Fluid Status in Peritoneal Dialysis Patients: The European Body Composition Monitoring (EuroBCM) Study Cohort

BACKGROUND: Euvolemia is an important adequacy parameter in peritoneal dialysis (PD) patients. However, accurate tools to evaluate volume status in clinical practice and data on volume status in PD patients as compared to healthy population, and the associated factors, have not been available so far. METHODS: We used a bio-impedance spectroscopy device, the Body Composition Monitor (BCM) to assess volume status in a cross-sectional cohort of prevalent PD patients in different European countries. The results were compared to an age and gender matched healthy population. RESULTS: Only 40% out of 639 patients from 28 centres in 6 countries were normovolemic. Severe fluid overload was present in 25.2%. There was a wide scatter in the relation between blood pressure and volume status. In a multivariate analysis in the subgroup of patients from countries with unrestricted availability of all PD modalities and fluid types, older age, male gender, lower serum albumin, lower BMI, diabetes, higher systolic blood pressure, and use of at least one exchange per day with the highest hypertonic glucose were associated with higher relative tissue hydration. Neither urinary output nor ultrafiltration, PD fluid type or PD modality were retained in the model (total R² of the model = 0.57). CONCLUSIONS: The EuroBCM study demonstrates some interesting issues regarding volume status in PD. As in HD patients, hypervolemia is a frequent condition in PD patients and blood pressure can be a misleading clinical tool to evaluate volume status. To monitor fluid balance, not only fluid output but also dietary input should be considered. Close monitoring of volume status, a correct dialysis prescription adapted to the needs of the patient and dietary measures seem to be warranted to avoid hypervolemia

A multicentric, international matched pair analysis of body composition in peritoneal dialysis versus haemodialysis patients

Volume status, lean and fat tissue are gaining interest as prognostic predictors in patients on dialysis. Comparative data in peritoneal dialysis (PD) versus haemodialysis (HD) patients are lacking. In a cohort of PD (EuroBCM) and HD (Euclid database) patients, matched for country, gender, age and dialysis vintage, body composition was assessed by bioimpedance spectroscopy (BCM, Fresenius Medical Care). Time-averaged volume overload (TAVO) was defined as the mean of pre- and post-dialysis volume overload (VO), and relative () (TA)VO as (TA)VO/ECV. Four hundred and ninety-one matched pairs (55.2 males, median age 60.0 years) were included. The body mass index (BMI, PD 26.5 4.7 versus HD 25.9 4.6 kg/m, P 0.18 in males and 27.4 5.8 versus 27.5 6.6 kg/m, P 0.75 in females) and fat tissue index (males: 11.5 5.3 versus 11.4 5.4 kg/m, P 0.90, females: 14.8 6.7 versus 15.4 7.2 kg/m, P 0.30) were not different in PD versus HD patients, whereas the lean tissue index (LTI) was higher in PD versus HD patients (males: 14.5 3.4 versus 13.7 3.1 kg/m, P 0.001, females: 12.6 3.3 versus 11.5 2.6 kg/m, P 0.0001). VO/extracellular water (ECW) was not different between PD versus just before the HD treatment (males: 10.8 12.1 versus 9.2 10.2, P 0.09; females: 6.5 10.8 versus 7.7 9.4, P 0.19). The relative TAVO was higher in PD versus HD (10.8 12.1 versus 3.2 11.2, and 6.5 10.8 versus 1.2 10.9, both P 0.0001). The LTI was impaired, and this was more in males versus females, but was better preserved on PD versus HD, whereas fat tissue index (FTI) was increased, but not different between PD and HD. Volume overload was more present in PD versus HD when TAVO, but not when predialysis volume status, was used as a reference

Cannulation technique influences arteriovenous fistula and graft survival

Hemodialysis patient survival is dependent on the availability of a reliable vascular access. In clinical practice, procedures for vascular access cannulation vary from clinic to clinic. We investigated the impact of cannulation technique on arteriovenous fistula and graft survival. Based on an April 2009 cross-sectional survey of vascular access cannulation practices in 171 dialysis units, a cohort of patients with corresponding vascular access survival information was selected for follow-up ending March 2012. Of the 10,807 patients enrolled in the original survey, access survival data were available for 7058 patients from nine countries. Of these, 90.6% had an arteriovenous fistula and 9.4% arteriovenous graft. Access needling was by area technique for 65.8%, rope-ladder for 28.2%, and buttonhole for 6%. The most common direction of puncture was antegrade with bevel up (43.1%). A Cox regression model was applied, adjusted for within-country effects, and defining as events the need for creation of a new vascular access. Area cannulation was associated with a significantly higher risk of access failure than rope-ladder or buttonhole. Retrograde direction of the arterial needle with bevel down was also associated with an increased failure risk. Patient application of pressure during cannulation appeared more favorable for vascular access longevity than not applying pressure or using a tourniquet. The higher risk of failure associated with venous pressures under 100 or over 150mmHg should open a discussion on limits currently considered acceptable

Analysis of 5′ junctions of human LINE-1 and Alu retrotransposons suggests an alternative model for 5′-end attachment requiring microhomology-mediated end-joining

Insertion of the human non-LTR retrotransposon LINE-1 (L1) into chromosomal DNA is thought to be initiated by a mechanism called target-primed reverse transcription (TPRT). This mechanism readily accounts for the attachment of the 3′-end of an L1 copy to the genomic target, but the subsequent integration steps leading to the attachment of the 5′-end to the chromosomal DNA are still cause for speculation. By applying bioinformatics to analyze the 5′ junctions of recent L1 insertions in the human genome, we provide evidence that L1 uses at least two distinct mechanisms to link the 5′-end of the nascent L1 copy to its genomic target. While 5′-truncated L1 elements show a statistically significant preference for short patches of overlapping nucleotides between their target site and the point of truncation, full-length insertions display no distinct bias for such microhomologies at their 5′-ends. In a second genome-wide approach, we analyzed Alu elements to examine whether these nonautonomous retrotransposons, which are thought to be mobilized through L1 proteins, show similar characteristics. We found that Alu elements appear to be predominantly integrated via a pathway not involving overlapping nucleotides. The results indicate that a cellular nonhomologous DNA end-joining pathway may resolve intermediates from incomplete L1 retrotransposition events and thus lead to 5′ truncations