SOD1 and diabetes mellitus: As shown in Figs. 1, 2 and 3, in all diabetes patients and control groups, asprosin was negatively correlated with IIEF-5 score (r=-0.562, P < 0.001), SOD was positively correlated with IIEF-5 score (r = 0.310, P < 0.001), and MDA was negatively correlated with IIEF-5 score (r=-0.556, P < 0.001).