TABLE 2.
Odds Ratios and 95% Confidence Intervals for the Association Between Serum 25(OH)D, DBP, and 25(OH)D:DBP and Total Prostate Cancer
| 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.
a
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.
b
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.
c
Additional mutual adjustment for DBP or 25(OH)D.
d
Further adjustment for baseline PSA.