KDR and diabetes mellitus: As shown in the heatmap (Figure 3A), Pearson correlation analysis of the relationships of cytokine levels and clinical features found no significant positive correlations between clinical characteristics, including age, body mass index, waist-to-hip ratio, diabetes duration, fasting blood glucose, HbA1c, fasting C-peptide, 2-h postprandial C-peptide, and the 5 plasma cytokines, including ANG-1, PDGF-BB, TIMP-1, VEGFR2 and CXCL16 (r < 0.3).