Table 3.
Metabolic pathways corresponding to metabolites identified in serum samples.
| Pathway | No. of Metabolites in the Pathway | No. of Metabolites Detected in Serum | p-Value | Pathway Impact |
|---|---|---|---|---|
| Sphingolipid metabolism | 21 | 8 | 0.00013 | 0.57 |
| Citrate cycle (TCA cycle) | 20 | 5 | 0.019 | 0.33 |
| Linoleic acid metabolism | 5 | 2 | 0.056 | 1.0 |
| Biosynthesis of unsaturated fatty acids | 36 | 6 | 0.068 | 0.0 |
| Alanine, aspartate and glutamate metabolism | 28 | 5 | 0.072 | 0.094 |
| Tryptophan metabolism | 41 | 6 | 0.11 | 0.17 |
| Glyoxylate and dicarboxylate metabolism | 32 | 5 | 0.11 | 0.12 |
| Tyrosine metabolism | 42 | 6 | 0.12 | 0.19 |
| Glycerolipid metabolism | 16 | 3 | 0.14 | 0.29 |
| Retinol metabolism | 17 | 3 | 0.16 | 0.46 |
| Glycerophospholipid metabolism | 36 | 5 | 0.17 | 0.35 |
| Pyruvate metabolism | 22 | 3 | 0.27 | 0.21 |
| Glycine, serine and threonine metabolism | 33 | 4 | 0.28 | 0.26 |
| Lysine degradation | 25 | 3 | 0.34 | 0.14 |
| Thiamine metabolism | 7 | 1 | 0.45 | 0.0 |
| Ascorbate and aldarate metabolism | 8 | 1 | 0.50 | 0.0 |
| Taurine and hypotaurine metabolism | 8 | 1 | 0.50 | 0.43 |
| Cysteine and methionine metabolism | 33 | 3 | 0.52 | 0.021 |
| Beta-alanine metabolism | 21 | 2 | 0.52 | 0.45 |
| One carbon pool by folate | 9 | 1 | 0.54 | 0.0 |
| Steroid hormone biosynthesis | 85 | 7 | 0.56 | 0.023 |
| Propanoate metabolism | 23 | 2 | 0.57 | 0.041 |
| Phenylalanine metabolism | 10 | 1 | 0.57 | 0.0 |
| Biotin metabolism | 10 | 1 | 0.57 | 0.15 |
| Arginine and proline metabolism | 38 | 3 | 0.61 | 0.012 |
| Glycolysis or Gluconeogenesis | 26 | 2 | 0.64 | 0.10 |
| Galactose metabolism | 27 | 2 | 0.66 | 0.0 |
| Alpha-linolenic acid metabolism | 13 | 1 | 0.67 | 0.0 |
| Glutathione metabolism | 28 | 2 | 0.68 | 0.023 |
| Arginine biosynthesis | 14 | 1 | 0.70 | 0.0 |
| Glycosylphosphatidylinositol(GPI)-anchor biosynthesis | 14 | 1 | 0.70 | 0.0040 |
| Histidine metabolism | 16 | 1 | 0.75 | 0.0 |
| Starch and sucrose metabolism | 18 | 1 | 0.79 | 0.073 |
| Terpenoid backbone biosynthesis | 18 | 1 | 0.79 | 0.18 |
| Pantothenate and CoA biosynthesis | 19 | 1 | 0.80 | 0.021 |
| Arachidonic acid metabolism | 36 | 2 | 0.81 | 0.0 |
| Fructose and mannose metabolism | 20 | 1 | 0.82 | 0.0 |
| Selenocompound metabolism | 20 | 1 | 0.82 | 0.0 |
| Ether lipid metabolism | 20 | 1 | 0.82 | 0.0 |
| Amino sugar and nucleotide sugar metabolism | 37 | 2 | 0.82 | 0.0058 |
| Pyrimidine metabolism | 39 | 2 | 0.84 | 0.057 |
| Steroid biosynthesis | 42 | 2 | 0.87 | 0.0 |
| Aminoacyl-tRNA biosynthesis | 48 | 2 | 0.92 | 0.17 |
| Drug metabolism - cytochrome P450 | 55 | 2 | 0.95 | 0.0 |
| Fatty acid elongation | 39 | 1 | 0.96 | 0.0 |
| Fatty acid degradation | 39 | 1 | 0.96 | 0.0 |
| Purine metabolism | 65 | 2 | 0.97 | 0.022 |
| Primary bile acid biosynthesis | 46 | 1 | 0.98 | 0.0076 |
| Fatty acid biosynthesis | 47 | 1 | 0.98 | 0.015 |
Pathway impact values and p-values were obtained from metabolic pathway analysis performed with MetaboAnalyst 4.0 software. Pathways highlighted in bold were identified in the case of both serum and AH samples.