Table 4.
Waist-hip ratio and breast cancer risk in Nigerian women, 1998–2009
| Cases | Controls | Age-adjusted OR (95% CI) | Adjusted OR (95% CI)† | Adjusted OR (95% CI)‡ | |
|---|---|---|---|---|---|
| Total | |||||
| < 0.77 | 211 | 298 | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) |
| 0.77 to <0.81 | 204 | 266 | 0.96 (0.74–1.26) | 0.98 (0.73–1.31) | 1.00 (0.74–1.34) |
| 0.81 to <0.87 | 398 | 303 | 1.54 (1.21–1.97) | 1.70 (1.30–2.22) | 1.77 (1.35–2.31) |
| ≥ 0.87 | 407 | 230 | 1.90 (1.47–2.44) | 2.01 (1.52–2.65) | 2.15 (1.61–2.85) |
| P for trend | <0.001 | <0.001 | <0.001 | ||
| Mean ± SD | 0.843±0.088 | 0.816±0.074 | |||
| Per 0.1 unit | 1.38 (1.23–1.54) | 1.42 (1.25–1.60) | 1.45 (1.28–1.65) | ||
|
| |||||
| Premenopausal | |||||
| < 0.77 | 146 | 246 | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) |
| 0.77 to <0.81 | 130 | 214 | 0.89 (0.65–1.22) | 0.93 (0.66–1.32) | 0.95 (0.67–1.35) |
| 0.81 to <0.87 | 222 | 216 | 1.47 (1.10–1.97) | 1.64 (1.19–2.27) | 1.71 (1.24–2.36) |
| ≥ 0.87 | 204 | 143 | 1.88 (1.38–2.56) | 1.99 (1.41–2.80) | 2.12 (1.49–2.99) |
| P for trend | <0.001 | <0.001 | <0.001 | ||
| Mean ± SD | 0.834±0.086 | 0.809±0.071 | |||
| Per 0.1 unit | 1.36 (1.18–1.56) | 1.40 (1.20–1.65) | 1.44 (1.22–1.69) | ||
|
| |||||
| Postmenopausal | |||||
| < 0.77 | 65 | 52 | 1.0 (ref.) | 1.0 (ref.) | 1.0 (ref.) |
| 0.77 to <0.81 | 74 | 52 | 1.19 (0.71–1.99) | 1.11 (0.64–1.92) | 1.11 (0.64–1.94) |
| 0.81 to <0.87 | 176 | 87 | 1.70 (1.08–2.68) | 1.84 (1.13–2.97) | 1.91 (1.17–3.09) |
| ≥ 0.87 | 203 | 87 | 2.02 (1.28–3.17) | 2.10 (1.30–3.39) | 2.26 (1.39–3.68) |
| P for trend | 0.001 | 0.001 | <0.001 | ||
| Mean ± SD | 0.856±0.088 | 0.835±0.078 | |||
| Per 0.1 unit | 1.40 (1.16–1.69) | 1.43 (1.18–1.74) | 1.47 (1.21–1.80) | ||
|
| |||||
| P for interaction* | 0.95 | 0.96 | 0.98 | ||
Abbreviations: OR, odds ratio; CI, confidence interval; SD, standard deviation
*
Interaction between waist-hip ratio and menopausal status
†
Adjusted for age at diagnosis or interview (categorical), ethnicity, education (categorical), age at menarche (continuous), number of live birth (categorical), age at first live birth (continuous), duration of breastfeeding (categorical), menopausal status, family history of breast cancer, benign breast disease, hormonal contraceptive use, alcohol drinking, and height (continuous).
‡
Adjusted for body mass index (continuous) in addition to the above variables.
Categories of waist-hip ratio are based on quartiles in controls.