The association of uremic toxins and inflammation in hemodialysis patients

Background: Cardiovascular disease is the leading cause of mortality in hemodialysis patients and is associated with chronic inflammation. Elevation of uremic toxins, particular protein-bound uremic toxins, is a possible cause of hyper-inflammation in hemodialysis patients. But the association between uremic toxins and inflammatory markers in hemodialysis is still unclear. Methods: We conducted a cross-sectional study to evaluate the association of the serum uremic toxins and inflammatory markers in hemodialysis patients. Results: The uremic toxins were not associated with inflammatory markers- including high sensitivity C-reactive protein, IL(Interleukin) -1β, IL-6, tumor necrosis factor-α. In multiple linear regression, serum levels of total p-cresol sulfate (PCS) were independently significantly associated with serum total indoxyl sulfate (IS) (standardized coefficient: 0.274, p<0.001), and co-morbidity of diabetes mellitus (DM) (standardized coefficient: 0.342, p<0.001) and coronary artery disease (CAD) (standardized coefficient: 0.128, p = 0.043). The serum total PCS levels in hemodialysis with co-morbidity of DM and CAD were significantly higher than those without co-morbidity of DM and CAD (34.10±23.44 vs. 16.36±13.06 mg/L, p<0.001). Serum levels of total IS was independently significantly associated with serum creatinine (standardized coefficient: 0.285, p<0.001), total PCS (standardized coefficient: 0.239, p = 0.001), and synthetic membrane dialysis (standardized coefficient: 0.139, p = 0.046). Conclusion: The study showed that serum levels of total PCS and IS were not associated with pro-inflammatory markers in hemodialysis patients. Besides, serum levels of total PCS were independently positively significantly associated with comorbidity of CAD and DM.