Fig. 1.

Differential plasma metabolites between subjects with high and normal pentosidine in cohort 1. Chemical structures of (A) PEN and (B) GlcA. (C) Volcano plot demonstrating the relationship between the mean rank difference in metabolites and the FDR (i.e., the q-value) of plasma metabolites. The high PEN group showed four upregulated and seven downregulated metabolites in the plasma compared to the normal PEN group. (D) Comparison of GlcA levels between high PEN and normal PEN groups. q = 5.40.E−05 using the Mann–Whitney test. (E) Correlation between GlcA and PEN in the plasma. Spearman’s correlation coefficient was r = 0.4111 (p < 0.0001). Comparison of known PEN-precursors levels between the high and normal PEN groups: (F) glucose, (G) fructose, (H) ribose, (I) arabinose, (J) xylose, and (K) ascorbate. Data are presented as the mean ± standard deviation (SD).