The epidemiological survey was carried out using internationally standardized methods and following a common protocol19 (link). Information on demographics, socioeconomic status, and lifestyle factors was collected using standardized questionnaires. The methods of measuring blood pressure, height, weight and waist circumference parameters were based on previous studies19 (link). Fasting venous blood samples were taken and the levels of serum TC, TG, HDL-C, and LDL-C in the samples were directly determined by enzymatic methods with commercially available kits, Tcho-1, TG-LH (RANDOX Laboratories Ltd., Ardmore, Diamond Road, Crumlin Co. Antrim, United Kingdom, BT29 4QY), Cholestest N HDL, and Cholestest LDL (Daiichi Pure Chemicals Co., Ltd., Tokyo, Japan); respectively. Serum ApoA1 and ApoB levels were assessed by the immunoturbidimetric assay using a commercial kit (RANDOX Laboratories Ltd.)19 (link)20 (link). All determinations were performed with an autoanalyzer (Type 7170A; Hitachi Ltd., Tokyo, Japan) in the Clinical Science Experiment Center of the First Affiliated Hospital, Guangxi Medical University. The normal values of serum TC, TG, HDL-C, LDL-C, ApoA1 and ApoB levels and the ratio of ApoA1 to ApoB in our Clinical Science Experiment Center were 3.10–5.17, 0.56–1.70, 1.16–1.42, 2.70–3.10 mmol/L, 1.20–1.60, 0.80–1.05 g/L and 1.00–2.50, respectively21 (link)22 (link).