An imbalance of reactive oxygen species and an endogenous enzyme was found in a metabolic syndrome group supported by increased O2•− production in liver tissues (400.88 ± 53.62 count/mg dry weight/min), MDA level in liver tissues (0.70 ± 0.03 μmol/g), plasma (7.10 ± 0.27 μM) and decreased CAT enzyme activity (8.22 ± 1.55 U/mL) in plasma compared to normal rats (161.32 ± 24.71 count/mg dry weight/min, 0.32 ± 0.01 μmol/g, 3.79 ± 0.13 μM), (43.86 ± 7.26 U/mL) (p < 0.05). Here, CAT is linked to metabolic syndrome.