Table 3.
Associations of Seasonally Adjusted Circulating 25-hydroxyvitamin D3 Concentrations With Incident, Sporadic Colorectal Adenoma Risk Stratified by Vitamin D–Binding Protein (Group Component Gene) Isoforms in Pooled Cancer Prevention Research Unit and Markers of Adenomatous Polyps Case-Control Studies, United States, 1991–2002
| Variable | Among Individuals With Gc1-1 Isoforma | Among Individuals With Gc1-2/Gc2-2 Isoformsb | P Value for Interaction | ||||||
|---|---|---|---|---|---|---|---|---|---|
| No. of Case Patients | No. of Control Subjects | ORc | 95% CI | No. of Case Patients | No. of Control Subjects | ORc | 95% CI | ||
| 25(OH)D3 concentration (per 10 ng/mL)d | 209 | 257 | 1.07 | 0.87, 1.32 | 208 | 264 | 0.71 | 0.56, 0.90 | 0.03 |
| 25(OH)D3 quartile | |||||||||
| 1 (<17.9 ng/mL) | 39 | 46 | 1.00 | Referent | 69 | 79 | 1.00 | Referent | |
| 2 (17.9–24.3 ng/mL) | 52 | 60 | 1.10 | 0.58, 2.08 | 57 | 66 | 0.80 | 0.47, 1.38 | |
| 3 (24.4–31.5 ng/mL) | 53 | 71 | 0.98 | 0.52, 1.85 | 47 | 65 | 0.55 | 0.31, 0.97 | |
| 4 (>31.5 ng/mL) | 65 | 80 | 1.02 | 0.55, 1.91 | 35 | 54 | 0.46 | 0.24, 0.88 | 0.04 |
| P for trende | 0.94 | 0.008 | |||||||
| Clinical 25(OH)D3 cutofff | |||||||||
| Deficient (<20 ng/mL) | 51 | 62 | 1.00 | Referent | 91 | 97 | 1.00 | Referent | |
| Nondeficient (≥20 ng/mL) | 158 | 195 | 1.11 | 0.68, 1.82 | 117 | 167 | 0.51 | 0.33, 0.80 | 0.05 |
| Deficient (<20 ng/mL) | 51 | 62 | 1.00 | Referent | 91 | 97 | 1.00 | Referent | |
| Insufficient (20–30 ng/mL) | 86 | 101 | 1.13 | 0.66, 1.93 | 71 | 102 | 0.52 | 0.32, 0.85 | |
| Sufficient (>30 ng/mL) | 72 | 94 | 1.08 | 0.62, 1.89 | 46 | 65 | 0.48 | 0.27, 0.87 | 0.09 |
| P for trende | 0.83 | 0.01 | |||||||
Abbreviations: 25(OH)D3, 25-hydroxyvitamin D3; CI, confidence interval; OR, odds ratio.
a Gc1-1: combined Gc1s-1s, Gc1s-1f, and Gc1f-1f.
b Gc1-2: combined Gc2-1s and Gc2-1f.
c Adjusted for age (continuous), sex, study (Cancer Prevention Research Unit or Markers of Adenomatous Polyps), regular use of aspirin or nonsteroidal anti-inflammatory drugs, family history of colorectal cancer in a first-degree relative, smoking status (current, ever, never), alcohol intake (continuous), total calcium intake from diet and supplements (continuous), body mass index (continuous), and physical activity (continuous).
d Coded as a continuous variable in the model.
e Calculated by including the 25(OH)D3 predictor variable as a continuous variable in the model.