TABLE 1.
Baseline characteristics of 1423 white postmenopausal women in the Women's Health Initiative Observational Study1
| Characteristics | n | Value |
|---|---|---|
| Age, y | 1423 | 67.1 ± 6.77 |
| BMI, kg/m2 | 1423 | 27.3 ± 5.72 |
| Physical activity, total METs per week | 1423 | 13.0 ± 13.0 |
| Residence location (US region) | ||
| Northeast | 359 | 25.2 |
| South | 309 | 21.7 |
| Midwest | 350 | 24.6 |
| West | 405 | 28.5 |
| History of colonoscopy or sigmoidoscopy | ||
| No | 593 | 41.7 |
| Yes | 830 | 58.3 |
| Polyps of colon/rectum ever removed | ||
| No | 630 | 44.3 |
| Yes | 177 | 12.4 |
| Unknown | 616 | 43.3 |
| Family history of colorectal cancer | ||
| No | 1053 | 74.0 |
| Yes | 260 | 18.3 |
| Unknown | 110 | 7.73 |
| Use of postmenopausal hormones | ||
| Never user | 632 | 44.4 |
| Past user | 250 | 17.6 |
| Current user | 541 | 38.0 |
| Smoking status | ||
| Never smoker | 695 | 48.8 |
| Past smoker | 642 | 45.1 |
| Current smoker | 86 | 6.04 |
| Biomarker | ||
| Choline, μmol/L | 1423 | 9.40 (9.28, 9.52) |
| Betaine, μmol/L | 1423 | 26.6 (26.0, 27.2) |
| Dimethylglycine, μmol/L | 1423 | 2.47 (2.42, 2.52) |
| Trimethylamine N-oxide, μmol/L | 1423 | 5.84 (5.39, 6.29) |
| Vitamin B-12, pg/mL | 1423 | 536.0 (521.8, 550.1) |
| Vitamin B-6, nmol/L | 1423 | 103.3 (98.1, 108.6) |
| RBC folate, ng/mL | 1423 | 625.2 (611.6, 638.8) |
| Plasma folate, ng/mL | 1423 | 20.7 (19.9, 21.5) |
1
Values are means ± SDs for continuous variables, percentages for categorical variables, or means (95% CIs) for plasma choline metabolites and B-vitamin concentrations. Because of rounding, not all percentages add up to 100. MET, metabolic equivalent.