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
 Coefficientp value/95% Confidence Intervals
Time on PD0.00910.000040 to 0.018
Centreχ 2 = 44.5, d.f. = 5p =<0.001
Urine Volume (L)-0.0400.0025 to 0.055
Urine Volume Time Interaction-0.010-0.017 to -0.003
Use of Icodextrin0.0230.0031 to 0.041
Icodextrin Time Interaction-0.011-0.021 to 0.002
Time varying dIL6 (log transformed pg/ml)0.0640.047 to 0.083

Table showing adjusted multilevel model for PSTR