TABLE 1.
Participant characteristics across quartiles (Q) of plasma pyridoxal 5′-phosphate (PLP)1
| PLP |
|||||
| Variables | Q1 (5.5–28.3 nmol/L) | Q2 (28.4–42.4 nmol/L) | Q3 (42.5–65.2 nmol/L) | Q4 (65.3–737 nmol/L) | P for trend |
| n | 301 | 305 | 299 | 300 | — |
| Mean PLP (nmol/L) | 20.4 ± 5.32 | 34.8 ± 4.1 | 52.0 ± 6.4 | 128.2 ± 92.1 | — |
| Age3 (y) | 57.4 ± 7.5 | 56.9 ± 7.3 | 57.1 ± 7.6 | 58.3 ± 7.8 | 0.27 |
| Female4 [n (%)] | 235 (71) | 234 (72) | 231 (72) | 225 (69) | 0.36 |
| BMI (kg/m2) | 32.9 ± 7.7 | 32.3 ± 6.6 | 31.7 ± 6.5 | 30.7 ± 5.6 | <0.001 |
| Waist (cm) | 104 ± 17 | 103 ± 16 | 101 ± 14 | 99 ± 13 | <0.001 |
| Current smoker [n (%)] | 106 (32) | 90 (28) | 73 (23) | 49 (15) | <0.001 |
| Current drinker [n (%)] | 109 (33) | 129 (40) | 136 (42) | 145 (45) | 0.019 |
| Total energy intake (kcal/d) | 2315 ± 1170 | 2380 ± 1218 | 2360 ± 1198 | 2282 ± 1274 | 0.78 |
| Vitamin B-6 intake5 (mg/d) | 2.49 ± 1.31 | 2.54 ± 1.19 | 2.76 ± 1.31 | 2.99 ± 1.59 | <0.001 |
| Folate intake5 (μg/d) | 495 ± 241 | 512 ± 236 | 548 ± 268 | 610 ± 317 | <0.001 |
| Vitamin B-12 intake5 (μg/d) | 9.8 ± 8.9 | 9.8 ± 8.8 | 10.3 ± 8 | 11 ± 10 | 0.006 |
| Vitamin C intake5 (mg/d) | 143 ± 104 | 135 ± 89 | 151 ± 114 | 169 ± 109 | <0.001 |
| β-Carotene intake5 (mg/d) | 3228 ± 3464 | 3026 ± 2824 | 3524 ± 4193 | 3634 ± 3117 | 0.006 |
| Vitamin E intake5 (mg/d) | 13.4 ± 11.3 | 15.4 ± 11.9 | 17.7 ± 14.4 | 22.5 ± 16.2 | <0.001 |
| Fruit intake5 (servings/d) | 2.0 ± 1.9 | 2.0 ± 1.7 | 2.1 ± 1.8 | 2.2 ± 1.9 | 0.13 |
| Vegetable intake5 (servings/d) | 3.6 ± 3.2 | 3.6 ± 2.8 | 3.7 ± 2.7 | 4.3 ± 3.5 | 0.012 |
| Physical activity | 30.6 ± 3.8 | 31.7 ± 5.3 | 31.6 ± 4.5 | 32.1 ± 5.0 | <0.001 |
1
Values were adjusted for age and sex, except where otherwise indicated, by using a general linear model.
2
Mean ± SD (all such values).
3
Adjusted for sex.
4
Adjusted for age.
5
Additionally adjusted for energy intake.