2.2. Sample collection

All study subjects were forbidden to drink water for 4 h and fasted for 8 h, and 4 mL of fasting elbow vein blood was collecting in the morning the next day. Venous blood was centrifuged at room temperature using a low-temperature high-speed centrifuge at a speed of 4500 r/min to separate the upper supernatant. The upper supernatant was stored at −80 °C for subsequent detections of various indicators such as apolipoprotein and hemodynamics.