Pyridinium crosslinks in patients on haemodialysis and continuous ambulatory peritoneal dialysis

BACKGROUND: The urine excretion of the pyridinium crosslinks of collagen,pyridinoline (PYD) and deoxypyridinoline (DPD) closely reflectbone resorption and their assay has been used as specific markersof mature collagen turnover. The aims of this study were toevaluate the use of these markers to predict the severity ofosteodystrophy in patients with chronic renal failure. METHODS: Using an isocratic ion-paired reverse-phase high-performanceliquid chromatography, PYD and DPD were determined in the serum,urine and dialysate of 48 patients with chronic renal failureundergoing haemodialysis (n=28) or continuous ambulatory peritonealdialysis (n=20). Nineteen apparently healthy subjects were studiedas controls. RESULTS: In all groups, serum and urine crosslinks excretion showed poorcorrelation with age. In the patients urine PYD/creatinine andDPD/creatinine were significantly (P0.03 and 0.001 respectively)higher than normal; urine PYD and DPD levels were highly correlatedwith each other (r=0.98) and with serum PTH (r=0.84 and 0.83respectively). The mean (SD) predialysis serum PYD, 269 (334)nmol/l, was significantly (P0.003) elevated compared with normalpatients, 4.1 (0.6) and pre-dialysis serum DPD was 82.9 (93.7)nmol/l. DPD was below the detection limit of the assay in normalsera. In the patients postdialysis decreases in serum PYD andDPD were statistically significant (P<0.0002 and P<0.0007respectively). PYD and DPD were found in the dialysate of patientson haemodialysis as well as 24-h dialysate in patients on CAPD.Dialysate PYD and DPD were highly correlated with each other(r=0.80) and with dialysate creatinine (r=0.76 and r=0.62 respectively).In the patients, the mean serum, urine and dialysate PYD andDPD increased with the duration on dialysis. These findingsconfirm that metabolic bone disease increases in patients withduration of chronic renal failure. CONCLUSION: Estimation of serum crosslinks levels has potential as an additionaltool in the diagnosis and monitoring of renal osteodystrophy.The ability to determine crosslink levels in serum and dialysateshould be particularly useful in patients who are unable toproduce urine.     

Effect of type of dialysis membrane on bone in haemodialysis patients.

BACKGROUND: Uraemic bone disease is the result of a number of factors modulating bone formation and resorption in a complex manner. In the present study, the hypothesis tested was that the type of haemodialysis membrane used for renal replacement therapy might also play a role. METHODS: We conducted a prospective, open study in 24 chronic haemodialysis patients who were randomized to dialysis treatment with either cellulosic (CELL group, n=11) or polyacrylonitrile (AN-69 group, n=13) membrane for 9 months. Repeated determinations of plasma parameters reflecting bone turnover were done in all patients, and a bone biopsy in a subgroup at the start and end of study. RESULTS: At the start, mean plasma intact parathyroid hormone levels were comparable between the two groups and they did not vary significantly at 9 months of treatment. Similarly, plasma bone-specific alkaline phosphatase and osteocalcin (markers of bone formation), and cross-laps (marker of bone resorption) remained unchanged. However, plasma insulin-like growth factor-I (IGF-I) progressively decreased from 169 to 119 ng/ml in AN-69 group (P<0.01), whereas it remained unchanged in CELL group. In addition, the levels of IGF binding protein (IGFBP)-1 and IGFBP-2 were increased while the levels of IGFBP-5 were decreased in AN-69 group. In the five patients of each group who had repeat bone biopsies, histomorphometric analysis showed a decrease in osteoblast surface, osteoclast surface and osteoclast number in AN-69 group at 9 months, compared with baseline values measured at the start of the study. In contrast, all three parameters significantly increased in the CELL group at 9 months (P<0.001 for the difference between each of the three parameters).Bone formation rate decreased by 31% in the AN-69 group, but increased by 50% in CELL group. However, this latter difference was not statistically significant. Plasma interleukin (IL)-6 and soluble IL-6 receptor levels did not change in the two groups of patients who had undergone bone biopsy. CONCLUSION: Dialysis with CELL membrane was associated with increased bone turnover whereas the use of AN-69 membrane was associated with decreased bone turnover, suggesting a beneficial effect of the latter on high-turnover uraemic bone disease. However, as the number of patients with repeat bone biopsies was small, these findings need to be confirmed in a larger study. Further studies are also needed to evaluate whether or not the changes in IGF system components play a role in decreased bone cell activity in patients on dialysis using the AN-69 polyacrylonitrile membrane.     

Comparison of peritoneal dialysis and haemodialysis after renal transplant failure

Background. A growing number of patients are returning to dialysisafter renal transplant failure. The aim of this study is todetermine whether peritoneal dialysis (PD) is a safe and goodtreatment option for these patients. Methods. All patients returning to PD or haemodialysis (HD)after renal transplant failure before 1 October 2002 at theUniversity Hospital Gasthuisberg, Leuven, Belgium, were evaluated.Data were collected until death, retransplantation (reTx), transferto HD or PD or until 1 January 2003. Results. Twenty-one patients starting PD (PDpostTx-group) and39 patients starting HD (HDpostTx-group) after renal transplantfailure were included in the study. There were no significantdifferences in age, sex, serum albumin- and CRP-levels at baseline.The total time on renal replacement therapy at transplant failureand time to transplant failure did not differ between the twogroups either. Furthermore, the baseline comorbidity was similarin both groups. During follow-up, the outcome did not differsignificantly between the two groups. However, there was a tendencytowards higher patient survival and reTx tended to be more frequentin the PDpostTx-group. Moreover, patients in the HDpostTx-grouptended to accrue more new comorbidity. The incidence of peritonitisand the evolution of dialysis adequacy (renal and peritonealKt/V and creatinine clearances) with time in the PDpostTx-groupwas similar to that seen in our centre's PD patients who hadnever undergone transplantation before. Conclusions. This study suggests that the outcome in patientsstarting PD after renal transplant failure is at least as goodas the outcome in those starting HD. Although these observationalfindings warrant further confirmation, PD therefore can be regardedas a safe and good treatment option for patients returning todialysis after renal transplant failure.     

Effect of renal transplantation on endothelial function in haemodialysis patients.

BACKGROUND: Haemodialysis patients (HD) have been characterized by a high incidence and prevalence of atherosclerotic cardiovascular disease. Based on the traditional cardiovascular risk factors in this population, we cannot explain this high incidence and prevalence. One of the mechanisms contributing to cardiovascular risk in HD patients may be to uraemic toxins. Cardiovascular risk factors and uraemic toxins themselves may cause endothelial dysfunction, which may play a pivotal role in the development and progression of atherosclerosis in this population. We hypothesized that elimination of uraemic toxins in response to renal transplantation (RTx) can improve endothelial function as assessed by flow-mediated dilatation of brachial artery in haemodialysis (HD) patients. METHODS: Endothelial function measured by flow-mediated dilatation of the brachial artery (FMD) and glyceryltrinitrate-induced dilatation of the brachial artery (NMD) were assessed twice, during haemodialysis treatment and after RTx in 30 chronic haemodialysis patients. All patients were characterized by absence of known atherosclerotic disease and traditional cardiovascular risk factors. We also studied age- and gender-matched 20 normotensive healthy controls. RESULTS: FMD values significantly improved after RTx (6.69+/-3.1% vs 10.50+/-3.0%, P<0.001) in HD patients. FMD of patients both during haemodialysis and after RTx was lower than in healthy controls (6.69+/-3.1%, 10.50+/-3.0% vs 14.02+/-2.3%, P<0.001 and P<0.01, respectively). There was no change in NMD values after RTx in HD patients (16.27+/-1.9% vs 16.30+/-1.8%, P>0.05). Also, NMD values in all patients were similar to healthy control values. CONCLUSIONS: There is an improvement of endothelial function as assessed by FMD of the brachial artery after RTx in HD patients. This may be attributed to the elimination of uraemic toxins by successful RTx.     

Risk factors for reduced bone density in haemodialysis patients.

BACKGROUND: Renal osteodystrophy may result in considerable morbidity for patients with end-stage renal disease. Secondary hyperparathyroidism, adynamic bone disease and osteomalacia, the main bony problems in chronic renal failure, may all be responsible for a reduction in bone mineral density (BMD). This can result in an increased fracture risk. By virtue of their age, post-menopausal status (in women), sedentary life-style and treatment (including previous corticosteroids), haemodialysis patients may be expected also to be at risk for developing osteoporosis, but little is known about the relative importance of these factors. METHODS: We report a prospective study examining the prevalence of reduced bone mineral density (BMD) and its association with a wide range of factors, in a heterogenous group of 88 chronic haemodialysis patients. Femoral neck and lumbar BMD were measured by dual-energy X-ray absorptiometry (DXA). Stepwise multiple linear regression analysis was used to identify risk factors associated with low bone mass. RESULTS: Forty three patients (48.9%) had reduced BMD, and in 17 (19.3%) BMD was below the fracture threshold as defined on DXA measurements by the World Health Organization (WHO). The BMD had significant negative associations with age, serum parathyroid hormone (PTH) levels, current gastric acid suppression therapy, female gender, age at menarche and history of previous fracture. Positive associations were found with weight, haemoglobin concentration, average serum phosphate, weekly heparin dose, oral calcium supplementation and history of parathyroidectomy. CONCLUSIONS: We have confirmed the importance of PTH-related bone disease in affecting BMD in haemodialysis patients, but have found that some other factors, which are known to be risk factors for osteoporosis, are also important.     

Removal of clodronate by haemodialysis in end-stage renal disease patients

BACKGROUND: Clodronate is a potent calcium-lowering drug. The effect ofhaemodialysis on clodronate pharm-acokinetics is unknown. METHODS: The removal of clodronate by haemodialysis was determined in10 end-stage renal disease patients (ESRD). A 2-h infusion of300 mg of clodronate was followed immediately by a 4-h haemodialysis.Vascular access was by AV fistula. A 1.5-m² cuprophane hollow-fibredialyser was applied. Blood flow was 205±15ml/min, dialysateflow 523±29 ml/min. Clodronate was determined by high-performanceliquid chromatography in total collected dialysate, and in bloodbefore and after the dialyser at initiation, 2 h, and 4 h ofHD. RESULTS: The initial predialyser serum concentration of clodronate was13.6 ± 4 ug/ml. It decreased to 4.9 ± 0.5 ug/mland 2.6 ± 0.5 ug/ml at 2h and 4h respectively. The clearanceof clodronate (86 ± 10 ml/min) remained unchanged duringHD. Clodronate in total collected dialysate per single 4-h HDwas 105 ± 16 mg (35% of injected dose). CONCLUSIONS: We conclude that clodronate is effectively removed from plasmaby HD. The present data together with information provided byprevious studies suggest that 300 mg of clodronate given asan 2-h infusion immediately prior to haemodialysis is an adequatedosage for ESRD patients.     

Comparison of residual renal function in patients undergoing twice-weekly versus three-times-weekly haemodialysis

Aim:   Patients with end-stage renal disease (ESRD) often start long-term haemodialysis (HD) thrice weekly, regardless of the level of residual renal function (RRF). In this study, we investigated whether ESRD patients having sufficient RRF can be maintained on twice-weekly HD, and how they fare compared to patients without RRF on thrice-weekly HD.
Methods:   We analyzed 74 patients who had undergone long-term HD and maintained on the same dialysis frequency from February 1998 to July 2005, and followed until December 2005. We compared the clinical variables between twice-weekly and thrice-weekly HD patients and a second analysis testing the residual urine output as an independent predictor for twice-weekly HD.
Results:   After a mean follow up of 18 months, twice-weekly HD patients ( n  = 23) had lower serum β2-microglobulin than thrice-weekly HD patients ( n  = 51). Moreover, the twice-weekly group had a slower decline of RRF, as indicated by their higher urine output and creatinine clearance, fewer intradialytic hypotensive episodes, and required less frequent hospitalization. There was no difference between the two groups in cardiothoracic ratio or indices of nutrition and inflammation. Multivariable logistic regression identified age (odds ratio (OR), 1.866; 95% CI, 1.093–3.183), dry body mass index (OR, 0.790; 95% CI, 0.625–0.999), and urine output (OR, 1.093; 95% CI, 1.026–1.164) as predictors for maintaining twice-weekly HD.
Conclusion:   Our data suggest that when patients who have sufficient urine output are given twice-weekly HD, they maintain dialysis adequacy and exhibit better preservation of RRF than patients on thrice-weekly HD.     

Review of clinical outcomes in nocturnal haemodialysis patients after renal transplantation.

BACKGROUND: Nocturnal haemodialysis (NHD) is a novel form of haemodialysis therapy that is associated with improved blood pressure control when compared to conventional haemodialysis (CHD). Current studies suggest that NHD lowers blood pressure through a decrease in peripheral resistance. The graft and blood pressure outcomes of NHD patients who undergo renal transplantation are unknown. METHODS: We reviewed the renal allograft and blood pressure outcomes of 15 NHD patients who underwent renal transplantation. An age and vintage matched cohort of 29 CHD patients was used as controls. RESULTS: The rate of delayed graft function (DGF) tended to be higher in the NHD group compared to the CHD group (64 vs 41%, P = 0.15), however the 1-year graft function (53+/-6 vs 59+/-5 ml/min, P = 0.426) and graft survival (92 vs 95%, P = 0.751) were similar. Intra-operatively, NHD patients had lower minimum systolic (92+/-5 vs 109+/-4, P = 0.03) and diastolic (48+/-3 vs 64+/-2, P = 0.02) blood pressures in comparison to the CHD cohort. Pathologically, acute tubular necrosis accounted for 100% of DGF in the NHD group in contrast to 75% in the CHD population (P = 0.01). Pre-transplant mean systolic BP (sBP) was significantly lower in the NHD group compared to the CHD group (113+/-6 vs 145+/-10 mmHg, P<0.001). At 12 months post-transplant, mean sBP increased from baseline in the NHD group ( triangle up sBP 22+/-7 mmHg, P = 0.009) while in the CHD group mean sBP fell (Delta sBP -14+/-5 mmHg, P = 0.014). Mean arterial and diastolic BP exhibited similar changes. These trends persisted after 24 months of post-transplant follow-up. CONCLUSIONS: One-year graft outcomes and blood pressures are similar for NHD and CHD patients who undergo renal transplantation. Unlike CHD patients, NHD patients experienced a significant fall in their intra-operative blood pressures, which likely contributed towards the delayed graft function in this cohort of patients. Further prospective studies are needed to examine the underlying differences in haemodynamics and long-term graft survival between the two renal replacement modalities.     

A registry of haemodialysis patients and the progress of haemodialysis services in Lithuania.

Background. Until 1990, haemodialysis (HD) in Lithuania wasunderdeveloped, but after independence, development of HD started.Until 1996, no precise data about HD patients in Lithuania wereavailable. In order to create a registry of HD, we started tocollect data about dialysis services and HD patients in 1996.Every collection of data was followed by distribution and discussionof the results within the nephrological community. This studydescribes the changes of Lithuanian HD between 1996–2002. Methods. Between 1996 till 2002 all HD centres in Lithuaniawere annually visited and data were collected about all HD patients(response rate of 100%). The evaluation of the results duringour observational study was made according to the European BestPractice Guidelines. During annual conferences for nephrologists,the guidelines and data of our HD registry were presented. Results. There was an increase in the number of HD stations(from 25 p.m.p. to 75 p.m.p., P<0.001), in HD patients (from60 p.m.p. to 237 p.m.p., P<0.001) and in the incidence ofnew HD patients (from 54.3 p.m.p. to 103 p.m.p., P<0.01).The mean age of HD patients increased from 47.2±16.1years in 1996 to 56.0±14.9 in 2002 (P<0.001). Themain underlying cause of ESRD was chronic glomerulonephritis,but its rate decreased from 54.5% in 1996 to 27.5% in 2002 (P<0.001).The percentage of diabetics increased from 7.1% to 16.4%, P<0.05,and in hypertensive nephropathy from 3.1% to 10.9%, P<0.05.We observed improvement of the quality of HD in Lithuania duringthese 5 years. The percentage of patients on bicarbonate HDincreased from 7.1% in 1996 to 100% in 2002 (P<0.001). Thepercentage of patients receiving more than 12 h HD/week increasedfrom 30.8% in 1996 to 53.5% in 2002 (P<0.001). The mean Kt/Vin 1999 was 0.81±0.53, but it increased in 2002 to 1.22±0.27,P<0.001. In 2002, 84.6% of all HD patients were examinedfor HB_sAg, 82.3% for anti–HCV, 31.2% for anti-HB_s and57.1% for anti-HB_c. The percentage of patients receiving phosphatebinders increased from 65.2% in 1996 to 84.4% in 1997 and 90.5%in 2002. Serum parathyroid hormone (PTH) levels were measuredin 27.3% of HD patients in 1999 but in 85.2% of patients in2002. The mean haemoglobin (Hb) concentration increased from92±15.4 g/l to 105±14.7 g/l; the percentage ofpatients with Hb>100 g/l increased from 27.5% to 64% in 2001.The percentage of HD patients receiving epoetin was 94.6% in2001 as compared with 78% in 1997. There was a marked increasein the use of intravenous iron (from 7.5% patients in 1997 to70.8% in 2000). The mean weekly dose of Epo was lower in HDpatients receiving intravenous iron than in patients receivingoral iron. Conclusions. Over the period of 1996–2002 the HD servicessignificantly expanded in Lithuania. The introduction of EuropeanBest Practice Guidelines and the establishment of a HD registrywith feedback of the results stimulated the significant progressin the quality of HD and in the management of the patients.     

Choice of dialysis membrane does not influence the outcome of residual renal function in haemodialysis patients

It has been recently proposed that haemodialysis membrane choicemay influence the maintenance of residual renal function. Theaim of the present study was to prospectively analyse the effectof membrane choice on the outcome of renal function in patientsentering a chronic haemodialysis programme. Twenty-two patientsfrom four hospitals have been randomly assigned to be dialysedwith either polysulphone(PSF)/polyacrylonitrile (PAN) (groupA; n=9), or cuprophane membranes (group B; n=13). Basal andmonthly serum biochemistry, residual creatinine clearance (C_cr)and urine volume (Vu), pharmacological and dialytic treatment,diet, and haemodialysis-related complications were recorded.A significant decrease was observed in the two most relevantvariables, i.e. remnant C_cr and Vu, within 3 months of startinghaemodialysis, with stabilization during the further follow-up.Such decrease was similar (P NS) for both groups A and B throughoutthe 9-month observation period. In conclusion, our results suggest that the choice of haemodialysismembrane does not influence the outcome of the residual renalfunction. Renal function decreased significantly within 3 monthson haemodialysis, independently of the type of dialyser membrane.     

Serum osteoprotegerin and renal osteodystrophy.

BACKGROUND: Numerous growth factors and cytokines are known to modulate bone turnover. An important, recently discovered complex involved in osteoclastogenesis is the osteoprotegerin/osteoprotegerin-ligand (OPG/OPGL) cytokine complex, which is produced by osteoblasts. Many factors, including parathyroid hormone (PTH), appear to affect bone turnover through this pathway. In this disorder, the role of the OPG/OPGL system in the pathogenesis of renal osteodystrophy, a disease with either low or high bone turnover, has not been investigated so far. METHODS: Thirty-nine chronic haemodialysis patients had bone biopsies, including histomorphometric and histodynamic examinations. In addition, the following serum biochemistry parameters were measured: serum OPG, intact PTH, PTH 1-84, total PTH, osteocalcin, total and bone alkaline phosphatases, 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol. RESULTS: On average, serum OPG levels were above the normal range. They were lower in adynamic bone disease (ABD) patients, than in patients with predominant hyperparathyroidism (HP) or mixed osteodystrophy (MO). Significant negative correlations were found between serum OPG and PTH levels, and between serum OPG and parameters of bone resorption (ES/BS) and bone formation (ObS/BS and BFR/BS) in HP and MO patients with PTH values < or =1000 pg/ml. For intact PTH levels < or =300 pg/ml, serum OPG was significantly lower in the group with ABD than in those with HP or MO (P<0.05). CONCLUSION: In renal osteodystrophy the OPG/OPGL system is involved in the regulation of bone turnover induced by PTH. The determination of serum OPG levels could be of use in the diagnosis of low turnover bone disease, at least in association with PTH levels < or =300 pg/ml.     

Childhood renal disorders in Saudi Arabia

An overview of childhood renal disorders in Saudi Arabia is presented, based largely on the experience in a large teaching hospital. The pattern of disorders is similar to that in other parts of the world, but the relative frequency of the various diseases appears to be different. Heredofamilial disorders are common, renal calculi are relatively frequent, and mesangioproliferative glomerulonephritis is a frequent cause of nonminimal change nephrotic syndrome. Preventable causes of end-stage renal failure include reflux nephropathy and posterior urethral valves. Although nephropathy associated with collagen vasculitides is not frequent, the prognosis of the disease is poor. IgA nephropathy appears to be a rarity.     

Efficacy and safety of long-term oral falecalcitriol treatment in patients with renal osteodystrophy

We investigated, in a multicenter study, the efficacy and safety of long-term administration of falecalcitriol, a new active vitamin D₃, in patients with renal osteodystrophy of the osteitis fibrosa type associated with secondary hyperparathyroidism caused by chronic renal failure. Falecalcitriol was orally administered every day for 48 weeks. Administration was started at a dosage of 0.3 μg/day, and the dosage was changed whenever necessary according to serum calcium (Ca) level. As a result, significant inhibition of the bone resorption markers, i.e., intact parathyroid hormone (i-PTH), pyridinoline (Pyr), and deoxypyridinoline (D-Pyr), was observed from the 8th week, and the bone formation markers, i.e., total activity and bone fraction of alkaline phosphatase, were also significantly inhibited from the 12th week. The bone mineral density (BMD) change rate in the bones of the whole body determined by dual-energy X-ray absorptiometry remained almost constant. When subjects were stratified according to the inhibition rate of bone metabolic parameters, BMD tended to increase in the group with strong inhibition and to decrease in the group with weak inhibition. Mean serum Ca level significantly increased from 9.5 mg/dl, but mean level was subsequently maintained at about 10 mg/dl until the end of administration by adjustment of the doses. These findings suggested that falecalcitriol may inhibit and normalize accelerated bone metabolic turnover without inducing excessive increases in serum Ca level in secondary hyperparathyroidism. With respect to safety, no specific adverse reactions associated with the prolonged administration period were observed. Received: July 1, 1997 / Accepted: Aug. 29, 1997     

Spinal cord compression in renal osteodystrophy

Summary A patient undergoing regular haemodialysis for chronic renal insufficiency developed neck pain followed by progressive spinal cord compression due to subluxation at the level C3-4. Decompression, laminectomy and osteosynthesis led to an almost complete recovery. A review of all the histological specimens suggested that hyperparathyroidism and not amyloidosis caused the vertebral destruction.     

Initial survival advantage of peritoneal dialysis relative to haemodialysis.

BACKGROUND: The influence of dialysis modality on prognosis is controversial. In the absence of randomized trials, epidemiological investigations present the best method for studying the problem. METHODS: 4568 haemodialysis (HD) and 2443 peritoneal dialysis (PD) records in 4921 dialysis patients treated between 1990 and 1999 were retrieved from the Danish Terminal Uremia register in order to determine the influence of dialysis form on prognosis. The register is national, comprehensive, and incident. RESULTS: Factors reducing survival included age, cardiovascular disease, malignancy, lung disease, diabetes, alcoholism, haematological disease, but not sex or hypertension. Transplant non-candidacy was associated with an adjusted relative risk of 4.7 (CI 4.0-5.6). PD mortality relative to HD (after correction for comorbidity and transplant candidacy) was 0.65 (CI 0.59-0.72, P<0.001) on an "as treated" and "history" analysis and 0.86 (CI 0.78-0.95, P<0.01) on an intention-to-treat (ITT) analysis. The difference was confined to the first 2 years of dialysis. Change in dialysis modality was associated with increased mortality, and change from PD to HD with an accelerated mortality for the first 6 months. This was presumably due to the transfer of sick PD patients, but did not explain the difference. The relative advantage of PD was lower for diabetic patients, where it was not significant on ITT analysis. Dialysis prognosis improved by 14% during the period, with similar results for HD and PD patients. PD patients who were subsequently transplanted had a significantly shorter time to onset of graft function (3.5 vs 5.1 days, P<0.05). CONCLUSIONS: These results show a survival advantage for PD during the first 2 years of dialysis treatment. This may be due to unregistered differences in comorbidity at the start of treatment, or may be causal, possibly due to better preservation of residual renal function. The study lends credence to the "integrative care" approach to uraemia, where patients are started on PD and transferred to HD when PD related mortality increases.     

Effect of fludrocortisone acetate on reducing serum potassium levels in patients with end-stage renal disease undergoing haemodialysis.

BACKGROUND: Hyperkalaemia is a commonly encountered problem in dialysis patients with end-stage renal disease (ESRD). The aim of the present study was to assess the effect of fludrocortisone acetate (FCA) on reducing serum potassium levels in haemodialysis (HD) patients with hyperkalaemia. METHODS: Prospectively, 21 HD patients with hyperkalaemia were enrolled in this study. Patients were divided into two groups, including FCA (0.1 mg/d, n = 13) administration or no treatment (control, n = 8) for 10 months. No changes in dialysis or drug regimens were made during this period. Result. There were no significant differences in the baseline characteristics and biochemical parameters between the two groups (FCA therapy and control). At 10-months after FCA therapy, serum potassium levels were not significantly different between the treatment and control groups [median value (range): 5.2 (4.4-6.0) vs 5.8 (4.8-6.3) mEq/l, P = 0.121]. However, using the Wilcoxon signed ranks test, serum potassium levels were significantly lower at the end of the 10 month time period after FCA therapy compared with serum potassium levels of the pre-treatment period [5.2 (4.4-6.0) vs 6.1 (5.3-6.8), P = 0.01]. The biochemical values, including sodium, chloride, protein, albumin, blood nitrogen, creatinine, interdialytic weight change and blood pressure, did not show significant difference in comparisons between the two groups and pre-and post-FCA therapy period. CONCLUSIONS: FCA therapy appears to slightly decrease serum potassium value in hyperkalaemic HD patients. However, these results are insufficient to explain the effectiveness of FCA. Therefore, potentially large-scale studies with increased dose concentrations are needed to minimize the positive potassium balance in hyperkalaemic HD patients.     

Calcitriol oral pulse therapy in children with renal osteodystrophy

A 6-month protocol of oral pulse calcitriol was used in nine uraemic children (2–14 years old) on dialysis who presented with renal osteodystrophy. Calcitriol was administered twice a week, 4 g per dose for patients over 30 kg and 3g for patients less than 30 kg. Plasma levels of parathyroid hormone, calcium, phosphorus and alkaline phosphatase were carefully controlled during the study. Parathyroid hormone levels decreased by 68% and 56% by the 2nd and 6th months of treatment in seven patients, while they remained unchanged in two patients with focal segmental glomerulosclerosis and massive proteinuria. Eight hypercalcaemic episodes from 77 determinations were observed, all of them recovered after 1 week of vitamin D withdrawal. We conclude that oral calcitriol pulse therapy is a good alternative for renal osteodystrophy in uraemic children. Careful monitoring of plasma parathyroid hormone and calcium is needed during follow-up when using this approach in paediatric patients.