Table 1.
OPLS‐DA coefficients and relative concentrations of metabolites derived from the nuclear magnetic resonance data in different groups
| Metabolites | r † | Relative concentration‡ | ||||
|---|---|---|---|---|---|---|
| C‐PanIN | C‐PDAC | PanIN‐PDAC | C | PanIN | PDAC | |
| 1‐Methylhistidine | 0.718 | — | −0.771 | 0.48 ± 0.30 | 1.25 ± 0.85** | 0.57 ± 0.40# |
| 2‐Hydroxybutyrate | 0.750 | 0.701 | — | 1.18 ± 0.35 | 2.07 ± 1.78* | 2.07 ± 0.71*** |
| 3‐Hydroxybutyrate | 0.912 | 0.612 | −0.728 | 0.42 ± 0.10 | 0.80 ± 0.30*** | 0.61 ± 0.20**,# |
| 3‐Methylhistidine | −0.775 | −0.753 | — | 0.42 ± 0.09 | 0.25 ± 0.12** | 0.26 ± 0.15** |
| Acetate | 0.793 | 0.657 | −0.730 | 0.77 ± 0.08 | 1.23 ± 0.18*** | 1.04 ± 0.19***,# |
| Acetylcholine | −0.673 | — | 0.643 | 3.24 ± 0.51 | 2.20 ± 0.76*** | 2.86 ± 1.03 |
| Adenosine | −0.578 | −0.651 | −0.712 | 1.71 ± 0.33 | 1.17 ± 0.75* | 1.07 ± 0.60** |
| Adipate | 0.711 | — | −0.698 | 1.01 ± 0.38 | 2.56 ± 1.62** | 1.28 ± 0.61# # |
| Ascorbate | — | 0.764 | 0.708 | 26.11 ± 2.63 | 26.74 ± 4.31 | 29.37 ± 3.32*,# |
| Aspartate | −0.900 | −0.745 | 0.796 | 21.10 ± 1.96 | 16.32 ± 2.34*** | 20.24 ± 2.51##, # |
| Betaine | −0.916 | −0.654 | — | 12.72 ± 0.89 | 9.89 ± 1.96*** | 10.90 ± 1.66*** |
| Citrate | 0.861 | — | −0.713 | 0.89 ± 0.13 | 1.64 ± 0.65*** | 0.94 ± 0.63# |
| Creatine | −0.936 | — | 0.844 | 2.90 ± 0.28 | 2.45 ± 0.37** | 2.79 ± 0.42# |
| Cytidine | −0.859 | −0.791 | −0.688 | 3.26 ± 0.53 | 1.78 ± 0.70*** | 1.88 ± 0.82*** |
| Dimethylglycine | 0.797 | — | −0.710 | 0.03 ± 0.02 | 0.09 ± 0.03*** | 0.03 ± 0.05# # |
| Glutamate | 0.726 | 0.586 | — | 11.43 ± 1.19 | 12.55 ± 1.91* | 12.33 ± 1.68* |
| Glycerol | — | 0.715 | 0.607 | 39.15 ± 2.70 | 37.56 ± 5.26 | 42.70 ± 5.30*,# |
| Inosine | −0.780 | −0.591 | — | 1.75 ± 0.24 | 0.85 ± 0.36*** | 1.21 ± 0.42*** |
| Isoleucine | 0.730 | 0.772 | — | 0.47 ± 0.10 | 0.72 ± 0.20*** | 0.79 ± 0.24*** |
| Kynurenate | 0.629 | −0.719 | −0.725 | 1.88 ± 0.51 | 2.26 ± 0.78* | 1.53 ± 0.66*,# |
| Lactate | 0.725 | 0.686 | −0.582 | 8.42 ± 1.38 | 15.43 ± 3.62*** | 14.41 ± 5.68** |
| Leucine | 0.780 | 0.761 | — | 1.55 ± 0.17 | 1.73 ± 0.25* | 2.03 ± 0.41*** |
| Lysine | 0.852 | — | −0.665 | 5.45 ± 0.60 | 7.25 ± 1.91*** | 5.69 ± 1.24**,# |
| Methionine | 0.874 | −0.620 | −0.645 | 1.03 ± 0.15 | 1.33 ± 0.33* | 0.92 ± 0.22*,# |
| myo‐Inositol | 0.591 | 0.730 | — | 7.67 ± 0.45 | 8.36 ± 0.93* | 8.67 ± 0.95*** |
| Nicotinamide | −0.851 | −0.825 | −0.740 | 0.30 ± 0.03 | 0.26 ± 0.05* | 0.32 ± 0.06# |
| NAD+ | −0.941 | −0.766 | — | 0.05 ± 0.05 | 0.02 ± 0.02* | 0.02 ± 0.02* |
| NADP+ | −0.779 | −0.804 | −0.750 | 0.02 ± 0.01 | 0.01 ± 0.01** | 0.02 ± 0.02 |
| Phenylalanine | 0.622 | 0.777 | — | 0.35 ± 0.10 | 0.55 ± 0.23** | 0.64 ± 0.32** |
| Sarcosine | 0.746 | — | −0.761 | 0.10 ± 0.02 | 0.21 ± 0.15* | 0.06 ± 0.05# |
| Taurine | — | 0.768 | 0.706 | 9.64 ± 1.59 | 11.47 ± 2.82 | 15.87 ± 4.40***,## |
| Uracil | −0.793 | −0.743 | −0.810 | 1.36 ± 0.13 | 0.98 ± 0.33** | 0.85 ± 0.39** |
| Uridine | −0.907 | −0.739 | −0.749 | 5.77 ± 0.97 | 3.38 ± 1.18*** | 3.77 ± 1.44*** |
| Uridine diphosphate | −0.817 | −0.810 | — | 4.01 ± 0.55 | 2.16 ± 0.96*** | 2.08 ± 1.18*** |
| Valine | 0.734 | 0.753 | — | 0.85 ± 0.17 | 1.24 ± 0.32*** | 1.27 ± 0.34*** |
| Vitamin K | −0.904 | −0.850 | — | 5.28 ± 1.03 | 2.26 ± 0.84*** | 3.01 ± 1.70*** |
| α‐Glucose | — | 0.732 | 0.659 | 2.31 ± 0.63 | 3.13 ± 1.49 | 4.85 ± 2.16***,# |
†Correlation coefficients: positive and negative signs indicate positive and negative correlation in the concentrations. |r| > 0.576 is the cut‐off value for significance based on significance of P = 0.05 and degrees of freedom = 10. “—” means |r| < 0.576. &Relative concentration derived by integrating the characteristic signals of each metabolite in the nuclear magnetic resonance spectra, and the concentrations are expressed as means ± SD *P < 0.05, **P < 0.01, ***P < 0.001 versus control group; # P < 0.05, ## P < 0.01, ### P < 0.001 versus PanIN group. C, control group. PanIN, pancreatic intraepithelial neoplasia; PDAC, pancreatic ductal adenocarcinoma.