Table 2.
B vitamin plasma concentrations in healthy controls and medicated patients with depression.
| Controls (n = 57) | Depressed Baseline (n = 94) | Cohen’s d | Unadjusted Statistics | Adjusted Statisticsa | |
|---|---|---|---|---|---|
| B vitamins | |||||
| Thiamine (B1) | 4.25 (2.00) | 5.80 (8.13) | 0.26 | U = 2520, p = 0.542; pFDR = 0.542 | |
| Thiamine Monophosphate (B1) | 7.50 (2.24) | 6.99 (2.80) | −0.20 | F1,149 = 2.85, p = 0.094; pFDR = 0.12 | F1,132 = 1.84, p = 0.18; pFDR = 0.18 |
| Riboflavin (B2) | 18.63 (16.55) | 17.36 (17.87) | −0.07 | U = 2901, p = 0.394; pFDR = 0.44 | |
| Flavin Mononucleotide (B2) | 13.27 (12.77) | 9.99 (10.61) | −0.28 | U = 3588.5, p < 0.001; pFDR= 0.002 | |
| Nicotinamide (B3) | 1126.58 (314.31) | 968.59 (355.20) | −0.47 | F1,149 = 7.64, p = 0.006; pFDR= 0.01 | F1,132 = 4.74, p = 0.031; pFDR= 0.04 |
| N1-methylnicotinamide (B3) | 149.92 (73.41) | 115.06 (63.62) | −0.51 | F1,149 = 10.51, p = 0.001; pFDR= 0.002 | F1,132 = 5.73, p = 0.018; pFDR= 0.036 |
| Pyridoxal 5ʹ-phosphate (B6) | 79.90 (46.56) | 51.24 (50.71) | −0.59 | F1,149 = 35.47, p = 1.79 × 10−8; pFDR= 0.002 × 10−7 | F1,132 = 13.70, p = 0.0003; pFDR= 0.001 |
| Pyridoxic Acid (B6) | 32.70 (15.63) | 37.09 (100.83) | 0.06 | U = 3272, p = 0.023; pFDR= 0.03 | |
| Pyridoxal (B6) | 16.68 (11.15) | 18.40 (76.96) | 0.03 | U = 4325.5, p < 0.001; pFDR= 0.002 | |
| Ratios indicative of B vitamin function | |||||
| PAr | 0.37 (0.27) | 0.54 (0.27) | 0.63 | U = 1503, p < 0.001 | |
| HK:XA | 2.69 (1.46) | 5.17 (3.23) | 0.99 | U = 984, p = 7.7 × 10−11 | |
| HK:HAA | 1.13 (0.32) | 1.45 (0.72) | 0.57 | U = 1994, p = 0.009 | |
| HKr | 0.34 (0.08) | 0.46 (0.18) | 0.86 | U = 1409, p = 0.000001 | |
Data are presented as mean (SD) nmol/L.
pFDR represents the adjusted p-value following Benjamini-Hochberg analysis (only B vitamins were included in this analysis and not functional ratios). pFDR highlighted in bold attains statistical significance.
PAr = PA:(PL + PLP), indicative of altered vitamin B6 homeostasis towards increased B6 catabolism. HK:XA and HK:XAA are indicative of increased HK in blood owing to reduction in the activity of the B6-dependent enzymes KAT and KYNU, respectively. HKr = HK: (KYNA + XA + HAA + AA).
Abbreviations: AA, anthranilic acid; BMI, body-mass index; HAA, 3-hydroxyanthranilinic acid; HK, 3-hydroxykynurenine; KAT, kynurenine aminotransferase; KYNA, kynurenic acid; KYNU, kynureninase; NSAID, non-steroidal anti-inflammatory drug; PA, pyridoxic acid; PL, pyridoxal; PLP, pyridoxal 5′-phosphate; XA, xanthurenic acid.
Adjusted for age, sex, BMI, smoking, education, presence of diabetes, presence of cardiovascular disease, use of NSAIDs.