SOD1 and type 2 diabetes mellitus: When the participants with type 2 diabetes were aged over 60 [I2 = 31%, SMD = 0.57, 95% CI [0.32–0.82], P < 0.0001], the intervention method was aerobic exercise [I2 = 0%, SMD = 1.0 0, 95% CI [0.61–1.39], P < 0.001], intervention duration >12 weeks [I2 = 28%, SMD = 0.63, 95% CI [0.36–0.89], P < 0.001] and intervention frequency <5 d/week [I2 = 0%, SMD = 0.45, 95% CI [0.25–0.64], P < 0.0001], the effect of exercise on SOD, an oxidative stress marker in patients with type 2 diabetes, was more significant.