Association between prediagnostic plasma C-peptide concentration and prostate cancer by stage and grade, CLUE II, 1989-2002
| Fourth of the C-peptide distribution (pmol/L) | P-trend* | ||||
|---|---|---|---|---|---|
| Lowest (<849) | Second (849-<1,367) | Third (1,367-<2,017) | Highest (≥2,017) | ||
| Localized (127 pairs) | |||||
| OR | 1.00 | 0.77 | 0.50 | 0.44 | 0.04 |
| 95% CI | Reference | 0.361-1.66 | 0.24-1.05 | 0.19-1.03 | |
| Advanced (57 pairs) | |||||
| OR | 1.00 | 1.39 | 1.50 | 1.83 | 0.39 |
| 95% CI | Reference | 0.47-4.09 | 0.47-4.82 | 0.50-6.78 | |
| Low grade (128 pairs) | |||||
| OR | 1.00 | 1.13 | 0.92 | 0.68 | 0.28 |
| 95% CI | Reference | 0.56-2.31 | 0.44-1.91 | 0.30-1.54 | |
| High grade (80 pairs) | |||||
| OR | 1.00 | 1.00 | 0.32 | 0.57 | 0.15 |
| 95% CI | Reference | 0.37-2.68 | 0.11-0.97 | 0.18-1.83 | |
NOTE: Adjusted for BMI (overweight or obese versus normal) and family history of prostate cancer (yes or missing versus no).
↵*From a Wald test of the coefficient estimated when entering C-peptide in the model as a single ordinal variable with values corresponding to the median of the fourth into which a man's concentration fell.