Table 2.
Predictors of kynureniners and KTR by mixed models.
| KTR | Tryptophan | Kynurenine | KA | AA | HK | XA | HAA | QA | |
|---|---|---|---|---|---|---|---|---|---|
| Age | 0.12 (0.09,0.14) | − 0.03 (− 0.06,0.0004) | 0.10 (0.07,0.12) | 0.05 (0.024,0.08) | 0.09 (0.06,0.12) | 0.006 (− 0.02,0.03) | − 0.05 (− 0.08,− 0.02) | − 0.09 (− 0.12,− 0.06) | 0.10 (0.08,0.12) |
| Sex | 0.35 (0.28,0.41) | − 0.44 (− 0.52,− 0.36) | − 0.02 (− 0.08,0.04) | 0.09 (0.02,0.16) | − 0.0003 (− 0.06,0.06) | 0.29 (0.22,0.36) | 0.01 (− 0.05,0.07) | − 0.27 (− 0.34,− 0.19) | 0.21 (0.15,0.27) |
| BMI | 0.03 (0.007,0.06) | 0.10 (0.07,0.13) | 0.13 (0.10,0.15) | 0.14 (0.11,0.16) | − 0.01 (− 0.04,0.02) | 0.07 (0.04,0.10) | 0.10 (0.07,0.13) | 0.12 (0.09,0.15) | 0.14 (0.12,0.16) |
| KTR | 0.28 (0.25,0.30) | 0.23 (0.20,0.26) | 0.31 (0.28,0.33) | − 0.11 (− 0.14,− 0.08) | 0.01 (− 0.02,0.04) | 0.46 (0.44,0.49) | |||
| Neopterin | 0.48 (0.45,0.51) | − 0.15 (− 0.18,− 0.12) | 0.36 (0.33,0.38) | 0.18 (0.14,0.21) | 0.18 (0.15,0.22) | 0.28 (0.25,0.31) | − 0.03 (− 0.06,0.006) | 0.15 (0.11,0.18) | 0.44 (0.41,0.46) |
| CRP | 0.10 (0.07,0.12) | − 0.001 (− 0.03,0.03) | 0.09 (0.07,0.12) | − 0.02 (− 0.05,0.005) | 0.03 (− 0.0002,0.06) | 0.06 (0.04,0.09) | − 0.03 (− 0.06,− 0.006) | 0.11 (0.08,0.13) | 0.14 (0.12,0.17) |
| Creatinine | 0.28 (0.25,0.31) | 0.04 (0.01,0.07) | 0.33 (0.30,0.36) | 0.47 (0.44,0.50) | 0.16 (0.13,0.19) | 0.30 (0.27,0.33) | 0.31 (0.28,0.35) | 0.10 (0.06,0.13) | 0.35 (0.32,0.37) |
| Cotinine | − 0.05 (− 0.08,− 0.03) | 0.01 (− 0.02,0.04) | − 0.05 (− 0.07,− 0.02) | − 0.02 (− 0.05,0.009) | − 0.13 (− 0.16,− 0.10) | − 0.07 (− 0.10,− 0.04) | − 0.04 (− 0.07,− 0.005) | − 0.04 (− 0.07,− 0.01) | − 0.16 (− 0.19,− 0.14) |
| Riboflavin | 0.02 (− 0.01,0.05) | − 0.01 (− 0.04,0.02) | 0.01 (− 0.01,0.04) | − 0.002 (− 0.03,0.03) | 0.06 (0.03,0.09) | 0.05 (0.02,0.08) | 0.03 (0.004,0.06) | 0.09 (0.06,0.12) | 0.07 (0.05,0.10) |
| PLP | − 0.13 (− 0.16,− 0.11) | 0.16 (0.13,0.19) | 0.01 (− 0.01,0.04) | 0.12 (0.09,0.15) | 0.05 (0.02,0.08) | − 0.28 (− 0.31,− 0.25) | 0.10 (0.07,0.13) | 0.17 (0.14,0.20) | − 0.001 (− 0.03,0.02) |
The numbes given are regression coefficients with 5,95% CI. The models were calculated by including cohorts and regions as random effects, and age, sex, BMI, CRP, KTR or neopterin (KTR and neopterin were included in separate models), creatinine, cotinine, riboflavin, PLP and sample storage time as fixed effects. All continuous variables were log-transformed and then centered on the mean and standardized by dividing by the standard deviation. For sex the regression coefficients represent the ratio of biomarker levels for women vs men.
AA: anthranilic acid; BMI: body mass index; CRP: C-reactive protein; HAA: 3-hydroxyanthranilic acid; HK: 3-hydroxykynurenine; KA: kynurenic acid; KTR: kynurenine/tryptophan ratio; PLP: pyridoxal 5′-phosphate; QA: quinolinic acid; XA: xanthurenic acid.