Effects of insulin on serum levels of A) MDA, B) CAT, C) GSH, vitamins C and E. The data are viewed as mean ± SD. (***p < 0.001; ****p < 0.0001) denotes statistically significant differences versus the control group; (##p < 0.01; ###p < 0.001) denotes statistically significant differences between insulin-treated and newly diagnosed patients, using the Kruskal-Wallis test followed by a Dunn’s multiple comparison test.