MPO and type 1 diabetes mellitus: MPO is important for understanding oxidative stress because it catalyzes the production of ROS, which can promote atherosclerosis and modify lipids and proteins.[62,63] Diabetic patients can inhibit MPO activity, reducing the efficiency of neutrophils to phagocytose bacteria and making them more susceptible to infection.[64] found no significant differences in plasma MPO levels in children and adolescents with type 1 diabetes compared to controls.