Abstract
BACKGROUND: High-density lipoprotein cholesterol's (HDL-C) long-held status as a cardiovascular disease (CVD) preventative has been called into question. Most of the evidence, however, focused on either the risk of death from CVD, or on single time point level of HDL-C. This study aimed to determine the association between changes in HDL-C levels and incident CVD in individuals with high baseline HDL-C levels (≥ 60 mg/dL). METHODS: 77,134 people from the Korea National Health Insurance Service-Health Screening Cohort were followed for 517,515 person-years. Cox proportional hazards regression was used to evaluate the association between change in HDL-C levels and the risk of incident CVD. All participants were followed up until 31 December 2019, CVD, or death. RESULTS: Participants with the greatest increase in their HDL-C levels had higher risks of CVD (adjusted hazard ratio [aHR], 1.15; 95% confidence interval [CI], 1.05-1.25) and CHD (aHR 1.27, CI 1.11-1.46) after adjusting for age, sex, household income, body mass index, hypertension, diabetes mellitus, dyslipidemia, smoking, alcohol consumption, moderate-to-vigorous physical activity, Charlson comorbidity index, and total cholesterol than those with the lowest increase in HDL-C levels. Such association remained significant even among participants with decreased low-density lipoprotein cholesterol (LDL-C) levels for CHD (aHR 1.26, CI 1.03-1.53). CONCLUSIONS: In people with already high HDL-C levels, additional increases in HDL-C levels may be associated with an increased risk of CVD. This finding held true irrespective of the change in their LDL-C levels. Increasing HDL-C levels may lead to unintentionally elevated risk of CVD.