Table 2.
Estimates of causal relationship between BMI and AMY1 or AMY2 plasma enzymatic activity, using two different methods
| Relationships to assess | Inverse variance weighting method | Two-stage least squares method | ||||
|---|---|---|---|---|---|---|
| Effect size ± SE | P value | Instrument | Effect size ± SE | P value | Instrument | |
| BMI → AMY1 (n = 3673) |
−4.15 ± 1.66 | 0.012 | GRS based on 83 SNPs | −0.97 ± 0.49 | 0.047 | GRS based on 83 SNPs |
| BMI → AMY2 (n = 3905) |
−2.53 ± 0.94 | 7.1 × 10−3 | GRS based on 83 SNPs | −0.75 ± 0.28 | 6.1 × 10−3 | GRS based on 83 SNPs |
| AMY1 → BMI (n = 3673) |
NAa | NAa | NAa | 0.013 ± 0.046 | 0.78 | rs10492100 (PRH1-PRR4) |
| AMY2 → BMI (n = 3905) |
NAa | NAa | NAa | 0.041 ± 0.097 | 0.67 | rs507666 (ABO) |
aThe inverse variance weighting scheme could not be properly applied to estimate the causal effect of AMY1 or AMY2 plasma enzymatic activity on BMI as to our knowledge, no data on association between SNPs and those activities have been published before
AMY1 salivary amylase, AMY2 pancreatic amylase, BMI body mass index, GRS genetic risk score, NA not applicable, SE standard error, SNP single nucleotide polymorphism