Background:Lipoprotein-associated phospholipase A2 (Lp-PLA2) enzyme, mainly associated with LDL, hydrolyzes its phospholipids producing proinflammatory compounds like lysophosphatidylcholine and oxidized non-esterified fatty acids. Accumulating evidence suggests Lp-PLA2 to be very good marker of coronary artery disease (CAD). However its role and levels have not been documented clearly in diabetic patients with CAD in an Indian population. The aim of this study was to explore the association of LpPLA2 levels between diabetic and non-diabetic patients with CAD and compare it with other established markers like hs-CRP.
Methods: Sixty individuals with angiographically proven CAD and 30 healthy individuals matched for age & sex were studied. CAD patients were divided into two groups based on presence (n=30) [Group I] and absence (n=30) [group II] of type 2 diabetes mellitus (DM). The serum levels of LpPLA2, hs-CRP were measured by ELISA and routine lipid profile was measured by automated analyzer. Angiographic clinical vessel scoring was also done for all the patients.Data is presented as Mean±S.D. and relationships were determined by Pearson correlations.
Results: Both groups of CAD with and without DM had significantly higher levels of LpPLA2 (Group I-408.48 +/- 38.96 ng/ml, Group II- 272.88 +/- 34.21ng/ml respectively) and hsCRP (Group I-10.61 +/- 1.34 mg/l, Group II-5.75 +/- 2.59 mg/l respectively) when compared with healthy control subjects (LpPLA2 =200.82 +/- 20.97ng/ml & hsCRP=1.89 +/- 1.34mg/l) [p<0.001]. LpPLA2 levels between the two CAD groups were highly significant(p<0.001), levels being maximum for CAD with type 2 diabetes (Group I) which could be due an increase in its substrate sLDL and oxidised LDL in DM. Angiographic clinical vessel score of CAD severity was also higher in CAD with DM. LpPLA2 levels correlated strongly (r=0.763,p<0.001) with the angiographic clinical vessel score in diabetes patients with CAD while hsCRP has moderate correlation with the vessel score (r=0.475, p<0.01).
Conclusion: LpPLA2 and hsCRP elevation is increased in patients of type 2 diabetes mellitus with CAD as compared to only CAD patients. Measurement of LpPLA2 may be considered as a marker for better prediction of cardiovascular risk in diabetes patients.