Table 11.
Metabolites related to BCAA metabolism and tryptophan-kynurenine-serotonin pathways in 24-hour urine samples across 3 groups in females, normalized for urine Cr (mmol/mol Cr)
| Lean (n = 17) | Obese without T2d (n = 33) | Obese with T2D (n = 28) | P | |
|---|---|---|---|---|
| BCAAs mmol/mol Cr | 12.34 ± 5.42 | 9.73 ± 3.77 | 15.55 ± 6.86 | .0027 |
| BCKAs mmol/mol Cr | 2.34 ± 1.02 | 1.89 ± .81 | 5.29 ± 4.51 | .00019 |
| KIV mmol/mol Cr | .36 ± .16 | .34 ± .15 | 1.17 ± 1.06 | 6.4e-06 |
| KMV mmol/mol Cr | 1.6 ± .76 | 1.21 ± .57 | 3.02 ± 2.35 | .00062 |
| KIC mmol/mol Cr | .38 ± .14 | .34 ± .14 | 1.1 ± 1.26 | .00011 |
| Tryptophan mmol/mol Cr | 7.93 ± 4.07 | 6.44 ± 2.99 | 9.17 ± 3.02 | .011 |
| Kynurenine mmol/mol Cr | .34 ± .25 | .29 ± .17 | .57 ± .36 | .00066 |
| Kynurenic acid mmol/mol Cr | 1.22 ± .55 | 1.27 ± .51 | 1.11 ± .47 | .47 |
| Serotonin nmol/mmol Cr | 84.94 ± 20.05 | 81.53 ± 35.77 | 85.11 ± 24.10 | .4726 |
| 5-HIAA mg/g Cr | 3.65 ± 1.89 | 2.78 ± .88 | 3.88 ± 4.23 | .15 |
| Kynurenine/tryptophan | .034 ± .012 | .047 ± .022 | .058 ± .036 | .043 |
| 5-HIAA/tryptophan | .54 ± .26 | .50 ± .19 | .46 ± .41 | .1131 |
| 5-HIAA/kynurenine | 18.10 ± 17.41 | 12.69 ± 7.93 | 8.61 ± 8.37 | .0084 |
| Kynurenine/serotonin | .0040 ± .0030 | .0036 ± .0015 | .0075 ± .0048 | <.0001 |
| Serotonin/tryptophan | 13.08 ± 5.65 | 13.66 ± 4.18 | 10.71 ± 5.31 | .0129 |
Abbreviations: BCAA, branched-chain amino acid; BCKA, branched-chain ketoacid; Cr, creatinine; HbA1c, hemoglobin A1c; KIC, α-keto-isocaproate; KIV, α-keto-valerate; KMV, α-keto-β-methylvalerate; T2D, type 2 diabetes.