Effect of membrane permeability on inflammation and arterial stiffness: a randomized trial.

BACKGROUND AND OBJECTIVES: Both larger molecule removal and dialyzer biocompatibility have been implicated in the high-flux hemodialysis (HD)-associated favorable outcome. In an attempt to delineate the effect of membrane permeability, we performed a randomized, crossover study to compare the inflammatory biomarkers, lipid profile, and aortic pulse wave velocity (PWV) of two dialyzers that are composed of identical membranes but with different flux characteristics. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Stable patients who had anuria and were on low-flux polysulfone membrane were randomly allocated either to HD with high-flux polyamide membrane (group A; 22 patients) or to HD with low-flux polyamide membrane (group B; 24 patients) for 24 weeks, then they were started on 24 weeks of the alternative HD treatment. Apart from the dialyzer, the dialysis prescription remained unchanged. RESULTS: Nineteen patients from group A and 23 patients from group B completed the study. Predialysis beta(2)-microglobulin levels decreased significantly when using the high-flux polyamide membrane. No difference between membranes was observed for serum albumin, high-sensitivity C-reactive protein, fibrinogen, IL-6, triglycerides, HDL cholesterol, LDL cholesterol, and lipoprotein(a) during the study. A significant increase in aortic PWV, a marker of aortic stiffness, was noted after patients switched from high-flux to low-flux polyamide membranes. Similarly, the rate of change in aortic PWV was significantly decreased with the use of the high-flux polyamide membrane. CONCLUSIONS: Our findings suggest that dialysis with polyamide membranes with different flux characteristics did not modify the inflammatory indices and lipid profile in stable HD patients; however, a seemingly beneficial effect on aortic stiffness was noted for patients who were maintained on high-flux polyamide membrane.

Development of the "peritoneal dialysis first" model in Hong Kong.

Maintenance dialysis is an expensive treatment modality for patients with end-stage renal-disease (ESRD). The number of patients on maintenance dialysis is rising rapidly and will reach 2.5 million globally by 2010. The predicted expenditure will be US$1 trillion. Since the 1960s, Hong Kong has faced financial restraints on the provision of dialysis. Continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis at home were found to be less expensive than in-centre chronic hemodialysis. The development of a "peritoneal dialysis first" (PD-First) policy has contributed significantly to a successful dialysis program in Hong Kong since 1960. Currently in Hong Kong, 80% of ESRD patients on maintenance dialysis are on PD, mainly CAPD; 20% are on hemodialysis. The success of the PD-First policy is a combination of accumulated experience of PD in each dialysis unit that has at least 200 CAPD patients under care and of impressive technique and patient survival rates for this modality. Concerted effort by government and charity organizations and commitment on the part of nephrologists and nursing staff to patient education are also important in making the PD program in Hong Kong a successful one.

Increased utilization of peritoneal dialysis to cope with mounting demand for renal replacement therapy--perspectives from Asian countries.

With the number of end-stage renal disease (ESRD) patients growing, one of the crucial questions facing health care professionals and funding agencies in Asia is whether funding for dialysis will be sufficient to keep up with demand. During the ISPD's 2006 Congress, academic nephrologists and government officials from China, Hong Kong, India, Indonesia, Japan, Macau, Malaysia, Philippines, Singapore, Taiwan, Thailand, and Vietnam participated in a roundtable discussion on dialysis economics in Asia. The focus was policy and health care financing. The roundtable addressed ESRD growth in Asia and how to obtain enough funding to keep up with the growth in patient numbers. Various models were presented: the "peritoneal dialysis (PD) first" policy model, incentive programs, nongovernmental organizations providing PD, and PD reimbursement in a developing economy. This article summarizes the views of the participant nephrologists on how to increase the utilization of PD to improve on clinical and financial management of patients with ESRD.

Hong Kong study using valsartan in IgA nephropathy (HKVIN): a double-blind, randomized, placebo-controlled study.

BACKGROUND: Previous studies showed that angiotensin-receptor blocker (ARB) therapy decreased proteinuria and possibly slowed the rate of renal function decline in patients with chronic proteinuric nephropathies. We performed a double-blind, randomized, placebo-controlled, multicenter study on the ARB valsartan in the treatment of patients with immunoglobulin A (IgA) nephropathy. METHODS: From 6 centers, we recruited 109 patients with IgA nephropathy who had either: (1) proteinuria with protein greater than 1 g/d and serum creatinine level less than 2.8 mg/dL (< 250 micromol/L), or (2) serum creatinine level of 1.4 to 2.8 mg/dL (120 to 250 micromol/L) regardless of degree of proteinuria. Patients were randomly assigned to administration of either valsartan, 80 mg/d (titrated up to 160 mg/d for blood pressure control), or placebo for 104 weeks. Additional antihypertensive therapy was allowed to achieve a target blood pressure of 140/90 mm Hg. The primary end point was doubling of serum creatinine level or dialysis-dependent renal failure. Secondary outcomes included change in proteinuria and decrease in glomerular filtration rate (GFR). RESULTS: There were 54 patients in the treatment group and 55 patients in the placebo group. Baseline clinical characteristics were similar between groups, although the treatment group had a marginally greater baseline GFR (87 +/- 36 versus 78 +/- 38 mL/min/1.73 m2 [1.45 +/- 0.60 versus 1.30 +/- 0.63 mL/s/1.73 m2];P = 0.29) and less proteinuria (protein, 1.8 +/- 1.2 versus 2.3 +/- 1.7 g/d; P = 0.21) than the placebo group. Average blood pressures during the study were 92.7 +/- 10.6 mm Hg in the treatment group and 100.9 +/- 9.1 mm Hg in the placebo group (P < 0.001). During the study period, 4 patients in the placebo group and 1 patient in the treatment group reached the primary end point (log-rank test, P = 0.18). Proteinuria decreased significantly in the treatment group (protein, 1.8 +/- 1.2 to 1.2 +/- 1.2 g/d; P = 0.03), but did not change in the placebo group. With multiple linear regression models, valsartan treatment resulted in a 33.0% decrease in proteinuria (95% confidence interval, 10.9 to 55.1) after adjusting for other confounding factors. There was a significant decrease in mean rate of GFR decrease in the valsartan-treated group (-5.62 +/- 6.79 mL/min/y [-0.09 +/- 0.11 mL/s/y]) compared with the placebo group (-6.98 +/- 6.17 mL/min/y [-0.12 +/- 0.10 mL/s/y]) throughout the study period after adjustment for average blood pressure and proteinuria (P = 0.014). CONCLUSION: Valsartan significantly decreases proteinuria and slows renal deterioration in patients with IgA nephropathy after adjustment for confounding factors, notably blood pressure. The long-term benefit of valsartan needs to be confirmed with additional studies.

Pulmonary hypertension, hyperthyroidism, and fenfluramine: a case report and review.

We report a case of pulmonary hypertension presenting with sudden cardiac arrest, hyperthyroidism and fenfluramine usage. This fatal case of pulmonary hypertension and valvular heart disease is associated with the use of an anorectic drug that had been withdrawn from the market more than eight years ago. Clinicians should alert to the side effects of appetite suppressant and slimming agents. The association between pulmonary hypertension in relation to hyperthyroidism and fenfluramine usage is reviewed.

Prevalence of silent kidney disease in Hong Kong: the screening for Hong Kong Asymptomatic Renal Population and Evaluation (SHARE) program.

BACKGROUND: End-stage renal disease (ESRD) is epidemic worldwide. In Hong Kong, the annual incidence of ESRD has risen from 100 pmp (per million population) in 1996 to 140 pmp in 2003. SHARE (Screening for Hong Kong Asymptomatic Renal Population and Evaluation program) is a population-based screening program aimed at identifying the prevalence of unrecognized renal disease in asymptomatic individuals, allowing further evaluation and disease-modifying interventions. METHODS: From November to December 2003, SHARE was conducted in several large residential communities in Hong Kong. The screening tool included a questionnaire documenting demographics and history or family history of diabetes mellitus (DM), hypertension (HT), and chronic kidney disease (CKD), together with on-site measurements of blood pressure (BP) and urine dipstick for protein, blood, and glucose. RESULTS: There were a total of 1811 participants. One thousand two hundred and one subjects were entered into the final analysis. Among the 1201 who were apparently "healthy" (asymptomatic and without history of DM, HT, or CKD), the prevalence of positive (> or =1+) urine dipstick for protein, glucose, blood, protein or blood, any urine abnormality, and HT (BP> or =140/90) was 3.2%, 1.7%, 13.8%, 16%, 17.4%, and 8.7%, respectively. Thirty three percent of the age over 60 years old group had either hypertension or urine abnormalities, compared with 24.0% in the 41- to 60-year-old group and 9.7% in the 20- to 40-year-old group. Having a family history of diabetes or hypertension increases the risk of having urine abnormalities, while a family history of hypertension also increases the risk of high blood pressure. CONCLUSION: It is concluded that subclinical abnormalities in urinalysis or BP readings are prevalent across all age groups in the adult population. An effective screening program at the primary care level that identifies these subjects for further evaluation is warranted, and the public in Hong Kong should be educated toward the significance of such findings in order to have regular health check for asymptomatic renal diseases.

Severe acute respiratory syndrome in dialysis patients.

Reviewed are the clinical features and outcome of 12 chronic dialysis patients (six men) who contracted severe acute respiratory syndrome (SARS) compared with 23 sex- and age-matched nonuremic SARS patients as controls. Eight were on peritoneal dialysis (PD) and four on hemodialysis. Mean age was 58 +/- 12 yr for the dialysis patients, and 57 +/- 12 yr for the controls. The presenting symptoms of dialysis patients were similar to the controls. With appropriate protection measures, hemodialysis was performed in a dedicated area of the SARS isolation ward, while PD was continued as intermittent PD. In all seven patients with PD effluent tested, SARS-related coronavirus (CoV) could not be identified by polymerase chain reaction (PCR) or viral culture. Three dialysis patients had persistent positive stool PCR after 5 wk, whereas all nondialysis patients had negative stool PCR after 1 wk. Despite dosage adjustment, ribavirin-induced hemolytic anemia was more severe in the dialysis patients. Dialysis patients required longer hospitalization than the controls, but the mortality was similar. With appropriate protective measures, dialysis could be safely performed. Dialysis patients with SARS often require prolonged hospitalization. Furthermore, these patients may have an extended period of viral shedding, which should be carefully monitored for the purpose of infection control.

Effect of Kt/V on survival and clinical outcome in CAPD patients in a randomized prospective study.

BACKGROUND: There has been a lack of randomized control study on the effect of Kt/V on patient outcome. This interventional study was designed to examine the effect of Kt/V on continuous ambulatory peritoneal dialysis (CAPD) patients' clinical outcome and nutritional status in a randomized prospective manner. METHOD: A total of 320 new CAPD patients with baseline renal Kt/V <1.0 were recruited from six centers in Hong Kong and were randomized into three Kt/V targets: group A, 1.5 to 1.7; group B, 1.7 to 2.0; and group C,>2.0. Kt/V and nutritional status were assessed every 6 months and dialysis prescription adjusted accordingly. Nutritional assessment included serum albumin and composite nutritional index (CNI). Patients were allowed to withdraw at the discretion of their physicians or themselves. RESULTS: Total Kt/V were significantly different between groups (P = 0.000) and the difference was contributed by peritoneal Kt/V only. The overall 2-year patient survival was 84.9%. There was no statistical difference in patient survival among the three groups (2-year survival in group A, 87.3%; group B, 86.1%; and group C, 81.5%). However, there were more patients withdrawn by physicians in group A (group A, 16; group B, 7; and group C, 6; P = 0.023). Total Kt/V or Kt did not significantly affect survival after adjustment to age and diabetes. There was no difference in serum albumin, CNI scores, and hospitalization rate, but there were more patients in group A requiring erythropoietin (EPO) treatment after 1 year. CONCLUSION: Patients with total Kt/V maintained below 1.7 had significantly more clinical problems and severe anemia but there was no difference in outcome demonstrated for patients with Kt/V maintained above 2.0 and between 1.7 and 2.0. We recommended that the minimal target of total Kt/V should be above 1.7.

Comparison of clinical outcome and ease of handling in two double-bag systems in continuous ambulatory peritoneal dialysis: a prospective, randomized, controlled, multicenter study.

BACKGROUND: We performed a prospective, randomized, controlled, multicenter study on the use of two double-bag disconnect systems: Stay-Safe (SS; Fresenius Deutschland GmbH2) and Ultrabag (UB; Baxter Healthcare, Deerfield, IL) to assess the ease of handling, peritonitis rate, exit-site infection rate, and clinical outcome. METHODS: We enrolled 110 new continuous ambulatory peritoneal dialysis (CAPD) patients; 55 patients were randomized to SS treatment, and 55 patients, to UB treatment. RESULTS: Patients using the UB and SS systems were followed up for 946 and 846 patient-months, respectively. There were 21 episodes of peritonitis in 18 patients in the UB group and 23 episodes in 18 patients in the SS group. No significant difference was observed in peritonitis rates between the two systems, which were 45 and 36.8 patient-months per episode for the UB and SS groups, respectively. At 12 months, 82.1% of patients in the UB group and 72.1% in the SS group were free of peritonitis; at 18 months, 71.1% and 62.2% were free of peritonitis for the UB and SS groups, respectively (P = 0.559). Gram-positive organisms accounted for 28.6% of infections in the UB group and 39.1% in the SS group. Exit-site infection rates were one episode per 21 patient-months versus 19.2 patient-months in the UB and SS groups, respectively (P = 0.743). Patients perceived SS as easier to handle in 4 of the 13 steps immediately post-CAPD training. However, there was no significant difference in rankings between the two systems after 1 month of adaptation. Median training periods were 4 and 5 days for the SS and UB groups, respectively (P = 0.640). CONCLUSION: The two double-bag systems (UB and SS) have similar incidences of peritonitis and exit-site infection. Both systems showed comparably good clinical outcome. The SS system is easier to learn during the initial training period, but the difference is not significant after 1 month's adaptation.

Effects of losartan or enalapril on hemoglobin, circulating erythropoietin, and insulin-like growth factor-1 in patients with and without posttransplant erythrocytosis.

Both angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists reduce hemoglobin (Hb) levels in patients with posttransplantation erythrocytosis (PTE). However, their effects in transplant recipients without PTE are not certain, and the mechanism by which they reduce Hb levels in patients with PTE remains unclear. This study evaluated the effects of losartan and enalapril on Hb levels in relation to serum erythropoietin (EPO) and insulin-like growth factor-1 (IGF-1) levels in 8 patients with PTE and 10 patients without PTE. All 18 patients were treated sequentially with 24 weeks of losartan therapy, followed by 24 weeks of enalapril therapy; the two treatment phases were separated by a washout period. Patients with PTE showed significantly greater baseline Hb and IGF-1 concentrations compared with patients without PTE before both losartan and enalapril treatments. Baseline serum EPO levels were similar for patients with and without PTE. Baseline Hb level correlated significantly with IGF-1 level (r = 0.517; P = 0.002), but not with EPO level. Treatment with enalapril, 5 mg, reduced Hb levels more markedly than treatment with losartan, 50 mg, in patients with PTE. In patients without PTE, enalapril, 5 mg, mildly reduced Hb levels, whereas losartan, 50 mg, had no significant Hb-lowering effect. The reduction in Hb levels with enalapril therapy in patients with PTE was associated with a significant reduction in circulating IGF-1 levels, but not EPO levels, whereas losartan reduced Hb levels with no significant change in circulating IGF-1 and EPO levels. In patients without PTE, no significant change was noted in serum EPO and IGF-1 levels with either treatment. The differential Hb-lowering effect with losartan and enalapril treatment in patients with and without PTE suggests that the pathogenesis for PTE is complex and heterogeneous. Different erythropoietic mechanisms may be involved in patients with and without PTE. Further large-scale study is needed to determine the exact interaction between the renin-angiotensin system and regulation of IGF-1 and EPO synthesis and define the exact mechanism by which losartan and enalapril reduce Hb levels.