Table 2

Association of blood C-peptide concentration and breast cancer risk from the Shanghai Breast Cancer Study, 1996–1998

Cases (n = 143)Controls (n = 143)Crude OR (95% CI)Adjusted OR (95% CI)a
All subjects (ng/ml)
 ≤0.7029461.0 (referent)1.0 (referent)
 0.71–1.0745491.9 (0.9–4.0)1.8 (0.8–3.8)
 >1.0769482.9 (1.4–5.9)2.7 (1.2–5.9)
 Trend testP = 0.004P = 0.01
Premenopausal (ng/ml)
 ≤0.709171.0 (referent)1.0 (referent)
 0.71–1.0716142.6 (0.8–9.0)2.9 (0.7–12.5)
 >1.0720143.5 (1.0–12.1)3.1 (0.7–14.2)
 Trend testP = 0.06P = 0.24
Postmenopausal (ng/ml)b
 ≤0.7020291.0 (referent)1.0 (referent)
 0.71–1.0729351.5 (0.6–4.0)1.6 (0.6–4.3)
 >1.0749342.5 (1.0–6.0)2.9 (1.1–8.0)
 Trend testP = 0.02P = 0.02
  • a All ORs are adjusted for BMI and age at the first live birth.

  • b ORs are also adjusted for age at menopause.