Table 1.2.
Baseline characteristics of survival analysis participants in the NHS (1990), NHSII (1999), and HPFS (1994) according to plasma IPA concentrations.
| Baseline plasma IPA concentration, log Z-score | |||||
|---|---|---|---|---|---|
|
| |||||
| Characteristics | Q1 (N=1,012) | Q2 (N=1,012) | Q3 (N=1,012) | Q4 (N=1,013) | Q5 (N=1,012) |
|
|
|||||
| Baseline plasma tryptophan metabolites, log Z-score * | |||||
| IPA | −1.1 (−1.7, −0.9) | −0.4 (−0.5, −0.2) | 0.08 (−0.01,0.2) | 0.5 (0.4,0.6) | 1.1 (0.9,1.4) |
| Tryptophan | −0.08 (−0.8,0.5) | −0.03 (−0.6,0.6) | 0.1 (−0.5,0.6) | 0.08 (−0.4,0.6) | 0.2 (−0.4,0.7) |
| Indoxyl sulfate | −0.07 (−0.7,0.5) | 0.2 (−0.4,0.7) | 0.2 (−0.4,0.7) | 0.2 (−0.4,0.7) | −0.02 (−0.7,0.5) |
| Serotonin | 0.02 (−0.6,0.7) | 0.2 (−0.5,0.8) | 0.10 (−0.6,0.7) | 0.1 (−0.6,0.7) | 0.3 (−0.4,0.8) |
| Kynurenine | −0.04 (−0.7,0.6) | −0.01 (−0.6,0.6) | 0.05 (−0.5,0.6) | 0.1 (−0.4,0.6) | 0.04 (−0.5,0.6) |
| Kynurenic acid | −0.08 (−0.7,0.6) | −0.02 (−0.7,0.7) | 0.06 (−0.5,0.7) | 0.03 (−0.6,0.7) | −0.03 (−0.6,0.6) |
| Quinolinic acid | 0.03 (−0.6,0.7) | −0.06 (−0.6,0.6) | −0.02 (−0.6,0.6) | 0.04 (−0.6,0.6) | −0.08 (−0.7,0.5) |
| Xanthurenic acid | 0.1 (−0.6,0.6) | 0.09 (−0.5,0.6) | 0.1 (−0.4,0.6) | 0.1 (−0.4,0.6) | 0.09 (−0.5,0.6) |
| Dietary tryptophan intake (g/d) | 1 (0.3) | 1 (0.3) | 1 (0.3) | 1 (0.3) | 1 (0.3) |
| Age (years) | 53 (8.9) | 53 (9.6) | 52 (9.7) | 52 (9.3) | 53 (9.8) |
| Ethnicity, % | |||||
| White | 96.7 | 97.5 | 98.7 | 97.2 | 97.2 |
| Black | 1.1 | 1.0 | 0.4 | 0.6 | 0.7 |
| Asian | 1.2 | 0.8 | 0 | 1.2 | 0.7 |
| Other | 1.0 | 0.7 | 0.9 | 1.0 | 1.4 |
| Cohort origins, % | |||||
| NHS | 50.0 | 43.0 | 39.3 | 42.3 | 45.5 |
| NHSII | 37.6 | 43.3 | 47.9 | 47.4 | 40.9 |
| HPFS | 12.4 | 13.7 | 12.7 | 10.3 | 13.6 |
| Smoking status, % | |||||
| Never smokers | 51.2 | 55.7 | 56.0 | 58.6 | 62.4 |
| Past smokers | 17.9 | 10.4 | 10.2 | 6.0 | 5.4 |
| Current smokers | 30.9 | 33.9 | 33.8 | 35.3 | 32.2 |
| BMI, % | |||||
| < 25 kg/m2 | 41.8 | 50.2 | 51.0 | 55.4 | 61.2 |
| 25-29.9 kg/m2 | 34.5 | 34.2 | 33.8 | 29.6 | 27.2 |
| BMI≥30 kg/m2 | 22.3 | 14.1 | 14.3 | 14.2 | 10.4 |
| Physical activity (MET-h/wk) | 8.6 (3.2, 20.3) | 11.2 (4.2, 24.3) | 12.4 (4.4, 25.7) | 12.7 (5.2, 25.9) | 13.9 (4.9, 27.7) |
| Alcohol consumption (g/d) | 1.8 (0, 6.9) | 1.5 (0, 6.9) | 1.1 (0, 6.0) | 1.8 (0, 6.5) | 1.8 (0, 7.9) |
| AHEI | 44.5 (9.9) | 45.6 (10.3) | 46.5 (10.2) | 47.5 (10.2) | 50.1 (11.0) |
| Total energy intake (Kcal/d) | 1800 (466) | 1820 (494) | 1800 (471) | 1830 (481) | 1820 (480) |
*
Values are means (SD) or median (IQR) for continuous variables and percentages (%) for categorical variables.