Table 4.

RRs (unconditional regression) for pancreatic cancer according to quartiles of plasma C-peptide in HPFS, NHS, PHS, and WHI cohorts, by age, sex, smoking status, BMI, and physical activity level

Cases/controlsRR* for quartiles of serum C-peptide
Ptrend
1234
Age (y)
    ≤6296/3121.00.65 (0.31-1.33)0.72 (0.32-1.59)1.64 (0.75-3.59)0.01
    >62101/2591.01.33 (0.62-2.82)1.04 (0.49-2.21)1.92 (0.89-4.15)0.03
Sex
    Women114/3291.01.11 (0.58-2.15)0.96 (0.48-1.95)1.65 (0.80-3.40)0.05
    Men83/2421.00.46 (0.20-1.06)0.46 (0.19-1.07)1.39 (0.61-3.17)0.03
Smoking status
    Never73/2151.00.65 (0.27-1.54)0.86 (0.34-2.21)3.13 (1.30-7.54)<0.001
    Ever124/3561.01.07 (0.56-2.03)0.77 (0.40-1.48)1.15 (0.58-2.28)0.46
BMI
    <2582/2741.00.79 (0.40-1.56)0.70 (0.31-1.58)2.14 (0.91-5.03)0.08
    ≥25114/2961.00.79 (0.35-1.81)0.74 (0.33-1.62)1.28 (0.60-2.73)0.03
Physical activity
    Low116/2971.00.88 (0.44-1.76)0.49 (0.23-1.06)1.32 (0.64-2.72)0.04
    High81/2741.00.73 (0.33-1.59)1.13 (0.53-2.43)1.82 (0.78-4.25)0.04
Fasting§
    Yes136/3931.00.79 (0.46-1.37)0.81 (0.45-1.44)1.21 (0.66-2.24)0.19
    No60/1771.01.21 (0.35-4.25)0.86 (0.22-3.29)4.24 (1.30-13.8)<0.001
  • * Controlling for age, month of blood draw, smoking status (never, past, current), cohort, fasting status, BMI (quartiles), physical activity (quartiles), current multivitamin use, and high smoking dose (25+ cigarettes/d for HPFS and NHS; 20+ cigarettes/d for PHS).

  • 95% CI for top quartile.

  • Controlling for age, month of blood draw, cohort, fasting status, BMI (quartiles), physical activity (quartiles), current multivitamin use, and time between last meal and blood draw.

  • § Test for interaction P = 0.02.