[Active surveillance for prostate cancer: usefulness of endorectal MR at 1.5 Tesla with pelvic phased array coil in detecting significant tumors]. / Cancer de la prostate localisé: l'IRM endorectale à 1,5 Tesla améliore-t-elle la sélection des patients en vue d'une surveillance active?

PURPOSE: To describe and assess MRI signs of significant tumor in a series of patients who all underwent radical prostatectomy and also fulfilled criteria to choose active surveillance according to French "SurAcaP" protocol. PATIENTS AND METHODS: The clinical reports of 681 consecutive patients operated on for prostate cancer between 2002 and 2007 were reviewed retrospectively. All patients had endorectal MR (1.5 Tesla) with pelvic phased array coil. (1.5 T erMR PPA). Sixty-one patients (8.9%) fulfilled "SurAcaP" protocol criteria. Preoperative data (MR+core biopsy) were assessed by comparison to whole-mount step section pathology. RESULTS: 85.3% of the 61 patients entering SurAcaP protocol had significant tumor at pathology. (Non Organ Confined Disease (Non OCD)=8.2%, Gleason sum score>6=39.2%). A new exclusion criterion has been assessed: T3MRI±NPS>1 as a predictor tool of significant tumor. ("T3MRI±NPS>1"=Non OCD at MR±number of positive sextants involved in tumor at MR and/or Core Biopsy > to 1). Sensitivity, specificity, PPV, NPV of the criterion "T3MRI±NPS>1" in predicting significant tumor were, respectively: 77%, 33%, 86%, 20%. Adding this criterion to other criteria of the "SurAcaP" protocol could allow the exclusion of all Non OCD, and a decrease in Gleason sum Score>6 rates (20%). CONCLUSION: Endorectal MR at 1.5 Tesla with pelvic-phased array coil should be considered when selecting patients for active surveillance in the management of prostate cancer. A criterion based upon MR and core biopsy findings, called "T3MR±NSP>1" may represent an exclusion citeria due to its ability to predict significant tumor.

[Retroperitoneal laparoscopic treatment of symptomatic caliceal diverticular calculi]. / Traitement par laparoscopie rétropéritonéale d'un amas lithiasique intradiverticulaire caliciel symptomatique.

Treatment of urinary calculi in caliceal diverticular is indicated when they are symptomatic. Minimally invasive techniques, in particularly laparoscopic approach, occupy an increasingly important place in the urological therapeutic armamentarium and have changed from an open surgical approach to endoscopic treatment for the management of symptomatic caliceal diverticular calculi. Herein, we report the case of a woman with symptomatic calculi in an upper caliceal diverticular managed by retroperitoneal laparoscopic approach.

A proposed nomenclature and diagnostic criteria for protein-energy wasting in acute and chronic kidney disease.

The recent research findings concerning syndromes of muscle wasting, malnutrition, and inflammation in individuals with chronic kidney disease (CKD) or acute kidney injury (AKI) have led to a need for new terminology. To address this need, the International Society of Renal Nutrition and Metabolism (ISRNM) convened an expert panel to review and develop standard terminologies and definitions related to wasting, cachexia, malnutrition, and inflammation in CKD and AKI. The ISRNM expert panel recommends the term 'protein-energy wasting' for loss of body protein mass and fuel reserves. 'Kidney disease wasting' refers to the occurrence of protein-energy wasting in CKD or AKI regardless of the cause. Cachexia is a severe form of protein-energy wasting that occurs infrequently in kidney disease. Protein-energy wasting is diagnosed if three characteristics are present (low serum levels of albumin, transthyretin, or cholesterol), reduced body mass (low or reduced body or fat mass or weight loss with reduced intake of protein and energy), and reduced muscle mass (muscle wasting or sarcopenia, reduced mid-arm muscle circumference). The kidney disease wasting is divided into two main categories of CKD- and AKI-associated protein-energy wasting. Measures of chronic inflammation or other developing tests can be useful clues for the existence of protein-energy wasting but do not define protein-energy wasting. Clinical staging and potential treatment strategies for protein-energy wasting are to be developed in the future.

Cystatin C improves the diagnosis and stratification of chronic kidney disease, and the estimation of glomerular filtration rate in diabetes.

AIMS: Estimation of glomerular filtration rate (GFR) is recommended to diagnose and stratify chronic kidney disease (CKD). Can cystatin-C (cysC) assay improve the results in diabetic patients? METHODS: In 124 diabetic patients with a wide range of GFR, as determined by 51Cr-EDTA clearance (i-GFR), we estimated 'e-GFR' by: the recommended Cockcroft-Gault (CG) formula and Modification of Diet in Renal Disease (MDRD) study equation; the new Mayo Clinic quadratic (MCQ) equation; the recently proposed composite estimation including both serum creatinine and cysC; and a simplified approach dividing the MDRD by cysC if less than 1.10mg/L. RESULTS: The highest diagnostic accuracy (receiver operating characteristic [ROC] curves) and the highest proportions of well-stratified patients were obtained by cysC and the MDRD which, however, underestimated i-GFR for patients without CKD (-17%, P<0.001). The CG overestimated GFR in KDOQI stages 1 and 2, ignored stage 5 and was the least accurate. The MCQ equation overrepresented stage 2, overestimating GFR at this stage (+23%, P<0.005). The composite estimation (54.7+/-27.0mL per minute 1.73m(2)) correlated best with i-GFR (56.1+/-35.3; r=0.90, P<0.001), and did not significantly differ from it across the entire population and within each Kidney Disease Outcome Quality Initiative (KDOQI) stage but was also biased (Bland-Altman procedure). Simply dividing the MDRD by cysC ifless than1.10mg/L produced a comparable performance and eliminated the bias. CONCLUSION: The recommended creatinine-based estimations of GFR need to be improved. CysC assay helps in the diagnosis and stratification of CKD and leads to better estimates of GFR in diabetic patients without any substantial increase in complexity.

[Low protein diet supplemented with ketoanalogues of amino acids in patients with chronic renal insufficiency]. / Régime pauvre en protéines supplémentés par les céto-analogues des acides aminés chez le patient atteint d'insuffisance rénale : pour qui ? Comment ?

Restricted protein diets in patients with chronic kidney disease have been debated for several decades. In chronic kidney disease as in other chronic diseases, the modulation of the nutritional intake is the object of a certain renewal. It is supported by recent studies that highlight the importance of modulating nutrient intake by diets that are healthier, less rich in animal proteins and richer in plants. The recent reintroduction in France of amino acid supplements and ketoanalogs of amino acids allows the prescription of a very restricted diet. Historical studies have only focused on the relationship between protein intake and renal function degradation. Recent studies on acid loading, bone metabolism or potassium intake allow revisiting the interest of restricted diets. As with any change in eating habits, the selection of patients, information, education and monitoring during the diet are very important and help prevent undernutrition: this is the purpose of this short review.

Role of metformin accumulation in metformin-associated lactic acidosis.

OBJECTIVE: To investigate the role of metformin accumulation in the pathophysiology of metformin-associated lactic acidosis. RESEARCH DESIGN AND METHODS: We used high-performance liquid chromatography to measure plasma metformin concentrations in 14 patients who experienced lactic acidosis (pH < 7.35 and lactate concentration 5 > mmol/l) while receiving chronic metformin treatment. Their treatment was generally based on alkalinization and dialysis therapy. RESULTS: Clinical shock and/or evidence of tissue hypoxia was found in all patients with the exception of one who had a nonsteroidal anti-inflammatory drug-induced anuria. Ten patients had significant metformin accumulation (plasma metformin concentrations 4.1-84.9 mg/l, normal value 0.6 +/- 0.5 mg/l before drug intake), generally because of failure to withdraw metformin despite intercurrent pathological conditions affecting its renal elimination (serum creatinine concentrations ranging from 269 to 1,091 mumol/l). There was no metformin accumulation (plasma metformin 0.03-0.7 mg/l) in the four other patients, who had less severe renal failure (serum creatinine 140-349 mumol/l). The severity of the patient's general condition did not predict early hospital mortality (death before discharge from the intensive care unit) even in patients in shock. Whereas it was high in those without metformin accumulation (only 1 of 4 patients recovered), early hospital mortality was low in the 10 patients with metformin accumulation and was not related to its extent (3 patients died with end-stage hepatic failure or cardiac failure). Correlation studies showed a positive correlation between serum creatinine and plasma metformin and between plasma metformin and arterial lactate but, for the latter correlation, only in patients with metformin accumulation. CONCLUSION: Metformin-associated lactic acidosis is not necessarily due to metformin accumulation; true type B (aerobic) lactic acidosis, i.e., without an apparent associated hypoxic factor, seems exceptional. Neither the severity of the clinical picture nor the degree of metformin accumulation predicted survival; rather, the prognosis was dependent upon the severity of the associated pathological conditions.

Mapping of the X-breakpoint involved in a balanced X;12 translocation in a female with mild mental retardation.

Balanced chromosomal abnormalities such as translocations and inversions have been identified in many genetic diseases. Cloning of the breakpoints involved in these abnormalities has led to the identification of the disease-related genes. Recent reports suggest the presence of a mental retardation locus at Xq11-12. We have identified a female patient with a balanced translocation t (X;12) (q11;q15) associated with mild mental retardation. We identified a yeast artificial chromosome spanning the X-chromosome breakpoint by using fluorescent in situ hybridization techniques. A cosmid library of this YAC has been constructed and the search for candidate genes is in progress.

Influence of renal insufficiency on the pharmacokinetics and pharmacodynamics of terazosin.

Renal insufficiency was not shown to affect the pharmacokinetics of terazosin in fifteen patients receiving oral terazosin (1 mg once daily) for two weeks. Five patients had normal renal function (creatinine clearance 80 ml per minute or more), five had moderate renal insufficiency (creatinine clearance 30 to 79 ml per minute), and five had severe renal insufficiency (creatinine clearance 10 to 29 ml per minute). Urine and blood samples were collected, and blood pressure and pulse rate were determined on days one and 15 of the study. Renal insufficiency had no significant effect on the absorption lag time, rate of absorption, rate of elimination in the urine, volume of distribution, or plasma clearance of terazosin. The plasma half-life of terazosin in patients with normal renal function was 10.0 hours, compared with 8.4 hours in patients with moderate renal insufficiency and 9.8 hours in the group with severe renal insufficiency. There was also no apparent relationship between renal insufficiency and the maximum change in blood pressure or pulse rate. Renal excretion was found to play a minor role in the elimination of terazosin, and this explains the lack of a relationship between renal insufficiency and the pharmacodynamics of terazosin. After the administration of terazosin on day 1 of the study, 1.6 +/- 0.3 percent and 5.1 +/- 1.4 percent of the total dose was excreted in the urine of patients with severe renal insufficiency and normal renal function, respectively. Adverse experiences were reported by four patients and caused one patient to withdraw from the study. Symptoms reported included gastralgia, headache, dizziness, malaise, weakness, and palpitations. The results of this study indicate that terazosin may be safely administered to patients with renal insufficiency without altering the usual dosing regimen.

Are supplemented low-protein diets nutritionally safe?

In patients with chronic renal failure (CRF), the reduction of dietary protein intake may correct uremic symptoms, slow the rate of progression of renal failure, and delay the onset on dialysis. Concerns have been made on the nutritional consequences of protein-restricted diets. Over 15 years, 239 patients were treated with a very-low-protein diet providing 0.3 g vegetable protein/kg/day supplemented (SLPD) with essential amino acids and keto analogs. Many adverse consequences of uremia were corrected by this regimen, such as metabolic acidosis, secondary hyperparathyroidism, resistance to insulin, decreased Na(+)-K(+)-ATPase activity. A joint physician-dietitian monitoring contributed to the maintenance or obtention of a satisfactory nutritional status, even in patients at risk, diabetics, patients with the nephrotic syndrome and with renal allograft chronic rejection. The outcome of these patients when treated by hemodialysis or transplantation was favorable, their nutritional status being preserved. Results from the present study and results of other studies show that SLPD can be used in patients with advanced CRF without adverse effects in carefully selected and monitored patients.

No change of hyperleptinemia despite a decrease in insulin concentration in patients with chronic renal failure on a supplemented very low protein diet.

Chronic renal failure (CRF) is often accompanied by hyperleptinemia caused by deficient renal metabolism of leptin and possibly increased leptin production, which in turn may result from the hyperinsulinemia and increased proinflammatory cytokine levels in patients with CRF. The hyperinsulinemia and insulin resistance observed in patients with CRF improve on supplemented very low protein diets (SVLPDs). The goal of our study is to determine whether the correction of hyperinsulinemia and insulin resistance in patients with CRF by SVLPDs is accompanied by improvement in hyperleptinemia. Thirteen patients were studied before and 1 year after following SVLPDs providing 0.3 g/kg/d of protein, supplemented with amino acids and ketoanalogues. After 1 year, patients showed markedly less hyperinsulinemia (7.4 +/- 1.6 versus 13.8 +/- 2 microU/mL at the start of diet; P: = 0.05) and insulin resistance, whereas serum leptin levels remained unchanged (16.1 +/- 4.7 versus 19.1 +/- 7.4 ng/mL at start of the study; P: = not significant). The initial correlation between serum leptin level and percentage of body fat persisted during follow-up. No correlation was found between insulin and leptin levels or between the variation of these two parameters during the study. Our study shows that the correction of hyperinsulinemia and insulin resistance in patients with CRF by SVLPDs is not accompanied by improvement in hyperleptinemia, which consequently does not appear to result from changes in carbohydrate metabolism.

Outcome of nutritional status and body composition of uremic patients on a very low protein diet.

Concern has been raised about the nutritional adequacy of a very low protein diet (VLPD). Monthly clinical evaluation by a physician and dietitian and quarterly dietary records, anthropometric measurements, blood testing, and dual energy X-ray absorptiometry (DEXA) were used to assess the course of nutritional status for 1 year in 10 clinically stable patients (six men, four women; age, 57.1 +/- 9.3 years) with advanced chronic renal failure (mean glomerular filtration rate, 13.2 +/- 4.8 mL/min/1.73 m(2)). These patients received a VLPD providing 0.3 g/kg/d of protein and were supplemented with amino acids and ketoanalogues. Conventional nutritional markers remained unchanged after 1 year of the VLPD. However, during the same period, whole-body DEXA showed a significant decrease in lean tissue from 46.2 +/- 10.2 to 45.0 +/- 9. 8 kg (P < 0.02); limb-trunk lean tissue ratio was reduced from 0.86 +/- 0.12 to 0.82 +/- 0.12 (P < 0.02), total-body fat increased from 20.0 +/- 6.9 to 21.4 +/- 7.0 kg (P < 0.05), and the percentage of total-body fat increased from 29.2% +/- 8.7% to 31.7% +/- 8.8% (P < 0.03). These different modifications occurred abruptly during the first 3 months, then stabilized or slightly improved thereafter. These mild changes do not appear to be deleterious given the favorable long-term outcome of these patients, even after they began treatment by dialysis or after renal transplantation.

Influence of nutritional factors and hemodialysis adequacy on the survival of 1,610 French patients.

Nutritional factors and dialysis adequacy are associated with outcome in hemodialyzed patients, but their relative contribution remains controversial, particularly when dialysis adequacy complies with current recommendations (Kt/V >1.2). Survival, clinical, and nutritional data from a cohort of prevalent 1,610 patients treated by hemodialysis in 20 centers in France have been collected over a 2.5-year period, from January 1996 to July 1998. Data including age, sex, cause of end-stage renal disease (ESRD), clinical outcome, time on dialysis, body mass index (BMI), blood levels of midweek predialysis albumin, prealbumin, and bicarbonate were analyzed. Normalized protein catabolic rate (nPCR), dialysis adequacy parameters, and estimation of lean body mass (LBM) from creatinine generation were computed from pre- and postdialysis urea and creatinine levels. The characteristics of the patients were as follows: age 59.6 +/- 16.5 years, 58.8% males, 11% of diabetics, time on dialysis 63.2 +/- 64.5 m. Weekly dialysis time was 12.18 +/- 1.78 hrs, Kt/V 1.34 +/- 0.34, nPCR 1.10 +/- 0.35 g/kg body weight/day. Albumin concentration was 39.4 +/- 5.3 g/L, prealbumin was 0.33 +/- 0.09 g/L, BMI was 23.0 +/- 4.5 kg/m(2). Overall survival was 89.7% +/- 0.8% and 78.4% +/- 1.1% after 1 and 2 years. In the Cox proportional hazard model, survival was significantly influenced by age, the presence of diabetes, and by concentrations of albumin and prealbumin, but not by other variables, including Kt/V and urea reduction ratio. These results indicate that nutritional protein concentrations were predictive of dialysis outcome, whereas variables reflecting actual body composition and dialysis dose were not. Furthermore, in this well-dialyzed population, dialysis adequacy had no influence on survival. In conclusion, when adequacy targets are met in hemodialyzed patients, survival is mainly dependent on age and nutritional status. Efforts should be focused on the most efficient ways to maintain nutritional status in these patients.

Factors influencing survival in hemodialysis patients aged older than 75 years: 2.5-year outcome study.

The incidence of malnutrition is widely held to be greater in the elderly, but this specific factor has not been extensively studied in elderly dialysis patients. In a 30-month follow-up prospective study, we evaluated the role of nutrition on the outcome of 290 stable hemodialysis (HD) outpatients aged older than 75 years followed up in 20 French HD centers (167 men, 123 women; age, 79.8 +/- 4.2 years; previous time on dialysis, 41 +/- 38 months). On the same day in January 1996, predialysis and postdialysis blood samples were collected according to recommended procedures for dialysis quantification. Normalized protein catabolic rate, dialysis adequacy parameters, and estimation of lean body mass (LBM; expressed as observed/expected LBM values [obs/exp LBM]) were computed from predialysis and postdialysis urea and creatinine levels. Overall survival rates were 80% and 65% after 1 and 2 years of follow-up, respectively, and were significantly less in patients with the lower quartile of obs/exp LBM. In univariate analysis using the Cox proportional hazards model, survival was significantly influenced by age, albumin level, prealbumin level, body mass index, and diabetes, but not by sex, Kt/V, duration of dialysis, cholesterol level, hemoglobin level, or obs/exp LBM. In multivariate analysis, no variable remained significant. Cardiovascular mortality accounted for 52.1% of the patient deaths. We conclude that in elderly HD patients, malnutrition influences overall survival despite adequate dialysis treatment.

Molecular analysis of 53 fragile X families with the probe StB12.3.

Fifty-three pedigrees with the fragile X syndrome have been studied for amplification of the CGG repeat sequence adjacent to the CpG island in the FMR1 gene. Probe StB12.3 allowed direct detection of affected males, carrier females, normal transmitting males, as well as prenatal diagnosis. Comparison of our molecular data with our previous linkage data from 38 families indicates the effectiveness of direct DNA analysis. A total of 325 individuals were studied and no new mutation was found. All daughters of males with a premutation had a premutation. When the mother had a full mutation no children had a premutation. In premutated mothers, the size of the premutation seems to be a determining factor for the transition to the full mutation. All affected males had a full mutation or mosaicism and only 42% of the females with a full mutation were mentally impaired. Analysis of large families over 3 generations illustrated clearly the Sherman paradox. Furthermore, the analysis of these families is in reasonable agreement with the multiallelic model of Morton and Macpherson [Proc Natl Acad Sci USA 89:4215-4217, 1992]. Mosaic cases in the offspring of the mothers with a full mutation suggest a maternal germinal mosaicism. Then an abnormal methylation and a somatic heterogeneity established in very early steps of embryogenesis could explain these cases.

Hyperhomocysteinemia, a risk factor for atherosclerosis in chronic uremic patients.

Hyperhomocysteinemia has been shown to constitute an independent risk factor for premature occlusive arterial disease (N Engl J Med 324:1149), a frequent complication in chronic uremic patients in whom homocysteine (Hcy) accumulation has been reported to occur. We prospectively determined fasting plasma level of total, protein-bound Hcy in 118 adult chronic uremic patients, either dialyzed or not. In 79 non-dialyzed patients (47 male) with various degrees of chronic renal failure (RF) assessed by creatinine clearance (CCr), none receiving folate, B6 or B12 vitamin supplementation, mean (+/- 1 SD) plasma Hcy level was 16.2 +/- 8.1 mumol/liter in 28 patients with mild RF (CCr 30 to 75 ml/min), 23.3 +/- 14.7 in 29 patients with moderate RF (CCr 10 to 29.9), and 29.5 +/- 14.4 in 22 patients with advanced RF (CCr < 10), a significant difference (P < 0.01 for all groups) compared to 45 healthy controls (8.2 +/- 2.2 mumol/liter). Linear regression analysis showed a significant correlation between plasma creatinine and Hcy concentrations (r = 0.49, P < 0.0001). Hcy was significantly higher in 20 patients (16 males) who had past histories of occlusive arterial disease than in the 59 (31 males) who did not (30.9 +/- 19.1 vs. 19.6 +/- 9.7 mumol/liter, P < 0.001) and all of the former had Hcy level > 14.1 mumol/liter (the upper limit in healthy controls) versus 35 of 59 in the latter.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies to hepatitis C virus by second generation test in hemodialyzed patients.

To assess the prevalence and the incidence of hepatitis C virus (HCV) in a dialysis unit, we prospectively tested for anti-HCV in chronic hemodialysis patients and staff members since January 1989, using a first generation assay. Incidence was nil in staff and low in patients (3.7% in 89, 1% in 90), and prevalence was 30% in patients. In January 1991 blood samples from 115 patients were tested by first (EL1) and second generation (EL2) ELISA (Ortho Diagnostic System). Positive subjects were tested by a RIBA-2 confirmation test. Fifty-three patients were negative by all tests. Positive tests were observed in 62 patients (54%) including 36 positive in EL1 and EL2, and 26 only by EL2. All positive patients were reactive by RIBA-2 but nine were classified undetermined (only one positive band). In five patients reactivity of antibodies to 5-1-1 and C-100-3 gradually declined during the study. Second generation tests gave a better correlation with time on dialysis and blood transfusion. We conclude that second generation tests for HCV are more accurate for estimating true prevalence of HCV infection in hemodialysis units.

Early alterations of plasma free amino acids in chronic renal failure.

In order to assess the influence of renal failure and nutritional status on the fasting concentrations of free plasma amino acids, we studied 81 ambulatory adult patients with varying degrees of chronic renal failure. Each of the patients was in good general and nutritional condition. Compared to 33 healthy controls, patients with mild renal failure (Ccr greater than 25 ml/mn) exhibited significantly (p less than 0.01, Student's t test) raised concentrations of cystine, citrulline, ornithine, taurine and 3-methyl-histidine and low level of serine. Concentrations of cystine, citrulline, and 3-methyl-histidine in plasma but not of taurine or ornithine rose in parallel with the progression of renal failure. A significant, but moderate decrease in valine, leucine and isoleucine concentrations was observed in patients with the most marked degree of renal failure (Ccr less than 10 ml/mn). We conclude that changes in the plasma concentration of several non essential amino acids are already present in the early stage of renal failure in patients with no sign of protein malnutrition: these may result from altered metabolic pathways of amino acids related to uremia and/or nephron loss per se whereas the moderate decrease in branched-chain amino acids that is observed only in the advanced stage of renal failure may be, at least in part, nutritional in origin.

Resting energy expenditure in uremic, diabetic, and uremic diabetic subjects.

We compared Harris and Benedict [H & B; Harris, J. A., & Benedict, F. G. (1919). A biometric study of basal metabolism in man. Washington, DC: Carnegie Institution of Washington. p. 279.] predicted resting energy expenditure (REE) to values measured by indirect calorimetry in normal, uremic, diabetic, and uremic diabetic subjects. Predicted REE were overestimated (+9.2%, P<.005) in uremic subjects, and underestimated (-8.5%, P<.0001) in diabetic subjects. Uremic diabetic subjects were submitted to the opposite influences of diabetes and uremia on REE. Differences in body composition (lower fat-free mass in uremia and higher fat-free mass in diabetes) played a major role in these influences. In uremic diabetic subjects, predicted REE seemed well fitted to measured REE (biases <2%), but they were less correlated, and limits of agreement between predicted and measured REE were large. Although their mean REE seems normal, prediction by the H&B equation leads to important individual errors in uremic diabetic subjects: direct measurement of energy expenditure by indirect calorimetry may be helpful to precise the adequate energy content of a diet for these subjects.

Low protein diets and outcome of renal patients.

Protein-restricted diets have been proposed in patients with chronic renal failure (CRF) to correct uremic symptoms and to slow the progression of CRF thus delaying the initiation of dialysis. Questions have been raised about the compliance to such diets, their nutritional safety and efficacy. In two-thirds of selected and motivated patients, satisfactory compliance is observed; however, in the overall predialysis population, compliance is fair and does not exceed 50%. When patients are carefully monitored, protein-restricted diets, rather than inducing malnutrition, may prevent it. Moreover, the outcome of these patients, when treated by dialysis, is not affected by prior dietary prescription. A small but real beneficial effect of low protein diet (LPD) on the rate of progression of CRF is observed in nondiabetic renal diseases, but their beneficial effect seems to be greater in diabetic renal disease. Meta-analyses confirm that LPD can effectively postpone renal replacement therapy by moderately slowing the decline in GFR and also by substantially delaying the onset of uremic symptoms.

Impact of high-flux/high-efficiency dialysis on folate and homocysteine metabolism.

High-flux/high-efficiency (HF/HE) dialysis may have detrimental effects on micro-nutrients and water-soluble vitamins, such as vitamin B6, whose levels are lowered. Folate deficiency may increase cardiovascular risk through an increase in homocysteine (Hcy) serum levels. We therefore investigated the effects of dialysis with a high-flux (HF) membrane on folate and Hcy metabolism. Twelve patients without any folate supplementation, receiving dialysis with a low-flux membrane prior to the study (TO), were switched to dialysis using a HF triacetate membrane for four months (T1, T2, T3, T4) and received an oral daily folate supplementation during the two last months (T3, T4). Mean predialysis plasma folate levels fell dramatically after one month of HF dialysis (T1) and remained significantly lower than the initial level (p<0.05) at T2. Hcy concentrations were high in all patients at TO (mean 47.3 +/- 17.6 microM, normal range 5 to 15 microM). They did not change during the first two months of the study but dropped steeply after the beginning of oral folate supplementation. Folate supplementation should be used in HF/HE dialysis to avoid folate depletion. The combination of folate supplementation and HF/HE may lower Hcy levels and reduce cardiovascular morbidity and mortality in these patients.