per 3 h in seven patients, 4-7 months after a successful kidney transplantation, and in 10 healthy volunteers. Similar to these healthy subjects, a normal circadian rhythm of GFR was detected in all but one patient with a maximum of 57 (range 45-82) ml/min in daytime, a minimum of 47 (range 36-70) ml/min during the night and a relative amplitude of 21 (range 10-41)%. The circadian rhythm of GFR was absent in the patient with the lowest value of GFR (39 ml/min). In conclusion, GFR has a circadian rhythm in patients studied within 6 months of a kidney transplantation, despite the absence of renal innervation

We analysed the peritoneal cellular immune system 24-48 h before the onset of a clinical peritonitis. Peritoneal cells were obtained from the overnight dialysis effluents 1 or 2 days (day-1 and day-2) preceding the day of peritonitis, the last overnight effluent before the peritonitis effluent (day P), and the first peritonitis effluent. Nine peritonitis episodes of six patients were studied. The number of Fc receptor positive cells, the chemotactic activity, and immunophenotype of the peritoneal cell population at day-2 and day-1 were similar to the postperitonitis control effluent. However, immunophagocytosis and phagocytosis capacity of the peritoneal macrophages was decreased in five of six episodes at day-2 and -1 compared to control peritoneal macrophages. The overnight effluents of day P revealed a moderate influx of neutrophilic granulocytes and an increase of bacterial killing capacity and chemotactic activity. Activation of the peritoneal T cells at day P was shown by the increase in MHC class II positive T cells and an increase in the CD4/CD8 ratio. Bacterial cell cultures of the effluents were positive in three episodes 24-48 h before peritonitis, and of all overnight effluents at day P. These results indicate that malfunctioning of phagocytosis by peritoneal macrophages may contribute to the development of a CAPD peritonitis

Two patients with Burkitt's lymphoma and acute renal failure are described, one with acute uric acid nephropathy and the other with acute renal failure due to hyperphosphataemia. Renal insufficiency caused by the precipitation of calcium phosphate salts only occurs after starting treatment of the lymphoma; uric acid nephropathy can also be present in an untreated patient. A uric acid/creatinine ratio in a random urine sample may help to confirm the diagnosis of acute uric acid nephropathy. Vigorous hydration, allopurinol and alkalinization of the urine have been advocated to prevent uric acid nephropathy. However, alkalinization may accelerate phosphate precipitation in the kidneys and thereby induce renal failure. Xanthine nephropathy may develop as a consequence of high doses of allopurinol. The administration of large volumes of fluid therefore remains the keystone in prevention of the tumour lysis syndrome

Two selected groups of 5 continuous ambulatory peritoneal dialysis (CAPD) patients (3 female, 7 male), mean age 60 years, were studied twice with an interval of 4 weeks. The first study was done with glucose-containing dialysate and the second study with dialysate containing glucose polymers (Dextrin 7.5%) after they had been treated with this solution (night dwell) for 4 weeks. The patients collected night bags for 3 consecutive days during the tests. Protein clearances were determined for beta 2-microglobulin, albumin, IgG, fibronectin, and alpha 2-macroglobulin in both periods to examine the influence of crystalloid-induced convection versus "colloid"-induced convection. Group I normally used 1.50% glucose and was therefore considered to have a "high ultrafiltration";group II was the "low ultrafiltration" group because they needed 4.25% glucose dialysate. For their usual glucose solutions the net ultrafiltration was not different between both groups, but the clearance of beta 2-microglobulin was higher in group II:839 +/- 98 microL/min (group I) and 1135 +/- 131 microL/min (group II) (p = 0.08). For glucose polymers the net ultrafiltration increased in both groups, but this was more pronounced in group II: 657 +/- 104 mL (group I) and 918 +/- 85 mL (group II) (p = 0.06). Also, the clearance of beta 2-microglobulin increased with the glucose polymer solution: 1268 +/- 94 microL/min (for glucose polymer) and 987 +/- 85 microL/min (for glucose) (p < 0.05), but the clearances of the larger serum proteins remained unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

The possible relationship between initial changes in functional characteristics of the peritoneal membrane in time and hemoglobin (Hb) or hematocrit (Ht) was analyzed as part of a prospective longitudinal study. The patients were investigated twice: the first time within 3 months after the start of continuous ambulatory peritoneal dialysis (CAPD), and again 4 months later. Mass transfer area coefficients (MTC) for low molecular weight solutes and net fluid removal were calculated during a 4-hour dwell, glucose 1.36%. Thirty-four patients were analyzed. MTC (mean +/- SD, mL/min/1.73 m2), were higher during the first examination: urea 22.6 versus 19.9, p < 0.05; lactate 15.6 versus 13.8, p < 0.001; creatinine 10.5 versus 9.3, p < 0.05; glucose 9.4 versus 7.9, p < 0.001. Net fluid removal was lower during the first examination: 28 versus 99 mL/min/1.73 m2, p < 0.05. Hb and Ht increased between the two examinations (Hb: 5.4 vs 6.1 mmol/L, p < 0.001: Ht: 0.26 vs 0.29, p < 0.001). No relation was found between the absolute or relative change in Hb or Ht and the absolute or relative change in solute and fluid transport between the same examinations. In conclusion, Hb and Ht increased between the first and second examinations. The simultaneously observed changes in peritoneal transport kinetics could not be attributed to changes in Hb or Ht. Therefore, the changes in transport kinetics during the first months on CAPD are probably due to the recent start of the treatment, possibly by an increase in peritoneal surface area. Local irritation by the dialysate may be the causative mechanism

Loss of net ultrafiltration capacity is an important complication in long-term continuous ambulatory peritoneal dialysis (CAPD). It has been reported in animal studies that the drained volumes after a dwell period were larger when amphotericin B had been given intraperitoneally. In this study the effect of intraperitoneally administered amphotericin B on fluid kinetics was evaluated in 3 CAPD patients. The first patient lost 2.5 kg body weight during the first 4 days of treatment, whereas the net ultrafiltration in the second patient was higher in the treatment period compared with the nontreatment period (750 +/- 38 mL/day vs 438 +/- 34 mL/day (mean +/- SEM), p < 0.0001). In the last patient it can be demonstrated that the increase in the net ultrafiltration was caused by an increase in the transcapillary ultrafiltration (570 vs 454 mL/4 hours), but that lymphatic absorption was not different (251 vs 265 mL/4 hours). The higher transcapillary ultrafiltration capacity is probably caused by an increase in the hydraulic permeability. It is likely that this phenomenon is governed by the interaction of amphotericin B with membrane-bound cholesterol leading to the formation of transcellular pores. However, the administration of amphotericin B caused a chemical peritonitis, probably due to its solvent, sodium desoxycholate. Therefore, before amphotericin B can be used for the treatment of CAPD patients with ultrafiltration failure, further investigations are necessary to obtain a solvent for amphotericin B that is nontoxic and causes no chemical peritonitis

To elucidate the disparity between circadian rhythmicity of inulin and creatinine clearance, we simultaneously measured inulin and creatinine clearances every 3 hours during 1 day in 14 normal subjects and in 8 patients with nephrotic syndrome. All patients and normal subjects had a circadian rhythm for inulin clearance with a maximum during daytime and a relative amplitude of 21% +/- 2%. For creatinine clearance a rhythm was either absent or reduced in relative amplitude (p less than 0.01). In all subjects the rate of tubular creatinine secretion was higher at minimum of inulin clearance (night) than at maximum (day). The fractional clearance (relative to inulin) of creatinine was also higher during the night: normal subjects, 1.28 +/- 0.02 versus 1.10 +/- 0.02; patients, 1.78 +/- 0.08 versus 1.45 +/- 0.05 (p less than 0.005). This demonstrates the inaccuracy of creatinine clearance as a measure of glomerular filtration rate (GFR). By subsequent blocking of the tubular secretion of creatinine with cimetidine in four normal subjects, creatinine clearance became similar to inulin clearance during day and night. This confirms that high tubular secretion of creatinine during the night counteracts the normal rhythmicity of glomerular filtration of creatinine. As a result, plasma creatinine concentration is nearly constant during a 24-hour period. In conclusion, tubular creatinine secretion has a circadian rhythm with a phase opposite to the rhythm of GFR, thus blunting or causing absence of a circadian rhythm for creatinine clearance

Accurate residual volume (RV) measurements are needed in studies on fluid kinetics during CAPD. In this study 10 stable CAPD patients were examined twice within 1 week. On both occasions RV after drainage was calculated by the indicator dilution method. Exogenous (dextran 70, inulin) and endogenous (albumin, IgG, urea, creatinine) solutes were used as markers. RV calculated with endogenous solutes (mean +/- SD) were significantly higher than those calculated with dextran (232 +/- 77 mL) and inulin (223 +/- 73): albumin (389 +/- 123), IgG (497 +/- 180), urea (465 +/- 129) and creatinine (429 +/- 109). The relationship between RV calculated with exogenous solutes was much better than between those calculated with endogenous solutes: dextran vs inulin (r = 0.91), albumin vs IgG (r = 0.69) and urea vs creatinine (r = 0.63). Since mass transport of endogenous solutes during rinsing time exceeds mass transport of dextran and inulin, RV was also calculated after corrections had been made for diffusive mass transport of endogenous solutes during the rinsing procedure. After this correction only albumin was similar to exogenous solutes (244 +/- 111 mL) and had an acceptable confidence interval when compared to dextran. No correlation was found between RV on the first and second day, suggesting large intra-individual variability. We conclude that RV should be calculated with dextran or inulin. When no exogenous solutes are used, albumin is the best alternative. However, only rough estimations are obtained when no correction for diffusion is applied

In this study we have investigated whether mesothelial cells (MC) and mesothelial extracellular matrix (ECM) are suitable substrates for the adherence of Staphylococci. Mesothelial cells were isolated from the peritoneal dialysis effluent by making use of their lack of Fc-receptors and capacity to attach firmly to plastic. After 10 days post-confluency the MC monolayer was removed with 0.1% Triton-X100 and the presence of an ECM shown by enzyme linked immunosorbent assay (ELISA). The ELISA showed the presence of fibronectin and laminin but not of type IV collagen and vitronectin. Bacterial adherence assays with Staphylococcus aureus (N:3 isolates) adhered well to both ECM (33.4%) and MC monolayers (40.2%; ECM vs. MC monolayers p < 0.03). Staphylococcus aureus adhered significantly better to both ECM (p < 0.05) and MC monolayers (p < 0.05) when compared to plastic. Staphylococcus epidermidis (N:3 isolates) showed similar adherence for plastic (22.1%) and MC monolayers (23.5%); mesothelial ECM was a relatively poor substrate for adherence (6.8%, p < 0.03). In conclusion, results obtained sofar do not indicate an increased risk for adherence of Staphylococci when the mesothelial ECM is exposed

CAPD is not a physiological condition. The continuous absorption of glucose from the dialysate and the losses of nutrients like protein in it may cause many metabolic abnormalities. This review deals with some effects of CAPD on carbohydrate, lipid and protein metabolism

Simultaneous measurement of transcapillary ultrafiltration (TCUF), lymphatic absorption rate (LAR), and intraperitoneal volume (IPV) was performed by means of intraperitoneally-administered polydisperse dextran 70 in nine CAPD patients during a 4 hr dialysis dwell (glucose 1.36%). The recovery of dextran was 88 +/- 1%. LAR, calculated as the amount of dextran lost, divided by the dialysate dextran concentration, was 1.30 +/- 0.12 ml/min. The time course of TCUF could be described as a hyperbola. Therefore, the application of the Lineweaver-Burke plot made it possible to calculate TCUFmax (median 641 mL) and its half-time (t50: median 211 min). delta IPV4h, calculated as the difference between the Lineweaver-Burke adjusted TCUF4h and LA4h, was correlated with measured delta IPV4h after drainage (r = 0.89, p less than 0.001). The latter was dependent upon LAR (r = -0.71) and effective peritoneal surface area, as represented by mass transfer area coefficients (MTC) of low molecular weight solutes (creatinine r = -0.76, glucose r = -0.81). High MTC values of these solutes were exponentially related to a short t50 (creatinine r = -0.76). LAR was correlated with the MTC of intraperitoneally administered inulin (r = 0.83). Dextran 70 had no measurable effect on solute transport. It is concluded that dextran 70 is a useful marker for the measurement of peritoneal fluid kinetics, even during CAPD with a low glucose concentration in the dialysate

The total cell count and cell differentiation of the overnight peritoneal dialysis effluent (PDE) was analysed in 34 long-term CAPD patients. The mean percentage and yield of mesothelial cells were 3.1% and 0.17 x 10(6) per PDE. There was a significant lower percentage and yield of mesothelial cells in the PDE of patients with a peritonitis incidence (PI) of more than 2 episodes a year. Independent of dwell time, a positive correlation between the total yield of leucocytes and the yield of mesothelial cells was found. No relation between the amount of phospholipids in the PDE and the yield of mesothelial cells could be shown. Mesothelial cells in the PDE are probably reflecting the turn-over rate of a reactive mesothelium. Whether a low turn-over rate of the mesothelium is causing or is caused by a high PI needs further investigation

The transport of macromolecules such as proteins and dextrans during CAPD is restricted by the permeability of the peritoneum. When its degree is determined by diffusion characteristics of macromolecules, the intrinsic permeability of the peritoneal membrane can be expressed as the relation between clearance of macromolecules and parameters of diffusion velocity. In order to characterize the peritoneal restriction barrier in individual patients, such a relationship has to meet the following conditions: (a) a good fit to linearity, (b) a low inter- and intra individual variability and (c) similarity for proteins and equal sized dextran fractions. In the present study a comparison is made between the reciprocal plot (RP): C-1 = s (esr) + A and the diffusion plot (DP): C = A'. Ds20,w. In these equations C is clearance, esr is Einstein Stokes radius, D20,w is the free diffusion coefficient in water, A and A' are constants, while s is the slope of the regression line and therefore represents intrinsic peritoneal permeability to macromolecules. The 95% confidence interval of the correlation coefficient r was above 0.95 in all studies for the RP and the DP. In general it was somewhat higher for the DP. The inter-individual coefficient of variation was lower in the DP than in the RP. This was also the case for the intra-individual coefficient of variation of the slope for proteins (DP 4% vs RP 27%, p less than 0.01) and for dextrans (DP 18% vs RP 47%, p less than 0.05). The correlation coefficient between dextran slopes and protein slopes was higher for DP (r = 0.68) than for RP (r = 0.50).(ABSTRACT TRUNCATED AT 250 WORDS)

The total cell count and cell differentiation of the overnight peritoneal dialysis effluent (PDE) was analysed in 34 long-term CAPD patients. The mean percentage and yield of mesothelial cells were 3.1% and 0.17 x 10(6) per PDE. There was a significant lower percentage and yield of mesothelial cells in the PDE of patients with a peritonitis incidence (PI) of more than 2 episodes a year. Independent of dwell time, a positive correlation between the total yield of leucocytes and the yield of mesothelial cells was found. No relation between the amount of phospholipids in the PDE and the yield of mesothelial cells could be shown. Mesothelial cells in the PDE are probably reflecting the turn-over rate of a reactive mesothelium. Whether a low turn-over rate of the mesothelium is causing or is caused by a high PI needs further investigation.

A 3-centre study was done to analyse the results of 70 patients with end-stage renal disease caused by diabetic nephropathy and treated with CAPD. Fifty patients had insulin-dependent diabetes (mean age 42, mean duration of diabetes 24 yr); 20 had non-insulin-dependent diabetes (mean age 61, mean duration 15 yr). Total treatment time was 1563 months and ranged from one to 83 months (median 18). Patient survival was 86% at 1 yr and 33% at 4 yr. Technique survival was 87% and 63%. Cox's multiple hazard regression analysis showed that age above 45 yr (relative risk 2.2), systolic hypertension (2.6) and cardiac disease (2.2) at the start of CAPD were associated with shorter patient survival. Metabolic control was good. Haemoglobin rose during the first 3 months. Plasma creatinine concentration increased with time, probably due to the loss of residual renal function. HbA1c levels were in the normal range for 60% of the patients. Mean hospital stay was 42 days per year, 26 as a consequence of vascular complications and 16 due to peritonitis and catheter-related problems. We conclude that CAPD is a good renal replacement modality for patients with diabetic renal failure. The patient survival is dependent on age, systolic hypertension and cardiac disease at the start of CAPD