Long-term average atherogenic index of plasma and cardiovascular mortality in 8.9 million Korean adults: A nationwide cohort study.

BACKGROUND AND AIMS: To evaluate the association between the atherogenic index of plasma (AIP) and cardiovascular disease (CVD) mortality, with a particular focus on young adults, individuals with low-density lipoprotein cholesterol (LDL-C) <100 mg/dL, and those with established diabetes. METHODS: We analyzed data from 8922312 adults without prior CVD or cancer in the Korean National Health Insurance Service database (2011-2012). Average AIP, calculated from repeated measurements as the base-10 logarithm of the triglyceride-to-high-density lipoprotein cholesterol ratio, was used as the exposure. The primary outcome was CVD mortality, including deaths from ischaemic heart disease (IHD), acute myocardial infarction (AMI), haemorrhagic stroke, ischaemic stroke, and heart failure. RESULTS: During a mean follow-up of 11.7 years, 83220 CVD deaths occurred. Among adults aged 18-44 years, each 0.1-unit increase in AIP was associated with higher CVD mortality in both men (hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.29-1.86) and women (HR 3.00, 95% CI 1.85-4.85; both P < 0.001). Higher AIP was also independently associated with increased CVD mortality among individuals with LDL-C <100 mg/dL (HR 1.48, 95% CI 1.41-1.54) and those with diabetes (HR 2.33, 95% CI 2.18-2.48; both P < 0.001). Similar associations were consistently observed across these subgroups for IHD- and AMI-related mortality. CONCLUSIONS: Elevated AIP was independently associated with increased CVD mortality, even among young adults, individuals with well-controlled LDL-C, and those with diabetes. AIP may provide incremental value for residual cardiovascular risk stratification in primary prevention.