Figure 4.

Metabolite biomarker identification of DKD. (A) Hierarchical clustering of differentially expressed metabolites. The median expression levels of metabolites for each group are presented in the heatmap. (B) Partial least squares discriminant analysis of the four groups. (C) Top significant pathways detected by the differentially expressed metabolites. (D) Network analysis based on the differentially expressed metabolites. Each node represents a metabolite, and the edges indicate the correlations between the metabolites. The metabolites highlighted are further grouped into metabolism pathways.