Elevated high-density lipoprotein triglycerides increase atherosclerotic risk.

The relationship between high-density lipoprotein (HDL) and atherosclerotic risk remains incompletely elucidated, potentially due to the inherent heterogeneity of HDL particles. Hypertriglyceridemia is associated with alterations in HDL composition. This study investigated the impact of elevated triglycerides (TG) on HDL and its association with coronary artery disease (CAD) risk using a large prospective cohort study and Mendelian randomization (MR). We found that elevated TG was associated with reduced HDL particle size, decreased concentrations of HDL components, and increased triglycerides in HDL (HDL-TG) (all P for trend < 0.001). The protective effects of HDL particle concentration and HDL cholesterol on CAD are attenuated with increasing serum TG levels. An independent and positive association between HDL-TG levels and incident CAD events (hazard ratio [HR] per 1 standard deviation increase: 1.066, 95% CI: 1.052-1.080, P < 0.001) was confirmed even after adjustment for established cardiovascular disease risk factors. MR analyses supported a causal role for HDL-TG in CAD development (inverse-variance weighted [IVW] method: odds ratios [ORs] of 1.120 (95% CI: 1.053-1.192, P < 0.001) and 1.141 (95% CI: 1.032-1.263, P = 0.010) for dataset groups 1 and 2, respectively). Drug-target MR analyses suggested a potential association between omega-3 fatty acids (OM3-FA) and lower HDL-TG levels, with LPL and DGAT2 as key pharmacological targets. Our findings suggest that elevated TG contributes to adverse alterations in HDL, elevating CAD risk. HDL-TG is an independent positive risk factor for CAD and a potential causal contributor to CAD development. OM3-FA supplementation may offer a therapeutic strategy for mitigating the CAD risk associated with elevated HDL-TG.