CAT and obesity due to melanocortin 4 receptor deficiency: The combination of low level vitamin E, activated SOD, and inhibited CAT in the group with uncomplicated obesity (Figures 1 and 2) allowed us to hypothesize that the high levels of hydrogen peroxide formed in the reaction of superoxide anion-radicals dismutation by SOD (2O2− + 2H+ + 2H2O → 2H2O2) persist due to inadequate activity of CAT, a hydrogen peroxide decomposing enzyme (2H2O2 → 2H2O + O2).