Table 1.
Characteristics of Women in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial According to Energy-adjusted Quartile of Glycemic Load, United States, 1993–2001
| Characteristic | Energy-adjusted Quartile of Glycemic Loada |
|||||||
|---|---|---|---|---|---|---|---|---|
| Quartile 1 (n = 9,029) |
Quartile 2 (n = 9,029) |
Quartile 3 (n = 9,029) |
Quartile 4 (n = 9,028) |
|||||
| No. | %b | No. | % | No. | % | No. | % | |
| Median age at DHQ completion, years | 64 | 65 | 65 | 66 | ||||
| Race/ethnicity | ||||||||
| Non-Hispanic white | 8,545 | 94.6 | 8,537 | 94.6 | 8,354 | 92.5 | 7,746 | 85.8 |
| Non-Hispanic black | 183 | 2.0 | 182 | 2.0 | 245 | 2.7 | 477 | 5.3 |
| Asian | 145 | 1.6 | 195 | 2.2 | 296 | 3.3 | 672 | 7.4 |
| Other | 156 | 1.7 | 115 | 1.3 | 134 | 1.5 | 133 | 1.5 |
| Body mass indexc | ||||||||
| <18.5 | 85 | 0.9 | 97 | 1.1 | 92 | 1.0 | 126 | 1.4 |
| 18.5–<25 | 3,726 | 41.3 | 3,690 | 40.9 | 3,730 | 41.3 | 4,265 | 47.2 |
| 25–<30 | 3,046 | 33.7 | 3,149 | 34.9 | 3,194 | 35.4 | 2,965 | 32.8 |
| ≥30 | 2,172 | 24.1 | 2,093 | 23.2 | 2,013 | 22.3 | 1,672 | 18.5 |
| Education | ||||||||
| Less than high school | 337 | 3.7 | 335 | 3.7 | 374 | 4.1 | 478 | 5.3 |
| High school/12 years | 3,249 | 36.0 | 3,121 | 34.6 | 3,155 | 34.9 | 3,104 | 34.4 |
| Some college/post-high school | 2,185 | 24.2 | 2,376 | 26.3 | 2,442 | 27.1 | 2,597 | 28.8 |
| College/postgraduate | 3,258 | 36.1 | 3,197 | 35.4 | 3,058 | 33.9 | 2,849 | 31.6 |
| Smoking status | ||||||||
| Never smoker | 3,944 | 43.7 | 5,027 | 55.7 | 5,408 | 59.9 | 5,729 | 63.5 |
| Former smoker | 3,870 | 42.9 | 3,247 | 36.0 | 2,995 | 33.2 | 2,663 | 29.5 |
| Current smoker | 1,215 | 13.5 | 755 | 8.4 | 626 | 6.9 | 636 | 7.0 |
| History of diabetes | ||||||||
| No | 8,581 | 95.0 | 8,574 | 95.0 | 8,621 | 95.5 | 8,623 | 95.5 |
| Yes | 448 | 5.0 | 455 | 5.0 | 408 | 4.5 | 405 | 4.5 |
| Age at menarche, years | ||||||||
| <12 | 1,768 | 19.6 | 1,642 | 18.2 | 1,709 | 18.9 | 1,642 | 18.2 |
| 12–13 | 4,926 | 54.6 | 5,085 | 56.3 | 4,972 | 55.1 | 4,878 | 54.0 |
| ≥14 | 2,335 | 25.9 | 2,302 | 25.5 | 2,348 | 26.0 | 2,508 | 27.8 |
| Age at menopause, years | ||||||||
| <50 | 3,039 | 33.7 | 2,939 | 32.6 | 3,016 | 33.4 | 3,106 | 34.4 |
| ≥50 | 5,990 | 66.3 | 6,090 | 67.5 | 6,013 | 66.6 | 5,922 | 65.6 |
| Median no. of livebirths | 3 | 3 | 3 | 3 | ||||
| Use of oral contraceptives | ||||||||
| Never use | 3,469 | 38.4 | 3,981 | 44.1 | 4,369 | 48.4 | 4,616 | 51.1 |
| Ever use | 5,560 | 61.6 | 5,048 | 55.9 | 4,660 | 51.6 | 4,412 | 48.9 |
| Use of hormone replacement therapy | ||||||||
| Never use | 3,303 | 36.6 | 3,515 | 38.9 | 3,651 | 40.4 | 3,823 | 42.4 |
| Former use | 4,182 | 46.3 | 4,013 | 44.5 | 3,793 | 42.0 | 3,641 | 40.3 |
| Current use | 1,544 | 17.1 | 1,501 | 16.6 | 1,585 | 17.6 | 1,564 | 17.3 |
| Vigorous physical activity, hours/week | ||||||||
| <1 | 1,487 | 16.5 | 1,282 | 14.2 | 1,200 | 13.3 | 1,193 | 13.2 |
| 1–4 | 1,932 | 21.4 | 1,985 | 22.0 | 1,933 | 21.4 | 1,766 | 19.6 |
| >4 | 844 | 9.4 | 873 | 9.7 | 906 | 10.0 | 924 | 10.2 |
| Unknown | 4,766 | 52.8 | 4,889 | 54.2 | 4,990 | 55.3 | 5,145 | 57.0 |
Abbreviation: DHQ, Diet History Questionnaire.
a Cutpoints for energy-adjusted quartiles of glycemic load were as follows: quartile 1, <57.8 units/1,000 kcal/day; quartile 2, 57.8–<65.2 units/1,000 kcal/day; quartile 3, 65.2–<72.6 units/1,000 kcal/day; quartile 4, ≥72.6 units/1,000 kcal/day.
b Percentages may not total 100 because of rounding.
c Weight (kg)/height (m)2.