Table II.
Associations between iron intake and prostate cancer risk in 661 nested cases and 1360 controls from CARET cohort, 1985–1996
| Dietary iron (mg/day) | Dietary intake of iron | P for trend | |||
| Continuousa | Tertile | ||||
| First <10.7 | Second 10.7–15.7 | Third ≥15.8 | |||
| Controls, N | 452 | 454 | 454 | ||
| All cases, N | 222 | 205 | 234 | ||
| Age- and race-adjusted OR (95% CI) | 1.0 (0.9–1.2) | 1.0 (reference) | 0.9 (0.7–1.2) | 1.0 (0.8–1.3) | 0.70 |
| Fully adjusted OR (95% CI)b | 1.0 (0.9–1.3) | 1.0 (reference) | 0.9 (0.7–1.2) | 1.1 (0.8–1.4) | 0.54 |
| Non-aggressive cases, N | 122 | 107 | 110 | ||
| Age- and race-adjusted OR (95% CI) | 1.0 (0.8–1.2) | 1.0 (reference) | 0.9 (0.7–1.2) | 0.9 (0.7–1.2) | 0.43 |
| Fully adjusted OR (95% CI)b | 1.0 (0.8–1.3) | 1.0 (reference) | 0.9 (0.6–1.2) | 0.9 (0.6–1.3) | 0.67 |
| Aggressive cases, N | 90 | 90 | 119 | ||
| Age- and race-adjusted OR (95% CI) | 1.1 (0.9–1.3) | 1.0 (reference) | 1.0 (0.7–1.4) | 1.3 (1.0–1.8) | 0.07 |
| Fully adjusted OR (95% CI)b | 1.1 (0.9–1.4) | 1.0 (reference) | 1.0 (0.7–1.5) | 1.4 (0.9–2.0) | 0.07 |
The ORs in overall were estimated by unconditional logistic regression model and the ORs among subgroups of cases according to disease status were tested by polychotomous logistic regression model adjusting for variables described below.
OR per 10 mg/day.
Adjusted for race, random assignment, family history of prostate cancer in first-degree relatives, alcohol consumption (non-drinker, below median, at or above median), smoking status (current versus former or never), smoking pack-year (<40, 40–60, ≥60), age at enrollment (continuous), BMI (<25.0, 25.0–29.9, ≥30.0), total energy intake (continuous, log transformed) and dietary antioxidants (carotenoids and vitamin C, continuous variables, log transformed).