Table 2 Mendelian randomization results.

From: Genome-wide meta-analysis of phytosterols reveals five novel loci and a detrimental effect on coronary atherosclerosis

Parameter

X

Y

Causal estimate

se

p-value

# SNPs

α

SIT

TC

0.419

0.052

7.6 × 10−16

6

β

TC

CAD

0.347

0.059

4.8 × 10−9

36

γ

SIT

CAD

0.308

0.065

1.9 × 10−6

6

Indirect effect (α * β) mediated by TC

SIT

CAD

0.145

0.031

2.2 × 10−6

 

Direct effect (γ − α * β)

SIT

CAD

0.163

0.072

2.3 × 10−2

 
  1. We performed Mendelian randomization analyses of total sitosterol, total cholesterol and CAD. A schematic figure of the investigated causal relationships is displayed in Supplementary Fig. S8. We provide single causal effect estimates based on the given number of SNPs used as instruments (method: inverse-variance weighting). From these estimates, the direct effect of total sitosterol on CAD and the indirect effect mediated by total cholesterol are calculated as described in the ‘Methods’ section. Both causal effects were positive and significant while the direct effect is slightly larger than the indirect effect. Considering more restricted sets of instrumental variables provided similar results (see Supplementary Data S14) as well as applying different methods of Mendelian randomization analysis (Supplementary Fig. S9).
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