Effect of Increasing the Plasma Phospholipase A2 Mass on the Risk of Masked Hypertension in Humans

Background: Masked Hypertension (MHT) is associated with an increased risk for Cardiovascular Disease (CVD). The etiopathogenesis of MHT is thought to be affected by oxidative stress and vascular inflammation. This study aimed to analyze the relationships between Lipoprotein-Associated Phospholipase A2 (Lp-PLA2), a unique vascular inflammation marker, with blood pressure variation and traditional risk factors in patients with MHT, and to determine the clinical significance. Methods: One hundred eighty-three patients without any prior therapeutic medications were included and divided into the following three groups: MHT (n=82); True Hypertension (THT) [n=52]); and normotensive (n=59). An Ambulatory Blood Pressure Monitor (ABPM) was used. Clinical biochemical parameters and the Lp-PLA2 mass in each group were measured, and the related clinical characteristics and risk factors for CVD were statistically analyzed. Results: The level of Lp-PLA2 in MHT group was significantly higher than the normotensive (191.8 ± 62.58 vs.108.3 ± 44.74 ng/ml, p<0.01) and true hypertension groups (191.8 ± 62.58 vs. 169.3 ± 54.55 ng/ml, p<0.05). Furthermore, the incidence of MHT was correlated with the increase in Lp-PLA2, around 65% of MHT patients with a Lp-PLA2 level ≥ 225 μ mol/L. The Lp-PLA2 level had a positive correlation with ABPM measurements, office-measured systolic blood pressure, and serum Uric Acid (UA) and Low-Density Lipoprotein Cholesterol (LDL-C) levels, but a negative correlation with the High-Density Lipoprotein Cholesterol (HDL-C) level. Conclusion: An increased LP-PLA2 level was closely associated with the metabolic stress and incidence of MHT, thus exhibit an important role in the pathophysiology and diagnostic assessment of MHT.