For each participant, a single blood collection was performed during the medical examination, after at least 8 hours of fasting. Total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) were measured using an ADIVA 1650 analyzer (Siemens, Tarrytown, NY, USA) in 2007 and a Hitachi Automatic Analyzer 7600 (Hitachi, Tokyo, Japan) from 2008–2015. HDL-C level was measured according to the Lipid Standardization Program of the US Centers for Disease Control and Prevention since 2009. Using the data from the US Centers for Disease Control and Prevention, conversion formulas for HDL-C were calculated [13 (link)]. LDL-C was then calculated using the Friedewald equation, as follows: LDL-C=TC–HDL-C–TG/5 [14 (link)]. The participants were categorized into five groups according to their LDL-C levels: C1 (<70 mg/dL), C2 (70–100 mg/dL), C3 (100–130 mg/dL), C4 (130–160 mg/dL), and C5 (≥160 mg/dL), based on the LDL-C target levels from the 2018 Korean guidelines for the management of dyslipidemia [15 (link)].