Exploring the relationship between lipid-lowering drug target genes and sensorineural hearing loss by Mendelian randomization

An increasing body of research indicates an association between lipid-lowering medications and sensorineural hearing loss (SNHL), although there is still controversy. Therefore, the aim of this study is to investigate the genetic correlation between different lipid-lowering therapeutic gene targets and SNHL. The genetic association between lipids, lipid-lowering drug target genes, and SNHL was analyzed using a 2-sample Mendelian randomization approach. The exposures included 5 circulating lipid levels (triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I, and apolipoprotein B) and 10 target genes simulating the effects of lipid-lowering drugs (HMGCR, PCSK9, Niemann-Pick C1-like 1 [NPC1L1], LDLR, APOB, CETP, LPL, ANGPTL3, APOC3, and PPARA). Summary data from a large-scale genome-wide association study on SNHL from the Finnish database were used as the outcome. The inverse variance-weighted method was employed as the primary approach, with sensitivity tests conducted to evaluate heterogeneity and pleiotropy in the results. The genetic prediction of lipid levels was not significantly associated with SSNL. However, genetic proxies for lowering low-density lipoprotein cholesterol, specifically variants in NPC1L1 (OR = 1.943 [95% CI 1.116-3.383]; P = .018) and LDL receptor (LDLR) (OR = 1.279 [95% CI 1.107-1.477]; P < .001), were associated with an increased risk of SNHL. Similarly, a genetic proxy for lowering triglycerides, the apoprotein C-III (APOC3) variant (OR = 1.174 [95% CI 1.054-1.307]; P = .003), was associated with an increased risk of SNHL. After Bonferroni correction, the genetic variants for LDLR and APOC3 remained significantly associated with an increased risk of SNHL, while the association with the NPC1L1 lipid-lowering variant was no longer significant. This study suggests that lipid-lowering medications potentially have a causal impact on increasing the risk of SNHL through the LDLR and APOC3 pathways. LDLR and APOC3 show potential as candidate drug targets for the prevention of SNHL. However, the results of the study and the potential mechanism of action require further experimental validation and evaluation.