Impact of hypertriglyceridaemia on cardiovascular mortality according to low-density lipoprotein cholesterol in a 15.6-million population

Abstract

Aims The aim of this study was to assess the association between triglyceride (TG) levels and cardiovascular disease (CVD) mortality concerning low-density lipoprotein cholesterol (LDL-C) and age in the general population. .

Methods From the Korean National Health Insurance Service database, 15 672 028 participants aged 18–99 who underwent routine and results health examinations were followed up for CVD mortality. Hazard ratios for CVD mortality were calculated using Cox models after adjusting for various confounders. During a mean of 8.8 years of follow-up, 105 174 individuals died of CVD. There was a clear log-linear association between TG and overall CVD mortality down to 50 mg/dL. Each two-fold increase in TG was associated with 1.10-fold (overall CVD), 1.22-fold [ischaemic heart disease (IHD)], 1.24-fold [acute myocardial infarction (AMI)], and 1.10-fold (ischaemic stroke) higher CVD mortality. Haemorrhagic stroke and heart failure were not associated with TG levels. The impact of hypertriglyceridaemia (HTG) on CVD weakened but remained present in persons with LDL-C < 100 mg/dL, in whom each two-fold higher TG was associated with 1.05-fold (overall CVD), 1.12-fold (IHD), 1.15-fold (AMI), and 1.05-fold (ischaemic stroke) higher CVD mortality. The younger population (18–44 years) had stronger associations between TG levels and mortality from overall CVD, IHD, and AMI than the older population.

Conclusion Hypertriglyceridaemia independently raises CVD mortality with lingering risks in young and older individuals with low LDL-C levels, suggesting the importance of management of HTG even with controlled LDL-C. - Lay Summary This prospective study evaluated the association between triglyceride (TG) levels and cardiovascular disease (CVD) mortality in the general population, particularly in individuals with well-controlled low-density lipoprotein cholesterol (LDL-C) levels. • The TG levels log-linearly increased the mortality from CVD, especially ischaemic heart disease and ischaemic stroke, down to at least 50 mg/dL (0.56 mmol/L), as residual CVD risks associated with high TG were apparent in individuals, even with LDL-C < 100 mg/dL (2.59 mmol/L). • Maintaining TG levels below 100 mg/dL may be beneficial even in seemingly low-risk groups, such as young people with normal or optimal LDL-C levels.