Abstract 14943: Trans-Biobank Mendelian Randomization Analyses Identify Distinct and Opposing Pathways in the Association of Lower Plasma Low-Density Lipoprotein-Cholesterol With Risk of Gallstone Disease

Background: Higher plasma LDL-cholesterol increases coronary artery disease risk, while biliary cholesterol promotes gallstone formation. Trial evidence suggests that lowering plasma LDL-cholesterol with bempedoic acid increases gallstone risk.

Hypothesis: Different plasma LDL-cholesterol lowering pathways have distinct effects on biliary cholesterol and thereby gallstone disease risk.

Methods: We conducted a Mendelian randomization (MR) study using data from the UK Biobank (30,547 gallstone disease cases/336,742 controls), FinnGen (34,461 cases/301,383 controls) and Biobank Japan (9,305 cases/168,253 controls). We firstly performed drug-target MR analyses substantiated by colocalization to investigate the effects of plasma LDL-cholesterol lowering therapies on gallstone risk. We then performed clustered MR analyses followed by pathway analyses to identify distinct pathways in the association of lower plasma LDL-cholesterol with gallstone risk.

Results: Genetic mimics of statins were associated with lower gallstone risk, but genetic mimics of PCSK9 inhibitors, mipomersen and bile acid sequestrants were associated with higher gallstone risk. The association for statins was supported by colocalization (posterior probability 98.7%). Clustered MR analyses consistently identified clusters showing opposing associations of lower plasma LDL-cholesterol with gallstone risk. Among variants predicting lower plasma LDL-cholesterol, those associated with lower gallstone risk were mapped to glycosphingolipid biosynthesis pathway, while those associated with higher gallstone risk were mapped to pathways relating to ATP-binding cassette transporters and plasma lipoprotein assembly, remodelling, and clearance.

Conclusions: Genetic evidence suggests that different plasma LDL-cholesterol lowering pathways may have opposing effects on gallstone disease risk. Specifically, statins may reduce gallstone disease risk.