Analysis of the data revealed that, in patients with DN, the activities of key antioxidant enzymes—superoxide dismutase (SOD; Figure 4), catalase (CAT; Figure 4), and glutathione peroxidase (GSH-Px; Figure 4)—were significantly diminished in cohorts with impaired renal function prior to dietary intervention (p < 0.05) relative to both healthy controls and diabetic patients with preserved renal function. This evidence concerns the gene CAT and liver dysplastic nodule.