Abstract: TH-PO872
Increasing Peritoneal Inflammation Over Time Drives Increasing Peritoneal Solute Transport: Results from the Global Fluid Study
Session Information
- Peritoneal Dialysis - I
November 02, 2017 | Location: Hall H, Morial Convention Center
Abstract Time: 10:00 AM - 10:00 AM
Category: Dialysis
- 608 Peritoneal Dialysis
Authors
- Zavvos, Vasileios, Cardiff University, Cardiff, United Kingdom
- Elphick, Emma H., Keele University, Crewe, United Kingdom
- Davies, Simon J., Keele University, Crewe, United Kingdom
- Topley, Nicholas, Cardiff University, Cardiff, United Kingdom
- Lambie, Mark, Keele University, Crewe, United Kingdom
- Fraser, Donald, Cardiff University, Cardiff, United Kingdom
Background
Local peritoneal inflammation is a feature of peritoneal dialysis (PD) treatment and high concentrations of dialysate IL-6 (dIL6) are a strong determinant of solute transport (PSTR). PSTR is associated with patient survival and increases during long term PD but it is not known to what extent the rise is driven by dIL-6.
Methods
We conducted a longitudinal analysis of the Global Fluid study, a multinational cohort study from UK, Canada and Korea. All incident patients with 3 or more paired dialysate/plasma samples were assayed for IL-6 by electrochemiluminescence. A linear mixed model with random intercept/slopes assessed associations with pIL6. Covariates included time on PD, centre, glucose exposure, icodextrin use, dIL6, gender, baseline age, comorbidity and urine volume in an adjusted model with backwards selection. pIL6 and dIL6 were log transformed. PSTR was assessed by modified peritoneal equilibration testing to calculate the dialysate to plasma creatinine ratio.
Results
There were 217 patients with 1274 measurements, with a median follow up time of 2.2 years from 6 centres. PSTR increased from a mean value of 0.715 within the first 6 months to 0.741 after 3.5 years, whilst dIL6 increased from 6.0 pg/ml to 12.0 pg/ml over the same period. When adjusted for centre, icodextrin use, urine volume and dIL6 were significant predictors of PSTR (β=0.069 95% CI 0.056 to 0.083 p<0.001). Time varying dIL6 was a better predictor than baseline dIL6 (AIC -1377 vs. AIC -1342). Time became insignificant with both varying and baseline dIL6. The effect of urine volume and icodextrin was reduced over time. Random slopes were significant for time (LRT 19 d.f.=2 p=<0.0005).
Conclusion
Both dIL6 and PSTR increase with duration of PD. The increase in PSTR over time is mostly accounted for by changes in dIL6 and urine volume.
Predictors of PSTR over time
Coefficient | p value/95% Confidence Intervals | |
Time on PD | 0.0091 | 0.000040 to 0.018 |
Centre | χ 2 = 44.5, d.f. = 5 | p =<0.001 |
Urine Volume (L) | -0.040 | 0.0025 to 0.055 |
Urine Volume Time Interaction | -0.010 | -0.017 to -0.003 |
Use of Icodextrin | 0.023 | 0.0031 to 0.041 |
Icodextrin Time Interaction | -0.011 | -0.021 to 0.002 |
Time varying dIL6 (log transformed pg/ml) | 0.064 | 0.047 to 0.083 |
Table showing adjusted multilevel model for PSTR