Table 4.
Mendelian randomization analysis
| Causal relationship tested (exposure on outcome) | Epidemiological association | Causal effect, instrumental variable (IV) approach | |||
|---|---|---|---|---|---|
| β (95%CI) | P-value | F-stat (IV) | βIV(95%CI) | P-value | |
| FG on BMI | 0.68 (0.54, 0.82) | 6.70 × 10−21 | 46.98 | 0.61 (−0.22, 1.43) | 0.15 |
| FI on BMI | 0.96 (0.89, 1.043) | 1.75 × 10−109 | 0.79 | −2.55 (−11.15, 6.053) | 0.56 |
| BMI on FG | 0.077 (0.061, 0.093) | 6.70 × 10−21 | 15.72 | 0.049 (−0.12, 0.21) | 0.56 |
| BMI on FI | 0.27 (0.25, 0.29) | 1.75 × 10−109 | 15.72 | 0.31 (0.078, 0.54) | 0.0085 |
Mendelian randomization analyses using the Two-Stage-Least Squares method. FG, fasting glucose (mmol/l); BMI, body mass index (kg/m2); FI, fasting insulin (ln(pmol/l)). For the instrumental variable analyses, estimates are reported in units of the outcome as described in the previous sentence per amount of increase in the exposure attributable to one unit increase in the genetic instrument of the exposure. For the statistically significant causal relationship of BMI on FI, one unit increase in BMI GRS corresponds to 0.14 (95%CI [0.070;0.21]) standard deviation score increase in BMI.