Table 1.
Characteristics of prostate cancer cases and matched controls.
| Characteristics | Controls (n = 272) | Cases (n = 146) | |||
|---|---|---|---|---|---|
| Mean/N | SD/% | Mean/N | SD/% | p-Value * | |
| Age at baseline (years) | 54.3 | 4.6 | 54.7 | 4.8 | 0.09 |
| Age at baseline (categories) | / | ||||
| <45 years | 6 | 2.2 | 3 | 2.1 | |
| ≥45–<50 years | 53 | 19.5 | 27 | 18.5 | |
| ≥50–<55 years | 71 | 26.1 | 38 | 26.0 | |
| ≥55–<60 years | 113 | 41.5 | 62 | 42.5 | |
| ≥60–<65 years | 29 | 10.7 | 16 | 11.0 | |
| Age at diagnosis (years) | 63.0 | 5.0 | / | / | / |
| Time between blood collection and diagnosis (years) | 8.3 | 3.0 | / | / | / |
| Gleason ≥ 7 ** | 62 | 42.5 | / | / | / |
| BMI (kg/m2) | 25.0 | 3.0 | 25.4 | 3.0 | 0.07 |
| BMI (categories) | / | ||||
| Underweight (<18.5 kg/m2) | 2 | 0.7 | 1 | 0.7 | |
| Normal weight (≥18.5–<25 kg/m2) | 133 | 48.9 | 72 | 49.3 | |
| Overweight (>25 kg/m2) | 137 | 50.4 | 73 | 50.0 | |
| Season of blood draw | / | ||||
| March–May (Spring) | 102 | 37.5 | 56 | 38.4 | |
| October–November (Fall) | 36 | 13.2 | 21 | 14.4 | |
| December–January (Winter) | 134 | 49.3 | 69 | 47.3 | |
| Smoking status | / | ||||
| Non smokers | 242 | 89.0 | 130 | 89.0 | |
| Smokers | 30 | 11.0 | 16 | 11.0 | |
| SU.VI.MAX intervention group | / | ||||
| Supplementation | 123 | 45.2 | 65 | 44.5 | |
| Placebo | 149 | 54.8 | 81 | 55.5 | |
| Family history of prostate cancer | 0.01 | ||||
| No | 261 | 96.0 | 130 | 89.0 | |
| Yes | 11 | 4.0 | 16 | 11.0 | |
| Prostate-specific antigen (ng/mL) | 1.3 | 1.2 | 3.4 | 3.4 | <0.0001 |
| Prostate-specific antigen (categories) | <0.0001 | ||||
| <3 ng/mL | 256 | 94.1 | 97 | 66.4 | |
| ≥3 ng/mL | 16 | 5.9 | 49 | 33.6 | |
| Physical activity | 0.7 | ||||
| Irregular | 68 | 25.0 | 32 | 21.9 | |
| <1 h walk or equivalent | 57 | 21.0 | 35 | 24.0 | |
| ≥1 h walk or equivalent | 147 | 54.0 | 79 | 54.1 | |
| Educational level | 0.9 | ||||
| Primary school | 63 | 23.2 | 31 | 21.2 | |
| Secondary school | 101 | 37.1 | 56 | 38.4 | |
| ≥High-school degree | 108 | 39.7 | 59 | 40.4 | |
| Alcohol intake (g/day) | 29.8 | 22.5 | 26.9 | 21.4 | 0.1 |
* p-value from conditional logistic regression models. ** missing for n = 10. Age (categories), BMI (categories), smoking status, season of blood draw, and SU.VI.MAX intervention group were the matching factors between cases and controls. BMI, body mass index; SD, standard deviation.