Interleukin-6 is a predictor of mortality in stable hemodialysis patients

Mortality in end-stage renal disease patients with dialysis remains high. A high percentage of dialysis patients display signs of chronic microinflammation. To clarify whether microinflammation is involved in the high incidence of poor prognosis in dialysis patients, we investigated the association of inflammatory markers with mortality in a prospective observational cohort study.

120 patients undergoing hemodialysis were enrolled. Baseline cross-sectional analysis of the relationship between inflammatory markers [interleukin-6 (IL-6), tumor necrosis factor-alpha and high-sensitivity C-reactive protein] and other factors, along with a survival analysis for death, were performed. All subjects were divided into 2 groups according to the median value of IL-6.

The mortality rate was significantly higher in the high (20.0%) compared with the low IL-6 group (3.3%, p = 0.0046). Receiver-operating characteristic curves indicated high mortality to be closely associated with a high IL-6 level rather than tumor necrosis factor-alpha. In stepwise multiple regression analyses, age, phosphorus and high-sensitivity C-reactive protein were independent predictors of IL-6 (R(2) = 0.466, p < 0.0001).

These data clearly show that plasma IL-6 is a powerful predictor of all-cause mortality in dialysis patients.