Objectives Lipoprotein-associated phospholipase A2(Lp-PLA2), a proinflammatory enzyme secreted primarily by macrophages, has been shown to be a predictor and potential therapeutic target of cardiovascular disease. The level and distribution of Lp-PLA2 and its associated factors are still unknown for Chinese population. Therefore, we aimed to study the level of Lp-PLA2 activity in men and women in a general population, and to investigate the association of Lp-PLA2 with known cardiovascular risk factors.
Methods A total of 1471 participants aged 45-74 were recruited from a cohort study in Beijing. Lp-PLA2 activity was determined by a colorimetric assay kit (Cayman Chemical, Ann Arbour, USA). Lp-PLA2 activity level and the correlation between Lp-PLA2 activityand risk factors were analysed in men and women.
Results 1. Lp-PLA2 activity was higher in males than in females (22.73 ± 8.52 nmol·min-1·ml-1 vs. 20.01 ± 8.06 nmol·min-1·ml-1, P < 0.001). 2. Age, waist circumference, systolic blood pressure, diastolic blood pressure and the prevalence of hypertension were higher in males than in females, while total cholesterol, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were higher in females than in males. 3. Lp-PLA2 activity was significantly correlated with lipids (LDL-C, total cholesterol, triglyceride, and HDL-C), blood pressure (systolic blood pressure and diastolic blood pressure), and adiposity associated parameters (waist circumference and BMI) in males; it was significantly correlated with lipid level (LDL-C, total cholesterol, triglyceride, and HDL-C) and age in females, while its correlation with variables associated with obesity or blood pressure were much weaker than those in males. 4. After adjustment for age, waist circumference, LDL-C, HDL-C, triglyceride, systolic blood pressure, glucose and high sensitivity C-reactive protein by Logistic regression model, Lp-PLA2 activity was still significantly higher in males than in females (OR = 1.72, 95% confidence interval = 1.34-2.21).
Conclusions The level of Lp-PLA2 activity and its association with known cardiovascular risk factors differed in males and females. The gender difference in Lp-PLA2 activity cannot be fully explained by known cardiovascular risk factors.