Oxidative Stress and Inflammation as Predictors of Mortality and Cardiovascular Events in Hemodialysis Patients: The DREAM Cohort
Keyaki Sasaki, Tetsuo Shoji, Daijiro Kabata, Ayumi Shintani, Yujiro Okute, Shoko Tsuchikura, Naoko Shimomura, Yoshihiro Tsujimoto, Shinya Nakatani, Katsuhito Mori, Atsushi Shioi, Masaaki Inaba, Masanori Emoto
Abstract
AIM: Both oxidative stress and inflammation are involved in the pathogenesis of cardiovascular disease (CVD). The serum level of derivatives of reactive oxygen metabolites (d-ROMs) is a measure of the total amount of hydroperoxides serving as a marker of oxidative stress. We investigated whether d-ROMs could predict the clinical outcomes in hemodialysis patients and whether the associations of d-ROMs with the outcomes are independent of a marker of inflammation, C-reactive protein (CRP). METHODS: This was a prospective cohort study in hemodialysis patients. The key exposures were the serum levels of d-ROMs and CRP. The outcome measures were all-cause mortality and new CVD events. RESULTS: A total of 517 patients were analyzed. d-ROMs correlated positively with CRP. During follow-up for 5 years, 107 patients died, and 190 patients experienced new CVD events. In the Kaplan-Meier analyses, both higher d-ROMs and higher CRP levels predicted higher risks for mortality and CVD events. By Cox proportional-hazard regression analysis adjusted for potential confounders excluding CRP, d-ROMs exhibited a significant association with all-cause mortality, but this association was no longer significant after further adjustment for CRP. Using the same model, CRP exhibited a significant association with all-cause mortality, but this association was no longer significant after further adjustment for d-ROMs. When we analyzed new CVD events as the outcome, CRP was a significant predictor, whereas the level of d-ROMs was not. CONCLUSIONS: Although d-ROMs predicted mortality and CVD events in unadjusted models, the associations of d-ROMs with these outcomes were not independent of CRP. Oxidative stress and inflammation appear to share common causal pathways.