Table 2. OPLS-DA coefficients and their variable importance in projection (VIP) for significantly changed metabolites in urine.
Metabolites | Multi-criteria assessment (MCA)a | |||||||
No. | Names | δ 1H (ppm) | HFD vs. Normal | HFD+GAH vs. HFD | ||||
Coefficient valueb | VIP | p valuec | Coefficient valueb | VIP | p valuec | |||
14 | Acetate | 1.92 (s) | 0.662 | 1.50 | –, 0.080 | 0.594 | 1.30 | ↑, 0.044 |
20 | Acetoacetate | 2.29 (s) | −0.920 | 1.38 | ↓, <0.001 | 0.519 | 1.75 | ↑, 0.040 |
21 | Pyruvate | 2.37 (s) | 0.863 | 1.98 | ↑, <0.001 | 0.020 | 0.34 | –, 0.801 |
22 | Succinate | 2.41 (s) | −0.842 | 2.43 | ↓, <0.001 | 0.653 | 3.36 | –, 0.081 |
23 | Citrate | 2.69 (d) | −0.701 | 3.70 | ↓, 0.005 | 0.681 | 2.48 | –, 0.970 |
26 | Creatine | 3.93 (s) | −0.750 | 3.32 | ↓, 0.001 | 0.076 | 1.38 | –, 0.564 |
27 | Creatinine | 3.05 (s) | 0.938 | 4.14 | ↑, <0.001 | 0.641 | 3.31 | ↑, 0.048 |
31 | Taurine | 3.27 (t) | 0.639 | 3.07 | ↑, 0.006 | −0.653 | 7.55 | ↓, 0.019 |
35 | Glycine | 3.55 (s) | 0.738 | 2.07 | ↑, 0.001 | −0.312 | 1.61 | –, 0.222 |
37 | Formate | 8.46 (s) | 0.909 | 0.42 | ↑,<0.001 | −0.396 | 0.32 | –, 0.179 |
43 | Butyrate | 0.90 (t) | 0.619 | 1.90 | ↑, 0.001 | 0.311 | 1.65 | –, 0.063 |
50 | 2-oxoglutaric acid (2-KG) | 2.44 (t) | −0.782 | 1.66 | ↓, 0.001 | 0.267 | 0.19 | –, 0.787 |
52 | Dimethylamine (DMA) | 2.72 (s) | −0.412 | 0.80 | –, 0.089 | −0.472 | 1.89 | ↓, 0.041 |
53 | Trimethylamine (TMA) | 2.89 (s) | −0.915 | 8.43 | ↓, <0.001 | −0.566 | 5.56 | ↓, 0.031 |
57 | Guanidoacetate | 3.80 (s) | 0.951 | 2.74 | ↑, <0.001 | −0.363 | 1.61 | –, 0.236 |
58 | Trans-aconitate | 6.59 (s) | −0.872 | 1.13 | ↓, <0.001 | 0.203 | 0.12 | –, 0.684 |
60 | Glucose (α & β form) | 3.90 (dd) | 0.835 | 1.73 | ↑, <0.001 | −0.588 | 2.40 | ↓, 0.013 |
61 | Hippurate | 7.64 (t) | −0.970 | 1.58 | ↓, <0.001 | 0.516 | 0.56 | ↑, 0.035 |
62 | Trigonelline | 8.84 (t) | −0.951 | 0.64 | ↓, <0.001 | 0.449 | 0.30 | –, 0.129 |
63 | 1-Methylnicotinamide | 8.90 (d) | 0.975 | 0.67 | ↑, <0.001 | −0.330 | 0.42 | –, 0.137 |
70 | Nicotinamide N-oxide | 8.49 (d) | 0.573 | 0.23 | ↑, <0.001 | −0.549 | 0.54 | –, 0.261 |
73 | Niacinamide | 8.94 (d) | −0.635 | 0.22 | ↓, 0.005 | 0.355 | 0.09 | –, 0.543 |
Multi-criteria assessment (MCA) was performed using the followed criteria: 1. Coefficient value |r| >0.576, 2. VIP>1, 3. p value <0.05.
Coefficient values were calculated using NOESY coefficient-coded loadings plots. The coefficients from the OPLS-DA results; positive and negative signs indicate positive and negative correlations in the concentrations of serum metabolites.
Independent t test (two-tailed).