Mendelian randomization of plasma lipidome, inflammatory proteome and heart failure

Aims Heart failure (HF) is a global health issue, with lipid metabolism and inflammation critically implicated in its progression. This study harnesses cutting-edge, expanded genetic information for lipid and inflammatory protein profiles, employing Mendelian randomization (MR) to uncover genetic risk factors for HF. Methods We assessed genetic susceptibility to HF across 179 lipidomes and 91 inflammatory proteins using instrumental variables (IVs) from recent genome-wide association studies (GWASs) and proteome-wide quantitative trait loci (pQTL) studies. GWASs involving 47 309 HF cases and 930 014 controls were obtained from the Heart Failure Molecular Epidemiology for Therapeutic Targets (HERMES) Consortium. Data on 179 lipids from 7174 individuals in a Finnish cohort and 91 inflammatory proteins from a European pQTL study involving 14 824 individuals are available in the HGRI-EBI catalogue. A two-sample MR approach evaluated the associations, and a two-step mediation analysis explored the mediation role of inflammatory proteins in the lipid-HF pathway. Sensitivity analyses, including MR-RAPS (robust adjusted profile score) and MR-Egger, ensured result robustness. Results Genetic IVs for 162 lipids and 74 inflammatory proteins were successfully identified. MR analysis revealed a genetic association between HF and 31 lipids. Among them, 18 lipids, including sterol ester (27:1/18:0), cholesterol, 9 phosphatidylcholines, phosphatidylinositol (16:0_20:4) and 6 triacylglycerols, were identified as HF risk factors [odds ratio (OR) = 1.037-1.368]. Cholesterol exhibited the most significant association with elevated HF risk [OR = 1.368, 95% confidence interval (CI) = 1.044-1.794, P = 0.023]. In the inflammatory proteome, leukaemia inhibitory factor receptor (OR = 0.841, 95% CI = 0.789-0.897, P = 1.08E-07), fibroblast growth factor 19 (OR = 0.905, 95% CI = 0.830-0.988, P = 0.025) and urokinase-type plasminogen activator (OR = 0.938, 95% CI = 0.886-0.994, P = 0.030) were causally negatively correlated with HF, whereas interleukin-20 receptor subunit alpha (OR = 1.333, 95% CI = 1.094-1.625, P = 0.004) was causally positively correlated with HF. Mediation analysis revealed leukaemia inhibitory factor receptor (mediation proportion: 23.5%-25.2%) and urokinase-type plasminogen activator (mediation proportion: 9.5%-10.7%) as intermediaries in the lipid-inflammation-HF pathway. No evidence of directional horizontal pleiotropy was observed (P > 0.05). Conclusions This study identifies a genetic connection between certain lipids, particularly cholesterol, and HF, highlighting inflammatory proteins that influence HF risk and mediate this relationship, suggesting new therapeutic targets and insights into genetic drivers in HF.