Causal association between metformin and arrhythmias: A Mendelian randomization study

Area of Science:

• Cardiology
• Pharmacogenomics
• Genetic Epidemiology

Background:

• Metformin is a widely used medication for type 2 diabetes.
• Its potential impact on cardiac arrhythmias remains a subject of ongoing medical discussion.
• Understanding this relationship is crucial for patient management and treatment optimization.

Purpose of the Study:

• To investigate the potential causal relationship between metformin usage and the incidence of cardiac arrhythmias.
• To leverage genetic data and advanced statistical methods to establish causality.
• To provide robust evidence regarding metformin's effect on arrhythmia risk.

Main Methods:

• Utilized a two-sample Mendelian randomization (MR) analysis.
• Employed genome-wide association study (GWAS) data for metformin and arrhythmias.
• Applied four statistical methods (MR-Egger, weighted median, weighted mode, IVW) and sensitivity analyses (leave-one-out, funnel plot).

Main Results:

• Identified 40 independent single nucleotide polymorphisms (SNPs) associated with metformin.
• The inverse-variance weighted (IVW) method indicated a causal link between metformin and reduced arrhythmia incidence (OR=0.0093).
• Weighted median and weighted mode methods also supported a causal association with decreased arrhythmia risk (P < 0.0001).
• Sensitivity analyses confirmed the robustness and stability of the findings, with no significant evidence of pleiotropy or heterogeneity.

Conclusions:

• This MR study provides robust evidence supporting a causal relationship between metformin use and a reduced risk of cardiac arrhythmias.
• The findings suggest a potential protective effect of metformin against arrhythmias.
• Further clinical studies may be warranted to confirm these genetic findings.