Table 3. Discriminative serum metabolites between OA and HC groups, as well as between OA and non-OA groups.
| NO | Metabolites | HMDB ID | Mode | RT (min) | Extract mass | OA vs HC | OA vs non-OA | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| VIP | FC | p value | AUC | VIP | FC | p value | AUC | ||||||
| 1 | PC (16:0/22:6) | HMDB0007991 | ESI+ | 8.36 | 806.571 | 20.61 | 1.18 | 0.015 | 0.658 | 26.47 | 1.43 | 0.003 | 0.749 |
| 2 | Unknown m/z 239.091 | HMDB0030254 | ESI− | 1.87 | 239.091 | 19.62 | 2.19 | <0.001 | 0.774 | 15.50 | 1.91 | 0.014 | 0.708 |
| 3 | PC (18:1/18:2) | HMDB0008072 | ESI+ | 9.15 | 784.586 | 18.89 | 1.28 | 0.008 | 0.673 | 18.88 | 1.48 | 0.016 | 0.706 |
| 4 | PC (16:0/18:1) | HMDB0007972 | ESI+ | 10.33 | 760.587 | 16.97 | 1.13 | 0.027 | 0.643 | / | / | / | / |
| 5 | PC (18:0/22:6) | HMDB0008057 | ESI+ | 10.42 | 834.602 | 15.92 | 1.40 | 0.002 | 0.706 | 14.39 | 1.68 | 0.002 | 0.761 |
| 6 | PC (18:0/18:0) | HMDB0008036 | ESI+ | 11.93 | 812.617 | 15.59 | 1.52 | <0.001 | 0.715 | 7.42 | 1.37 | 0.041 | 0.674 |
| 7 | PC (20:4/16:1) | HMDB0008463 | ESI+ | 7.70 | 802.537 | 12.99 | 1.70 | <0.001 | 0.720 | 8.79 | 1.82 | 0.006 | 0.689 |
| 8 | p-Cresol sulfate | HMDB0011635 | ESI− | 1.75 | 187.005 | 9.28 | 1.72 | 0.042 | 0.632 | / | / | / | / |
| 9 | Unknown m/z 195.101 | HMDB0030984 | ESI− | 1.87 | 195.101 | 8.98 | 2.12 | <0.001 | 0.768 | 7.18 | 1.88 | 0.015 | 0.705 |
| 10 | PC (22:6/18:0) | HMDB0008727 | ESI+ | 11.76 | 834.598 | 7.37 | 1.34 | 0.040 | 0.634 | / | / | / | / |
| 11 | 12-hydroperoxy-5,8,10,14-eicosatetraenoic acid | HMDB0062287 | ESI− | 2.63 | 319.226 | 6.59 | 0.46 | <0.001 | 0.776 | / | / | / | / |
| 12 | PC (22:6/20:3) | HMDB0008737 | ESI+ | 10.30 | 856.582 | 5.28 | 1.23 | 0.021 | 0.650 | 7.71 | 1.54 | 0.008 | 0.722 |
| 13 | Cis-vaccenic acid | HMDB0040219 | ESI+ | 4.24 | 282.279 | 4.46 | 0.44 | <0.001 | 0.774 | / | / | / | / |
| 14 | Perfluorooctane sulfonic acid | HMDB0059586 | ESI− | 2.31 | 498.928 | 4.19 | 1.51 | 0.003 | 0.693 | 8.32 | 1.76 | 0.004 | 0.742 |
| 15 | PC (20:4/18:0) | HMDB0008431 | ESI+ | 10.70 | 810.602 | / | / | / | / | 20.92 | 1.27 | 0.002 | 0.757 |
| 16 | Docosahexaenoic acid | HMDB0002183 | ESI− | 3.48 | 327.231 | / | / | / | / | 14.54 | 1.51 | 0.039 | 0.676 |
| 17 | PC (18:1/22:6) | HMDB0008123 | ESI+ | 10.67 | 832.583 | / | / | / | / | 9.15 | 1.16 | 0.025 | 0.689 |
| 18 | Phenylalanine | HMDB0000159 | ESI− | 1.10 | 164.070 | / | / | / | / | 7.41 | 0.75 | 0.012 | 0.713 |
| 19 | PC (22:6/18:2) | HMDB0008730 | ESI+ | 7.59 | 830.569 | / | / | / | / | 7.03 | 1.70 | 0.005 | 0.733 |
| 20 | Indoxyl sulfate | HMDB0000682 | ESI− | 1.65 | 212.000 | / | / | / | / | 5.79 | 1.59 | 0.010 | 0.716 |
Note:
The importance in the projection (VIP) was acquired from OPLS-DA models with a threshold of 4.0; The fold change (FC) refers to the ratio of the average concentrations of metabolites in two groups of samples; p value was calculated by Kruskal-Wallis test with a threshold of 0.05; The area under the curve (AUC) was calculated using ROC analysis.