The epidemiology of Lp-PLA 2: Distribution and correlation with cardiovascular risk factors in a population-based cohort

Abstract

Lipoprotein-associated phospholipase A 2 (Lp-PLA 2) is an enzyme that is produced by inflammatory cells (macrophages, T-lymphocytes and mast cells) and hydrolyzes oxidized phospholipids in LDL. Several epidemiology studies indicate that Lp-PLA 2 appears to be an independent marker of cardiovascular risk. This study was conducted to define the distribution of Lp-PLA 2 in a large population-based cohort and to determine associations between Lp-PLA 2 and other risk factors for CVD. The study group consisted of participants from the Malmö Diet and Cancer study (1992–1994). Lp-PLA 2 (activity and mass) was measured from samples obtained at baseline for 5402 participants (3167 women). A strong correlation was observed between Lp-PLA 2 activity and mass in this study ( r = 0.57). Highest correlations were observed between Lp-PLA 2 activity and LDL ( r = 0.45) and LDL/HDL ratio ( r = 0.54) and a strong inverse correlation to HDL ( r = −0.31). The correlations between Lp-PLA 2 mass and lipids were not as strong as the correlation between activity and lipids. Lp-PLA 2 activity and mass were correlated with increased ultrasound determined carotid intima-media thickness. We conclude that Lp-PLA 2 is strongly correlated with several cardiovascular risk factors, especially lipid fractions, and with the degree of carotid artery atherosclerosis. However, the measured variables accounted for only 19% and 35% of the variation in Lp-PLA 2 mass and activity respectively.