Risk of breast cancer according to quintile of BMI (based on the distribution of BMI in controls)
| Quintile of BMI | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤21.79 | (21.79-23.30) | (23.30-25.02) | (25.02-27.64) | >27.64 | No. | P* | ||||||||
| All subjects | ||||||||||||||
| Cases | 245 | 218 | 208 | 212 | 231 | 1,114 | ||||||||
| Controls | 232 | 217 | 220 | 224 | 221 | 1,114 | ||||||||
| OR† (95% CI), not adjusted for density | 1 | 0.93 (0.7-1.2) | 0.89 (0.7-1.2) | 0.91 (0.7-1.2) | 1.04 (0.8-1.4) | 0.86 | ||||||||
| OR‡ (95% CI), adjusted for density | 1 | 1.07 (0.8-1.4) | 1.12 (0.8-1.5) | 1.21 (0.9-1.6) | 1.60 (1.2-2.2) | 0.002 | ||||||||
| Premenopausal | ||||||||||||||
| Cases | 86 | 54 | 49 | 42 | 51 | 282 | ||||||||
| Controls | 64 | 59 | 46 | 46 | 52 | 267 | ||||||||
| OR† (95% CI), not adjusted for density | 1 | 0.69 (0.4-1.1) | 0.79 (0.5-1.3) | 0.68 (0.4-1.2) | 0.76 (0.5-1.3) | 0.37 | ||||||||
| OR‡ (95% CI), adjusted for density | 1 | 0.88 (0.5-1.5) | 1.13 (0.6-2.0) | 1.06 (0.6-1.9) | 1.47 (0.8-2.7) | 0.18 | ||||||||
| Postmenopausal | ||||||||||||||
| Cases | 159 | 164 | 159 | 170 | 180 | 832 | ||||||||
| Controls | 168 | 158 | 174 | 178 | 169 | 847 | ||||||||
| OR† (95% CI), not adjusted for density | 1 | 1.05 (0.8-1.4) | 0.95 (0.7-1.3) | 1.02 (0.8-1.4) | 1.17 (0.9-1.6) | 0.43 | ||||||||
| OR‡ (95% CI), adjusted for density | 1 | 1.16 (0.8-1.6) | 1.13 (0.8-1.6) | 1.28 (0.9-1.8) | 1.67 (1.2-2.3) | 0.004 | ||||||||
NOTE: Unmatched logistic regression, adjusted for age, age at menarche, age at first birth, parity, number of live births, menopausal status, age at menopause, hormone replacement therapy (ever/never), breast cancer in first-degree relatives (0, 1, 2+), study (NBSS, OBSP, and SMPBC), and observation time (≤2, 2-4, and >4 years), not adjusted for percentage of mammographic density. Menopausal status was omitted from the analysis for the separate menopausal groups, and age at menopause from the analysis of the premenopausal group.
↵* P value for testing the linear trend.
↵† Adjusted only above factors.
↵‡ Adjusted with above factors and percent mammographic density.