APOB and metabolic syndrome: In total, we found 16 significant associations between clinical variables and the cluster groups in our one-way ANOVA tests (for continuous variables) and chi-squared tests (for categorical variables): (1) the SBP clusters were associated with age, smoking, hypertension, and triglyceride levels; (2) the DBP clusters with age, smoking, hypertension, prior history of MI, and BMI; (3) the HR clusters with age, smoking, hypertension, dyslipidemia, and ApoA-I levels; and (4) the sympathetic tone clusters with age, DM, BMI, T-C, HDL-C, and ApoB levels.