Table 1.
Characteristics of participants.
| n | 5364 |
| n (US) | 2400 |
| n (nordic) | 835 |
| n (Asia) | 1775 |
| n (Australia) | 354 |
| Age, yearsa | 62 (47, 75) |
| Male (%) | 2456 (45.8) |
| BMI, kg/m2a | 24.7 (19.3, 33.4) |
| Never smokers, n (%)a | 1327 (24.7) |
| Former smokers, n (%)a | 1518 (28.3) |
| Current smokers, n (%)a | 2519 (47.0) |
| KTR, nmol/µmol | 22.6 (16.4, 34.5) |
| Neopterin, nmol/L | 11.0 (5.14, 23.6) |
| CRP, mg/L | 1.77 (0.24, 13.2) |
| Tryptophan, µmol/L | 66.5 (46.2, 90.7) |
| Kynurenine, µmol/L | 1.51 (1.05, 2.22) |
| KA, nmol/L | 43.9 (22.0, 91.2) |
| AA, nmol/L | 13.9 (7.99, 29.1) |
| HK, nmol/L | 36.6 (20.3, 70.6) |
| XA, nmol/L | 12.4 (4.6, 29.1) |
| HAA, nmol/L | 32.6 (16.1, 59.5) |
| QA, nmol/L | 353 (208, 685) |
| Creatinine, µmol/L | 74.5 (52, 105) |
| Cotinine, nmol/L | 14.4 (1, 1870) |
| Riboflavin, nmol/L | 19.2 (5.85, 89.6) |
| PLP, nmol/L | 37.1 (13.8, 196) |
Values are median (95% CI) or n (%). AA: anthranilic acid; BMI: body mass index; CRP: C-reactive protein; HAA: 3-hydroxyanthranilic acid; HK: 3-hydroxykynurenine; KA: kynurenic acid; KTR: kynurenine/tryptophan; PLP: pyridoxal 5′-phosphate; QA: quinolinic acid; XA: xanthurenic acid.
aAge, BMI and self-reported smoking status at date of blood draw.