Appendix 1—table 4. Mendelian randomization results using the IVW, Egger, weighted median and weighted mode methods of for the causal effect of moderate or vigorous physical activity or sedentary time on BMI.
| Before outlier extraction | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Vigorous physical activity → BMI | Moderate physical activity → BMI | Sedentary time → BMI | ||||||||||
| MR method | SNP | beta | SE | p-value | SNP | beta | SE | p-value | SNP | beta | SE | p-value |
| Egger | 5 | 1.33 | 2.21 | 0.59 | 3 | 0.12 | 0.45 | 0.84 | 8 | 0.46 | 0.64 | 0.50 |
| Weighted median | 5 | –0.18 | 0.10 | 0.08 | 3 | –0.18 | 0.12 | 0.13 | 8 | 0.02 | 0.09 | 0.82 |
| IVW | 5 | –0.17 | 0.08 | 0.04 | 3 | –0.24 | 0.12 | 0.05 | 8 | 0.04 | 0.11 | 0.72 |
| Weighted mode | 5 | –0.19 | 0.12 | 0.19 | 3 | –0.14 | 0.15 | 0.43 | 8 | –0.05 | 0.18 | 0.78 |
| Sensitivity test | Estimate | p-value/CI | Estimate | p-value/CI | Estimate | p-value/CI | ||||||
| Q (p-value) | 1.65 | 0.8 | 3.6 | 0.17 | 23.08 | 1.70E-03 | ||||||
| I2 (CI) | 0.00% | (0,0%; 49,5%) | 44.30% | (0,0%; 83,4%) | 69.70% | (36,8%; 85,4%) | ||||||
| Q-Q' (p-value) | 0.46 | 0.5 | 1.75 | 0.19 | 1.96 | 0.16 | ||||||
| Egger intercept (p-value) | –0.04 | 0.29 | –0.01 | 0.19 | –0.01 | 0.75 | ||||||
| Rucker Test | IVW | IVW | IVW | |||||||||
| After outlier extraction | ||||||||||||
| Vigorous physical activity → BMI | Moderate physical activity → BMI | Sedentary time → BMI | ||||||||||
| MR method | SNP | beta | SE | p-value | SNP | beta | SE | p-value | SNP | beta | SE | p-value |
| Egger | NA | NA | NA | NA | NA | NA | NA | NA | 5 | 0.49 | 0.36 | 0.26 |
| Weighted median | NA | NA | NA | NA | NA | NA | NA | NA | 5 | 0.10 | 0.10 | 0.29 |
| IVW | NA | NA | NA | NA | NA | NA | NA | NA | 5 | 0.11 | 0.08 | 0.16 |
| Weighted mode | NA | NA | NA | NA | NA | NA | NA | NA | 5 | 0.08 | 0.14 | 0.59 |
| Sensitivity test | Estimate | p-value/CI | Estimate | p-value/CI | Estimate | p-value/CI | ||||||
| Q (p-value) | NA | NA | NA | NA | 4.7 | 0.32 | ||||||
| I2 (CI) | NA | NA | NA | NA | 15 | (0·0%; 82·3%) | ||||||
| Q-Q' (p-value) | NA | NA | NA | NA | 1.41 | 0.24 | ||||||
| Egger intercept (p-value) | NA | NA | NA | NA | –1.00E-02 | 0.24 | ||||||
| Rucker Test | NA | NA | IVW | |||||||||
BMI, Body mass index (BMI); MR, Mendelian randomization; SNP, single nucleotide polymorphism; SE, standard error; NA, not applicable; IVW, inverse variance weighted; CI, 95% confidence interval. NA: not applicable. Note: No outlier extraction was performed for moderate physical activity → BMI and vigorous physical activity → BMI directions, since Q test and I2 did not indicate heterogeneity.