# Table 2 Common insulin-like growth factor (IGF) haplotypesa and percentage mammographic density, Nurses' Health Study

Block 1 (p = 0.03)b Block 2 (p = 0.95)b Block 3 (p = 0.009)b Block 4 (p = 0.007)b
Haplotype Frequency (percentage) βc (95% CI) Haplotype Frequency (percentage) βc (95% CI) Haplotype Frequency (percentage) βc (95% CI) Haplotype Frequency (percentage) βc (95% CI)
1A (TG) 82.9 0.16 2A (GCC) 55.0 -0.002 3A (AGGCC) 46.5 0.08 4A (GGAA) 42.4 0.09
(-0.04 to 0.35)    (-0.15 to 0.14)    (-0.07 to 0.22)    (-0.06 to 0.23)
1B (TA) 13.3 -0.29 2B (GCG) 22.6 -0.04 3B (AGGCG) 13.6 0.03 4B (ACGA) 14.3 -0.03
(-0.52 to -0.07) d    (-0.21 to 0.14)    (-0.18 to 0.24)    (0.24 to 0.19)
Rare 3.9 -- 2C (AAC) 12.7 0.03 3C (AGTCC) 11.0 0.15 4C (GGGA) 14.5 0.19
(-0.17 to 0.24)    (-0.09 to 0.38)    (-0.02 to 0.41)
2D (ACC) 9.0 0.03 3D (GGGGC) 9.1 -0.39 4D (ACGG) 8.8 -0.34
(-0.23 to 0.29)    (-0.65 to -0.14) e    (-0.61 to -0.06) h
Rare 0.8 -- 3E (GGGCC) 8.2 0.35 4E (GGGG) 8.1 0.28
(0.07 to 0.62) f    (0.0007 to 0.55) i
3F (GAGGC) 7.6 -0.38 4F (AGAA) 7.6 -0.45
(-0.65 to -0.12) g    (-0.73 to -0.16) j
Rare 4.0 -- Rare 4.3 --
1. CI, confidence interval. aIGF1 haplotype blocks are based on SNPs defined in Table 1. Block 1, SNPs 1 and 2; block 2, SNPs 3 to 5; block 3, SNPs 6 to 10; block 4, SNPs 11 to 14. bGlobal test of association based on F statistic comparing model with haplotypes in block and covariates with covariates only. cβ coefficients from models that used square-root-transformed mammographic density as the dependent variable. Multivariate-adjusted models including age (continuous), body mass index (continuous), alcohol consumption (category), age at first birth/parity, history of benign breast disease (yes/no), family history of breast cancer (yes/no), menopausal status/postmenopausal hormone use (premenopausal, postmenopausal never user, postmenopausal current user, postmenopausal past user). Results in bold show significant differences: d p = 0.009; e p = 0.003; f p = 0.02; g p = 0.005; h p = 0.02; i p = 0.05; j p = 0.002.