TABLE 2.
Baseline sociodemographic characteristics and lifestyle factors by dietary soy isoflavone intake by country: After Breast Cancer Pooling Project (n = 9514)1
| Quintile of soy isoflavone intake (mg/d) | ||||||||||
| China | United States | |||||||||
| Q1 | Q2 | Q3 | Q4 | Q5 | Q1 | Q2 | Q3 | Q4 | Q5 | |
| Age (y) | 54.5 ± 10.42 | 53.5 ± 10.0 | 53.6 ± 10.2 | 52.8 ± 9.6 | 52.8 ± 9.73 | 54.9 ± 10.7 | 55.6 ± 10.7 | 55.0 ± 10.5 | 53.4 ± 10.2 | 52.7 ± 9.64 |
| Education (%) | ||||||||||
| <High school | 49.8 | 47.0 | 45.9 | 45.6 | 44.2 | 4.3 | 2.7 | 2.9 | 1.4 | 1.0 |
| High school | 34.7 | 37.9 | 38.4 | 36.7 | 40.7 | 26.6 | 20.1 | 18.1 | 11.5 | 11.3 |
| Some college/technical school | 9.6 | 8.5 | 8.4 | 9.7 | 8.2 | 37.2 | 36.4 | 34.9 | 31.3 | 26.1 |
| ≥College graduate | 5.9 | 6.6 | 7.2 | 8.0 | 6.9 | 31.9 | 40.8 | 44.1 | 55.8 | 61.74 |
| Menopausal status (%) | ||||||||||
| Postmenopausal | 54.2 | 51.2 | 51.0 | 49.8 | 49.3 | 57.9 | 62.1 | 57.6 | 50.1 | 46.74 |
| BMI (%) | ||||||||||
| <18.5 kg/m2 | 3.9 | 3.4 | 2.1 | 3.2 | 2.0 | 0.4 | 0.8 | 1.0 | 0.9 | 2.1 |
| 18.5–24.99 kg/m2 | 63.1 | 64.5 | 62.8 | 62.8 | 56.1 | 35.2 | 37.2 | 38.6 | 42.3 | 49.8 |
| 25.0–29.99 kg/m2 | 27.4 | 28.0 | 29.4 | 28.7 | 34.4 | 31.9 | 31.7 | 33.1 | 32.9 | 30.5 |
| ≥30 kg/m2 | 5.6 | 4.1 | 5.8 | 5.4 | 7.54 | 32.5 | 30.4 | 27.4 | 23.9 | 17.74 |
| Physical activity (MET-h/wk) | 5.8 ± 9.4 | 6.0 ± 8.4 | 7.9 ± 10.8 | 7.8 ± 9.7 | 9.8 ± 12.54 | 11.0 ± 14.0 | 12.2 ± 16.4 | 14.1 ± 16.8 | 16.9 ± 17.2 | 19.1 ± 18.14 |
| Cruciferous vegetable intake (g/d) | 50.9 ± 36.1 | 55.5 ± 37.0 | 60.1 ± 35.7 | 66.6 ± 44.1 | 78.6 ± 51.34 | 23.8 ± 29.7 | 29.6 ± 35.0 | 32.6 ± 33.5 | 39.4 ± 43.5 | 51.9 ± 56.54 |
| Smoking status (%) | ||||||||||
| Never | 97.8 | 97.5 | 97.6 | 96.8 | 97.2 | 51.7 | 54.6 | 52.2 | 53.9 | 55.9 |
| Past | 1.7 | 1.7 | 1.8 | 2.6 | 2.1 | 39.3 | 38.9 | 41.4 | 42.6 | 41.4 |
| Current | 0.5 | 0.8 | 0.6 | 0.6 | 0.7 | 9.1 | 6.6 | 6.4 | 3.5 | 2.74 |
1
The table excludes missing data by characteristic. P values were derived by using a chi-square test for categorical variables and by using the Kruskal-Wallis test for continuous variables. MET-h, metabolic equivalent task hours; Q, quintile.
2
Mean ± SD (all such values).
3
P < 0.05.
4
P < 0.01.