Table 5.

Adjusted hazard ratios (95% CI) for the associations of free IGF-I and insulin with endometrioid adenocarcinoma, with stratification by BMI

Quartile 1Quartile 2Quartile 3Quartile 4Ptrend*
BMI <25 kg/m2
    Free IGF-I
        Cases (n)32262217
        Age adjusted1.000.79 (0.40-1.55)0.72 (0.35-1.46)0.59 (0.27-1.26)0.16
        Age + HT + estradiol1.000.89 (0.44-1.83)1.03 (0.48-2.17)0.72 (0.33-1.61)0.54
        Age + insulin1.000.72 (0.35-1.50)0.71 (0.34-1.50)0.54 (0.24-1.21)0.15
    Insulin
        Cases (n)3827257
        Age adjusted1.000.89 (0.47-1.65)1.66 (0.86-3.19)0.90 (0.32-2.53)0.44
        Age + HT + estradiol1.000.79 (0.41-1.52)1.69 (0.84-3.40)0.79 (0.26-2.38)0.57
        Age + free IGF-I1.000.89 (0.47-1.70)1.73 (0.86-3.46)0.94 (0.32-2.74)0.37
BMI ≥ 25 kg/m2
    Free IGF-I
        Cases (n)29253217
        Age adjusted1.000.64 (0.32-1.26)0.78 (0.48-1.47)0.39 (0.19-0.80)0.03
        Age + HT + estradiol1.000.69 (0.34-1.41)0.87 (0.44-1.72)0.43 (0.20-0.97)0.07
        Age + insulin1.000.67 (0.32-1.40)0.85 (0.43-1.67)0.40 (0.18-0.88)0.05
        Full model§1.000.76 (0.35-1.65)0.97 (0.47-1.99)0.46 (0.20-1.04)0.12
    Insulin
        Cases (n)5172553
        Age adjusted1.001.92 (0.67-5.54)2.25 (0.79-6.37)4.38 (1.64-11.64)<0.001
        Age + HT + estradiol1.002.06 (0.71-6.02)2.29 (0.80-6.56)4.30 (1.62-11.43)0.001
        Age + free IGF-I1.001.80 (0.62-5.22)2.20 (0.36-6.31)4.40 (1.65-11.71)<0.001
        Full model1.001.77 (0.61-5.14)1.96 (0.68-5.68)3.95 (1.49-10.47)0.001
  • * Significance tests for trend were calculated using ordinal quantile variables (1-4 for quartile and 1-3 for tertile) entered into the model as a single continuous variable.

  • Reference category.

  • Concurrent stratification by hormone therapy use was precluded by sample size.

  • § Age, hormone therapy and estradiol, and insulin.

  • Age, hormone therapy and estradiol, and free IGF-I.