Association between Low-Density Lipoprotein Cholesterol Level and Cardiovascular Outcomes in Korean Adults: A Nationwide Cohort Study

BACKGROUND: To validate the treatment target of low-density lipoprotein cholesterol (LDL-C) level according to the cardiovascular disease (CVD) risk which was recommended by Korean dyslipidemia guideline. METHODS: We used the Korean National Health Insurance Service database which included 3,958,048 people aged 20 to 89 years who underwent regular health screening. The primary outcome was incident CVD, defined as a composite of myocardial infarction and stroke during the follow-up period from 2009 to 2018. RESULTS: The risk of CVD increased from LDL-C level of 70 mg/dL in very high-risk and high-risk groups and from 130 mg/dL in moderate-risk and low-risk groups. Adjusted hazard ratios (HRs) of LDL-C ranges 70–99, 100–129, 130–159, 160–189, and ≥190 mg/dL were 1.20 (95% confidence interval [CI], 1.08–1.33), 1.27 (1.15–1.42), 1.39 (1.23–1.56), 1.69 (1.45–1.96), and 1.84 (1.49– 2.27) in very high-risk group, and 1.07 (1.02–1.13), 1.16 (1.10–1.21), 1.29 (1.22–1.36), 1.45 (1.36–1.55), and 1.73 (1.58–1.90) in high-risk group. Adjusted HRs (95% CI) of LDL-C ranges 130–159, 160–189, and ≥190 mg/dL were 1.15 (1.11–1.20), 1.28 (1.22– 1.34), and 1.45 (1.36–1.54) in moderate-risk group and 1.07 (1.02–1.13), 1.20 (1.13–1.26), and 1.47 (1.37–1.57) in low-risk group. CONCLUSION: We confirmed the incidence of CVD was increased in higher LDL-C range. The risk of CVD increased from ≥70 mg/dL of LDL-C in very high-risk and high-risk groups, and from ≥130 mg/dL of LDL-C in moderate-risk and low-risk groups in Korean adults.