The impact of glycemic traits on breast cancer risk in Breast Cancer Association Consortium using Mendelian randomization, stratified by estrogen receptor subtypes
| All SNPs | Inverse variance weighting with multiplicative random effects | MR-Egger | Weighted median | ||||||
| OR | 95% CI | I2 | OR | 95% CI | Intercept | Intercept p value | OR | 95% CI | |
| Estrogen receptor (+ve) | |||||||||
| Glucose (mmol/L) (n=21) | 1.03 | 0.85 to 1.24 | 0.638 | 1.05 | 0.69 to 1.60 | −0.001 | 0.90 | 1.02 | 0.87 to 1.18 |
| HbA1c (%) (n=32) | 1.06 | 0.75 to 1.50 | 0.776 | 1.15 | 0.60 to 2.23 | −0.002 | 0.78 | 1.00 | 0.79 to 1.27 |
| Type 2 diabetes (n=147) | 0.98 | 0.95 to 1.02 | 0.651 | 1.00 | 0.93 to 1.07 | −0.001 | 0.61 | 1.01 | 0.97 to 1.05 |
| Excluding pleiotropic SNPs | |||||||||
| Glucose (mmol/L) (n=11) | 1.00 | 0.81 to 1.24 | 0.603 | 1.06 | 0.67 to 1.67 | −0.003 | 0.79 | 1.02 | 0.86 to 1.20 |
| HbA1c (%) (n=19) | 1.06 | 0.89 to 1.27 | 0.00 | 1.08 | 0.77 to 1.51 | 0.000 | 0.92 | 1.00 | 0.78 to 1.27 |
| Type 2 diabetes (n=108) | 0.98 | 0.93 to 1.02 | 0.555 | 0.87 | 0.76 to 0.99 | 0.007 | 0.08 | 0.99 | 0.94 to 1.05 |
| Estrogen receptor (-ve) | |||||||||
| Glucose (mmol/L) (n=21) | 1.06 | 0.82 to 1.38 | 0.577 | 1.06 | 0.59 to 1.90 | 0.000 | 0.98 | 1.03 | 0.80 to 1.31 |
| HbA1c (%) (n=32) | 1.12 | 0.68 to 1.84 | 0.751 | 1.76 | 0.69 to 4.52 | −0.01 | 0.28 | 1.26 | 0.86 to 1.85 |
| Type 2 diabetes (n=147) | 0.97 | 0.93 to 1.01 | 0.467 | 1.00 | 0.92 to 1.09 | −0.003 | 0.39 | 1.00 | 0.94 to 1.06 |
| Excluding pleiotropic SNPs | |||||||||
| Glucose (mmol/L) (n=11) | 1.01 | 0.80 to 1.26 | 0.200 | 1.28 | 0.81 to 2.02 | −0.011 | 0.27 | 1.02 | 0.79 to 1.31 |
| HbA1c (%) (n=19) | 1.31 | 0.87 to 1.96 | 0.547 | 1.26 | 0.57 to 2.78 | 0.001 | 0.92 | 1.27 | 0.87 to 1.84 |
| Type 2 diabetes (n=108) | 0.95 | 0.89 to 1.00 | 0.342 | 0.87 | 0.74 to 1.03 | 0.005 | 0.31 | 0.93 | 0.87 to 1.00 |
SNP, single-nucleotide polymorphism.