The results showed that SM preparations group reduced ET-1 and improved FMD significantly better than the control group in patients with DKD (ET-1: MD = -110.76, 95% CI [-201.79, −19.74], I2= 100%, P =0.02; FMD: MD = 3.70, 95% CI [3.22, 4.18], I2= 0%, P < 0.00001). The gene discussed is EDN1; the disease is diabetic kidney disease.