Vitamin D status in patients with recurrent kidney stones.

Data regarding the prevalence of 25-hydroxyvitamin D (25(OH)D) insufficiency in patients with nephrolithiasis, and the effects of vitamin D supplementation on parathyroid hormone (PTH) are few and conflicting. In this article, we examined the prevalence of vitamin D insufficiency and deficiency in 236 recurrent kidney stone formers and the correlation of vitamin D levels with other parameters of stone formation. The prevalent stone composition was calcium oxalate (80.4%) and uric acid (16.45%). One third of stone formers had vitamin D insufficiency and a quarter of them high PTH levels (PTH >7.5 pmol/l) with normal serum (total and ionized) calcium values. Predictor of high PTH was low 25(OH)D level (r = 0.989, r(2) = 0.977, p < 0.001). Stone formers with hypercalciuria had higher 25(OH)D values (72.26 ± 4.21 vs. 59.29 ± 1.76, p = 0.0013) compared to stone formers with urine calcium within normal ranges. Further studies are needed in order to better define the consequences of vitamin D insufficiency and to evaluate the impact of the therapeutic interventions in this cohort.

Normocalcemic hyperparathyroidism in patients with recurrent kidney stones: a disease entity or vitamin D deficiency?

This retrospective data analysis was undertaken to examine the biochemical differences between renal stone formers with normocalcemic hyperparathyroidism (NHPT) and those with normal parathyroid hormone (PTH) levels. Our goal was to ascertain whether 25-hydroxyvitamin D (25(OH)D) status related to PTH levels in this patient cohort. Our findings among 74 patients with NHPT indicate that stone formers with NHPT had significantly lower 25(OH)D levels compared to 192 controls (p = 0.0001) and that 25(OH)D is positively correlated with 1,25-dihydroxyvitamin D values (R = 0.736, p = 0.015). Sequential measurements (after 3 - 5 years), among 11 patients with NHPT who did not receive vitamin D (VitD) preparations, showed a significant increase in urinary calcium (3.43 ± 1.96 vs. 5.72 ± 3.95, p = 0.0426) without a significant change in PTH levels. VitD supplementation, to 3 patients resulted in significant PTH decrease (11.8 ± 1.8 vs. 9.8 ± 1.3, p = 0.003). Prospective studies are needed to confirm the role of vitamin supplementation in renal stone formers with NHPT.

Aging and physiological changes of the kidneys including changes in glomerular filtration rate.

In addition to the structural changes in the kidney associated with aging, physiological changes in renal function are also found in older adults, such as decreased glomerular filtration rate, vascular dysautonomia, altered tubular handling of creatinine, reduction in sodium reabsorption and potassium secretion, and diminished renal reserve. These alterations make aged individuals susceptible to the development of clinical conditions in response to usual stimuli that would otherwise be compensated for in younger individuals, including acute kidney injury, volume depletion and overload, disorders of serum sodium and potassium concentration, and toxic reactions to water-soluble drugs excreted by the kidneys. Additionally, the preservation with aging of a normal urinalysis, normal serum urea and creatinine values, erythropoietin synthesis, and normal phosphorus, calcium and magnesium tubular handling distinguishes decreased GFR due to normal aging from that due to chronic kidney disease.

Diabetic patients on peritoneal dialysis.

During the past two decades, a number of studies have tried to evaluate the clinical status of dialyzed diabetic patients and the factors that may affect their outcomes. However, only a small number of diabetic patients on peritoneal dialysis (PD) have been followed for over 5 years, which is largely because of the presence of various comorbid conditions at the start of dialysis, the coexisting, far-advanced, target-organ damage that may gradually progress during the course of dialysis and limit the long-term survival on PD. On the contrary, among renal replacement therapies, survival of diabetic patients undergoing either PD or hemodialysis (HD) is probably similar, while diabetic patients on PD and HD have a lower actuarial survival than nondiabetic counterparts. This paper reviews our experience and the literature concerning the long-term outcome of diabetic patients on PD.

Sources of variation in estimates of lean body mass by creatinine kinetics and by methods based on body water or body mass index in patients on continuous peritoneal dialysis.

OBJECTIVE: We identified factors that account for differences between lean body mass computed from creatinine kinetics (LBM(cr)) and from either body water (LBM(V)) or body mass index (LBM(BMI)) in patients on continuous peritoneal dialysis (CPD). DESIGN: We compared the LBM(cr) and LBM(V) or LBM(BMI) in hypothetical subjects and actual CPD patients. PATIENTS: We studied 439 CPD patients in Albuquerque, Pittsburgh, and Toronto, with 925 clearance studies. INTERVENTION: Creatinine production was estimated using formulas derived in CPD patients. Body water (V) was estimated from anthropometric formulas. We calculated LBM(BMI) from a formula that estimates body composition based on body mass index. In hypothetical subjects, LBM values were calculated by varying the determinants of body composition (gender, diabetic status, age, weight, and height) one at a time, while the other determinants were kept constant. In actual CPD patients, multiple linear regression and logistic regression were used to identify factors associated with differences in the estimates of LBM (LBM(cr)LBM(V). The differences in determinants of body composition between groups with high versus low LBM(cr) were similar in hypothetical and actual CPD patients. Multivariate analysis in actual CPD patients identified serum creatinine, height, age, gender, weight, and body mass index as predictors of the differences LBM(V)-LBM(cr) and LBM(BMI)-LBM(cr). CONCLUSIONS: Overhydration is not the sole factor accounting for the differences between LBM(cr) and either LBM(V) or LBM(BMI) in CPD patients. These differences also stem from the coefficients assigned to major determinants of body composition by the formulas estimating LBM.

Association between pulse pressure and mortality in patients undergoing peritoneal dialysis.

BACKGROUND: Pulse pressure has been shown to be associated with adverse outcomes in the general population and in patients on hemodialysis (HD). However, the significance of pulse pressure has not been studied in peritoneal dialysis (PD) patients. This study examined the association between pulse pressure and mortality in patients undergoing chronic PD. METHODS: All patients aged 18 years or older that commenced PD between 1 January 2000 and 31 December 2005 at the University Health Network, Toronto, were included. The association between pulse pressure and mortality was assessed using the Cox proportional hazards model. RESULTS: A total of 306 patients were included in the study. Mean pulse pressure of the study cohort was 56.8 +/- 17.8 mmHg. Age and diabetes were significant predictors of elevated pulse pressure (p < 0.001). After adjusting for the level of systolic blood pressure and other demographic and clinical parameters, multivariable Cox proportional hazards modeling showed a direct and consistent association between pulse pressure and death risk. Each increment of 1 mmHg in pulse pressure was associated with a 2.7% increased hazard of all-cause death [95% confidence interval (CI) 1.001 - 1.054, p = 0.039] and a 4.1% increase in risk for cardiovascular mortality (hazard ratio 1.041, 95% CI 1.003 - 1.081; p = 0.035). CONCLUSION: Elevated pulse pressure is associated with an increased risk of all-cause and cardiovascular death in patients on PD. Recognition of this characteristic as an important predictor of mortality suggests that one goal of antihypertensive therapy in PD patients should be to decrease elevated pulse pressure.

The variability in ultrafiltration achieved with icodextrin, possibly explained.

BACKGROUND: A recent study by Jeloka et al. (Perit Dial Int 2006; 26:336-40) highlighted the high variability in maximum ultrafiltered volume (UF(max)) and the corresponding dwell time (t(max)) obtained using 7.5% icodextrin solution. We aimed to pinpoint the possible sources of this phenomenon by simulating the icodextrin ultrafiltration (UF) profiles according to the three-pore model of peritoneal transport. METHOD: The individual UF time courses observed in the study by Jeloka et al. (n = 29) were first characterized by linear and quadratic regression. We were then able to identify four main patterns. These were then adapted to UF profiles generated by the three-pore model by systematically altering the values of some model parameters, namely, the mass transfer area coefficient (MTAC or PS) for icodextrin/glucose, the peritoneal UF coefficient (LpS), the plasma colloid osmotic pressure gradient (DeltaPi), and the macromolecular clearance out of the peritoneal cavity (Cl(LF)). RESULTS: Modifications in the PS values caused only marginal variations in UF(max) and t(max), while more significant changes were produced by altering LpS and Cl(LF). However, far more evident was the importance of changes in DeltaPi. In fact, lowering DeltaPi to 14 mmHg caused a steady increase in UF with 10 - 14 hour dwells. On the contrary, the UF profiles became nearly "flat" when DeltaPi was increased to 30 mmHg. The parallel shifts induced by altering icodextrin metabolite concentrations did not markedly influence UF(max) or t(max). CONCLUSION: The UF pattern in icodextrin dwells seem to be mainly determined by the plasma colloid osmotic pressure, while only moderate changes can be seen with alterations in LpS and Cl(LF). The result is not completely unexpected considering that icodextrin acts by inducing a strong colloid osmotic gradient. A number of clinical studies would be needed, however, in order to prove this hypothesis.

Elderly diabetic patients on peritoneal dialysis.

Diabetes mellitus is the fastest-growing cause of end-stage renal disease (ESRD) among patients requiring renal replacement therapy (RRT). While diabetes mellitus has become the leading cause of ESRD, the number of elderly patients who need dialysis has grown almost exponentially. Most elderly patients with diabetes are treated with hemodialysis; only a small percentage are treated with peritoneal dialysis (PD). Elderly PD patients with diabetes have a lower survival rate than do nondiabetic patients and younger diabetic patients, perhaps because of the increased comorbidity seen in diabetic patients at dialysis initiation. Also, diabetic patients on RRT are at higher risk of developing de novo cardiovascular disease, one of the major causes of mortality. In Canada, survival in elderly diabetic patients undergoing PD is similar to that in hemodialysis patients; in the United States, patients over 45 - 55 years of age with diabetes have experienced higher mortality on PD than on hemodialysis. It is important, however to emphasize that survival on PD in these elderly patients has greatly improved in recent years. Fluid volume expansion may be one of the reasons for the higher mortality in elderly diabetic patients in some countries; but overall, PD remains a viable form of long-term RRT for elderly diabetic patients with ESRD.

Assisted peritoneal dialysis: what is it and who does it involve?

Together with the obvious increase of elderly patients with end-stage renal disease (ESRD), utilization of peritoneal dialysis (PD) has declined since the mid-1990s in a number of countries--a decline that is particularly marked in this elderly ESRD population. A major obstacle that affects any dialysis modality in elderly patients is the greater disease burden than is seen in younger patients. However; this factor may be overcome if patients start PD with assistance provided by visiting helpers (nurses or others) or people at home, mostly family members. Assisted PD (aPD) is suitable for; but not limited to, elderly patients who are unable to perform PD for themselves at home. Important considerations of an assisted model of care include frequency of visits, type of health care, and tasks to be performed for the patient at home. Clinical experience worldwide shows that aPD offers acceptable survival for most elderly and disabled patients, with no significant difference in modality-related complications from those seen in self-performed PD. Elderly patients on aPD experience more frequent hospitalizations, with longer hospital stays. Costs of aPD vary from country to country, depending on the frequency of visits and on reimbursement policies. Most authors believe that aPD can be cost-effective when compared with in-center hemodialysis.

Use of ACE inhibitors or angiotensin receptor blockers and survival in patients on peritoneal dialysis.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors have been shown to improve outcome in patients with renal failure not on dialysis therapy and patients on haemodialysis (HD). However, their effect on survival has not been studied in peritoneal dialysis (PD) patients. The present study examined the association between therapy with ACE inhibitor/ARB and mortality in patients undergoing chronic PD. METHODS: All patients who commenced PD between 1 January 2000 and 31 December 2005 at the University Health Network were included. Patients were grouped according to whether they had been treated with ACE inhibitor/ARB. They were followed up from the date of PD initiation until death, cessation of PD, transfer to other centres or to the end of the study (31 December 2006). RESULTS: A total of 306 patients were included in the study. One hundred and sixty-five were treated with ACE inhibitors/ARB (treated group) and 141 were not (untreated group). The treated group patients were younger (56.9 +/- 16.6 versus 62.3 +/- 17.8 years, P < 0.01) and more likely to have a history of hypertension than the untreated group. At the initiation of PD, systolic and diastolic blood pressures were higher in the treated than the untreated group (138.8 +/- 21.8 versus 128.6 +/- 22.4 mmHg, P < 0.001; 79.8 +/- 14.1 versus 74.5 +/- 12.5 mmHg, P = 0.001) and remained significantly higher during the follow-up (133.5 +/- 16.4 versus 125.1 +/- 16.7 mmHg; 77.3 +/- 9.8 versus 73.2 +/- 9.7 mmHg, both P < 0.001). The treated group had a significantly longer survival compared to the untreated group (log rank 19.191, P < 0.001). After adjusting for age, blood pressure and other demographic and clinical parameters, multivariable Cox proportional hazards modelling showed that the use of ACE inhibitor/ARB was associated with 62% reduced risk for death (HR 0.382, 95% CI 0.232-0.631, P < 0.001). CONCLUSION: In this retrospective analysis, ACE inhibitor/ ARB therapy was associated with a dramatically reduced mortality in patients on peritoneal dialysis independent of blood pressure and other clinical and demographic variables.

Comparison of peritoneal dialysis practice patterns and outcomes between a Canadian and a Chinese centre.

UNLABELLED: Objective. We compared patient characteristics, dialysis practice patterns and outcomes of peritoneal dialysis (PD) patients between one Chinese centre and one Canadian centre to determine whether observed differences in demographics and practices are associated with patient and technique survival. METHODS: This study included all patients who started on PD between 1 January 2000 and 31 December 2004 at the University Health Network, University of Toronto, Canada and Renji Hospital, Shanghai Jiao Tong University School of Medicine, China. They were followed up from the date of PD initiation until death, cessation of PD, transfer to other centres or to the end of the study (31 December 2006). RESULTS: We studied 496 patients, 256 from the Canadian centre and 240 from the Chinese centre. Canadian patients were older and more likely to have diabetes and cardiovascular comorbidities at the initiation of PD, while the Chinese patients had lower residual renal function (RRF). More Canadian patients were treated with APD, whereas all Chinese patients were on CAPD with a lower PD volume. Crude patient survival rates at 1, 2, 3 and 5 years were similar between the two centres: 90%, 79%, 72% and 61% for Canadian and 90%, 79%, 71% and 64% for Chinese patients, respectively. After adjustment for demographic and clinical variables, there is no significant difference in mortality between Chinese patients and Canadian patients. Age, cardiovascular disease, diabetes, RRF and serum albumin were independent predictors of patient survival. The death-censored technique survival rates were significantly lower among the Canadian patients compared to Chinese patients. Chinese patients showed a lower risk of technique failure (HR 0.491, 95% CI 0.269-0.898, P = 0.021) after adjustment for patient characteristics. Chinese centre, BMI, serum albumin and gender were independent predictors of technique survival. The average peritonitis rate was one episode every 36.1 patient-months in Canadian patients and one episode every 60.6 patient-months in their Chinese counterparts. CONCLUSION: Patient characteristics, dialysis practice patterns and outcomes vary between Canadian and Chinese patients. The variability in patient outcomes between these two centres indicates that further improvements may be possible in both centres. We have identified several areas for improving outcomes.

High peritoneal permeability is not associated with higher mortality or technique failure in patients on automated peritoneal dialysis.

BACKGROUND: Patients on continuous ambulatory peritoneal dialysis (CAPD) who have high small-molecule peritoneal transport have increased mortality. OBJECTIVE: To investigate the impact of baseline peritoneal transport characteristics on patient and technique survival in incident peritoneal dialysis (PD) patients, most of whom are on automated PD (APD), with the use of icodextrin. DESIGN: Retrospective observational cohort study. SETTING: A single PD unit. PATIENTS AND METHODS: 193 new patients that began PD between January 2000 and September 2004, and had an initial peritoneal equilibration test within 6 months of commencement of PD. Patients were divided into low (L), low average (LA), high average (HA), and high (H) peritoneal transport groups. Death-censored technique failure and patient survival were examined. RESULTS: Of the 193 patients, 151 (78.1%) were on APD or on APD with icodextrin or on CAPD with icodextrin. At the end of 1, 3, and 5 years, patient survival was 91%, 82%, and 67% in LA group; 95%, 77%, and 69% in HA group; and 96%, 71%, and 71% in H group. Technique survival was 100%, 90%, and 77% in LA group; 96%, 84%, and 72% in HA group; and 92%, 87%, and 77% in H group. High peritoneal permeability did not predict worse patient survival or technique failure, while age, diabetes, a lower glomerular filtration rate, and high body mass index (> or =30 kg/m(2)) were independent predictors of death. CONCLUSION: This study suggests that higher peritoneal transport is not a significant independent risk factor for either mortality or death-censored technique failure. The favorable outcome for high transporters in this study may be due to improved management of volume status by the increased use of APD and the use of icodextrin-based dialysis fluid.

Comparison between bicarbonate/lactate and standard lactate dialysis solution in peritoneal transport and ultrafiltration: a prospective, crossover single-dwell study.

OBJECTIVE: It has been proposed that biocompatible bicarbonate/lactate based (Bic/Lac), physiologic-pH peritoneal dialysis (PD) solutions will be beneficial in long-term PD. However, we do not yet have detailed knowledge concerning the comparative physiology of buffer transport for these new solutions and their impact on underlying peritoneal transport of solutes and ultrafiltration (UF). The purpose of this study was to investigate the profile of buffer handling and peritoneal membrane transport characteristics during a single dwell of the new Bic/Lac-based versus standard lactate-based (Lac) PD solution. METHODS: In this prospective crossover study, we compared a 25 mmol/L bicarbonate/15 mmol/L lactate buffered, physiologic pH, low glucose degradation product (GDP) solution (Physioneal; Baxter Healthcare, McGaw Park, Illinois, USA) with a standard lactate buffered, acidic pH, conventional solution (Dianeal; Baxter). 18 patients underwent two peritoneal equilibration tests (PETs) with 2.5% Dianeal and 2.5% Physioneal separated by 1 week. Buffer transport, mass transfer area coefficients (MTACs), solute transport, and UF were determined for the two PETs. All bags were weighed by a nurse before instillation and after drainage to assess the net UF in each dwell. RESULTS: 18 patients that met the inclusion criteria were enrolled in this study. Whereas intraperitoneal pH remained constant at 7.52 +/- 0.11 throughout the dwell with the Bic/Lac solution, pH was still in the acidic range with the Lac solution after 1 hour (7.29 +/- 0.13, p < 0.001); this difference disappeared after the second hour of dwell. The MTACs for creatinine (10.68 +/- 3.66 vs 10.73 +/- 2.96 mL/minute/1.73 m(2), p > 0.05) and urea (27.94 +/- 10.50 vs 27.62 +/- 6.95 mL/min/1.73 m(2), p > 0.05), for Bic/Lac versus Lac respectively, did not differ between these two solutions; transport of glucose and other solutes was also similar. However, after a 4-hour dwell with Bic/Lac solution, net UF was significantly lower than that observed with Lac solution (274.2 +/- 223.3 mL vs 366.1 +/- 217.3 mL, p = 0.026). CONCLUSIONS: Compared to standard Lac-based solution, Bic/Lac based, pH neutral, low-GDP solution avoids intraperitoneal acidity. Peritoneal mass transport kinetics are similar for small solutes. Net UF is significantly lower with Bic/Lac solution; the mechanism for this is unclear.

Unusually prolonged vitamin D intoxication after discontinuation of vitamin D: possible role of primary hyperparathyroidism.

A 77-year-old woman had taken 50,000 IU of vitamin D2 daily, instead of once weekly, for over 2 years. She developed severe hypercalcemia, and after stopping vitamin D, her serum 25-hydroxyvitamin D (25(OH)D) remained higher than 250 nmol/l for almost 2(1/2) years. Inappropriately high parathyroid (PTH) concentrations were particularly evident after serum calcium was suppressed to slightly above the reference range by the administration of intravenous pamidronate and prednisone. It seems that an underlying primary hyperparathyroidism that was masked initially by the hypercalcemia of vitamin D intoxication was responsible for the unusually prolonged half-life of 25(OH)D in the blood. After vitamin D2 had been stopped, the decline in serum 25(OH)D was unusually slow. In this unusual case, primary hyperparathyroidism probably prevented an appropriate increase in the vitamin D-catabolizing enzyme, 25(OH)D-24-hydroxylase, thereby slowing metabolic clearance of 25(OH) vitamin D.

Assisted peritoneal dialysis as a method of choice for elderly with end-stage renal disease.

In the last two decades, most developed countries have seen a continuous growth in the number of elderly patients with end-stage renal disease commencing renal replacement therapy. Despite the many advantages that peritoneal dialysis (PD) offers to elderly patients with ESRD, it is still underutilized in older patients. Older patients are much more vulnerable to the problems associated with aging, which may affect their level of independence and their long-term prognosis. Those patients have physiological changes related to aging and common health problems such as anxiety, depression, dementia, visual impairment, and cognitive impairment, all of which interfere with self-performing PD. Assistance with home-care nurses and assistance by a family member may overcome this problem. Some old but also more recent literature data justifies the idea that assisted PD may significantly contribute to increase the overall number of elderly patients who can be treated with PD at home. With assisted PD, free choice can be offered to patients with high comorbidity index who cannot perform their peritoneal exchanges by themselves. Automated peritoneal dialysis is the ideal treatment modality for elderly patients with end-stage renal disease who require assistance since this limits home-care nurse visits to only two a day. As expected, the elderly have a higher mortality rate than younger patients treated by assisted PD, but technique failure rate, overall peritonitis rate, and most quality-of-life (QoL) measures are comparable with those of younger patients. Peritoneal dialysis in nursing homes offers treatment for elderly patients without family support. In this regard, automated PD or nightly PD keeps the patient's daytime free for nursing home activities, increases socialization, and enables better rehabilitation that improves their QoL. Although withdrawal from dialysis is more frequent among nursing-home dialysis patients, this high discontinuation rate is not due to dialysis per se but rather to associated social and medical circumstances. Better communication between nursing staff and renal team is crucial for improving staff confidence and will contribute to higher utilization of PD in nursing homes.

Magnesium carbonate for phosphate control in patients on hemodialysis. A randomized controlled trial.

BACKGROUND: Magnesium salts bind dietary phosphorus, but their use in renal patients is limited due to their potential for causing side effects. The aim of this study was to evaluate the efficacy and safety of magnesium carbonate (MgCO(3)) as a phosphate-binder in hemodialysis patients. METHODS: Forty-six stable hemodialysis patients were randomly allocated to receive either MgCO(3) (n=25) or calcium carbonate (CaCO(3)), (n=21) for 6 months. The concentration of Mg in the dialysate bath was 0.30 mmol/l in the MgCO(3) group and 0.48 mmol/l in the CaCO(3) group. RESULTS: Only two of 25 patients (8%) discontinued ingestion of MgCO(3) due to complications: one (4%) because of persistent diarrhea, and the other (4%) because of recurrent hypermagnesemia. In the MgCO(3) and CaCO(3) groups, respectively, time-averaged (months 1-6) serum concentrations were: phosphate (P), 5.47 vs. 5.29 mg/dl, P=ns; Ca, 9.13 vs. 9.60 mg/dl, P<0.001; Ca x P product, 50.35 vs. 50.70 (mg/dl)(2), P=ns; Mg, 2.57 vs. 2.41 mg/dl, P=ns; intact parathyroid hormone (iPTH), 285 vs. 235 pg/ml, P<0.01. At month 6, iPTH levels did not differ between groups: 251 vs. 212 pg/ml, P=ns. At month 6 the percentages of patients with serum levels of phosphate, Ca x P product and iPTH that fell within the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines were similar in both groups, whereas more patients in the MgCO(3) group (17/23; 73.91%) than in the CaCO(3) group (5/20, 25%) had serum Ca levels that fell within these guidelines, with the difference being significant at P<0.01. CONCLUSION: Our study shows that MgCO(3) administered for a period of 6 months is an effective and inexpensive agent to control serum phosphate levels in hemodialysis patients. The administration of MgCO(3) in combination with a low dialysate Mg concentration avoids the risk of severe hypermagnesemia.

Improvement in eGFR in patients with chronic kidney disease attending a nephrology clinic.

BACKGROUND: The adverse effects arising from late referral to a nephrologist of patients with chronic kidney disease (CKD) are well known. Retrospectively we examined the initial characteristics of patients referred in various stages of CKD to our nephrology division and tried to identify potential baseline factors associated with subsequent changes in estimated glomerular filtration rate (eGFR). PATIENTS AND METHODS: Between September 1997 and June 2006 1,443 patients (909 male, 534 female) with CKD, with eGFRs ranging from 15 to 89 ml/min, were referred to our nephrology division and categorized using the National Kidney Foundation classification for CKD based on eGFR. The slope of eGFR change (ml/min-1/1.73/m2-1/year-1) was determined by linear regression analysis and the patients were divided into five groups: (1) significantly progressive slope (deterioration) (more negative than -5 ml/min/year); (2) mildly progressive slope (>-5 to -1 to +1 to or=+5). RESULTS: At the first nephrology referral, 5.8% of the patients were on CKD stage 2 (eGFR: 90-60 ml/m), 46.7% on CKD stage 3 (eGFR: 59-30 ml/m), and 47.5% on CKD stage 4 (eGFR: 29-15 ml/m) CKD. Significantly improved slope was detected in 48.2% of CKD stage 2 patients, 29.3% of CKD stage 3 patients, and only 14.7% of CKD stage 4 patients (P<0.05). Being in stage 4 or stage 3 versus being in stage 2 significantly reduced the likelihood of an improved slope in logistic regression analysis whereas age, gender, presence of hypertension, and diabetes mellitus did not reach the level of significance. CONCLUSION: Referral to a nephrology clinic can lead not only to arrest of progression of CKD but also to regression/improvement. Early referral is a positive predictive factor for improvement in eGFR, which emphasizes the importance of such referral. The previously held idea that, once established, CKD progresses invariably is not valid anymore.

Physiological similarities and differences between renal aging and chronic renal disease.

Even though there are some functional similarities between the aged kidney and the chronically damaged one, such as the reduction in glomerular filtration rate and in the sodium-water reabsorption capability, there are many physiological differences between these two groups, as is the case of erythropoietin, urea, potassium, calcium, phosphorus and magnesium renal handling. Thus, the data presented demonstrate that renal aging and chronic kidney disease constitute different clinical scenes.

Reversing the decreasing peritoneal dialysis (PD) trend in Ontario: a government initiative to increase PD use in Ontario to 30% by 2010.

In September 2005, the Ontario Ministry of Health and Long-Term Care established the Provincial PD Coordinating Committee to make recommendations to increase the use of PD among prevalent dialysis patients in Ontario from the present 18% to 30% by 2010. In the present paper, we describe the process through which the Committee produced its recommendations and we highlight the proposed implementation plan.

The use of nocturnal home hemodialysis as salvage therapy for patients experiencing peritoneal dialysis failure.

BACKGROUND: Failure of peritoneal dialysis (PD) results in poor quality of life and worsening morbidity in patients with end-stage renal disease (ESRD). Traditionally, hospital-based conventional hemodialysis has been the only option for this patient population. We hypothesized that nocturnal home hemodialysis (NHD), 3-6 sessions per week, 6-8 hours per session, is a suitable alternative salvage therapy for this vulnerable patient group. METHODS: This is a descriptive cohort study of all consecutive ESRD patients failing PD that were converted to NHD at the University Health Network and Humber River Regional Hospital from 2003 to 2005. Our primary objective was to describe the changes in clinical and biochemical indices before and after conversion from PD to NHD. RESULTS: 69 patients required transfer from PD to another form of renal replacement therapy during the period of interest. Our pilot cohort included 8 ESRD patients (5 males, 3 females; age 53 +/- 7 years). Mean duration on PD was 4.8 +/- 4.6 years. NHD delivered a higher dose of dialysis, as reflected by lower plasma creatinine concentration 1 year after beginning NHD (from 1107 +/- 312 micromol/L with PD to 649 +/- 309 micromol/L, p = 0.01) and a rise in standardized Kt/V (from 2.21 +/- 0.73 with PD to 4.49 +/- 1.92 after 6 months of NHD, to 4.51 +/- 1.77 after 1 year of NHD; p < 0.001). There was a progressive and sustained rise in plasma albumin after conversion to NHD (from 31 +/- 4 g/L with PD to 36 +/- 4 g/L after 6 months of NHD, to 39 +/- 2 g/L after 1 year of NHD; p = 0.001). Hemoglobin concentrations increased (from 102 +/- 13 to 125 +/- 7 g/L, p = 0.03), while erythropoietin requirement tended to fall (from 17500 +/- 8669 to 9197 +/- 7573 U/week). Plasma phosphate fell (from 2.1 +/- 0.6 to 1.1 +/- 0.3 mmol/L, p = 0.01) despite a decrease in phosphate binder requirement. Blood pressure profile also tended to improve after conversion to NHD. CONCLUSION: Nocturnal HD represents a promising, viable, alternative renal replacement therapy for patients experiencing PD failure. The clinical impact of transferring ESRD patients failing PD to NHD deserves further investigation.