Table 2.
Adjusteda OR for the association between dietary vitamin C and risk of prostate cancer, for all cancers and by disease aggressiveness.
| Tertiles of intake, mg/dayb | Controls |
All cases |
Non-aggressive casesc |
Aggressive casesc |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | N | OR | 95%CI | n | OR | 95% CI | n | OR | 95%CI | |
| Model 1 – Dietary intakes expressed as absolute amounts | ||||||||||
| T1: ≤107.7 | 656 | 613 | (ref.) | 471 | (ref.) | 141 | (ref.) | |||
| T2: >107.7–167.6 | 655 | 611 | 0.93 | 0.78, 1.11 | 471 | 0.93 | 0.77, 1.13 | 139 | 0.95 | 0.71, 1.26 |
| T3: >167.6 | 674 | 692 | 0.95 | 0.77, 1.18 | 541 | 0.98 | 0.79, 1.23 | 150 | 0.89 | 0.64, 1.24 |
| Model 2 – Dietary intakes calculated using the residual method | ||||||||||
| T1: ≤109.8 | 655 | 638 | (ref.) | 491 | (ref.) | 146 | (ref.) | |||
| T2: >109.8–164.9 | 656 | 609 | 0.96 | 0.80, 1.14 | 465 | 0.94 | 0.78, 1.14 | 143 | 1.00 | 0.76, 1.33 |
| T3: >164.9 | 674 | 669 | 0.97 | 0.79, 1.19 | 527 | 0.99 | 0.80, 1.23 | 141 | 0.91 | 0.66, 1.27 |
CI, confidence interval; n, number of subjects; OR, odds ratio; (ref.), reference category. aAdjusted for age (continuous), ancestry (Caucasian, Asian, Sub-Saharan African, other, and don’t know), first-degree family history of prostate cancer (no, yes, and don’t know), education (elementary, high school, college, university, and other), income (5 categories), physical activity level (sedentary, moderately active, and very active), body mass index in kg/m2 (continuous), type II diabetes (no, yes, and don’t know), respondent status (self, proxy), number of PSA tests in the previous 5 years (0, 1–4, ≥ 5, and don’t know), cigarette-years (4 categories), beer-years (4 categories), red meat consumption in grams/day (3 categories), saturated fat in grams/day (continuous), energy intake in Kcal/day (continuous), selenium (3 categories), and dietary intakes (continuous) of calcium, lycopene, folates, alpha-tocopherol and beta-carotene. bTertiles based on the frequency distribution of energy-adjusted vitamin C intake among controls. cGleason grades ≥ 8 or 7[4+3] were considered as indicative of aggressive cancers, whereas lower grades were classified as non-aggressive cancers. Excludes 3 subjects for whom the primary or the secondary Gleason grade is missing.