Table 1.
Baseline Characteristics by Level of Sedentary Time in the Black Women’s Health Study
| Time Spent Sitting | ||||
|---|---|---|---|---|
|
| ||||
| <5 hours/day N (%) |
5–9 hours/day N (%) |
≥10 hours/day N (%) |
P-valuea | |
| Cohort | 10,924 (23.4) | 32,098 (68.7) | 3,712 (7.9) | --- |
| Age (years) | <0.001 | |||
| <30 | 2,187 (20.8) | 7,384 (70.2) | 942 (9.0) | |
| 30–39 | 3,364 (21.1) | 11,301 (70.8) | 1,299 (8.1) | |
| 40–49 | 2,981 (22.7) | 9,104 (69.4) | 1,028 (7.8) | |
| 50–59 | 1,544 (29.0) | 3,431 (64.4) | 353 (6.6) | |
| ≥60 | 848 (46.7) | 878 (48.3) | 90 (5.0) | |
| Education (years) | <0.001 | |||
| ≤12 | 2,303 (28.6) | 4,897 (60.8) | 859 (10.7) | |
| 13–15 | 3,529 (20.9) | 11,768 (69.8) | 1,565 (9.3) | |
| ≥16 | 5,071 (23.3) | 15,387 (70.8) | 1,276 (5.9) | |
| Current BMI (kg/m2) | <0.001 | |||
| <25 | 4,248 (23.7) | 12,492 (69.8) | 1,167 (6.5) | |
| 25–29 | 3,502 (24.0) | 9,879 (67.8) | 1,184 (8.1) | |
| 30–34 | 1,814 (24.9) | 5,139 (67.7) | 644 (8.5) | |
| ≥35 | 1,261 (20.2) | 4,308 (69.0) | 678 (10.9) | |
| BMI at 18 years (kg/m2) | <0.001 | |||
| <20 | 4,533 (24.2) | 12,795 (68.4) | 1,388 (7.4) | |
| 20–24 | 4,817 (23.1) | 14,419 (69.2) | 1,596 (7.7) | |
| 25–29 | 1,043 (23.2) | 3,170 (67.9) | 453 (9.7) | |
| ≥30 | 393 (20.2) | 1,334 (68.7) | 216 (11.1) | |
| Adult weight gain (kg) | <0.001 | |||
| <10 | 3,691 (24.0) | 10,624 (69.2) | 1,048 (6.8) | |
| 10–19 | 3,155 (23.0) | 9,518 (69.5) | 1,030 (7.5) | |
| 20–25 | 1,398 (23.2) | 4,082 (67.7) | 547 (9.1) | |
| ≥25 | 2,538 (22.9) | 7,490 (67.7) | 1,034 (9.4) | |
| Waist-Hip Ratio | <0.001 | |||
| <0.70 | 1,074 (23.5) | 3,206 (70.0) | 298 (6.5) | |
| 0.70–0.77 | 2,875 (23.8) | 8,401 (69.6) | 799 (6.6) | |
| 0.78–0.85 | 2,164 (22.8) | 6,579 (69.4) | 738 (7.8) | |
| ≥0.86 | 1,667 (24.5) | 4,416 (64.9) | 719 (10.6) | |
| Waist Circumference (cm) | <0.001 | |||
| <71 | 2,446 (23.7) | 7,197 (69.9) | 660 (6.4) | |
| 72–79 | 1,659 (23.8) | 4,843 (69.5) | 471 (6.8) | |
| 80–87 | 1,799 (24.0) | 5,092 (67.8) | 619 (8.2) | |
| ≥88 | 2,081 (22.9) | 6,096 (67.2) | 897 (9.9) | |
| Physical Activityb | <0.001 | |||
| Low | 4,188 (23.2) | 12,296 (68.1) | 1,564 (8.7) | |
| Moderate | 2,704 (23.6) | 8,023 (69.9) | 747 (6.5) | |
| High | 3,469 (22.8) | 10,524 (69.1) | 1,249 (8.2) | |
| Caloric intake (kcal) | <0.001 | |||
| Quartile 1 | 2,778 (23.7) | 8,189 (69.8) | 763 (6.5) | |
| Quartile 2 | 2,804 (24.0) | 8,057 (69.0) | 815 (7.0) | |
| Quartile 3 | 2,692 (23.1) | 8,056 (69.0) | 931 (8.0) | |
| Quartile 4 | 2,650 (22.8) | 7,796 (66.9) | 1,202 (10.3) | |
| Age at menarche | <0.001 | |||
| ≤11 years | 3,011 (22.5) | 9,330 (69.7) | 1,048 (7.8) | |
| 12–13 years | 6,787 (23.4) | 19,906 (68.7) | 2,284 (7.9) | |
| ≥14 years | 1,079 (25.8) | 2,748 (65.5) | 360 (8.6) | |
| Parity | <0.001 | |||
| Nulliparous | 3,175 (19.0) | 12,010 (71.9) | 1,523 (9.1) | |
| 1–2 children | 5,008 (23.9) | 14,399 (68.7) | 1,554 (7.4) | |
| ≥3 children | 2,688 (30.4) | 5,534 (62.6) | 618 (7.0) | |
| Family History | 0.80 | |||
| Yes | 835 (23.8) | 2,397 (68.4) | 274 (7.8) | |
| No | 10,089 (23.3) | 29,701 (68.7) | 3,438 (8.0) | |
| Mammogram | <0.001 | |||
| Yes | 6,544 (24.9) | 17,805 (67.6) | 1,986 (7.5) | |
| No | 4,245 (21.3) | 13,973 (70.2) | 1,685 (8.5) | |
Abbreviations: BMI, body mass index; cm, centimeters; kcal, kilocalories; kg, kilograms; m, meters.
a
Wald chi-square test
b
Low=<1 hour vigorous activity per week and/or <2 hours walking for exercise per week; Moderate=1–<3 hours vigorous activity per week and/or 2–<5 hours walking for exercise per week; High=≥3 hours vigorous activity per week and/or ≥5 hours walking for exercise per week.