Table 1.
Age-standardised characteristics according to quintiles of gluten intake at the midpoint of follow-up (NHS1998, NHSII 1999, HPFS1998)
| Characteristic | NHS |
NHSII |
HPFS |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Q1 | Q3 | Q5 | Q1 | Q3 | Q5 | Q1 | Q3 | Q5 | |
| n | 12083 | 12090 | 12088 | 16630 | 16633 | 16608 | 7177 | 7181 | 7180 |
| Gluten, g/day | 3.37 | 5.08 | 7.16 | 3.90 | 6.29 | 9.27 | 3.97 | 6.48 | 9.71 |
| Age, years | 64.4 | 63.3 | 63.4 | 46.7 | 46.1 | 46.0 | 67.1 | 65.4 | 64.8 |
| White, % | 95 | 98 | 99 | 91 | 97 | 98 | 91 | 96 | 97 |
| Current smoking, % | 15 | 9 | 7 | 13 | 8 | 6 | 6 | 4 | 3 |
| Alcohol intake, g/day | 7.01 | 5.12 | 3.77 | 3.61 | 4.05 | 3.79 | 12.0 | 11.5 | 8.9 |
| Physical activity, METs | 17.6 | 17.6 | 17.7 | 19.1 | 20.5 | 22.3 | 32.2 | 32.9 | 34.6 |
| BMI, kg/m2 | 26.5 | 26.6 | 25.9 | 27.6 | 26.6 | 25.7 | 26.6 | 26.2 | 25.4 |
| Family history of diabetes, % | 23 | 24 | 25 | 17 | 15 | 15 | 16 | 19 | 18 |
| Multivitamin use, % | 52 | 56 | 59 | 44 | 49 | 51 | 45 | 54 | 57 |
| Any use of postmenopausal hormone, % | 65 | 67 | 66 | 26 | 24 | 23 | |||
| Current use of oral contraceptive, % | 7 | 8 | 8 | ||||||
| Total energy, kJ | 7296 | 7464 | 6970 | 7464 | 7665 | 7267 | 8267 | 8455 | 7949 |
| AHEI | 46.0 | 45.8 | 47.2 | 43.2 | 44.6 | 47.2 | 46.8 | 47.0 | 50.2 |
| Trans fat, % energy | 1.54 | 1.64 | 1.63 | 1.59 | 1.61 | 1.51 | 1.36 | 1.45 | 1.34 |
| P/S ratio | 0.54 | 0.57 | 0.61 | 0.49 | 0.52 | 0.58 | 0.56 | 0.59 | 0.67 |
| Fruits, servings/day | 2.42 | 2.38 | 2.12 | 1.18 | 1.23 | 1.18 | 2.48 | 2.48 | 2.44 |
| Vegetables, servings/day | 3.37 | 3.24 | 2.92 | 3.31 | 3.28 | 3.09 | 3.30 | 3.24 | 3.11 |
| Red meat, servings/day | 0.96 | 0.88 | 0.70 | 0.90 | 0.79 | 0.55 | 1.26 | 1.10 | 0.74 |
| Folic acid, μg/day | 443 | 449 | 471 | 464 | 497 | 533 | 502 | 522 | 578 |
| Magnesium, mg/day | 305 | 309 | 321 | 313 | 325 | 341 | 359 | 368 | 396 |
| Carbohydrate, % energy | 47.6 | 50.0 | 52.9 | 48.6 | 50.3 | 53.9 | 45.6 | 48.8 | 53.4 |
| Glycaemic index | 51.7 | 52.8 | 53.9 | 53.1 | 53.6 | 54.6 | 52.1 | 53.1 | 54.3 |
| Glycaemic load | 98.3 | 105.1 | 113.8 | 117.1 | 121.6 | 132.9 | 118.9 | 129.5 | 144.7 |
| Cereal fibre, g/day | 3.42 | 4.98 | 7.07 | 3.89 | 5.82 | 8.48 | 4.16 | 6.42 | 9.81 |
| Bran, g/day | 3.69 | 5.20 | 7.59 | 4.13 | 5.72 | 8.18 | 4.64 | 7.06 | 10.81 |
| Starch, g/day | 53.8 | 65.9 | 78.7 | 65.5 | 82.1 | 101.9 | 65.0 | 80.4 | 98.5 |
| Germ, g/day | 0.68 | 0.82 | 1.10 | 0.91 | 1.11 | 1.33 | 0.936 | 1.17 | 1.77 |
Values are means or number (percentages) and are standardised to the age distribution of the study population