Table 2.
Multivariate Odds Ratio of Breast Cancer Associated with Specific Gravity-adjusted Urinary Lead
| Cases | Controls | Odds | Odds | |||||
|---|---|---|---|---|---|---|---|---|
| Lead concentration levels‡ | N | (%) | N | (%) | Ratio* | 95% CI* | Ratio† | 95% CI† |
| All participants | ||||||||
| 1 | 48 | 20% | 64 | 25% | 1.00 | 1.00 | ||
| 2 | 43 | 17% | 63 | 25% | 0.91 | 0.5-1.6 | 0.90 | 0.5-1.7 |
| 3 | 68 | 28% | 64 | 25% | 1.46 | 0.9-2.5 | 1.73 | 1.0-3.2 |
| 4 | 87 | 35% | 63 | 25% | 1.93 | 1.1-3.3 | 1.91 | 1.0-3.5 |
| continuous | 1.36 | 1.1-1.6 | 1.34 | 1.1-1.7 | ||||
| p-value | 0.001 | 0.006 | ||||||
| Excluding users of non-steroidal aromatase inhibitors not taking bisphosphonates | ||||||||
| 1 | 46 | 24% | 63 | 25% | 1.00 | 1.00 | ||
| 2 | 37 | 19% | 64 | 25% | 0.83 | 0.5-1.5 | 0.82 | 0.4-1.6 |
| 3 | 63 | 32% | 64 | 25% | 1.48 | 0.9-2.5 | 1.75 | 0.9-3.2 |
| 4 | 48 | 25% | 63 | 25% | 1.17 | 0.7-2.0 | 1.01 | 0.5-2.0 |
| continuous | 1.12 | 0.9-1.3 | 1.10 | 0.9-1.3 | ||||
| p-value | 0.20 | 0.31 | ||||||
*
Adjusted for age.
†
Adjusted for age, parity, age at first birth, family history of breast cancer, recent alcohol consumption, body mass index, age at menarche, menopausal status, age at menopause, type of postmenopausal hormone use, education, marital status and physical activity.
‡
Lead concentration levels (in μg/L): 1 = < 0.42; 2 = 0.42-0.64; 3 = 0.0.65-1.10; 4 = ≥1.10.