TABLE 2.
Q1 | Q2 | Q3 | Q4 | P-Trend | |
---|---|---|---|---|---|
25(OH)Da | |||||
No. of cases/controls | 66/114 | 52/112 | 49/113 | 59/113 | |
OR (95% CI)b | 1.0 (ref) | 0.78 (0.49–1.25) | 0.72 (0.45–1.17) | 0.88 (0.56–1.38) | .58 |
OR (95% CI)c | 1.0 (ref) | 0.81 (0.50–1.30) | 0.78 (0.48–1.26) | 0.94 (0.60–1.49) | .79 |
OR (95% CI)d | 1.0 (ref) | 0.70 (0.37–1.30) | 0.50 (0.26–0.94) | 0.73 (0.40–1.33) | .25 |
DBP | |||||
Range, nmol/L | ≤6136 | >6136-≤7394 | >7394-≤8628 | >8628 | |
No. cases/ controls | 64/113 | 63/113 | 56/113 | 43/113 | |
OR (95% CI)b | 1.0 (ref) | 0.85 (0.51–1.41) | 0.68 (0.38–1.21) | 0.51 (0.28–0.95) | .02 |
OR (95% CI)c | 1.0 (ref) | 0.86 (0.52–1.44) | 0.71 (0.39–1.29) | 0.53 (0.28–0.99) | .04 |
OR (95% CI)d | 1.0 (ref) | 0.93 (0.49–1.76) | 0.68 (0.32–1.47) | 0.45 (0.20–1.00) | .03 |
25(OHD:DBP, ×103 | |||||
Range, nmol/L | ≤4.3 | >4.3-≤6.4 | >6.4-≤8.9 | >8.9 | |
No. of cases/controls | 59/115 | 51/111 | 62/114 | 54/112 | |
OR (95% CI)b | 1.0 (ref) | 0.90 (0.55–1.45) | 1.06 (0.64–1.73) | 0.93 (0.55–1.57) | .93 |
OR (95% CI)d | 1.0 (ref) | 1.12 (0.62–2.02) | 0.81 (0.43–1.54) | 0.73 (0.37–1.44) | .23 |
Abbreviations: 25(OH)D, 25-hydroxyvitamin D; CI, confidence interval; DBP, vitamin D binding protein; OR, odds ratio; Q, quartile.
Season-specific quartiles (nmol/L). Darker months (November-April): Q1, ≤28.5; Q2, >28.5–40.3; Q3, >40.3–55.8; Q4, >55.8. Lighter months (May–October): Q1, ≤38.8; Q2, >38.8–51.8; Q3, >51.8–67.8; Q4, >67.8.
Conditional logistic regression analyses conditioned on matching factors: age at randomization, date of blood draw, calendar year of cohort entry, and time since baseline prostate cancer screening.
Additional mutual adjustment for DBP or 25(OH)D.
Further adjustment for baseline PSA.