| Description: |
Pharmacological modulation of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) through dual GIP/GLP-1 receptor agonists, commonly used for diabetes and obesity, shows promise in reducing alcohol consumption. We applied drug-target Mendelian randomization (MR) using genetic variation at these loci to assess their long-term effects on problematic alcohol use (PAU), binge drinking, alcohol misuse classifications, liver health, and other substance use behaviors. Genetic proxies for lowered BMI, modeling the appetite-suppressing and weight-reducing effects of variants in both the GIPR and GLP1R loci (“GIPR/GLP1R”), were linked with reduced binge drinking in the primary (β = −0.44, 95% CI [−0.72, −0.15], P = 2.42 × 10−3) and replication data (β = −0.13, [−0.22, −0.04], P = 0.0058). HbA1c lowering via GIPR/GLP1R variants was associated with reduced risk of heavy drinking with psychiatric comorbidities versus low-risk drinking (odds ratio [OR] = 0.62, [0.45, 0.85], P = 0.0031), with replication in independent HbA1c data (OR = 0.71, [0.60, 0.84], P = 5.22 × 10−5) and directional consistency with reduced PAU. Analysis of individual loci indicated that both GIPR and GLP1R were protective against heavy drinking, underscoring the importance of both targets. While estimates for other substance use disorders (tobacco, cannabis, opioid) were consistently null, food preference analyses revealed that BMI lowering via GIPR/GLP1R reduced fatty food liking (β = −1.58, [−2.01, −1.14], P = 1.62 × 10−12) and increased vegetarian food liking (β = 2.08, [1.17, 2.99], P = 8.22 × 10−6), implicating metabolic and appetite regulation pathways for the alcohol consumption findings. For liver health, HbA1c lowering via GIPR/GLP1R was associated with reduced NAFLD (β = −0.34, [−0.50, −0.18], P = 2.74 × 10−5) and lower ALT levels (β = −0.26, [−0.38, −0.15], P = 8.39 × 10−6), with replication supporting these findings. Consistency across multiple MR methods and colocalization analyses strengthened causal ... |