Table 1.
Descriptive characteristics at study enrollment among women with EC and cancer-free women in the Women’s Health Initiative, n=93,607
| Characteristic | No Type I,II EC (n=92,217) |
Incident Type I EC (n=1,179) |
Incident Type II EC (n=211) |
|---|---|---|---|
| Age at screening | |||
| <50 years | 31,748 (34%) | 424 (36%) | 74 (35%) |
| 60–69 years | 40,909 (44%) | 533 (45%) | 96 (45%) |
| ≥70 years | 19,560 (21%) | 222 (19%) | 41 (19%) |
| Age at screening, mean (SD) | 63.1 (10.7) | 62.8 (7.0) | 63.0 (11.3) |
| Ethnicity | |||
| White (not of Hispanic origin) | 78,079 (85%) | 1074 (91%) | 179 (85%) |
| Black or African-American | 6360 (7%) | 51 (4%) | 23 (11%) |
| Hispanic/Latino | 3474 (4%) | 17 (1%) | 6 (3%) |
| Asian or Pacific Islander | 2694 (3%) | 14 (1%) | 3 (1%) |
| American Indian or Alaskan Native | 329 (<1%) | 2 (<1%) | 0 (0%) |
| Other | 1027 (1%) | 18 (2%) | 0 (0%) |
| Education | |||
| Less than High school diploma or GED | 4,162 (5%) | 31 (3%) | 7 (3%) |
| High school diploma or GED | 14,590 (16%) | 169 (14%) | 30 (14%) |
| Some college | 32,617 (35%) | 384 (33%) | 72 (34%) |
| College graduate or higher | 40,182 (44%) | 591 (50%) | 101 (48%) |
| Smoking status | |||
| Never smoked | 45,870 (50%) | 631 (54%) | 105 (50%) |
| Past smoker | 38,785 (42%) | 484 (41%) | 90 (43%) |
| Current smoker | 6,367 (7%) | 53 (4%) | 12 (6%) |
| BMI | |||
| <25 kg/m2 | 34,877 (38%) | 373 (32%) | 69 (33%) |
| 25–29 kg/m2 | 31,327 (34%) | 317 (27%) | 63 (30%) |
| ≥30 kg/m2 | 25,161 (27%) | 479 (41%) | 77 (36%) |
| BMI, mean (SD) | 27.5 (5.8) | 29.5 (7.2) | 29.1 (6.5) |
| Age at menarche | |||
| ≤11 years | 19,101 (21%) | 285 (24%) | 42 (20%) |
| 12–13 years | 50,835 (55%) | 687 (58%) | 133 (63%) |
| ≥14 years | 21,914 (24%) | 204 (17%) | 36 (17%) |
| Parity | |||
| Nulliparous | 11,961 (13%) | 187 (16%) | 20 (9%) |
| 1–2 | 31909 (35%) | 422 (36%) | 75 (36%) |
| ≥3 | 47756 (52%) | 566 (48%) | 114 (54%) |
| Hormone use | |||
| Never | 50708 (55%) | 533 (45%) | 111 (53%) |
| Past user | 13064 (14%) | 163 (14%) | 28 (13%) |
| Current user <5 years | 11483 (12%) | 130 (11%) | 22 (10%) |
| Current user 5 to <10 years | 8449 (9%) | 135 (11%) | 22 (10%) |
| Current user ≥10 years | 8454 (9%) | 216 (18%) | 28 (13%) |
| Type of hormone use | |||
| Never used E alone or E+P | 50708 (55%) | 533 (45%) | 111 (53%) |
| Past user of either E alone or E+P | 13064 (14%) | 163 (14%) | 28 (13%) |
| E alone | 1994 (2%) | 58 (5%) | 6 (3%) |
| E+P | 26392 (29%) | 423 (36%) | 66 (31%) |
| Oral contraceptive use | |||
| No | 53132 (58%) | 705 (60%) | 121 (57%) |
| Yes | 39085 (42%) | 474 (40%) | 90 (43%) |
| Diabetes status | |||
| No | 87524 (95%) | 1119 (95%) | 197 (93%) |
| Yes | 4632 (5%) | 60 (5%) | 14 (7%) |
| Use of anti-diabetic drugs | |||
| No | 88732 (96%) | 1134 (96%) | 201 (95%) |
| Yes | 3410 (4%) | 45 (4%) | 10 (5%) |
| Energy expenditure | |||
| None | 12866 (14%) | 157 (13%) | 26 (12%) |
| >0 – 3.75 MET-hours/week | 12240 (13%) | 152 (13%) | 28 (13%) |
| 3.75–8.75 MET-hours/week | 17863 (19%) | 220 (19%) | 40 (19%) |
| 8.75–17.5 MET-hours/week | 20336 (22%) | 275 (23%) | 48 (23%) |
| ≥17.5 MET-hours/week | 24694 (27%) | 318 (27%) | 58 (27%) |
| HEI-2005 Score, quartiles | |||
| 20.7 – 60.3 | 2521 (3%) | 13 (1%) | 6 (3%) |
| 60.3 – 68.9 | 22400 (24%) | 313 (27%) | 53 (25%) |
| 58.9 – 75.8 | 22444 (24%) | 283 (24%) | 40 (19%) |
| 86.9 – 93. 4 | 22417 (24%) | 295 (25%) | 55 (26%) |
| Hypertension history | |||
| Never hypertensive | 61219 (66%) | 755 (64%) | 138 (65%) |
| Currently untreated hypertensive | 6664 (7%) | 83 (7%) | 14 (7%) |
| Currently treated hypertensive | 19512 (21%) | 272 (23%) | 48 (23%) |
| WHI trial membership | |||
| WHI-OS | 53373 (58%) | 677 (57%) | 125 (59%) |
| E+P | 11811 (13%) | 92 (8%) | 16 (8%) |
| DM | 22456 (24%) | 360 (31%) | 60 (28%) |
| E+P and DM | 4577 (5%) | 50 (4%) | 10 (5%) |
| History of CVD | |||
| No | 73346 (80%) | 949 (80%) | 177 (84%) |
| Yes | 13695 (15%) | 165 (14%) | 24 (11%) |
| History of cancer (non-endometrial) | |||
| No | 85448 (93%) | 2159 (92%) | 392 (93%) |
| Yes | 6022 (7%) | 182 (8%) | 26 (6%) |
WHI-OS: WHI Observational study; E+P: Estrogen plus progestin; DM: Dietary modification; GED: General Educational Development; HEI: Healthy Eating Index; MET: metabolic equivalent of task