Table 3.
Plasma concentrations of amino acids at baseline and at 6 weeks after the antidepressant treatment in depressive patients (n = 68)
| Amino acid (μmol/L) | At baseline | At 6 weeks | P‐valuea | ||
|---|---|---|---|---|---|
| Median | Q1–Q3 | Median | Q1–Q3 | ||
| Alanine | 446 | 351–540 | 434 | 357–599 | 0.851 |
| Beta‐alanine | 11.0 | 7.80–17.5 | 11.9 | 8.32–17.7 | 0.383 |
| Anserine | 0.00 | 0.00–4.73 | 0.00 | 0.00–4.77 | 0.760 |
| Aminoadipic acid | 0.85 | 0.58–1.12 | 0.74 | 0.57–1.16 | 0.829 |
| Alpha‐aminobutyric acid | 16.2 | 12.7–21.1 | 16.0 | 12.6–23.0 | 0.553 |
| Gamma‐aminobutyric acid | 1.16 | 0.00–2.01 | 1.15 | 0.00–1.89 | 0.194 |
| Beta‐aminoisobutyric acid | 1.12 | 0.27–1.92 | 1.07 | 0.00–1.96 | 0.795 |
| Arginine | 69.7 | 49.0–94.1 | 70.0 | 58.3–103 | 0.039 |
| Asparagine | 50.9 | 41.3–70.3 | 56.7 | 44.6–75.0 | 0.017 |
| Aspartic acid | 3.51 | 2.60–5.73 | 3.26 | 2.34–4.31 | 0.261 |
| Carnosine | 0.00 | 0.00–0.00 | 0.00 | 0.00–0.00 | 0.644 |
| Citrulline | 34.0 | 25.2–45.6 | 35.5 | 23.4–49.5 | 0.909 |
| Cystathionine | 0.00 | 0.00–0.00 | 0.00 | 0.00–0.00 | 0.570 |
| Cystine | 59.0 | 36.3–90.6 | 67.4 | 47.3–102 | 0.039 |
| Ethanolamine | 35.4 | 23.6–36.8 | 34.8 | 18.4–36.7 | 0.479 |
| Glutamic acid | 59.6 | 39.1–76.9 | 50.6 | 36.6–67.0 | 0.071 |
| Glutamine | 621 | 495–794 | 616 | 490–861 | 0.485b |
| Glycine | 251 | 186–298 | 241 | 176–383 | 0.231 |
| Histidine | 73.8 | 63.1–96.5 | 72.8 | 58.1–106 | 0.467 |
| Homocystine | 0.00 | 0.00–0.00 | 0.00 | 0.00–0.00 | 0.500 |
| 5‐hydroxylysine | 0.00 | 0.00–0.75 | 0.25 | 0.00–0.77 | 0.222 |
| Hydroxyproline | 7.94 | 5.08–14.3 | 7.65 | 5.01–12.5 | 0.995 |
| Isoleucine | 64.4 | 48.8–81.5 | 62.3 | 53.5–80.1 | 0.483 |
| Leucine | 117 | 89.4–148 | 114 | 92.4–136 | 0.590 |
| Lysine | 182 | 153–232 | 188 | 135–251 | 0.926b |
| Methionine | 27.3 | 21.6–40.6 | 29.0 | 23.1–42.8 | 0.832 |
| 1‐methylhistidine | 0.68 | 0.00–1.49 | 0.58 | 0.00–1.24 | 0.317 |
| 3‐methylhistidine | 4.23 | 2.48–5.49 | 3.49 | 2.50–5.20 | 0.718b |
| Ornithine | 98.1 | 70.5–129 | 95.9 | 67.5–136 | 0.672 |
| Phenylalanine | 59.3 | 47.7–74.9 | 58.9 | 45.9–77.8 | 0.541 |
| O‐phosphoethanolamine | 1.64 | 1.10–2.27 | 1.57 | 0.98–2.46 | 0.911 |
| O‐phospho‐L‐serine | 0.00 | 0.00–0.61 | 0.00 | 0.00–0.71 | 0.666 |
| Proline | 162 | 123–231 | 174 | 133–242 | 0.229 |
| Sarcosine | 2.67 | 2.20–4.40 | 2.93 | 2.10–5.53 | 0.204 |
| Serine | 114 | 92.8–150 | 122 | 90.6–172 | 0.545 |
| Taurine | 55.6 | 42.2–79.1 | 54.3 | 35.1–77.0 | 0.376 |
| Threonine | 111 | 88.3–150 | 113 | 91.7–160 | 0.467b |
| Tryptophan | 43.6 | 35.7–52.7 | 43.6 | 33.7–55.0 | 0.762 |
| Tyrosine | 61.4 | 49.6–74.6 | 61.2 | 47.6–80.7 | 0.431 |
| Valine | 237 | 206–311 | 245 | 196–296 | 0.957 |
| Tyrosine/LNAA | 0.12 | 0.11–0.14 | 0.13 | 0.11–0.14 | 0.400 |
| Tryptophan/LNAA | 0.09 | 0.08–0.10 | 0.09 | 0.08–0.10 | 0.603 |
| Glutamine/glutamic acid | 10.9 | 8.10–15.0 | 12.8 | 9.42–16.9 | 0.039 |
| Serine/glycine | 0.50 | 0.41–0.57 | 0.51 | 0.41–0.56 | 0.725b |
Q1, lower quartile; Q3, upper quartile; LNAA, large neutral amino acid. a P‐values from Wilcoxon rank‐sum test. b P‐values from t‐test.