Plasma metabolomics reveals progressive alterations across glycemic states

Figure 1 Principal component analysis score plot of the four study groups. The principal component analysis score plot illustrates the overall distribution of samples across the four study groups: (1) Group A: Normal glucose tolerance; (2) Group B: Isolated impaired fasting glucose; (3) Group C: Isolated impaired glucose tolerance; and (4) Group D: Diabetes. The X-axis indicates the first principal component, explaining 23.3% of the variance, and the Y-axis indicates the second principal component, explaining 6.8% of the variance. First principal component and second principal component together explained 30.1% of the total variance; therefore, this plot was used as an exploratory visualization of overall group trends rather than a complete representation of all sample-level variation. Each point represents an individual sample, and ellipses indicate the confidence regions for each group. PC1: First principal component; PC2: Second principal component.