Table 3.
Baseline weekday sleep duration and breast cancer risk among black women, by hormone receptor status
| Breast cancer subtype | Weekday sleep duration, hr | p for trend | ||||
|---|---|---|---|---|---|---|
| <6 | 6 | 7 | 8 | ≥9 | ||
| ER + | ||||||
| No. of cases | 33 | 47 | 34 | 56 | 31 | |
| Multivariate OR (95% CI) a | 1.03 (0.66, 1.59) | 0.98 (0.66, 1.45) | 1.05 (0.68, 1.62) | ref | 1.18 (0.76, 1.85) | 0.63 |
| ER − | ||||||
| No. of cases | 24 | 27 | 24 | 20 | 15 | |
| Multivariate OR (95% CI) a | 2.10 (1.15, 3.83) | 1.65 (0.92, 2.96) | 2.30 (1.26, 4.19) | ref | 1.64 (0.84, 3.23) | 0.10 |
| PR + | ||||||
| No. of cases | 29 | 37 | 24 | 50 | 26 | |
| Multivariate OR (95% CI) a | 0.98 (0.62–1.56) | 0.82 (0.54, 1.26) | 0.80 (0.49, 1.30) | ref | 1.12 (0.69, 1.81) | 0.41 |
| PR − | ||||||
| No. of cases | 27 | 37 | 32 | 26 | 20 | |
| Multivariate OR (95% CI) a | 1.85 (1.08, 3.19) | 1.78 (1.07, 2.95) | 2.36 (1.40, 3.99) | ref | 1.66 (0.92, 2.98) | 0.12 |
| ER+/PR+ | ||||||
| No. of cases | 28 | 35 | 23 | 47 | 23 | |
| Multivariate OR (95% CI) a | 1.02 (0.63, 1.63) | 0.83 (0.53, 1.29) | 0.82 (0.49, 1.36) | ref | 1.06 (0.64, 1.76) | 0.62 |
| ER−/PR− | ||||||
| No. of cases | 23 | 26 | 22 | 19 | 12 | |
| Multivariate OR (95% CI) a | 2.13 (1.15, 3.93) | 1.66 (0.92, 3.02) | 2.22 (1.19, 4.12) | ref | 1.38 (0.67, 2.85) | 0.04 |
a
adjusted for age, enrollment year, enrollment state, race, education, income, marital status, body-mass index, moderate-to-vigorous physical activity, overall sitting, smoking status, pack-year, number of live birth, age at first birth, length of breast feeding, age at menarche, menopause, use of menopausal hormone therapy, use of multivitamin, use of aspirin, history of diabetes, family history of cancer, alcohol consumption, and dietary intakes of total fat, fiber, folate and total calories.