Cases (n = 380) | Controls (n = 380) | P* | |
---|---|---|---|

Plasma C-Peptide (ng/mL), geometric mean (25-75%) | 1.91 (1.19-2.80) | 1.71 (1.12-2.49) | 0.006 |

Plasma IGFBP-1^{†} (ng/mL), geometric mean (25-75%) | 22.1 (14.4-40.1) | 23.9 (14.9-43.8) | 0.25 |

HbA1c^{‡} (mean % ± SD) | 5.41 ± 0.30 | 5.38 ± 0.3 | 0.06 |

Age at blood draw (mean ± SD) | 58.2 ± 6.6 | 58.2 ± 6.5 | 0.68^{§} |

BMI (kg/m^{2}) (mean ± SD) | 24.9 ± 3.7 | 24.7 ± 3.8 | 0.54 |

Physical activity (average 1980-1990; mean MET-h/wk ± SD) | 14.5 ± 18.5 | 15.7 ± 18.0 | 0.34 |

Alcohol (average intake 1980-1990; mean g/d ± SD) | 7.3 ± 10.5 | 6.8 ± 9.7 | 0.57 |

Cigarette smoking^{∥} (mean pack-years ± SD) | 23.9 ± 18.0 | 21.5 ± 18.6 | 0.71 |

Postmenopausal hormone use in 1990 (%) | 32.6 | 39.5 | 0.05 |

Endoscopy before 1990 (%) | 31.6 | 33.7 | 0.32 |

Family history of colorectal cancer (%) | 24.0 | 17.6 | 0.03 |

Multivitamin use in 1990 (%) | 37.1 | 39.7 | 0.46 |

Regular aspirin use ≥10 y before 1990 (%) | 6.8 | 9.0 | 0.28 |

↵*

*P*from paired*t*test for geometric means (plasma biomarkers), Wilcoxon signed rank for all other continuous variables, and χ^{2}test for categorical variables.↵† Among fasting women (cases,

*n*= 234; controls,*n*= 234).↵‡ HbA1c available for 371 cases and 371 controls.

↵§ Matching factor.

↵∥ Among cigarette smokers.