Enhanced Qualities of High-Density Lipoproteins (HDLs) with Antioxidant Abilities Are Associated with Lower Susceptibility of Hypertension in Middle-Aged Korean Participants: Impaired HDL Quality and Hypertension Risk

The quality of high-density lipoproteins (HDLs) is characterized by lipid and protein composition, oxidation and glycation extent, and particle size, while the quantity of HDL-C is just the cholesterol amount in HDL. The inverse association between HDL-C and cardiovascular disease (CVD) and hypertension has been well established; however, the U-shaped mortality risk observed from HDL-C underscores that HDL quality and function are equally important. The present cross-sectional study assessed the correlations of serum lipid and glucose profiles, and low-density lipoprotein (LDL) and HDL characteristics, with blood pressure (BP) distribution in ordinary middle-aged Korean participants (n = 50; mean age 47.0 ± 11.7 years; males: n = 25, 49.2.0 ± 11.7 years; females: n = 25, 44.8 ± 11.5 years), with particular focus on HDL quality and its antioxidant capacity. This study observed that serum elevated triglyceride (TG) and glucose levels were directly proportional to elevated systolic BP (SBP) and diastolic BP (DBP), whereas serum total cholesterol (TC), LDL-C, and HDL-C were not correlated with BP. However, HDL-C/TC (%) was negatively associated with SBP (<i>p</i> = 0.036), while TG/HDL-C and glucose/HDL-C ratios were positively associated with both SBP and DBP, suggesting that TG and glucose proportions relative to HDL-C are probable predictors of hypertension. Elevations of TG, oxidation, and glycation in LDL were positively associated with elevations of BP, whereas LDL particle size was negatively correlated with BP. Similarly, elevations of TG and glycation in HDL₂ and HDL₃ were positively correlated with elevations of BP, while the particle size of HDL₂ was negatively correlated with BP. The heightened HDL₂-associated paraoxonase (PON) activity and ferric ion reduction ability (FRA) negatively correlated with LDL oxidation and particle size, whereas elevated HDL₃-associated PON and FRA activities were inversely related to LDL glycation. An enhanced glycation in HDL₂ was negatively correlated with HDL₂-associated PON activity and FRA, while an increase in HDL₂ particle size was only dependent on the associated PON activity but not on FRA. In conclusion, observational outcomes demonstrated that improved HDL quality and functionality (characterized by large particle size, reduced glycation, and higher FRA and PON activities) were inversely correlated with LDL oxidation, glycation, particle shrinkage, and the risk of hypertension.