Table 1.
The characteristics and plasma concentrations of amino acids between healthy controls (n = 22) and major depressive patients (n = 68) at baseline
| Characteristics; Amino acid (μmol/L) | Controls | Patients | P‐valuea | ||
|---|---|---|---|---|---|
| Median | Q1–Q3 | Median | Q1–Q3 | ||
| Age | 68.0 | 65.3–73.3 | 65.0 | 60.8–70.0 | 0.118b |
| Sex, M:F | 4:18 | 16:52 | 0.771c | ||
| Alanine | 406 | 345–412 | 446 | 351–540 | 0.043 |
| Beta‐alanine | 23.5 | 9.00–62.2 | 11.0 | 7.80–17.5 | 0.024 |
| Anserine | 0.03 | 0.00–0.16 | 0.00 | 0.00–4.73 | 0.364 |
| Aminoadipic acid | 0.78 | 0.67–0.85 | 0.85 | 0.58–1.12 | 0.615 |
| Alpha‐aminobutyric acid | 12.5 | 11.1–17.6 | 16.2 | 12.7–21.1 | 0.144 |
| Gamma‐aminobutyric acid | 0.19 | 0.12–0.74 | 1.16 | 0.00–2.01 | 0.050 |
| Beta‐aminoisobutyric acid | 3.89 | 1.02–6.58 | 1.12 | 0.27–1.92 | <0.001 |
| Arginine | 58.7 | 39.1–75.2 | 69.7 | 49.0–94.1 | 0.099 |
| Asparagine | 53.5 | 47.1–64.6 | 50.9 | 41.3–70.3 | 0.662 |
| Aspartic acid | 4.30 | 3.14–5.49 | 3.51 | 2.60–5.73 | 0.411 |
| Carnosine | 0.02 | 0.00–0.08 | 0.00 | 0.00–0.00 | 0.055 |
| Citrulline | 30.3 | 25.7–36.6 | 34.0 | 25.2–45.6 | 0.194 |
| Cystathionine | 0.08 | 0.00–0.16 | 0.00 | 0.00–0.00 | <0.001 |
| Cystine | 97.5 | 54.4–126 | 59.0 | 36.3–90.6 | 0.083 |
| Ethanolamine | 5.49 | 4.92–6.23 | 35.4 | 23.6–36.8 | <0.001 |
| Glutamic acid | 51.8 | 35.1–61.6 | 59.6 | 39.1–76.9 | 0.047 |
| Glutamine | 600 | 554–686 | 621 | 495–794 | 0.796 |
| Glycine | 232 | 182–289 | 251 | 186–298 | 0.455 |
| Histidine | 82.4 | 74.7–92.3 | 73.8 | 63.1–96.5 | 0.304 |
| Homocystine | 0.02 | 0.00–0.06 | 0.00 | 0.00–0.00 | <0.001 |
| 5‐hydroxylysine | 0.53 | 0.00–1.89 | 0.00 | 0.00–0.75 | 0.057 |
| Hydroxyproline | 6.12 | 4.14–8.79 | 7.94 | 5.08–14.3 | 0.088 |
| Isoleucine | 55.6 | 46.1–63.7 | 64.4 | 48.8–81.5 | 0.061 |
| Leucine | 114 | 88.6–121 | 117 | 89.4–148 | 0.478 |
| Lysine | 189 | 158–224 | 182 | 152–232 | 0.884 |
| Methionine | 21.0 | 19.3–25.6 | 27.3 | 21.6–40.6 | 0.004 |
| 1‐methylhistidine | 0.54 | 0.09–0.99 | 0.68 | 0.00–1.49 | 0.882 |
| 3‐methylhistidine | 4.86 | 3.78–5.52 | 4.23 | 2.48–5.49 | 0.109 |
| Ornithine | 109 | 88.2–132 | 98.1 | 70.5–129 | 0.242 |
| Phenylalanine | 53.0 | 49.0–57.1 | 59.3 | 47.7–74.9 | 0.072 |
| O‐phosphoethanolamine | 1.49 | 0.93–1.94 | 1.64 | 1.10–2.27 | 0.242 |
| O‐phospho‐L‐serine | 5.45 | 4.42–6.29 | 0.00 | 0.00–0.61 | <0.001 |
| Proline | 142 | 127–185 | 162 | 123–231 | 0.258 |
| Sarcosine | 5.75 | 4.44–10.8 | 2.67 | 2.20–4.40 | <0.001 |
| Serine | 119 | 103–143 | 114 | 92.8–150 | 0.870 |
| Taurine | 52.5 | 41.1–60.9 | 55.6 | 42.2–79.1 | 0.300 |
| Threonine | 118 | 102–150 | 111 | 88.3–150 | 0.450 |
| Tryptophan | 43.2 | 39.4–46.1 | 43.6 | 35.7–52.7 | 0.662 |
| Tyrosine | 56.6 | 50.1–61.6 | 61.4 | 49.6–74.6 | 0.258 |
| Valine | 215 | 196–251 | 237 | 206–311 | 0.144 |
| Tyrosine/LNAA | 0.13 | 0.12–0.15 | 0.12 | 0.11–0.14 | 0.270 |
| Tryptophan/LNAA | 0.10 | 0.09–0.11 | 0.09 | 0.08–0.10 | 0.176 |
| Glutamine/glutamic acid | 11.8 | 8.87–16.7 | 10.9 | 8.10–15.0 | 0.228 |
| Serine/glycine | 0.52 | 0.48–0.56 | 0.50 | 0.41–0.57 | 0.313 |
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. c P‐values from Fisher's exact test.