Characteristics, cardiovascular comorbidity and medicines management in patients with type 2 diabetes and CKD: results of the IRIDIEM study.

BACKGROUND: Type 2 diabetes is a leading cause of chronic kidney disease (CKD). The purpose of the Individual Risk-Profiling and Treatment in Diabetes Management (IRIDIEM) study was to evaluate the characteristics of CKD and associated comorbidities in patients with type 2 diabetes and CKD. METHODS: IRIDIEM was conducted as a cross-sectional survey in 109 centres in 11 countries and included 1,205 patients aged >or=50 years with type 2 diabetes for >or=5 years and CKD stage 2-4. RESULTS: 50% of patients were in CKD stage 4; 42% had CKD stage 3, and 4% were in CKD stage 2. Concomitant risk factors for cardiovascular disease and/or progression of CKD included hypertension (92% of patients), proteinuria (74%), hypercholesterolaemia (65%), and hypertriglyceridaemia (44%). Only 64% of patients with hypertension had received antihypertensive medication. Anaemia was present in 34% of patients and increased markedly with advanced CKD stages. Of patients with documented anaemia, only 19% had received epoetin and only 7% had received iron treatment. CONCLUSION: IRIDIEM documents the need to improve adherence to current best practice guidelines for management of cardiorenal risk factors including earlier initiation of antihypertensive treatment, lipid and anaemia management in this high-risk patient population.

Functional analysis of vascular dysfunction in cyclosporin treated rats.

OBJECTIVE: The aim was to analyse vascular damage after chronic cyclosporin treatment (20 mg.kg-1 during 10 d) in rats. METHODS: The reactivity to different vasoactive agents was studied on thoracic aortic rings from control rats, and from rats subjected to renal ablation or cyclosporin treatment. RESULTS: After cyclosporin treatment the endothelium dependent vasodilator responses to acetylcholine and to the endothelium independent NO donors were suppressed. These defects were restored after a 7 d recovery period. The contractile response after inhibition of basal endothelial NO synthesis was unaffected. Further analysis of the blunted vasodilatations not only points to impairments of cGMP mediated mechanisms but shows that other pathways are possibly involved as well. Renal insufficiency induced by renal mass reduction did not influence the aortic reactivity. CONCLUSIONS: Cyclosporin induced vasculotoxicity is a reversible phenomenon, and is not due to renal dysfunction as such. It seems to provoke a defect in the vasodilator mechanisms at the level of the vascular smooth muscle cells and most likely no impairment of endothelial nitric oxide production.

Single-dose pharmacokinetics of cefpirome in patients with renal impairment.

The pharmacokinetic parameters of cefpirome (HR 810) were examined in 22 patients with different degrees of renal impairment. HPLC was used to analyze samples of blood and urine for cefpirome; and enzymatic assay of creatinine in serum and urine was used to assess kidney function. Creatinine clearance correlated linearly with both total and renal clearance of cefpirome. The loss of kidney function resulted in a decreased renal clearance, whereas the volume of distribution remained the same. This result led to an increase in the terminal half-life of the drug, from 2 hours in healthy subjects to 14 1/2 hours in patients with uremia. This increase also resulted in a prolonged high serum concentration well above the minimum inhibitory concentration. The following dosages are thus recommended: (1) creatinine clearance greater than 50 ml/min: normal daily dose, (2) creatinine clearance from 20 to 50 ml/min: 50% of normal daily dose, and (3) creatinine clearance less than 20 ml/min: 25% of normal daily dose. An initial loading dose of 1 gm, independent of renal function, is advised. Cefpirome was safe and well tolerated.

Single-dose pharmacokinetics of cefpirome in patients receiving hemodialysis and in patients treated by continuous ambulatory peritoneal dialysis.

Cefpirome is eliminated primarily by renal excretion, compelling dosage reduction in kidney failure. We studied the elimination kinetics after intravenous administration of 1 gm cefpirome in patients undergoing hemodialysis (n = 9) and after intravenous (n = 6) or intraperitoneal administration (n = 6) of 1 gm cefpirome in subjects treated by continuous ambulatory peritoneal dialysis (CAPD). Four hours of hemodialysis removed 48% +/- 9% of the drug present in the body at the start of hemodialysis. Consequently, a supplementary dose equal to 50% of the daily dose recommended in end stage renal disease (ESRD) should be administered after each hemodialysis treatment. In patients receiving CAPD, therapeutic levels in both serum and dialysate were reached after intravenous and intraperitoneal administration. The bioavailability after intraperitoneal administration was 84%. After systemic administration, the elimination of cefpirome in the dialysate was negligible. Consequently, systemic dosage of cefpirome in patients receiving CAPD and in patients with ESRD should be identical.

Effect of simvastatin treatment on the dyslipoproteinemia in CAPD patients.

HMG-CoA reductase inhibitors have been proven effective in decreasing the plasma cholesterol levels in patients affected with various forms of hypercholesterolemia, familial dysbetalipoproteinemia, familial combined hyperlipidemia and in nephrotic and diabetic dyslipidemia. The purpose of this study was to monitor and evaluate the efficiency and safety of the therapy with simvastatin, an HMG-CoA reductase inhibitor, in a group of patients treated by continuous ambulatory peritoneal dialysis (CAPD) with severe hypercholesterolemia. Monitoring of the changes occurring in the various lipids and apolipoproteins in these patients included the measurements of the plasma lipids and apolipoproteins A-I, A-II, B, C-II, A-IV and Lp(a). Lipoproteins were separated by gel filtration, on a Superose 6HR column, before and after 24 weeks of treatment. The patterns were compared to those observed in a group of primary hyperlipidemic patients treated with Lovastatin, a compound of the same class. The drug was well tolerated by the CAPD patients and no adverse reaction was observed. In addition to the decrease of the total and LDL cholesterol, similar to that reported in other groups of patients, we further observed a decrease of the apo E concentration in both the CAPD and the hyperlipidemic patients. This decrease was especially pronounced in the HDLE fraction and could involve an upregulation of the apo B-E and/or apo E receptor. These results should provide information about the mechanism of action of this drug in patients with end-stage renal disease.

Life-threatening hyperkalemia during combined therapy with angiotensin-converting enzyme inhibitors and spironolactone: an analysis of 25 cases.

PURPOSE: The beneficial effects of spironolactone are additive to those of ACE inhibitors among patients with heart failure and/or hypertension; however, it is essential to identify patients prone to develop serious hyperkalemia during combined treatment and to evaluate the associated morbidity and mortality. SUBJECTS AND METHODS: We studied 25 patients treated with ACE inhibitors and spironolactone who were admitted to the emergency room with a serum potassium level > 6 mmol/L. Patients were followed up for at least one month after admission. RESULTS: The mean age of the patients (11 males, 14 females) was 74 +/- 13 years. Five patients were diabetics. On admission, the serum potassium was 7.7 +/- 0.7 mmol/L and the serum creatinine was 3.8 +/- 1.8 mg/dL; these values were significantly higher than the most recent follow-up laboratory measurements (4.6 +/- 0.5 mmol/L and 1.9 +/- 1.2 mg/dL, respectively) obtained at 13 +/- 5 weeks before admission. The arterial pH on admission was 7.3 +/- 0.1 and the plasma bicarbonate was 18 +/- 5 mmol/L. The main causes for acute renal failure were dehydration (n = 12) and worsening heart failure (n = 9). The mean daily dose of spironolactone was 57 +/- 32 mg and 12 patients were concomitantly treated with other drugs that may cause hyperkalemia. Two patients died, and 2 patients were resuscitated but survived. Hemodialysis was necessary in 17 patients; 12 patients were admitted to the intensive care unit. The mean duration of hospitalization was 12 +/- 6 days. Two patients needed to be started on maintenance hemodialysis therapy. CONCLUSION: A combination of ACE inhibitors and spironolactone should be considered with caution and monitored closely in patients with renal insufficiency, diabetes, older age, worsening heart failure, a risk for dehydration, and in combination with other medications that may cause hyperkalemia. A daily spironolactone dose of 25 mg should not be exceeded.

Diquat intoxication: report of two cases and review of the literature.

Animal experiments have suggested that diquat is less toxic than the more widely used paraquat. In this paper, nine previously reported cases of diquat intoxication are reviewed, together with the description of our personal observations in two additional patients. These two patients, like four other patients described in the literature, died from complications involving the gastrointestinal tract, brain and kidneys. Thus, diquat intoxication is apparently not as innocent as was originally thought. In this paper, special attention has been given to the major clinical differences between diquat and paraquat intoxication. In contrast with the latter, severe diquat intoxication induces gastrointestinal fluid sequestration and is associated with cerebral hemorrhagic lesions and a higher incidence of severe acute renal failure. Despite an asymptomatic clinical interval of up to 48 hours after ingestion, hemoperfusion should be started as soon as possible to prevent toxic levels of diquat in tissue.

Acceptability of rilmenidine and long-term surveillance of plasma concentrations in hypertensive patients with renal insufficiency.

Acceptability and plasma concentrations of rilmenidine, a new antihypertensive agent mainly eliminated via the kidney, were evaluated in 17 hypertensive patients (supine diastolic blood pressure, 104 +/- 3 mmHg) with renal insufficiency (creatinine clearance, 35 +/- 4 ml.minute-1/1.73 m2; range, 12 to 58). Patients were treated for six months with rilmenidine at the dose of 1 mg in the morning or 1 mg twice daily as single-drug therapy in untreated patients, or in combination or as substitution in patients already treated. Plasma concentrations of rilmenidine were measured by gas chromatography combined with mass spectrometry at Days 0, 1, 5, 7, 9, and 11, and Months 1.5, 3, 4.5, and 6 before administration. Supine and erect blood pressure (sphygmomanometer) measurements and side effects were noted at the same times. Laboratory and electrocardiographic parameters were evaluated at Days 0 and 11, and Months 1.5 and 6. Blood pressure was effectively controlled during the trial in 12 patients (mean decrease in systolic/diastolic blood pressure of 12/8 mmHg). Five patients were removed from the trial after Month 1.5 because of a rise in blood pressure (three cases) or noncompliance (two cases). Side effects were moderate and transient (dry mouth, constipation, daytime drowsiness, mood disturbances, insomnia) never requiring treatment withdrawal. Surveillance of renal function revealed no significant mean variation. Rilmenidine plasma concentrations reached steady state the fifth day at the latest and were related to the degree of renal insufficiency. When renal function was stable (13 cases), plasma concentrations did not vary until the end of the trial. When renal function was progressive (four cases), plasma concentrations increased in parallel in two patients, without the onset of side effects, and remained stable in the other two patients. In conclusion, this study confirmed the good acceptability of rilmenidine in hypertensive patients with chronic renal insufficiency. It showed stable plasma concentrations of rilmenidine during a six-month treatment in hypertensive patients with renal insufficiency, reflecting the absence of accumulation of the drug.

Peritoneal dialysis favorably influences early graft function after renal transplantation compared to hemodialysis.

BACKGROUND: Delayed graft function (DGF) and acute renal failure (ARF) after renal transplantation negatively influence short- and long-term graft outcome. Peritoneal dialysis as pretransplantation dialysis modality was reported to influence favorably the recovery of renal function immediately after kidney transplantation. It has been hypothesized that fluid status was the factor explaining this better outcome. This hypothesis was tested in this study by multivariate analysis, also including other factors related to DGF and ARF. METHODS: The records of peritoneal dialysis (PD; n=40) and hemodialysis (HD; n=79) patients receiving a first cadaveric kidney transplantation at the University Hospital Gent were analyzed. RESULTS: DGF and ARF were observed in 33 (27 HD and 6 PD, P=0.03) and 14 (14 HD and 0 PD, P=0.01) patients, respectively. The number of days needed to reach a serum creatinine 50% below that before transplantation (T1/2(SCr)), was correlated with cold ischemia time (CIT) (P<0.001) and body weight gain (BWG) (P<0.01) and was inversely correlated with urinary output in the first 24 hr (P<0.001), fluid load (P<0.001), and central venous pressure (P<0.001). A multivariate model with CIT (P<0.001), PD as pretransplantation dialysis mode (P=0.01), urinary output in the first 24 hr (P=0.001), BWG (P=0.05), and fluid load (P=0.01) resulted in an R2 of 0.32 (P<0.001). Using Cox regression analysis, the relative risk for a prolonged T1/2(SCr) increased with 4%/hr CIT (P=0.01) and with 1%/kg BWG (P=0.02). Fluid load decreased the relative risk with 5%/liter (P<0.001) and PD as pretransplantation modality favorably modified the relative risk by a factor of 1.6 (P=0.01). CONCLUSION: PD as pretransplantation dialysis modality can reduce the incidence and the severity of delayed recovery of renal function after renal transplantation. This protective effect was independent from CIT, and fluid status, two other major influencing factors.

[Methyl-carbon-11] thymidine for in vivo measurement of cell proliferation.

UNLABELLED: [Methyl-11C]thymidine and PET provide an in vivo, noninvasive, quantitative approach for studying nucleoside uptake in cells on condition that the fraction of metabolites in the total accumulated activity is known. METHODS: Using an animal model (Wistar rats), two independent approaches were followed. In the first approach, total accumulated activity in rapidly dividing tissue after intravenous injection of [methyl-11C]thymidine, respectively, [methyl-11C]thymine (first metabolite), was compared. In the second approach, the liver was surgically isolated to avoid thymidine catabolism. RESULTS: After injection of [methyl-11C]thymidine, tissue activity consists of both labeled thymidine and metabolites, while after injection of [methyl-11C]thymine, it consists only of metabolites. The fraction of metabolites ranged from 9% to 44%. Comparing the specific activity with and without liver function yielded similar results. The calculated amount of metabolites was about 10%. CONCLUSION: In spite of the intense in vivo catabolism, major activity in rapidly dividing tissue consists of [methyl-11C]thymidine.

Ofloxacin pharmacokinetics in chronic renal failure and dialysis.

Data on the pharmacokinetics of ofloxacin in chronic renal failure, in patients who were not dialysed or were receiving haemodialysis or continuous ambulatory peritoneal dialysis (CAPD), are reviewed. In addition, a large pool of data obtained in patients with a wide range of renal dysfunction is provided. The good absorption of ofloxacin after oral administration is not influenced by renal failure. Total plasma clearance (CL) is largely dependent on renal elimination of the drug, and renal clearance (CLR) and urinary recovery are reduced in parallel with reductions in renal function. Consequently, the serum half-life progressively increases when creatinine clearance decreases. Although there is wide variation in the published absolute values for the CL and CLR of ofloxacin, all studies show a similar pattern in the pharmacokinetic behaviour of the drug in chronic renal failure. A proposed protocol for ofloxacin dosage adjustment in chronic renal failure is reported which differs slightly but significantly from that recommended by the manufacturer. This new dosage regimen was derived from the pharmacokinetic results after single and multiple oral administration of the drug to patients with chronic renal failure. Since no clinically relevant losses of ofloxacin occur during haemodialysis or continuous ambulatory peritoneal dialysis (CAPD), the same protocol should be followed in these patients as in undialysed patients with terminal chronic renal failure.

Endothelial dysfunction in diabetes.

Endothelial dysfunction plays a key role in the pathogenesis of diabetic vascular disease. The endothelium controls the tone of the underlying vascular smooth muscle through the production of vasodilator mediators. The endothelium-derived relaxing factors (EDRF) comprise nitric oxide (NO), prostacyclin, and a still elusive endothelium-derived hyperpolarizing factor (EDHF). Impaired endothelium-dependent vasodilation has been demonstrated in various vascular beds of different animal models of diabetes and in humans with type 1 and 2 diabetes. Several mechanisms of endothelial dysfunction have been reported, including impaired signal transduction or substrate availibility, impaired release of EDRF, increased destruction of EDRF, enhanced release of endothelium-derived constricting factors and decreased sensitivity of the vascular smooth muscle to EDRF. The principal mediators of hyperglycaemia-induced endothelial dysfunction may be activation of protein kinase C, increased activity of the polyol pathway, non-enzymatic glycation and oxidative stress. Correction of these pathways, as well as administration of ACE inhibitors and folate, has been shown to improve endothelium-dependent vasodilation in diabetes. Since the mechanisms of endothelial dysfunction appear to differ according to the diabetic model and the vascular bed under study, it is important to select clinically relevant models for future research of endothelial dysfunction.

A pharmacokinetic study of roxatidine acetate in chronic renal failure.

The pharmacokinetics of a single oral dose of roxatidine acetate 150 mg were studied in 31 patients with varying degrees of chronic renal failure. The patients were divided into 5 groups according to their creatinine clearance (Clcr): controls (Clcr 94.5 +/- 13.9 ml/min; n = 6); mild chronic renal failure (Clcr 47 +/- 6 ml/min; n = 4); moderate chronic renal failure (Clcr 27.3 +/- 3.1 ml/min; n = 4); severe chronic renal failure (Clcr 12.8 +/- 1.4 ml/min; n = 5) and uraemia (Clcr 6.6 +/- 0.6 ml/min; n = 12). Serum and urine samples were analysed with capillary gas chromatography to measure the salt of the desacetyl metabolite of roxatidine acetate (roxatidine). The terminal half-life was 6.02 +/- 0.31 hours in controls and 7.35 +/- 0.57, 9.3 +/- 0.83, 14.6 +/- 3.7 and 18.10 +/- 2.77 hours, respectively, in the 4 other groups, with progressively decreasing creatinine clearance. Maximum serum concentration and time to maximum serum concentration rose from 816 +/- 75 ng/ml and 2.08 +/- 0.22 hours, respectively, in controls to 1364.7 +/- 156 ng/ml and 4.05 +/- 0.47 hours, respectively, in uraemic patients. Relative total clearance progressively decreased with decreasing glomerular filtration rate (GFR) [from 353.6 +/- 26 ml/min in controls to 90.31 +/- 12.2 ml/min in patients with uraemia]. Renal clearance decreased from a control of 243.9 +/- 56 ml/min to 12.32 +/- 0.18 ml/min in uraemic patients. A linear correlation between creatinine clearance and both relative total clearance and renal drug clearance was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin E-bonded cellulose membrane and hemodialysis bioincompatibility: absence of an acute benefit on expression of leukocyte surface molecules.

Dialysis with unmodified cellulose membranes is associated with such bioincompatibility phenomena as leukopenia, increased expression of adhesion molecules on leukocytes, and release of reactive oxygen species. Dialysis biocompatibility can be improved by modifications in the structure of the cellulose membrane to diminish leukocyte activation and/or protect against the released free oxygen radicals. Excebrane (Terumo Corp, Tokyo, Japan) is a vitamin E-modified cellulose membrane. In the present study, the effect of dialysis with Excebrane membranes on granulocyte and monocyte counts; CD11b, CD11c, and CD45 expression on the surface of granulocytes; and CD14 expression on monocytes was evaluated and compared with low-flux polysulfone membranes. Fifteen minutes after the start of dialysis, granulocytopenia and monocytopenia were more pronounced with the Excebrane membrane compared with polysulfone. The increase in basal expression of CD11b and CD45 on circulating granulocytes was more pronounced during dialysis with Excebrane than polysulfone membranes. Regarding the increased expression on in vitro stimulation with phorbol myristate acetate, blunted upregulation was obtained during dialysis using Excebrane membranes for CD11c and CD45 expression on granulocytes and CD14 expression on monocytes. In conclusion, such indices of membrane bioincompatibility as leukocyte counts and expression of leukocyte surface molecules show more profound alterations with Excebrane than the standard low-flux polysulfone membrane in both basal and in vitro activated states.

Rifampicin-associated acute renal failure: pathophysiologic, immunologic, and clinical features.

A 71-year-old woman was treated for a relapsing pulmonary tuberculosis with reinstitution of rifampicin after a medication-free interval of 2 years. After ingestion of the second dose, she developed severe hemolytic anemia and acute renal failure (ARF) necessitating dialysis. We demonstrated the presence in the patient's serum of rifampicin-dependent immunoglobulin G (IgG) and IgM antibodies, which caused red blood cell lysis through interaction with the I antigen on the erythrocyte surface. A review of the literature yielded 48 cases of rifampicin-associated renal failure. A subgroup of 37 patients could be distinguished, which, analogous to our case, suddenly developed ARF and frequently also developed hemolytic anemia and/or thrombocytopenia during intermittent or interrupted treatment. Regarding the pathogenesis of the ARF, renal biopsy consistently revealed tubular lesions. Although intravascular hemolysis with hemoglobinuria may play a role, it is not uniformly present. Our demonstration of an antibody with anti-I specificity provides a possible explanation. The I antigen is also expressed on tubular epithelium and may, therefore, be the target structure through which rifampicin-antibody complexes lead to tubular cell destruction. The other cases of rifampicin-associated ARF were unrelated to this subgroup: two cases of rapidly progressive glomerulonephritis, five cases of acute interstitial nephritis, and four cases of light chain proteinuria were recorded.

Delayed gastric emptying in dyspeptic chronic hemodialysis patients.

Hemodialysis patients frequently experience such dyspeptic symptoms as nausea, vomiting, abdominal distension, early satiety, and anorexia. Gastroparesis might be a cause of malnutrition, and parameters of gastric emptying are inversely correlated with serum albumin levels. The aim of the present study is to determine whether delayed gastric emptying is related to dyspeptic symptoms. In 54 hemodialysis patients, a standardized history for dyspeptic symptoms was taken. In addition, gastric emptying for solids was measured in 26 patients, using the (13)C-octanoic acid breath test. There was a high prevalence of dysmotility-like dyspepsia in the hemodialyzed population. A significant difference in gastric emptying between dyspeptic hemodialysis patients and healthy volunteers and between dyspeptic and nondyspeptic hemodialysis patients was shown. There was a significant correlation between gastric emptying and dysmotility-like dyspepsia. Serum albumin level inversely correlated with gastric emptying. In conclusion, there is a high prevalence of dysmotility-like dyspepsia in hemodialysis patients. Dyspeptic patients have significantly delayed gastric emptying compared with both healthy volunteers and nondyspeptic patients.

Reduced incidence of acute renal graft failure in patients treated with peritoneal dialysis compared with hemodialysis.

In a case-control study performed in two centers, the incidence of delayed graft function (DGF), defined as the necessity to perform dialysis after transplantation, was analyzed according to prior treatment with continuous ambulatory peritoneal dialysis (CAPD; n = 117) or hemodialysis (HD; n = 117). The patients were matched for age, sex, HLA compatibility, and cold ischemia time. The patients were followed up for 6 months to monitor renal graft function (serum creatinine [Screa] level immediately after transplantation, at 6 weeks, at 6 months) and postoperative complications. No significant differences were found in the warm ischemia time of the graft or previous time on dialysis. DGF occurred in 27 CAPD patients (23.1%) and 59 HD patients (50.4%; P < 0.0001). The decline in Screa level after transplantation was faster in CAPD patients: the time for Screa level to decrease 50% after transplantation (T1/2Screa) was reached after 5.0 +/- 6.6 days in the CAPD group compared with 9.8 +/- 11.5 days in the HD group (P < 0.0001). A greater number of patients developed acute rejection episodes in the CAPD group (P < 0. 05), but Screa level was not different in the two groups 6 weeks and 6 months after transplantation. No differences were observed in infectious or surgical complications. This study shows that immediate renal function after transplantation is better in CAPD patients and that peritoneal dialysis should be considered as a first choice for pretransplantation therapeutic modality.

Protein-bound uremic solutes: the forgotten toxins.

The present concept of dialysis focuses mainly on the removal of small water-soluble compounds, and also, the currently applied kinetic parameters of dialysis adequacy are based on the behavior of water-soluble compounds. Nevertheless, many of the currently known biological effects in uremia are attributable to compounds with different physicochemical characteristics, and among these, protein-bound solutes play an important role. In this article, we review the characteristics and consequences of changes in protein binding in uremia, as well as the toxicity of the protein-bound uremic solutes 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF), indoxyl sulfate, hippuric acid, homocysteine, and p-cresol. Starting from the example of p-cresol, we then summarize the impact of protein-binding on dialytic removal, whereby it is concluded that this removal is largely hampered by this protein-binding compared with that of classic markers such as urea and creatinine. Alternative removal strategies, such as strategies to modify intestinal generation or absorption, are considered.

Uremic toxins and peritoneal dialysis.

Uremic toxicity is related in part to the accumulation of toxic substances, the nature of which has only partly been characterized. Because of the use of a highly permeable membrane and better preservation of the residual renal function, it could be anticipated that some of these uremic toxins are more efficiently cleared across the peritoneal membrane, and that the plasma and tissue levels of these compounds are lower than in hemodialysis patients. This article analyzes the generation and removal of several uremic toxins in peritoneal dialysis patients. The following uremic toxins are discussed: beta2-microglobulin, advanced glycation end products, advanced oxidation protein products, granulocyte inhibitory proteins, p-Cresol, and hyperhomocysteinemia. Some recent studies are reviewed suggesting that uremic toxins are involved in the progression of renal failure and are at least partially removed by peritoneal dialysis. We conclude that, although the plasma levels of some of these compounds are lower in peritoneal dialysis versus hemodialysis patients, it does not mean that the peritoneal dialysis patient is "better" protected against the numerous disturbances caused by these toxins.