Table 1.
Description of the genome-wide association study data sets and instrumental variables used in our study
| Phenotype | IV | Sample size | Ethnicity | Consortium | R 2 | F-statistic | Author, year |
|---|---|---|---|---|---|---|---|
| Exposures | |||||||
| BMI | 281 | 434 794 females | European | Genetic Investigation of ANthropometric Traits (GIANT) and UK Biobank | 0.040 | 63.799 | Pulit, 2019 |
| WHR | 203 | 381 152 females | European | Genetic Investigation of ANthropometric Traits (GIANT) and UK Biobank | 0.040 | 78.191 | Pulit, 2019 |
| WHRadjBMI | 266 | 379 501 females | European | Genetic Investigation of ANthropometric Traits (GIANT) and UK Biobank | 0.036 | 53.242 | Pulit, 2019 |
| Childhood BMI | 25 | 55 354 | European | Early Growth Genetics (EGG) | 0.036 | 58.975 | Vogelezang, 2020 |
| Outcomes | |||||||
| BC overall | 170 | 133 384 cases/113 789 controls | European | Breast Cancer Association Consortium (BCAC) | 0.302 | 608.642 | Zhang, 2020 |
| ER+ | NA | 69 501 cases/105 974 controls | European | Breast Cancer Association Consortium (BCAC) | NA | NA | Michailidou, 2017 |
| ER– | NA | 21 468 cases/105 974 controls | European | Breast Cancer Association Consortium (BCAC) | NA | NA | Michailidou, 2017 |
| Confounders | |||||||
| AAM | 375 | 329 345 | European | Reproductive Genetics (ReproGen) | 0.074 | 67.656 | Day, 2017 |
| ANM | 290 | 201 323 | European | Reproductive Genetics (ReproGen) | 0.130 | 103.187 | Ruth, 2021 |
| Smoking | 378 | 1 232 091 | European | GWAS & Sequencing Consortium of Alcohol and Nicotine (GSCAN) | 0.023 | 77.222 | Liu, 2019 |
| Drinking | 99 | 941 280 | European | GWAS & Sequencing Consortium of Alcohol and Nicotine (GSCAN) | 0.002 | 17.811 | Liu, 2019 |
GWAS, genome-wide association study; IV, instrumental variable; BMI, body mass index; WHR, waist-to-hip ratio; WHRadjBMI, waist-to-hip ratio adjusted for body mass index; BC, breast cancer; ER, oestrogen receptor; AAM, age at menarche; ANM, age at natural menopause.