TABLE 3.
Tests of MR-Steiger causal direction, MR-Egger I2, heterogeneity, and pleiotropy.
| Exposure | Outcome | Heterogeneity test | MR-Egger intercept | p-value | MR-Steiger causal direction | MR-Egger I2 | |||
| MR method | Q | Q_p-value | I 2 | ||||||
| IGF-1 | Vitamin D | MR-Egger | 251.7 | 3.4 × 10–4 | 0.28 | 5.1 × 10–5 | 0.90 | True | 0.99 |
| Inverse-variance weighted | 251.7 | 4.0 × 10–4 | 0.28 | ||||||
| Vitamin D | IGF-1 | MR-Egger | 10.3 | 3.5 × 10–2 | 0.61 | 6.6 × 10–4 | 0.91 | True | 0.99 |
| Inverse-variance weighted | 10.4 | 6.6 × 10–2 | 0.52 | ||||||
| IGF-1 | Serum 25-OHD | MR-Egger | 694.5 | 5.3 × 10–35 | 0.58 | 6.4 × 10–4 | 0.14 | True | 0.99 |
| Inverse-variance weighted | 699.8 | 1.7 × 10–35 | 0.58 | ||||||
| Serum 25-OHD | IGF-1 | MR-Egger | 245.7 | 1.7 × 10–18 | 0.67 | 1.9 × 10–3 | 0.05 | True | 0.99 |
| Inverse-variance weighted | 258.0 | 4.4 × 10–20 | 0.68 | ||||||
25-OHD, 25-hydroxyvitamin D; MR, Mendelian randomization.