Table 2.
Selected participant characteristics at baseline across quintiles of the mineral scorea; Iowa Women’s Health Study, 1986–2012
| Characteristicsb | Mineral score quintiles | ||||
|---|---|---|---|---|---|
| 1 (< 15) median = 12 (N = 5,369) | 2 (15 – 16) median = 15 (N = 6,464) | 3 (17 – 18) median = 17 (N = 7,637) | 4 (19 – 20) median = 18 (N = 7,287) | 5 (21 – 30) median = 21 (N = 8,464) | |
| Age (years) | 61.7 (4.3) | 61.5 (4.1) | 61.5 (4.2) | 61.5 (4.2) | 61.5 (4.2) |
| Education < college graduate (%) | 13.5 | 16.3 | 18.8 | 18.9 | 19.7 |
| Family history of colorectal cancerc (%) | 2.5 | 3.3 | 3.0 | 3.4 | 3.1 |
| Diabetes at baseline (%) | 0.8 | 1.1 | 1.2 | 1.3 | 1.5 |
| Hormone replacement therapy (%) | |||||
| Never | 67.8 | 64.6 | 61.3 | 59.6 | 56.1 |
| Former | 8.5 | 9.7 | 11.1 | 12.1 | 14.3 |
| Current | 23.7 | 25.7 | 27.6 | 28.3 | 29.7 |
| Height (cm) | 159.9 (6.4) | 160.1 (6.2) | 160.2 (6.2) | 160.5 (6.2) | 160.7 (6.19) |
| Body mass index category (%) | |||||
| < 25 kg/m2 | 36.9 | 39.5 | 41.4 | 42.7 | 48 |
| 25 – 30 kg/m2 | 37.5 | 36.8 | 36.9 | 37.8 | 36.3 |
| ≥ 30 kg/m2 | 25.6 | 23.6 | 21.7 | 19.5 | 15.7 |
| Waist-hip ratio | 0.852 (0.092) | 0.844 (0.084) | 0.841 (0.081) | 0.834 (0.082) | 0.833 (0.093) |
| Physical activity (%) | |||||
| Low | 57.5 | 54.9 | 48.9 | 43.7 | 37.7 |
| Medium | 25.3 | 26.1 | 27.7 | 28.4 | 29.0 |
| High | 17.3 | 19.0 | 23.4 | 27.9 | 33.4 |
| Smoking status (%) | |||||
| Never | 68.2 | 63.1 | 67.0 | 65.1 | 61.8 |
| Former | 15.4 | 16.5 | 18.0 | 20.8 | 24.4 |
| Current | 16.4 | 16.2 | 15.1 | 14.1 | 13.8 |
| Alcohol intake (%) | |||||
| None | 59.6 | 56.3 | 54.7 | 54.5 | 51.8 |
| > 0 – < 15 g/day | 34.2 | 36.3 | 38.6 | 39.5 | 41.9 |
| ≥ 15 g/day | 6.2 | 7.4 | 6.7 | 6.0 | 6.4 |
| Total energy intake (kcal/day) | 2,093 (938) | 1,968 (735) | 1,859 (697) | 1,728 (650) | 1,546 (503) |
| Total fat intake (% kcal/day) | 50.6 (19.2) | 59.1 (21.3) | 65.3 (23.1) | 74.5 (27.5) | 86.0 (43.2) |
| Dietary fiber intake (g/1,000 kcal/day) | 5.0 (2.6) | 5.1 (2.5) | 5.5 (2.8) | 5.7 (3.4) | 5.6 (2.6) |
| Take multivitamin (%) | 9.3 (8.3) | 11.4 (9.9) | 35.6 (14.2) | 41.3 (12.5) | 52.4 (17.3) |
| Take calcium supplement (%) | 30.3 (25.1) | 36.2 (23.7) | 37.9 (27.2) | 35.4 (12.9) | 34.3 (10.7) |
| Total fruits & vegetables intake (servings/wk.) | 39.1 (22.3) | 41.1 (21.1) | 44.8 (25.7) | 47.7 (32.5) | 47.5 (24. 6) |
| Total red & processed meats intake (servings/wk.) | 8.7 (7.2) | 8.1 (5.3) | 7.1 (5.0) | 6.0 (4.1) | 4.8 (3.1) |
| Dietary OBSd | −0.78 (0.20) | −0.73 (0.11) | −0.69 (0.13) | −0.67 (0.22) | −0.58 (0.11) |
a
Mineral score calculated from food and supplemental intakes of calcium, magnesium, manganese, zinc, selenium, potassium, iodine, iron, copper, phosphorus, and sodium as described in the text.
b
All variables measured at baseline (1986) and are presented as mean (SD) except as otherwise specified.
c
In a first degree relative.
d
Oxidative balance score; a composite of 11 anti- and pro-oxidant dietary exposures (see text); a higher score represents higher anti-oxidant relative to pro-oxidant dietary exposures; study population range: −0.97 to −0.48.