We aimed to investigate the association between oxidative stress (OS), inflammation, and kidney function and the predictive ability of OS for mortality and cardiovascular disease in 143 patients with type 2 diabetes (T2DM) and various degrees of kidney function. At baseline, we assessed catalase, nitrogen oxides (NOx), malondialdehyde (MDA), advanced oxidation products (AOPPs), myeloperoxidase (MPO)], kidney function, and C-reactive protein (CRP). All patients were followed for 57 months, with the combined primary outcome of death/cardiovascular (CV) event, whichever occurred first. NOx was an independent predictor of estimated glomerular filtration rate (B = −0.097, p = 0.006), and MPO was correlated with glycated hemoglobin (r = 0.17, p = 0.046), CRP (r = −0.18, p = 0.032), and serum albumin (r = 0.2, p = 0.011, Spearman’s rho). During the follow-up, 24 composite events were documented. Kaplan–Meier curves showed that smoking (p = 0.029), serum albumin (p = 0.014), and MPO (p = 0.024, log-rank test) were associated with the outcome. In multivariate Cox regression models, smoking and MPO were independent predictors of the composite outcome (hazard ratio—HR = 2.8, p = 0.004, 955 confidence interval—CI 1.05–7.5 and HR = 0.99, p = 0.015, 95% CI: 0.98–1.00, respectively), after adjustment for several cofactors. OS might be associated with CV disease in T2DM.
