Interrelationships among platelet-activating factor and lipoprotein-associated phospholipase A2 activity and traditional cardiovascular risk factors.

Abstract

Traditionally cardiovascular disease (CVD) risk has been assessed through blood lipids and inflammatory marker C-reactive protein (hsCRP). Recent clinical interest in novel pro-inflammatory markers platelet-activating factor (PAF) and lipoprotein-associated phospholipase A2 (Lp-PLA2 ) recognizes that vascular damage can exist in the absence of traditional risk factors. This cross-sectional study investigated the potential relationship between circulating PAF, Lp-PLA2 , hsCRP, and traditional risk factors for CVD. One hundred adults (49 ± 13 years, 31% male) with variable CVD risk were recruited. Fasting inflammatory markers PAF, Lp-PLA2 and hsCRP and total, high-density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol, and triglycerides were measured. Blood pressure, body mass index, and waist circumference were measured. Medical and physical activity data were self-reported. Linear and multiple regressions were performed. PAF, Lp-PLA2 , and hsCRP independently correlated with several CVD risk factors. PAF was correlated significantly with risk factors in an unexpected way; there was a medium positive correlation between PAF and HDL cholesterol (r= 0.394, p< 0.001) and medium negative correlations with Total:HDL cholesterol; (r= -0.436, p< 0.001) systolic blood pressure; (r= -0.307, p= 0.001); BMI (r= -0.381, p< 0.001); and waist circumference (r= -0.404, p< 0.001). There were large positive correlations between Lp-PLA2 and LDL (r= 0.525, p< 0.001) and non-HDL cholesterol (r= 0.508, p< 0.001). There were large positive correlations between hsCRP and Total:HDL cholesterol (r= 0.524, p< 0.001); BMI (r= 0.668, p< 0.001); and waist circumference (r= 0.676, p< 0.001). PAF, Lp-PLA2 , and hsCRP are implicated in the pathophysiology of inflammation in CVD; however, the relationships between each marker and traditional risk factors were different suggesting they may be involved in different atherogenic pathways.