The role of lipoprotein-associated phospholipase A₂ in the metabolic syndrome and diabetes

Objectives: Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) is a novel inflammation marker. We investigated its association with other coronary risk factors and evaluated its role as a comprehensive marker of the metabolic syndrome in individuals with type 2 diabetes. Methods: Our cross-sectional study evaluated 92 insulin-treated subjects with type 2 diabetes. Biochemical measurements of Lp-PLA₂, glycemic control, lipid profiles, and C-reactive protein were carried out. Seventy-seven subjects were diagnosed as having the metabolic syndrome, which was defined according to the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Results: Lp-PLA₂ was significantly correlated with waist-hip ratio (r=.25), triglycerides (r=.50), high-density lipoprotein cholesterol (r=-.31), and low-density lipoprotein cholesterol (LDL-C; r=.27; all P<.02). In a multiple-regression model, triglycerides and LDL-C levels were the significant predictors of Lp-PLA₂. Lp-PLA₂ was significantly higher in subjects with the metabolic syndrome than in those without it (268±23.4 vs. 127±15.8 ng/ml, P<.001). There was a linear increase in Lp-PLA₂ with an increment of the number of the metabolic syndrome criteria (P_trend=.041). Another multiple-regression model showed that the hypertriglyceridemia component was the only predictor of Lp-PLA₂. Conclusions: Our findings suggest that Lp-PLA₂ assay potentially facilitates a more comprehensive assessment of the metabolic syndrome in patients with type 2 diabetes on insulin.