SOD1 and familial dilated cardiomyopathy: The results of serum oxidative stress indexes showed that, compared with control group, the level of serum SOD in DCM group was significantly lower (P < 0.01), MDA was significantly higher (P < 0.01), compared with DCM group, the level of SOD in DCM + MTDP group and DCM + PLZ group was significantly higher (P < 0.05), and MDA was significantly lower (P < 0.05) (Figure 3).