Online haemodiafiltration (OL-HDF) is considered to confer clinical benefits over haemodialysis (HD) in terms of solute removal in patients undergoing maintenance HD. The aim of this study was to compare postdilution OL-HDF and high-flux HD in terms of morbidity and mortality. In this prospective, randomized, controlled trial, we enrolled 782 patients undergoing thrice-weekly HD and randomly assigned them in a 1:1 ratio to either postdilution OL-HDF or high-flux HD. The mean age of patients was 56.5 ± 13.9 years, time on HD 57.9 ± 44.6 months with a diabetes incidence of 34.7%. The follow-up period was 2 years, with the mean follow-up of 22.7 ± 10.9 months. The primary outcome was a composite of death from any cause and nonfatal cardiovascular events. The major secondary outcomes were cardiovascular and overall mortality, intradialytic complications, hospitalization rate, changes in several laboratory parameters and medications used. The filtration volume in OL-HDF was 17.2 ± 1.3 L. Primary outcome was not different between the groups (event-free survival of 77.6% in OL-HDF versus 74.8% in the high-flux group, P = 0.28), as well as cardiovascular and overall survival, hospitalization rate and number of hypotensive episodes. In a post hoc analysis, the subgroup of OL-HDF patients treated with a median substitution volume >17.4 L per session (high-efficiency OL-HDF, n = 195) had better cardiovascular (P = 0.002) and overall survival (P = 0.03) compared with the high-flux HD group. In adjusted Cox-regression analysis, treatment with high-efficiency OL-HDF was associated with a 46% risk reduction for overall mortality {RR = 0.54 [95% confidence interval (95% CI) 0.31-0.93], P = 0.02} and a 71% risk reduction for cardiovascular mortality [RR = 0.29 (95% CI 0.12-0.65), P = 0.003] compared with high-flux HD. The composite of all-cause mortality and nonfatal cardiovascular event rate was not different in the OL-HDF and in the high-flux HD groups. In a post hoc analysis, OL-HDF treatment with substitution volumes over 17.4 L was associated with better cardiovascular and overall survival.

Background. Most haemodialysis (HD) centres use anti-hypertensive drugs for the management of hypertension, whereas some centres apply dietary salt restriction strategy. In this retrospective cross-sectional study, we assessed the effectiveness and cardiac consequences of these two strategies. Methods. We enrolled all patients from two dialysis centres, who had been on a standard HD programme at the same centre for at least 1 year. All patients underwent echocardiographic evaluation. Clinical data were obtained from patients’ charts. Centre A ( n = 190) practiced ‘salt restriction’ strategy and Centre B ( n = 204) practiced anti-hypertensive-based strategy. Salt restriction was defined as managing high blood pressure (BP) via lowering dry weight by strict salt restriction and insistent ultrafiltration without using anti-hypertensive drugs. Results. There was no difference regarding age, gender, diabetes, history of cardiovascular disease and efficiency of dialysis between centres. Antihypertensive drugs were used in 7% of the patients in Centre A and 42% in Centre B ( P < 0.01); interdialytic weight gain was significantly lower in Centre A (2.29 ± 0.83 kgversus 3.31 ± 1.12 kg, P < 0.001). Mean systolic and diastolic blood pressures were similar in the two centres. However, Centre A had lower left ventricular (LV) mass (indexed for height ^2.7 : 59 ± 16 versus 74 ± 27 g/m ^2.7 , P < 0.0001). The frequency of LV hypertrophy was lower in Centre A (74% versus 88%, P < 0.001). Diastolic and systolic functions were better preserved in Centre A. Intradialytic hypotension (hypotensive episodes/100 patient sessions) was more frequent in Centre B (11 versus 27, P <0.01). Conclusions. This cross-sectional study suggests that salt restriction and reduced prescription of antihypertensive drugs may limit LV hypertrophy, better preserve LV functions and reduce intradialytic hypotension in HD patients.

Vascular calcification (VC), mainly due to elevated phosphate levels, is one major problem in patients suffering from chronic kidney disease. In clinical studies, an inverse relationship between serum magnesium and VC has been reported. However, there is only few information about the influence of magnesium on calcification on a cellular level available. Therefore, we investigated the effect of magnesium on calcification induced by β-glycerophosphate (BGP) in bovine vascular smooth muscle cells (BVSMCs). BVSMCs were incubated with calcification media for 14 days while simultaneously increasing the magnesium concentration. Calcium deposition, transdifferentiation of cells and apoptosis were measured applying quantification of calcium, von Kossa and Alizarin red staining, real-time reverse transcription–polymerase chain reaction and annexin V staining, respectively. Calcium deposition in the cells dramatically increased with addition of BGP and could be mostly prevented by co-incubation with magnesium. Higher magnesium levels led to inhibition of BGP-induced alkaline phosphatase activity as well as to a decreased expression of genes associated with the process of transdifferentiation of BVSMCs into osteoblast-like cells. Furthermore, estimated calcium entry into the cells decreased with increasing magnesium concentrations in the media. In addition, higher magnesium concentrations prevented cell damage (apoptosis) induced by BGP as well as progression of already established calcification. Higher magnesium levels prevented BVSMC calcification, inhibited expression of osteogenic proteins, apoptosis and further progression of already established calcification. Thus, magnesium is influencing molecular processes associated with VC and may have the potential to play a role for VC also in clinical situations.

Background. Longer dialysis sessions may improve outcome in haemodialysis (HD) patients. We compared the clinical and laboratory outcomes of 8- and 4-h thrice-weekly HD.

We analysed the survival of 218 patients (132 male, 86 female, age 48 +/- 15 years) who were treated in our dialysis units since we adopted the strategy of strict volume control without antihypertensive drugs. The mean observation period was 47 +/- 34 (6-140) months. Follow-up was ended because of death (57 patients), transfer to another center (35 patients), continous ambulatory peritoneal dialysis (CAPD) (15 patients) or transplantation (23 patients), while 88 were still under our treatment at the time of writing. Blood pressure (BP) decreased from a mean of 150 +/- 31/89 +/- 16 at the start to 121 +/- 14/75 +/- 8 mmHg at the end of observation (P < 0.001). Only nine patients needed a drug (enalapril) to reach this goal. Cardiothoracic index (CTI) dropped from 0.50 +/- 0.06 to 0.46 +/- 0.05 (P < 0.001). Interdialytic weight gain decreased from 1440 +/- 360 to 930 +/- 240 g/day (P < 0.001). Mortality rate was 68, 2 per 1000 patient-years, better than in most published series. There was a striking influence of age, but also of CTI and systolic BP on survival rate. Patients with CTI > or = 0.48 showed mortality 3.8 times higher than CTI < 0.48 (log rank P < 0.001). Consequently, the mean CTI of the deceased patients was much higher (0.50) than the average of the group (0.46) while their mean BP (123 +/- 16/75 +/- 9 mmHg) was not significantly different from the other patients. We found no increased mortality at low-normal pressure levels (systolic BP between 100 and 130 mmHg), but mortality was increased in small groups of patients whose pressures were lower or higher than these values. Thus, the curve, relating mortality to blood pressure was shifted markedly to the left. These results strongly suggest that the strategy of 'volume control', also when applied with conventional dialysis times, normalizes BP and increases survival of dialysis patients. Cardiomegaly, as evidenced on the chest X-ray despite normal BP, had a strong negative influence on survival. The large majority of the patients had low-normal BP after long periods of treatment and showed the lowest mortality, favouring the view that target BP should be lower than advised by most authors.