Table 3

Results of analyses of interaction of AIB1 and other factors

FactorGenotypecORa (95% CI) associated with AIB1 polyglutamine length cutpointb at:
28 repeats29 repeats
Age at first live birth <3001.0d1.0d
11.82 (1.11–2.98)3.04 (1.66–5.55)
Age at first live birth04.95 (1.66–14.75)3.46 (1.67–7.14)
 ≥30 or nulliparous14.62 (2.02–10.56)6.97 (1.71–28.43)
Menarche <1301.0d1.0d
12.07 (1.06–4.05)3.06 (1.31–7.17)
Menarche ≥1301.14 (0.54–2.40)0.86 (0.56–1.35)
11.48 (0.78–2.80)2.34 (1.10–4.96)
Parous01.0d1.0d
11.82 (1.14–2.90)2.96 (1.65–5.31)
Nulliparous01.67 (0.39–7.27)0.65 (0.25–1.70)
10.83 (0.30–2.34)1.32 (0.24–7.09)
  • a Adjusted for year of birth, age at first live birth, age at menarche, parity, and smoking, except where that variable was involved in the interaction analysis.

  • b AIB1 cutpoint made at polyglutamine repeat length longer than or equal to the indicated number, compared with genotypes containing only shorter number of repeats.

  • c Genotype 0, individuals with alleles shorter than the cutpoint of interest; genotype 1, individuals with alleles as long or longer than the cutpoint of interest.

  • d Reference group.