Association of Vascular Access Type with Inflammatory Marker Levels in Maintenance Hemodialysis Patients

Abstract

Aggressive NIH is a common histopathological lesion found at the sites of venous stenosis in arteriovenous fistula (AVF) and arteriovenous grafts (AVG). Inflammatory mediators have been proposed to play a pathogenic role in NIH, but there is paucity of data evaluating this hypothesis in clinical studies or in animal models. Serum levels of inflammatory mediators can potentially identify patients at high risk of AVF and AVG dysfunction. In a cross-sectional cohort study of 754 HD patients who were part of the NIED study cohort, we examined the associations between inflammatory markers including serum interleukin (IL) 1β, IL-6, C-reactive protein (CRP), and tumor necrosis factor-α (TNF-α) and type of vascular access. Unadjusted and multivariate-adjusted linear regression models were used. In addition, time-dependent regression model was used to assess the association between inflammatory markers and mortality. We observed that in the multivariate-adjusted model, inflammatory mediators interleukin-6 (IL-6), interleukin-1L-ß (IL-1ß), and C-reactive protein (CRP), the predicted value in hemodialysis patients, are lowest in patients with AVF and highest in central venous catheter (CVC) and AVG even in case-mix and malnutrition-inflammation complex syndrome (MICS)-adjusted models. IL-6 and CRP levels fall consistently in the same patients when AVG or CVC is changed to AVF and increase if the same patient changes access from AVF to AVG or CVC. Obesity is a risk factor for fistula failure and fistulas are associated with the lowest mortality compared with CVC and AVG. We did not find any statistically significant association between tumor necrosis factor-α (TNF- α) and vascular access outcomes. Higher levels of inflammatory mediators seen in CVC and AVG compared with AVF could potentially explain the higher mortality seen in patients with CVC and AVG compared with AVF.